replace Redis with an embedded SQLite string->string KV store (group commit, in-tx events, SQL search)

.gitea/workflows/docker-publish.yml

@@ -0,0 +1,87 @@
+# Gitea twin of .github/workflows/docker-publish.yml. Gitea runs only .gitea/workflows/ once this
+# folder exists, and GitHub never reads it.
+#
+# Publishes to IPCR on watch.nsl.sh instead of ghcr.io:
+#   push  ipcr-push-85-17-246-67.nip.io/metadec.eth/<repo>:<tag>   docker login as metadec.eth with the
+#         IPCR_PUSH_TOKEN secret (the metadec.eth namespace token from the IPCR dashboard)
+#   pull  ipcr-watch.nsl.sh/ipns/metadec.eth/metadec.eth/<repo>:<tag>   anonymous
+# The push goes to ipcr-push-85-17-246-67.nip.io, the box's own address, not ipcr-push-watch.nsl.sh: Cloudflare fronts
+# *.watch.nsl.sh and refuses any request over 100 MB (413), which a large image layer is.
+# That host's certificate is signed by the box's private Mesh Router CA, given to buildkit from
+# the IPCR_CA_PEM repo variable. docker login would make the job's Docker daemon check the
+# certificate without that CA, so the login is written straight into ~/.docker/config.json.
+# The runner's job image (node:22-bookworm) has no docker CLI, so the static one is
+# installed first; buildx installs itself. No `type=gha` cache: the runner has none.
+
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Tag for the image (optional, defaults to sha)'
+        required: false
+        type: string
+
+env:
+  REGISTRY: ipcr-push-85-17-246-67.nip.io
+  IMAGE_NAME: metadec.eth/${{ github.event.repository.name }}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install Docker CLI
+        run: curl -fsSL https://download.docker.com/linux/static/stable/x86_64/docker-28.5.1.tgz | tar -xz -C /usr/local/bin --strip-components=1 docker/docker
+
+      - name: Trust the Mesh Router CA
+        run: printf '%s\n' "$IPCR_CA_PEM" > /tmp/ipcr-ca.pem
+        env:
+          IPCR_CA_PEM: ${{ vars.IPCR_CA_PEM }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          version: latest
+          buildkitd-config-inline: |
+            [registry."${{ env.REGISTRY }}"]
+              ca = ["/tmp/ipcr-ca.pem"]
+
+      - name: Log in to IPCR
+        env:
+          IPCR_PUSH_TOKEN: ${{ secrets.IPCR_PUSH_TOKEN }}
+        run: |
+          mkdir -p ~/.docker
+          printf '{"auths":{"%s":{"auth":"%s"}}}\n' "$REGISTRY" "$(printf 'metadec.eth:%s' "$IPCR_PUSH_TOKEN" | base64 -w0)" > ~/.docker/config.json
+
+      - name: Extract metadata (tags, labels)
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=sha,prefix=
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=raw,value=${{ inputs.tag }},enable=${{ inputs.tag != '' }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -6,20 +6,20 @@
 # - Bash-based leader election script (flock on shared volume)
 # - meta-core Go binary (HTTP API, Mount API, Watcher)
 # - nginx (dashboard, WebDAV, API proxy)
-# - Redis (managed by supervisord on leader)
+# - SQLite metadata store, embedded in the Go binary (/meta-core/db/meta-core.db)
 # - rclone (single mount executor — SMB goes through rclone's :smb: backend)
 # - supervisord (process management - runs on leader only)
 #
 # Architecture:
 # - leader-election.sh handles flock, starts supervisord on leader
 # - Followers remain dormant, retry flock every 5s
-# - Only leader runs Redis, meta-core, nginx, rclone, mount-watcher
+# - Only leader runs meta-core, nginx, rclone, mount-watcher
 # =============================================================================
 
 # -----------------------------------------------------------------------------
 # Stage 1: Build Go binary
 # -----------------------------------------------------------------------------
-FROM golang:1.21-alpine AS go-builder
+FROM golang:1.26-alpine AS go-builder
 
 RUN apk add --no-cache git
 
@@ -74,7 +74,7 @@ ARG RCLONE_VERSION=1.73.5
 # Install runtime dependencies. Native NFS/CIFS clients intentionally absent —
 # all remote mounts go through rclone now.
 RUN apk add --no-cache \
-    redis \
+    sqlite \
     nginx \
     nginx-mod-http-dav-ext \
     supervisor \
@@ -104,7 +104,7 @@ RUN chmod +x /usr/local/bin/meta-core
 # Create directories
 RUN mkdir -p \
     /meta-core/locks \
-    /meta-core/db/redis \
+    /meta-core/db \
     /meta-core/services \
     /meta-core/mounts/errors \
     /files \
@@ -140,13 +140,12 @@ ENV META_CORE_PATH=/meta-core \
     SERVICE_VERSION=1.0.0 \
     META_CORE_HTTP_PORT=9000 \
     META_CORE_HTTP_HOST=0.0.0.0 \
-    REDIS_PORT=6379 \
     WATCH_INTERVAL_MS=1000
 
 # Expose ports
-# 80: nginx (dashboard + API proxy + WebDAV)
-# 6379: Redis (for other services)
-EXPOSE 80 6379
+# 80: nginx (dashboard + API proxy + WebDAV). The metadata store has no port:
+# it is a file inside this container, reachable only through the HTTP API.
+EXPOSE 80
 
 # Health check
 HEALTHCHECK --interval=10s --timeout=5s --start-period=10s --retries=3 \

README.md

@@ -1,39 +1,50 @@
 # meta-core
 
-Standalone Go service that owns Redis, the leader-info file, the HTTP+SSE
-metadata surface, and a WebDAV file server for the MetaMesh dev/prod stack.
+Standalone Go service that owns the metadata store (an embedded SQLite file),
+the HTTP+SSE metadata surface, the
+User Data Layer store and signing keystore, and a WebDAV file server for the
+MetaMesh dev/prod stack.
 
 ## Overview
 
 meta-core runs as its own container (`metacore-app`). Other MetaMesh services
-(meta-sort, meta-fuse, meta-stremio, meta-dup, meta-share) discover it by
-reading `/meta-core/locks/kv-leader.info` and then call its HTTP API. Redis
-is not exposed outside the container — all metadata I/O is mediated by the
-HTTP API.
+(meta-sort, meta-fuse, meta-stremio, meta-dup, meta-search, meta-share,
+meta-gateway, meta-watch, …) locate it over UDP multicast (beacon v2 —
+its `metamesh.core` advertise carries the full `/urls` payload) and then call its
+HTTP API. `META_CORE_URL` on a client pins it instead. The store is embedded
+in the Go binary (no database port at all) — all metadata I/O is mediated by the HTTP/SSE API
+(see [`docs/api-mediated-access.md`](docs/api-mediated-access.md)).
 
 ### Key capabilities
 
 | Feature | Description |
 |---------|-------------|
-| **Leader gate** | Bash `flock` loop in `docker/leader-election.sh` only `exec`s supervisord on the winner. The Go binary therefore only ever runs as leader. |
-| **Redis owner** | Supervisord starts Redis with AOF + RDB persistence inside the container; meta-core connects to it on localhost. |
-| **HTTP API** | Typed REST surface (gorilla/mux) for metadata, KV browsing, snapshots, schema inference, mounts, watchers, services, and file access by CID. |
-| **SSE event streams** | `/api/events/files` and `/api/events/meta` mirror the underlying Redis Streams so external services never speak Redis. |
+| **DB-file mutex** | Bash `flock` loop in `docker/leader-election.sh` only `exec`s supervisord on the winner, so two containers sharing one `/meta-core` volume can never run two writers on the database file. It is a mutex, not discovery — nothing reads the lock. |
+| **Embedded SQLite store** | One schema-free `kv(k, v)` table in `/meta-core/db/meta-core.db` (pure-Go `modernc.org/sqlite`, WAL, `synchronous=NORMAL`). One writer goroutine with group commit; a record write (fields + root index + CID aliases + FTS row + events) is atomic. Replaced Redis in 2026-10 (Redis + the in-memory search copy needed ~6.6 GB on watch.nsl.sh's 169k records; the SQLite file is ~2.5 GB on disk with a bounded page cache). |
+| **HTTP API** | Typed REST surface (gorilla/mux) for metadata, KV browsing, snapshots, schema inference, mounts, watchers, neighbours, identity, UDL, and file access by CID. |
+| **Indexed search** | `POST /api/metadata/search` builds a superset of candidates in SQL — a partial expression index `kv_field` over (field name, value) of every record key, plus an FTS5 trigram table — then verifies each with the unchanged Go matchers. Fresh immediately, no in-memory copy (`internal/storage/search.go`, `internal/api/search_index.go`). |
+| **SSE event streams** | `/api/events/files` and `/api/events/meta` mirror the store's `file:events` / `meta:events` streams so external services never touch the store. `meta:events` entries are written in the same transaction as the change. |
 | **WebDAV server** | `/webdav/*` exposes the `/files` volume (read+write) for cross-service file access. nginx in front of meta-core handles caching. |
-| **Service discovery** | File-based registry under `/meta-core/services/*.json` with heartbeat + dead-service cleanup. |
-| **File watcher / scanner** | Recursive scan + MidHash256 computation; emits events on `file:events`. |
+| **Service discovery** | beacon v2: UDP multicast advertise/listen on `239.255.99.1:9099`, neighbours served at `/neighbors`. The file-based registry under `/meta-core/services/*.json` it replaced is gone. |
+| **File watcher / scanner** | Recursive scan + MidHash256 computation; emits events on `file:events`. Watched roots are POSTed watcher configs (`/meta-core/watchers.json`), not env vars. |
 | **Mount management** | rclone-only mount manager (SMB rendered into `:smb:`, plus pre-defined remotes). Read-only by construction. |
 | **UUID-rooted storage** | Roots are UUIDv7 (Crockford Base32, ULID layout); CIDs are reverse-index aliases. Schema-version sentinel refuses to boot against stale data. |
+| **Identity keystore** | Multi-account secp256k1 signing keys under `/meta-core/identity/accounts/`, created from the dashboard's Identity menu (never auto-generated). A private key is returned only by generate, or by reveal against a proof-of-possession signature (delete needs the same proof); `/api/identity/sign` refuses challenge-domain payloads. |
+| **User Data Layer** | Version-gated store for per-user signed (and, for private-tier keys, encrypted) records — My List, Continue Watching, ratings — indexed by user and CID. meta-core never inspects the crypto. See [User Data Layer](../../docs/project-architecture/user-data-layer.md). |
+| **Dashboard + editor** | nginx serves a React dashboard at `/` and the standalone metadata editor at `/editor/`. |
 
 ### Design characteristics
 
-- **Single-leader** — flock on a shared volume; no external consensus.
-- **HTTP-only externally** — Redis is bound to the container, never published.
+- **Single writer** — flock on the `/meta-core` volume; no external consensus.
+- **HTTP-only externally** — there is no database port; debug read-only with
+  `docker exec metacore-app sqlite3 -readonly /meta-core/db/meta-core.db …`
+  (dev stacks: `/meta-core-db/meta-core.db`).
 - **Schema-gated boot** — `EnsureSchemaVersion` aborts startup when the
-  on-disk Redis layout predates the current build (alpha clean-wipe policy;
+  on-disk store layout predates the current build (alpha clean-wipe policy;
   see `docs/uuid-rooted-metadata.md`).
-- **Static binary** — CGO disabled, single Go binary plus a thin Alpine
-  image with `redis-server`, `rclone`, nginx, and supervisord.
+- **Static binary** — CGO disabled (pure-Go SQLite), single Go binary plus a
+  thin Alpine image with `rclone`, nginx, supervisord and the `sqlite` CLI
+  (for debugging).
 
 ## Architecture
 
@@ -41,34 +52,31 @@ HTTP API.
 ┌──────────────────────────────────────────────────────────────────────────┐
 │                    metacore-app  (standalone container)                  │
 │                                                                          │
+│  leader-election.sh  (flock /meta-core/locks/kv-leader.lock,             │
+│                       then exec supervisord)                             │
 │  supervisord                                                             │
-│   ├─ leader-election.sh  (flock /meta-core/locks/kv-leader.lock,         │
-│   │                       writes kv-leader.info, exec supervisord)      │
-│   ├─ redis-server        (AOF + RDB on /meta-core/db/redis)              │
-│   ├─ nginx               (TLS termination, proxy_cache for /webdav)      │
-│   ├─ rclone rcd          (mount daemon, RC API)                          │
+│   ├─ nginx  :80          (dashboard, /editor, API proxy,                 │
+│   │                       proxy_cache for /webdav, rclone GUI /rclone)   │
+│   ├─ rclone rcd          (mount daemon, RC API on :5572)                 │
 │   ├─ mount-watcher.sh    (rclone mount lifecycle)                        │
 │   └─ meta-core (Go)      ─►  HTTP API + SSE + WebDAV on :9000            │
+│                          ─►  embedded SQLite (db/meta-core.db)           │
+│                          ─►  UDP advertise/listen 239.255.99.1:9099      │
 └──────────────────────────────────────────────────────────────────────────┘
                                        │
                 ┌──────────────────────┴──────────────────────┐
-                │  /meta-core (shared volume)                 │
-                │   locks/kv-leader.{lock,info}               │
-                │   db/redis/                                 │
-                │   services/*.json                           │
+                │  /meta-core (meta-core's own volume)        │
+                │   locks/kv-leader.lock                      │
+                │   db/meta-core.db (+ -wal, -shm)            │
+                │   identity/accounts/*.json                  │
                 │   mounts/{mounts.json, errors/}             │
                 │   watchers.json                             │
                 │   cache/ (nginx proxy_cache)                │
                 └─────────────────────────────────────────────┘
-                                       ▲
-        ┌──────────────────────────────┼────────────────────────────────┐
-        │                              │                                │
-┌─────────────┐               ┌─────────────┐                ┌─────────────┐
-│  meta-sort  │               │  meta-fuse  │                │ meta-stremio│
-│             │               │             │                │             │
-│  reads      │  HTTP+SSE     │  reads      │  HTTP+SSE      │  reads      │
-│  leader.info├──────────────►│  leader.info├───────────────►│  leader.info│
-└─────────────┘               └─────────────┘                └─────────────┘
+
+   meta-sort / meta-fuse / meta-stremio / meta-search / meta-share / …
+      │  1. hear the metamesh.core advertise on UDP multicast (carries /urls)
+      └─ 2. HTTP + SSE (+ WebDAV) to metacore-app — never the store, never the volume
 ```
 
 ## Quick start
@@ -82,8 +90,9 @@ make test            # run Go unit tests
 ```
 
 `make docker` tags the image as `:1.0.0`, `:latest`, **and** `:local`. The
-`:local` tag is the one every sub-stack docker-compose.yml references
-(meta-share 10-peer federation, meta-gateway dev stacks); without it the
+`:local` tag is the one the sub-stack docker-compose files reference
+(meta-share federation, meta-read and meta-listen dev stacks); the meta-gateway
+dev stack (`docker-compose.gateway.yml`) uses `:latest`. Without these tags the
 sub-stacks can't see a freshly-built image by name.
 
 > **Source-change → recreate.** `make docker` rebuilds and re-tags the
@@ -94,12 +103,14 @@ sub-stacks can't see a freshly-built image by name.
 >
 > ```bash
 > make docker
-> docker compose -f packages/meta-gateway/dev/docker-compose.yml \
->   up -d --force-recreate metagateway-generic-core
-> docker compose -f packages/meta-gateway/dev/docker-compose.torznab.yml \
->   up -d --force-recreate metagateway-torznab-core
+> docker compose -f packages/meta-gateway/dev/docker-compose.gateway.yml \
+>   up -d --force-recreate metagateway-hub-metacore
 > docker compose -f packages/meta-share/dev/docker-compose.yml \
 >   --profile share-10node up -d --force-recreate metashare-core metashare-core-test
+> docker compose -f packages/meta-read/dev/docker-compose.yml \
+>   up -d --force-recreate metaread-dev-core
+> docker compose -f packages/meta-listen/dev/docker-compose.yml \
+>   up -d --force-recreate metalisten-dev-core
 > ```
 >
 > The symptom of a missed recreate is missing API fields on `/urls`
@@ -109,7 +120,7 @@ sub-stacks can't see a freshly-built image by name.
 >
 > ```bash
 > docker inspect meta-core:local --format '{{.Id}}'                # fresh SHA
-> docker ps --filter ancestor=meta-core:local --format '{{.Names}}'
+> docker ps --filter ancestor=meta-core:local --format '{{.Names}}'   # repeat for :latest
 > # any container whose Image SHA doesn't match the fresh SHA needs --force-recreate.
 > ```
 
@@ -126,36 +137,43 @@ HTTP port (no auth, bypasses Caddy) is `http://localhost:18083`.
 
 ## Configuration
 
-Environment variables consumed by `internal/config/config.go`:
+Environment variables (from `internal/config/config.go` unless noted):
 
 | Variable | Default | Description |
 |---|---|---|
-| `META_CORE_PATH` | `/meta-core` | Shared volume root (locks, db, services, mounts, cache). |
+| `META_CORE_PATH` | `/meta-core` | meta-core's own volume root (lock, SQLite DB, identity, mounts, watchers, cache). No other service mounts it. |
 | `FILES_PATH` | `/files` | Files volume root. |
-| `SERVICE_NAME` | `meta-core` | Identity in the service registry. |
-| `SERVICE_VERSION` | `1.0.0` | Reported via `/status` and registry. |
-| `API_PORT` | `8180` | External port baked into the leader-info `baseUrl`. |
-| `BASE_URL` | _empty_ | Overrides the constructed `baseUrl` if set (used for HTTPS perimeter). |
-| `REDIS_PORT` | `6379` | Local Redis port. |
+| `SERVICE_NAME` | `meta-core` | Name in the beacon v2 advertise. |
+| `SERVICE_VERSION` | `1.0.0` | Reported via `/status`. |
+| `API_PORT` | `8180` | External port baked into the constructed `baseUrl` when `BASE_URL` is unset. |
+| `BASE_URL` | _empty_ | Overrides the constructed `baseUrl` (the Caddy/HTTPS perimeter URL). |
+| `META_CORE_PUBLIC_URL` | _empty_ | Browser-facing nav URL in the announce; wins over `BASE_URL` (e.g. a debug-direct port with no Caddy). |
+| `META_CORE_DB_PATH` | `<META_CORE_PATH>/db/meta-core.db` | SQLite database file. Dev stacks set `/meta-core-db/meta-core.db` on a named volume (the `/meta-core` bind is 9p on Windows dev boxes and SQLite WAL is unsafe there). |
+| `META_CORE_DB_CACHE_MB` | `64` | Page cache of the writer connection (`internal/storage/client.go`). |
+| `META_CORE_DB_READER_CACHE_MB` | `16` | Page cache per reader connection. |
+| `META_CORE_DB_READERS` | `8` | Reader connection pool size. |
 | `META_CORE_HTTP_PORT` | `9000` | Go HTTP+SSE+WebDAV port. |
 | `META_CORE_HTTP_HOST` | `0.0.0.0` | HTTP bind. |
-| `HEALTH_CHECK_INTERVAL_MS` | `5000` | Internal health-loop cadence. |
-| `HEARTBEAT_INTERVAL_MS` | `30000` | Service registry heartbeat. |
-| `STALE_THRESHOLD_MS` | `60000` | Age past which a registry entry is marked stale. |
-| `CLEANUP_INTERVAL_MS` | `600000` | Dead-service cleaner cadence. |
-| `DEAD_SERVICE_THRESHOLD_MS` | `600000` | Age past which a stale entry is deleted. |
-| `WATCH_INTERVAL_MS` | `1000` | Watcher poll cadence. |
-| `DEBOUNCE_MS` | `30000` | File-event debounce window. |
-| `ENABLE_FILE_WATCHER` | `true` | Disable to suppress the in-process watcher entirely. |
+| `ENABLE_FILE_WATCHER` | `true` | Disable to suppress the in-process watcher entirely (`POST /api/files/register` stays available). |
+| `ENABLE_UDP_DISCOVERY` | `true` | beacon v2 advertise + listen. |
+| `BEACON_GROUP` / `BEACON_PORT` | `239.255.99.1` / `9099` | Multicast group and UDP port. |
+| `BEACON_INTERVAL_MS` | `10000` | Unsolicited advertise interval. |
+| `ELECTION_RETRY_SECS` | `5` | flock retry interval (read by `docker/leader-election.sh`, not the Go binary). |
 
-Note: there is no `META_CORE_REDIS_PORT`, no `META_CORE_SERVICE_NAME`, and
-no `META_CORE_LEADER_TIMEOUT`. The Redis URL is discovered locally; service
-identity uses `SERVICE_NAME`; leader timeout is governed by the bash flock
-retry interval (`ELECTION_RETRY_SECS`, default `5`).
+`HEALTH_CHECK_INTERVAL_MS`, `HEARTBEAT_INTERVAL_MS`, `STALE_THRESHOLD_MS`,
+`CLEANUP_INTERVAL_MS`, `DEAD_SERVICE_THRESHOLD_MS`, `WATCH_INTERVAL_MS` and
+`DEBOUNCE_MS` are still parsed by `internal/config/config.go` but nothing reads
+them (leftovers of the file-based registry); setting them has no effect. There
+is no `REDIS_PORT` / `META_CORE_REDIS_PORT` / `META_CORE_INDEX_EXCLUDE_PREFIXES`
+(gone with Redis and the in-memory search index; search results now include
+`categories/newznab/*` like every record read) / `META_CORE_SERVICE_NAME` /
+`META_CORE_LEADER_TIMEOUT`, and no `WATCH_PATHS` — watched folders are watcher
+configs created via `/api/watchers`.
 
 ## API reference
 
-All endpoints below are served by `internal/api/server.go`. Examples assume
+All endpoints below are registered in `internal/api/server.go` (mounts,
+watcher and watchers routes in their own packages' `handlers.go`). Examples assume
 the in-container Go port `:9000`; from the host use
 `https://metacore-dev.localhost:8083` (Caddy) or `http://localhost:18083`
 (debug-direct).
@@ -163,16 +181,47 @@ the in-container Go port `:9000`; from the host use
 ### Health, leader, URLs
 
 ```bash
-GET  /health           # storage + role
+GET  /health           # storage + role (`redis: bool` kept for compatibility = store open)
 GET  /status           # version, uptime, etc.
 GET  /leader           # current leader info (hostname, PID, timestamps)
-GET  /urls             # baseUrl, apiUrl, webdavUrl, webdavUrlInternal (redisUrl is intentionally empty)
-GET  /services         # registered services + heartbeats
-GET  /api/services     # alias for /services
-GET  /services/{name}  # one service
-GET  /services/cleanup/stats
+GET  /urls             # baseUrl, apiUrl, webdavUrl, webdavUrlInternal (redisUrl is always "", kept for compatibility)
+GET  /neighbors        # neighbours heard over UDP (beacon v2)
+GET  /api/neighbors    # same, under /api
+GET  /api/stats        # dashboard counters (see below)
 ```
 
+`/services`, `/api/services`, `/services/{name}` and `/services/cleanup/stats`
+are **gone** — the registration-and-heartbeat registry they served was replaced
+by beacon v2 (`/neighbors`). nginx answers an unknown non-`/api` path
+with the dashboard's `index.html`, so a stale caller gets `200 text/html` rather
+than a 404; that is what made the dashboard fail with
+`SyntaxError: Unexpected token '<'` until 1.0.21.
+
+#### `GET /api/stats`
+
+Every headline counter in one request, split by cost:
+
+```jsonc
+{
+  "records": 88709,        // count of idx:roots/* — metadata roots, file or not
+  "redisKeys": 3115447,    // kv row count (name kept for compatibility; cached 60 s)
+  "redisMemory": "588.74M",// DB + WAL file size (name kept for compatibility)
+  "identities": 3,         // signing accounts on disk
+  "files": { "count": 4864, "totalSize": 64587914424 },  // null until first sweep
+  "udlUsers": 5,           // accounts holding User Data Layer records
+  "sweptAt": 1789402401970,
+  "sweeping": false
+}
+```
+
+`records` and `identities` are live on every call; `redisKeys` is cached 60 s. `files` and
+`udlUsers` need a keyspace walk (~0.5s and ~3s respectively on an 88k-record
+box), so they are served from a single-flight cache refreshed in the background
+with a 60s TTL — the walk is **never** on the request path, because the
+dashboard polls and ten open tabs must not cost ten keyspace walks. Prefer this
+over `/api/kv/info`, which does one `GET` per root (6s+) and sums `sizeByte`
+across records that share a file.
+
 ### Metadata — primary surface
 
 These are the routes other services use. `{hash}` may be a UUID root or
@@ -198,6 +247,8 @@ GET    /api/meta/{cid}                # resolve CID → metadata document
 GET    /api/file/{cid}/info           # CID resolution metadata
 GET    /file/{cid}                    # serve file bytes (range-aware)
 POST   /file/cid                      # compute CID for an uploaded file
+POST   /api/files/register        # mint + alias one file under /files/plugin by midhash
+                                  # (the watcher's path for one file; works with the watcher OFF)
 HEAD   /data/{hash}                   # existence + size
 GET    /data/{hash}/path              # absolute path on /files
 ```
@@ -209,6 +260,7 @@ the `/file/{cid}` reverse-lookup path.)
 
 ```bash
 GET    /api/metadata/hash-ids
+GET    /api/files/tuples
 GET    /api/metadata/list
 POST   /api/metadata/search
 POST   /api/metadata/batch
@@ -221,10 +273,10 @@ PUT    /api/metadata/{hashId}/property
 
 GET    /api/kv/info
 GET    /api/kv/keys
-GET    /api/kv/tree
+GET    /api/kv/tree            # cursor is an opaque next-key ("0" when exhausted)
 GET    /api/kv/search
 GET    /api/kv/find
-GET    /api/kv/value
+GET    /api/kv/value           # type is always "string" for an existing key
 PUT    /api/kv/value
 DELETE /api/kv/value
 GET    /api/kv/key/{key...}
@@ -239,7 +291,8 @@ POST   /api/snapshot/wipe
 
 ### SSE event streams
 
-The HTTP-mirror of the Redis Streams. External services never read Redis
+The HTTP-mirror of the store's event streams (Redis Streams until 2026-10;
+IDs keep the `<ms>-<seq>` form). External services never read the store
 directly — they subscribe here with `Last-Event-ID` for resume. See
 [`docs/api-mediated-access.md`](docs/api-mediated-access.md) for the wire
 contract (one event per stream entry, opaque IDs, heartbeats, gap
@@ -248,6 +301,44 @@ signalling).
 ```bash
 GET /api/events/files     # file:events stream (watcher events)
 GET /api/events/meta      # meta:events stream (metadata mutations)
+GET /api/events/poll      # DEPRECATED long-poll over file:events — use SSE
+```
+
+### Identity (signing keystore)
+
+Reached through meta-search's identity proxy (and directly by meta-gateway,
+meta-read, meta-listen) for record signing, UDL writes and keypair sign-in.
+
+```bash
+GET    /api/identity               # status (never the private key)
+GET    /api/identity/accounts
+POST   /api/identity/generate      # the only call that returns a new private key
+POST   /api/identity/import
+POST   /api/identity/challenge     # one-shot challenge for proof-of-possession
+POST   /api/identity/reveal        # needs proof-of-possession
+DELETE /api/identity               # needs proof-of-possession; reports purged UDL counts
+POST   /api/identity/sign
+POST   /api/identity/sign-batch
+GET    /api/identity/aead-key
+```
+
+### User Data Layer
+
+Records arrive signed (private-tier ones encrypted) as opaque base64 CBOR;
+writes are version-gated (stale → `409 stale_version`, or `accepted:false` per
+cell in a batch). Storage model in `internal/storage/udl.go` (`udl:rec:<uid>/<cid>/<key>` → JSON `{record,version,ts,value?}`; index sets as one key per member).
+
+```bash
+GET  /api/udl/record?uid&cid&key
+PUT  /api/udl/record
+PUT  /api/udl/records                      # batch
+GET  /api/udl/user/{uid}/key/{key}
+GET  /api/udl/user/{uid}/cid/{cid}
+GET  /api/udl/user/{uid}/all
+GET  /api/udl/user/{uid}/count
+GET  /api/udl/cid/{cid}/users
+GET  /api/udl/cid/{cid}/aggregate          # meta-watch Aggregate wire shape
+GET  /api/udl/users/stats
 ```
 
 ### Mounts
@@ -283,42 +374,43 @@ The legacy `/api/scan/trigger` and `/api/scan/status` still respond but
 return a deprecation pointer at the `/api/watchers/*` routes
 (`internal/watcher/handlers.go:32-33`).
 
-### Admin / WebDAV
+### WebDAV
 
 ```bash
-POST   /api/admin/migrate-dual-roots  # reunify stranded midhash-rooted entries
 GET/PUT/DELETE /webdav/...            # mounted on /files
 ```
 
+The one-shot Redis-era admin migrations (`/api/admin/migrate-dual-roots`,
+`migrate-domain-screen`, `migrate-user-cids`, `sweep-literature-echoes`) were
+removed with the 2026-10 SQLite switch; they had been run once on
+watch.nsl.sh before the migration.
+
 No `/metrics` endpoint is exposed; observability is via container logs and
 the `/health` / `/status` JSON.
 
-## Leader gate
+## DB-file mutex
 
-Leader election is a bash flock loop in `docker/leader-election.sh`, not a
-Go-level state machine. When `flock` succeeds on `kv-leader.lock`, the
-script writes the leader API URL to `kv-leader.info` and `exec`s
-supervisord. When the process tree dies, the kernel releases the lock and
-any standby instance can take over. There is no follower path inside the
-Go binary — there is no `OnBecomeLeader` / `OnBecomeFollower` callback API.
+`docker/leader-election.sh` is a bash flock loop, not a Go-level state
+machine. When `flock` succeeds on `/meta-core/locks/kv-leader.lock`, the
+script `exec`s supervisord; a second container mounting the same volume
+retries every `ELECTION_RETRY_SECS` and stays dormant. When the process tree
+dies, the kernel releases the lock. There is no follower path inside the Go
+binary.
 
-`kv-leader.info` is a single plaintext line containing the API base URL:
-
-```
-http://10.0.1.50:9000
-```
-
-Other services read this file, then call `GET /urls` for full discovery.
-
-The dev compose runs a single `metacore-app`; the flock primitive is
-retained as a correctness anchor (one process owns Redis and the
-writable state under `/meta-core`), not as live failover.
+The lock is a **mutex, not service discovery** — it only stops two
+writers landing on one database file (`db/meta-core.db`). Nothing reads it, and the `kv-leader.info`
+file it used to publish is gone: siblings locate meta-core over UDP
+(see [beacon-v2.md](../../docs/project-architecture/beacon-v2.md)).
+`internal/leader` keeps its name for history, but only builds the `/urls`
+payload (`baseUrl`, `apiUrl`, `webdavUrl`, `webdavUrlInternal`) that `/urls`
+and the UDP announce share.
 
 ## Metadata storage shape (one-line summary)
 
-Roots are opaque UUIDv7 strings; every property is a separate Redis
-STRING at `file:<uuid>/<property>`; every known CID for a file is a
-reverse-index entry `cid:<algorithm>:<value> → <uuid>`. Full details in
+Roots are opaque UUIDv7 strings; every property is a separate row
+of the `kv` table at `file:<uuid>/<property>`; every known CID is a key-set member
+`file:<uuid>/cids/<bareCid>` plus a reverse-index entry `cid:<bareCid> → <uuid>`
+(the canonical CID is derived by rank on read, never stored). Full details in
 [`docs/metadata-storage-structure.md`](docs/metadata-storage-structure.md)
 and design rationale in [`docs/uuid-rooted-metadata.md`](docs/uuid-rooted-metadata.md).
 The authoritative registry of field semantics and value formats lives in
@@ -328,14 +420,16 @@ the repo-root [`METADATA_KEYS.md`](../../METADATA_KEYS.md).
 
 | Package | Purpose |
 |---------|---------|
-| `cmd/meta-core` | Entry point; Redis connect + schema sentinel + service wiring. |
+| `cmd/meta-core` | Entry point; store open + schema sentinel + UDP discovery + service wiring. |
 | `internal/config` | Env-driven configuration, path helpers. |
-| `internal/leader` | `LeaderInfoProvider` (builds the leader info from local hostname/IP/config; no election logic). |
-| `internal/storage` | Redis wrapper (`client.go`), UUIDv7 minting (`uuid.go`), CID reverse index (`cid_resolution.go`), schema sentinel (`schema_version.go`), dual-root migration (`dual_root_migration.go`). |
-| `internal/cid` | CID parsing + algorithm ranking for canonical-CID selection. |
-| `internal/discovery` | Service registry + dead-service cleaner. |
-| `internal/events` | Keyspace-notification → `meta:events` stream publisher (`meta_publisher.go`). |
-| `internal/api` | HTTP server + all handlers + SSE event endpoints. |
+| `internal/leader` | `LeaderInfoProvider` — builds the `/urls` payload from hostname/IP/config; no election logic. |
+| `internal/meshdisco` | beacon v2 node (advertise, probe, neighbour map) — the Go port of the spec. |
+| `internal/kv` | Storage engine: SQLite `kv` table, single writer + group commit, reader pool, in-transaction change events (`kv.go`), event streams as rows (`stream.go`). |
+| `internal/storage` | Flat-key records (`client.go`), UUIDv7 minting, CID reverse index (`cid_resolution.go`), schema sentinel, search over `kv_field` + FTS (`search.go`), UDL store (`udl.go`, `udl_admin.go`), stats. |
+| `internal/cid` | CID parsing + rank ladder for canonical-CID selection (`cid-rank-vectors.json`, guarded by the meta-root `scripts/check-cid-vectors.sh`). |
+| `internal/identity` | Multi-account secp256k1 keystore, challenge/proof-of-possession, signature verification. |
+| `internal/events` | Boot-time republish of every field into `meta:events` (`meta_publisher.go`); live events are written by `internal/kv`. |
+| `internal/api` | HTTP server + all handlers + SSE event endpoints + search matchers + `/api/stats`. |
 | `internal/schema` | Live per-field schema indexer (consumes `meta:events`). |
 | `internal/snapshot` | Snapshot export / import / wipe. |
 | `internal/watcher` | File system scanner, MidHash256 computation, dispatcher, state registry. |
@@ -348,12 +442,14 @@ the repo-root [`METADATA_KEYS.md`](../../METADATA_KEYS.md).
 ```
 1. Load configuration from environment
 2. Build LeaderInfoProvider (no election — the bash gate already won)
-3. Connect to local Redis (retry up to 30× / 1s)
-4. EnsureSchemaVersion — abort if the existing Redis layout is stale
-5. Start service discovery + dead-service cleaner
-6. Construct API server (initialises watcher, mounts, WebDAV)
-7. Start API server; on first connect, start MetaPublisher + schema Indexer
-   and republish existing metadata onto meta:events
+3. Open the SQLite store (META_CORE_DB_PATH or /meta-core/db/meta-core.db)
+4. EnsureSchemaVersion — abort if the existing store layout is stale
+5. Start beacon v2 node (unless ENABLE_UDP_DISCOVERY=false)
+6. Construct API server (identity keystore migration, watcher, watchers,
+   mounts, WebDAV)
+7. Start API server + pollers; start MetaPublisher + schema Indexer, then
+   republish existing metadata onto meta:events in the background
+   (5k events per transaction)
 8. Wait for SIGINT/SIGTERM, shutdown in reverse order
 ```
 
@@ -362,13 +458,14 @@ the repo-root [`METADATA_KEYS.md`](../../METADATA_KEYS.md).
 | Dependency | Purpose |
 |------------|---------|
 | `github.com/gorilla/mux` | HTTP router |
-| `github.com/redis/go-redis/v9` | Redis client |
+| `modernc.org/sqlite` | Embedded SQLite (pure Go, CGO off) |
 | `github.com/google/uuid` | UUIDv7 minting |
+| `github.com/decred/dcrd/dcrec/secp256k1/v4`, `golang.org/x/crypto`, `github.com/mr-tron/base58` | Identity keys, signing, AEAD key derivation |
 | `golang.org/x/net` | WebDAV support |
-| Go stdlib | context, net/http, os, sync, syscall |
 
-Runtime requirements: Go 1.21+ at build time; the container ships Redis,
-rclone, nginx, and supervisord alongside the binary.
+Runtime requirements: Go 1.21+ at build time; the container ships
+rclone, nginx, and supervisord alongside the binary, plus the React dashboard
+and metadata editor (built from `dashboard/` and `editor/` in the Dockerfile).
 
 ## License
 

cmd/meta-core/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"log"
 	"os"
@@ -10,8 +11,8 @@ import (
 
 	"github.com/metazla/meta-core/internal/api"
 	"github.com/metazla/meta-core/internal/config"
-	"github.com/metazla/meta-core/internal/discovery"
 	"github.com/metazla/meta-core/internal/leader"
+	"github.com/metazla/meta-core/internal/meshdisco"
 	"github.com/metazla/meta-core/internal/storage"
 )
 
@@ -29,51 +30,73 @@ func main() {
 	// Create leader info provider (Go binary only runs as leader - followers loop in bash)
 	leaderProvider := leader.NewLeaderInfoProvider(cfg)
 
-	// Connect to local Redis (supervisord starts Redis before meta-core)
-	// Retry connection since Redis may still be loading its dataset
-	redisURL := fmt.Sprintf("redis://localhost:%d", cfg.RedisPort)
-	log.Printf("[meta-core] Connecting to Redis at %s", redisURL)
-
-	storageClient := storage.NewClient("")
-	maxRetries := 30
-	retryDelay := 1 // seconds
-	var err error
-	for i := 0; i < maxRetries; i++ {
-		err = storageClient.Connect(redisURL)
-		if err == nil {
-			break
+	// Open the metadata store: an embedded SQLite file (internal/kv). There
+	// is no separate database process to wait for.
+	storageClient := storage.NewClient()
+	if err := storageClient.Connect(cfg.DBPath()); err != nil {
+		log.Fatalf("[meta-core] Failed to open the metadata store: %v", err)
 	}
-		log.Printf("[meta-core] Redis connection attempt %d/%d failed: %v", i+1, maxRetries, err)
-		time.Sleep(time.Duration(retryDelay) * time.Second)
-	}
-	if err != nil {
-		log.Fatalf("[meta-core] Failed to connect to Redis after %d attempts: %v", maxRetries, err)
-	}
-	log.Println("[meta-core] Connected to Redis")
 
 	// Schema-version sentinel: alpha clean-wipe gate. Refuses to boot when
-	// the existing Redis store predates the UUID-rooted schema, so legacy
-	// data can't silently leak into the new code paths. See
+	// the existing store predates the UUID-rooted schema, so legacy data
+	// can't silently leak into the new code paths. See
 	// docs/uuid-rooted-metadata.md.
 	if err := storageClient.EnsureSchemaVersion(storage.SchemaVersion); err != nil {
 		log.Fatalf("[meta-core] %v", err)
 	}
-	log.Printf("[meta-core] Redis schema version OK (v%d)", storage.SchemaVersion)
+	log.Printf("[meta-core] Store schema version OK (v%d)", storage.SchemaVersion)
 
-	// Create and start service discovery
-	disc := discovery.NewService(cfg)
-	if err := disc.Start(); err != nil {
-		log.Fatalf("[meta-core] Failed to start service discovery: %v", err)
+	// Beacon v2 (docs/project-architecture/beacon-v2.md): advertise meta-core
+	// as metamesh.core — carrying the /urls block services locate us by — plus
+	// its own metamesh.service/<name> nav entry. The payload is rebuilt from
+	// leaderProvider on every tick, which keeps it and GET /urls from drifting.
+	var mesh *meshdisco.Node
+	if cfg.EnableUDPDiscovery {
+		hostname, _ := os.Hostname()
+		mesh = meshdisco.New(meshdisco.Config{
+			Name:     cfg.ServiceName,
+			Instance: hostname,
+			Version:  Version,
+			Group:    cfg.DiscoveryGroup,
+			Port:     cfg.DiscoveryPort,
+			Interval: time.Duration(cfg.DiscoveryIntervalMS) * time.Millisecond,
+			Payload: func() (string, []meshdisco.Resource) {
+				service := meshdisco.Resource{
+					ID:        "service",
+					Caps:      []string{meshdisco.CapServicePrefix + cfg.ServiceName},
+					Endpoints: map[string]string{"ui": coreBaseURL(cfg)},
 				}
-
-	// Create and start dead service cleaner
-	cleaner := discovery.NewCleaner(cfg)
-	if err := cleaner.Start(); err != nil {
-		log.Printf("[meta-core] Warning: failed to start service cleaner: %v", err)
+				info := leaderProvider.LeaderInfo()
+				if info == nil {
+					return "starting", []meshdisco.Resource{service}
+				}
+				data, _ := json.Marshal(map[string]meshdisco.URLs{"urls": {
+					Hostname:          info.Hostname,
+					BaseUrl:           info.BaseUrl,
+					ApiUrl:            info.ApiUrl,
+					WebdavUrl:         info.WebdavUrl,
+					WebdavUrlInternal: info.WebdavUrlInternal,
+				}})
+				core := meshdisco.Resource{
+					ID:        "core",
+					Caps:      []string{meshdisco.CapCore},
+					Endpoints: map[string]string{"http": info.ApiUrl},
+					Data:      data,
+				}
+				return "running", []meshdisco.Resource{core, service}
+			},
+		})
+		if err := mesh.Start(); err != nil {
+			log.Printf("[meta-core] Warning: UDP discovery disabled: %v", err)
+			mesh = nil
+		}
+	} else {
+		log.Println("[meta-core] UDP discovery disabled by ENABLE_UDP_DISCOVERY")
 	}
 
 	// Create and start API server
-	apiServer := api.NewServer(cfg, leaderProvider, disc, cleaner, storageClient)
+	apiServer := api.NewServer(cfg, leaderProvider, storageClient)
+	apiServer.SetMeshNode(mesh)
 	if err := apiServer.Start(); err != nil {
 		log.Fatalf("[meta-core] Failed to start API server: %v", err)
 	}
@@ -90,12 +113,10 @@ func main() {
 		log.Printf("[meta-core] Error stopping API server: %v", err)
 	}
 
-	if err := cleaner.Stop(); err != nil {
-		log.Printf("[meta-core] Error stopping service cleaner: %v", err)
+	if mesh != nil {
+		if err := mesh.Stop(); err != nil {
+			log.Printf("[meta-core] Error stopping UDP discovery: %v", err)
 		}
-
-	if err := disc.Stop(); err != nil {
-		log.Printf("[meta-core] Error stopping service discovery: %v", err)
 	}
 
 	if err := storageClient.Close(); err != nil {
@@ -112,3 +133,17 @@ func waitForShutdown() {
 	<-sigChan
 }
 
+// coreBaseURL is the browser-facing URL announced for the nav menu. It keeps
+// the three-way fallback the file registry used (discovery/service.go):
+// META_CORE_PUBLIC_URL wins (the reachable URL when there is no Caddy
+// perimeter, e.g. a debug-direct port), then BASE_URL (the Caddy URL), then
+// the container IP.
+func coreBaseURL(cfg *config.Config) string {
+	if cfg.PublicURL != "" {
+		return cfg.PublicURL
+	}
+	if cfg.BaseURL != "" {
+		return cfg.BaseURL
+	}
+	return fmt.Sprintf("http://%s:%d", meshdisco.LocalIPv4(), cfg.APIPort)
+}

dashboard/dist/index.html

@@ -21,7 +21,7 @@
         min-height: 100vh;
       }
     </style>
-    <script type="module" crossorigin src="/assets/index-Cbd1uH5A.js"></script>
+    <script type="module" crossorigin src="/assets/index-Bgo6moAc.js"></script>
     <link rel="stylesheet" crossorigin href="/assets/index-DtR_2V4s.css">
   </head>
   <body>

dashboard/package-lock.json

@@ -8,6 +8,7 @@
       "name": "@meta-core/dashboard",
       "version": "1.0.0",
       "dependencies": {
+        "@noble/secp256k1": "^3.1.0",
         "iso-639-3": "^3.0.1",
         "react": "^18.2.0",
         "react-dom": "^18.2.0",
@@ -744,6 +745,15 @@
         "@jridgewell/sourcemap-codec": "^1.4.14"
       }
     },
+    "node_modules/@noble/secp256k1": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/@noble/secp256k1/-/secp256k1-3.1.0.tgz",
+      "integrity": "sha512-+F7iS7tUMaNGXcc9X3PjmjvuQnXEuSjCRNzVVA2xAcKXgCaP0dHYz4SFyt4FKNHef7sOP//xihowcySSS7PK9g==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
     "node_modules/@remix-run/router": {
       "version": "1.23.2",
       "resolved": "https://registry.npmjs.org/@remix-run/router/-/router-1.23.2.tgz",

dashboard/package.json

@@ -9,10 +9,11 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@noble/secp256k1": "^3.1.0",
+    "iso-639-3": "^3.0.1",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
-    "react-router-dom": "^6.20.0",
-    "iso-639-3": "^3.0.1"
+    "react-router-dom": "^6.20.0"
   },
   "devDependencies": {
     "@types/react": "^18.2.38",

dashboard/src/components/ServiceNav.tsx

@@ -1,155 +1,53 @@
-import { useState, useEffect } from 'react';
+import { useEffect } from 'react';
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore -- plain ES module, no .d.ts; imported for its side effect
+// of defining the custom element.
+import '../meta-service-menu.js';
 
-interface ServiceInfo {
-  name: string;
-  hostname: string;
-  baseUrl: string;
-  status: string;
-  lastHeartbeat: string;
+/**
+ * ServiceNav — the neighbouring meta-* services, as a burger menu.
+ *
+ * Since meta-discovery v1 this is a thin wrapper around <meta-service-menu>,
+ * a framework-free custom element shared by every meta-* UI (see
+ * scripts/check-mirrors.sh). The old implementation was ~165 lines of React
+ * that existed in four near-identical copies and polled meta-core's
+ * /api/services; the element polls this service's own /api/neighbors instead,
+ * so the nav still renders when meta-core is down.
+ *
+ * The element lives in shadow DOM and cannot see this app's CSS variables, so
+ * the four --mm-nav-* tokens below map our palette onto it.
+ */
+
+declare global {
+    // eslint-disable-next-line @typescript-eslint/no-namespace
+    namespace JSX {
+        interface IntrinsicElements {
+            'meta-service-menu': React.DetailedHTMLProps<
+                React.HTMLAttributes<HTMLElement>,
+                HTMLElement
+            > & { current?: string; endpoint?: string; label?: string };
         }
-
-interface ServicesResponse {
-  services: ServiceInfo[];
-  current: string;
     }
-
-const serviceIcons: Record<string, string> = {
-  'meta-core': '🗄️',
-  'meta-sort': '📁',
-  'meta-fuse': '🗂️',
-  'meta-stremio': '🎬',
-  'meta-orbit': '🌐',
-  'default': '📦'
-};
-
-function formatServiceName(name: string): string {
-  return name.split('-').map(word =>
-    word.charAt(0).toUpperCase() + word.slice(1)
-  ).join(' ');
 }
 
 function ServiceNav() {
-  const [services, setServices] = useState<ServiceInfo[]>([]);
-  const [loading, setLoading] = useState(true);
-  const currentService = 'meta-core';
-
     useEffect(() => {
-    const fetchServices = async () => {
-      try {
-        const response = await fetch('/services');
-        if (response.ok) {
-          const data: ServicesResponse = await response.json();
-          setServices(data.services || []);
-        }
-      } catch (error) {
-        console.error('Failed to fetch services:', error);
-      } finally {
-        setLoading(false);
-      }
-    };
-
-    fetchServices();
-    const interval = setInterval(fetchServices, 30000);
-    return () => clearInterval(interval);
+        // Import above is for the side effect of defining the element; this
+        // keeps bundlers from tree-shaking it away in production builds.
     }, []);
 
-  if (loading) return null;
-
-  const sortedServices = [...services].sort((a, b) => a.name.localeCompare(b.name));
-
-  if (sortedServices.length === 0) return null;
-
     return (
-    <nav className="services-nav">
-      <span className="services-nav-label">Services:</span>
-      <div className="services-nav-items">
-        {sortedServices.map(service => {
-          const icon = serviceIcons[service.name] || serviceIcons.default;
-          const isActive = service.name === currentService;
-          return (
-            <a
-              key={service.name}
-              href={isActive ? '#' : service.baseUrl}
-              className={`service-link${isActive ? ' active' : ''}`}
-              onClick={(e) => {
-                e.preventDefault();
-                if (!isActive) {
-                  window.location.href = service.baseUrl;
-                }
-              }}
-            >
-              <span className="service-icon">{icon}</span>
-              <span>{formatServiceName(service.name)}</span>
-              <span className="service-status"></span>
-            </a>
-          );
-        })}
-      </div>
-
+        <>
+            <meta-service-menu current="meta-core" />
             <style>{`
-        .services-nav {
-          display: flex;
-          align-items: center;
-          gap: 0.5rem;
-        }
-
-        .services-nav-label {
-          color: #888;
-          font-size: 0.8rem;
-          white-space: nowrap;
-        }
-
-        .services-nav-items {
-          display: flex;
-          gap: 0.35rem;
-        }
-
-        .service-link {
-          display: inline-flex;
-          align-items: center;
-          gap: 0.3rem;
-          padding: 0.35rem 0.6rem;
-          border-radius: 6px;
-          text-decoration: none;
-          font-size: 0.8rem;
-          font-weight: 500;
-          transition: all 0.2s;
-          color: #ccc;
-          background: #0f3460;
-          border: 1px solid #1a4a7a;
-        }
-
-        .service-link:hover {
-          background: #1a4a7a;
-          border-color: rgba(78, 205, 196, 0.5);
-          text-decoration: none;
-          color: #fff;
-        }
-
-        .service-link.active {
-          background: linear-gradient(135deg, rgba(78, 205, 196, 0.2), rgba(68, 160, 141, 0.2));
-          border-color: rgba(78, 205, 196, 0.5);
-          color: #fff;
-        }
-
-        .service-link .service-icon {
-          font-size: 0.9rem;
-        }
-
-        .service-link .service-status {
-          width: 5px;
-          height: 5px;
-          border-radius: 50%;
-          background: #4ecdc4;
-        }
-
-        @media (max-width: 800px) {
-          .services-nav-label {
-            display: none;
-          }
+                meta-service-menu {
+                    --mm-nav-fg: var(--text-primary, #e0e0e0);
+                    --mm-nav-bg: var(--bg-tertiary, var(--bg-secondary, #1a1a2e));
+                    --mm-nav-border: var(--border-color, rgba(255,255,255,0.14));
+                    --mm-nav-accent: var(--accent-primary, #4ecdc4);
                 }
             `}</style>
-    </nav>
+        </>
     );
 }
 

dashboard/src/lib/api.ts

@@ -0,0 +1,28 @@
+// JSON fetch that fails with a sentence instead of a parser error.
+//
+// nginx serves the dashboard with `try_files $uri $uri/ /index.html`, so ANY
+// path it does not have a proxy rule for answers 200 text/html with the SPA
+// shell. A caller that does `res.ok && res.json()` on such a path gets
+// `SyntaxError: Unexpected token '<', "<!doctype "... is not valid JSON` and
+// no clue which request produced it — which is exactly how a route deleted
+// from the Go router (`/services`, removed in favour of /api/neighbors) sat
+// broken on the dashboard.
+//
+// So: check the content type, and name the URL in every error.
+
+export async function getJSON<T>(url: string, init?: RequestInit): Promise<T> {
+  const res = await fetch(url, init);
+  const ct = res.headers.get('content-type') || '';
+
+  if (!res.ok) {
+    throw new Error(`${url} → HTTP ${res.status}`);
+  }
+  if (!ct.includes('application/json')) {
+    // The SPA fallback is the overwhelmingly likely cause; say so.
+    throw new Error(
+      `${url} → ${res.status} ${ct || 'no content-type'} (not JSON — the route is ` +
+        `missing and nginx served the dashboard shell instead)`
+    );
+  }
+  return (await res.json()) as T;
+}

dashboard/src/lib/sign.ts

@@ -0,0 +1,127 @@
+// Client-side proof of possession for account operations.
+//
+// meta-core stores every private key in plaintext, so it can sign as anybody —
+// which means a signature it produced proves nothing about who asked. The only
+// signature that carries authority is one made where the key actually is, and
+// for a browser-driven admin console that is here. meta-core enforces the other
+// half by refusing to sign anything in the challenge domain
+// (identity.ChallengeDomain), so this path cannot be short-circuited.
+//
+// The secret key entered on this page is used for exactly one signature and is
+// never sent anywhere: `/api/identity/challenge` receives only the uid, and the
+// request that follows carries only the challenge and its signature.
+//
+// Same scheme, same curve and same encodings as meta-watch's sign-in
+// (packages/meta-watch/ui/js/auth.js) — deliberately, so one implementation on
+// the server verifies both.
+
+import * as secp from '@noble/secp256k1';
+
+export type IdentityAction = 'reveal' | 'delete';
+
+function hexToBytes(hex: string): Uint8Array | null {
+  let h = hex.trim();
+  if (h.startsWith('0x') || h.startsWith('0X')) h = h.slice(2);
+  if (h.length !== 64 || /[^0-9a-fA-F]/.test(h)) return null;
+  const out = new Uint8Array(32);
+  for (let i = 0; i < 32; i++) out[i] = parseInt(h.slice(i * 2, i * 2 + 2), 16);
+  return out;
+}
+
+function bytesToBase64(bytes: Uint8Array): string {
+  let s = '';
+  for (const b of bytes) s += String.fromCharCode(b);
+  return btoa(s);
+}
+
+const B58 = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
+
+/// base58btc, the multibase "z" alphabet. Spelled out rather than pulled in:
+/// the alternative is a second dependency for thirty lines of arithmetic.
+function base58Encode(bytes: Uint8Array): string {
+  const digits: number[] = [0];
+  for (const byte of bytes) {
+    let carry = byte;
+    for (let i = 0; i < digits.length; i++) {
+      carry += digits[i] << 8;
+      digits[i] = carry % 58;
+      carry = (carry / 58) | 0;
+    }
+    while (carry) {
+      digits.push(carry % 58);
+      carry = (carry / 58) | 0;
+    }
+  }
+  // Leading zero bytes encode as leading '1's rather than being dropped.
+  let out = '';
+  for (let i = 0; i < bytes.length && bytes[i] === 0; i++) out += B58[0];
+  for (let i = digits.length - 1; i >= 0; i--) out += B58[digits[i]];
+  return out;
+}
+
+/// The uid a secret key belongs to: "z" + base58btc(33-byte compressed pubkey).
+/// Derived locally so a mistyped or wrong-account key is caught before any
+/// request goes out. Mirrors `identityFromPrivKey` in meta-core's identity.go.
+export function uidFromSecretKey(secretKeyHex: string): string | null {
+  const raw = hexToBytes(secretKeyHex);
+  if (!raw) return null;
+  try {
+    return 'z' + base58Encode(secp.getPublicKey(raw, true));
+  } catch {
+    return null; // not a valid scalar
+  }
+}
+
+/// Whether this page can sign at all.
+///
+/// noble's signAsync takes its sha256 from crypto.subtle, which browsers expose
+/// only in a secure context. The dashboard behind Caddy is https and fine; the
+/// debug-direct port (18083) is plain http, where every signature would fail
+/// with a cryptic error unless we say so first.
+export function canSign(): boolean {
+  return Boolean(globalThis.crypto?.subtle);
+}
+
+export const INSECURE_CONTEXT_MESSAGE =
+  'This page cannot sign over a plain-http connection — browsers only expose the ' +
+  'needed crypto on https (or localhost). Reach the dashboard through Caddy ' +
+  '(https://metacore-dev.localhost:8083) rather than the debug-direct port.';
+
+/// Ask meta-core for a challenge, sign it locally, and hand back the proof.
+///
+/// Throws with a message fit to show the user. The caller passes the proof
+/// straight into the reveal/delete request body.
+export async function proveOwnership(
+  uid: string,
+  action: IdentityAction,
+  secretKeyHex: string
+): Promise<{ challenge: string; signature: string }> {
+  if (!canSign()) throw new Error(INSECURE_CONTEXT_MESSAGE);
+
+  const raw = hexToBytes(secretKeyHex);
+  if (!raw) {
+    throw new Error('That is not a valid secret key: expected 64 hex characters.');
+  }
+  const derived = uidFromSecretKey(secretKeyHex);
+  if (!derived) throw new Error('That is not a valid secp256k1 secret key.');
+  if (derived !== uid) {
+    // Caught here rather than by the server, so the message can say which
+    // account the key actually is — the useful half of the answer.
+    throw new Error(`That key belongs to a different account (${derived}), not this one.`);
+  }
+
+  const cRes = await fetch('/api/identity/challenge', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ uid, action }),
+  });
+  const cBody = await cRes.json().catch(() => ({}));
+  if (!cRes.ok || !cBody.challenge) {
+    throw new Error(cBody.message ?? `Could not start verification (HTTP ${cRes.status}).`);
+  }
+
+  // signAsync prehashes with sha256 and returns a 64-byte compact (r‖s)
+  // signature — noble v3 dropped DER. meta-core's identity.Verify accepts both.
+  const sig = await secp.signAsync(new TextEncoder().encode(cBody.challenge), raw);
+  return { challenge: cBody.challenge, signature: bytesToBase64(sig) };
+}

dashboard/src/meta-service-menu.js

@@ -0,0 +1,308 @@
+/**
+ * <meta-service-menu> — the neighbouring meta-* services, as a burger menu.
+ *
+ * Replaces the eight divergent "services bar" implementations (four copies of
+ * a React `ServiceNav.tsx`, two mirrored `services.js`, two bespoke inline
+ * ones) with a single framework-free custom element. It drops into the React
+ * dashboards as a plain tag — no React dependency — and into the vanilla UIs
+ * as an ES module.
+ *
+ * Data comes from the host service's own `GET /api/neighbors`, same-origin.
+ * Never cross-origin: the dev stack's self-signed certs and the OIDC redirects
+ * make a fetch to a neighbour a dead end. Links are plain navigations.
+ *
+ * ⚠ MIRRORED FILE. Byte-identical copies live in every meta-* UI tree; see
+ * `scripts/check-mirrors.sh`. Edit one → edit all.
+ *
+ * Shadow DOM is not optional here. The eight UIs use four incompatible token
+ * vocabularies, and two of them define *different colours under the same
+ * names* (`--bg-secondary` is #12121a in meta-sort, #16213e in meta-core,
+ * #161b22 in meta-dup). meta-search and meta-share are also the only
+ * light-mode-capable UIs, so a hardcoded dark palette would break them.
+ * The element therefore styles itself from four tokens with dark defaults:
+ *
+ *     --mm-nav-fg, --mm-nav-bg, --mm-nav-border, --mm-nav-accent
+ *
+ * Each host maps its own variables onto those, e.g.
+ *     meta-service-menu { --mm-nav-bg: var(--bg-secondary); }
+ *
+ * Attributes:
+ *   current   name of the host service, so it can be marked and not linked
+ *   endpoint  override the default "/api/neighbors"
+ *   label     button tooltip (default "Services")
+ *
+ * Property:
+ *   rewriteUrl  optional (name, url, neighbour) => url, for hosts that must
+ *               translate internal hostnames into browser-reachable ones
+ *               (meta-gateway does this for its dev/prod split).
+ */
+
+const ICONS = {
+  "meta-core": "⚙️",
+  "meta-sort": "📁",
+  "meta-fuse": "🗂️",
+  "meta-stremio": "🎬",
+  "meta-dup": "🔍",
+  "meta-search": "🔎",
+  "meta-share": "🔗",
+  "meta-gateway": "🌉",
+  "meta-watch": "📺",
+  "meta-listen": "🎧",
+  "meta-read": "📖",
+};
+const DEFAULT_ICON = "📦";
+const POLL_MS = 30000;
+
+function titleCase(name) {
+  return String(name || "")
+    .split("-")
+    .map((w) => w.charAt(0).toUpperCase() + w.slice(1))
+    .join(" ");
+}
+
+const TEMPLATE = `
+<style>
+  :host {
+    --_fg: var(--mm-nav-fg, #e8eaed);
+    --_bg: var(--mm-nav-bg, #1a1a2e);
+    --_border: var(--mm-nav-border, rgba(255, 255, 255, 0.14));
+    --_accent: var(--mm-nav-accent, #4ecdc4);
+    position: relative;
+    display: inline-block;
+    font-family: inherit;
+    font-size: 14px;
+    line-height: 1.4;
+  }
+  button.trigger {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    gap: 0.4rem;
+    width: 2.1rem;
+    height: 2.1rem;
+    padding: 0;
+    cursor: pointer;
+    color: var(--_fg);
+    background: transparent;
+    border: 1px solid var(--_border);
+    border-radius: 8px;
+    font: inherit;
+    transition: border-color 0.15s, background 0.15s;
+  }
+  button.trigger:hover { border-color: var(--_accent); }
+  button.trigger:focus-visible {
+    outline: 2px solid var(--_accent);
+    outline-offset: 2px;
+  }
+  button.trigger[aria-expanded="true"] { border-color: var(--_accent); }
+  .bars { display: block; width: 15px; }
+  .bars span {
+    display: block;
+    height: 2px;
+    margin: 3px 0;
+    border-radius: 2px;
+    background: currentColor;
+  }
+  .panel {
+    position: absolute;
+    top: calc(100% + 6px);
+    right: 0;
+    z-index: 1000;
+    min-width: 13rem;
+    max-height: 70vh;
+    overflow-y: auto;
+    padding: 0.3rem;
+    background: var(--_bg);
+    border: 1px solid var(--_border);
+    border-radius: 10px;
+    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
+  }
+  .panel[hidden] { display: none; }
+  a.item, .item {
+    display: flex;
+    align-items: center;
+    gap: 0.55rem;
+    padding: 0.45rem 0.6rem;
+    border-radius: 6px;
+    color: var(--_fg);
+    text-decoration: none;
+    white-space: nowrap;
+  }
+  a.item:hover { background: color-mix(in srgb, var(--_accent) 18%, transparent); }
+  .item.active { color: var(--_accent); font-weight: 600; cursor: default; }
+  .item.dead { opacity: 0.55; cursor: not-allowed; }
+  .icon { font-size: 1rem; line-height: 1; }
+  .dot {
+    width: 6px;
+    height: 6px;
+    margin-left: auto;
+    border-radius: 50%;
+    background: var(--_accent);
+  }
+  .empty {
+    padding: 0.6rem;
+    opacity: 0.7;
+    font-size: 0.85em;
+    white-space: nowrap;
+  }
+  /* Respect a host that opts out of motion. */
+  @media (prefers-reduced-motion: reduce) {
+    button.trigger { transition: none; }
+  }
+</style>
+<button class="trigger" type="button" aria-haspopup="menu" aria-expanded="false">
+  <span class="bars" aria-hidden="true"><span></span><span></span><span></span></span>
+</button>
+<div class="panel" role="menu" hidden></div>
+`;
+
+class MetaServiceMenu extends HTMLElement {
+  constructor() {
+    super();
+    this.attachShadow({ mode: "open" });
+    this.shadowRoot.innerHTML = TEMPLATE;
+    this._btn = this.shadowRoot.querySelector("button.trigger");
+    this._panel = this.shadowRoot.querySelector(".panel");
+    this._neighbors = [];
+    this._timer = null;
+    this._open = false;
+
+    this._onDocClick = (e) => {
+      if (!this._open) return;
+      if (e.composedPath().includes(this)) return;
+      this._setOpen(false);
+    };
+    this._onKey = (e) => {
+      if (e.key === "Escape" && this._open) {
+        this._setOpen(false);
+        this._btn.focus();
+      }
+    };
+  }
+
+  connectedCallback() {
+    this._btn.title = this.getAttribute("label") || "Services";
+    this._btn.setAttribute("aria-label", this._btn.title);
+    this._btn.addEventListener("click", () => this._setOpen(!this._open));
+    document.addEventListener("click", this._onDocClick);
+    document.addEventListener("keydown", this._onKey);
+
+    this.refresh();
+    this._timer = setInterval(() => this.refresh(), POLL_MS);
+  }
+
+  disconnectedCallback() {
+    if (this._timer) clearInterval(this._timer);
+    this._timer = null;
+    document.removeEventListener("click", this._onDocClick);
+    document.removeEventListener("keydown", this._onKey);
+  }
+
+  get endpoint() {
+    return this.getAttribute("endpoint") || "/api/neighbors";
+  }
+
+  get current() {
+    return this.getAttribute("current") || "";
+  }
+
+  async refresh() {
+    try {
+      const res = await fetch(this.endpoint, {
+        headers: { Accept: "application/json" },
+      });
+      if (!res.ok) throw new Error(String(res.status));
+      const data = await res.json();
+      // `services` is the legacy alias some backends still emit.
+      this._neighbors = data.neighbors || data.services || [];
+    } catch {
+      // Silent: the menu is navigation, not a health indicator. Keep whatever
+      // we last had rather than blanking the list on one failed poll.
+    }
+    this._render();
+  }
+
+  _setOpen(open) {
+    this._open = open;
+    this._panel.hidden = !open;
+    this._btn.setAttribute("aria-expanded", String(open));
+    if (open) this.refresh();
+  }
+
+  _render() {
+    const panel = this._panel;
+    panel.textContent = "";
+
+    const seen = new Set();
+    const rows = [];
+    for (const n of this._neighbors) {
+      const name = n.name || "";
+      if (!name || seen.has(name)) continue;
+      // Beacon v2 neighbours include plugins; the nav lists services only.
+      // (A row without `caps` comes from a pre-v2 backend — keep it.)
+      const isService = (c) => String(c).startsWith("metamesh.service/");
+      if (Array.isArray(n.caps) && !n.caps.some(isService)) continue;
+      seen.add(name);
+      rows.push(n);
+    }
+    // Always show the host itself, even before its own echo comes back.
+    if (this.current && !seen.has(this.current)) {
+      rows.push({ name: this.current, baseUrl: "" });
+    }
+    rows.sort((a, b) => String(a.name).localeCompare(String(b.name)));
+
+    if (rows.length === 0) {
+      const empty = document.createElement("div");
+      empty.className = "empty";
+      empty.textContent = "No services found";
+      panel.appendChild(empty);
+      return;
+    }
+
+    for (const n of rows) {
+      const isActive = n.name === this.current;
+      let url = n.baseUrl || "";
+      if (typeof this.rewriteUrl === "function") {
+        try {
+          url = this.rewriteUrl(n.name, url, n) || "";
+        } catch {
+          /* a bad hook must not blank the menu */
+        }
+      }
+
+      // A neighbour with no reachable URL is shown but not linked — better
+      // than a link that goes nowhere.
+      const el = document.createElement(isActive || !url ? "span" : "a");
+      el.className =
+        "item" + (isActive ? " active" : "") + (!isActive && !url ? " dead" : "");
+      if (el.tagName === "A") {
+        el.href = url;
+        el.setAttribute("role", "menuitem");
+      }
+      if (!isActive && !url) el.title = "No reachable URL advertised";
+
+      const icon = document.createElement("span");
+      icon.className = "icon";
+      icon.textContent = ICONS[n.name] || DEFAULT_ICON;
+
+      const label = document.createElement("span");
+      label.textContent = titleCase(n.name);
+
+      el.append(icon, label);
+      // Beacon v2 omits `status` when running.
+      if ((n.status || "running") === "running" || isActive) {
+        const dot = document.createElement("span");
+        dot.className = "dot";
+        dot.title = n.status || "running";
+        el.appendChild(dot);
+      }
+      panel.appendChild(el);
+    }
+  }
+}
+
+if (!customElements.get("meta-service-menu")) {
+  customElements.define("meta-service-menu", MetaServiceMenu);
+}
+
+export default MetaServiceMenu;

dashboard/src/pages/Dashboard.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useState } from 'react';
+import { getJSON } from '../lib/api';
 
 interface HealthStatus {
   status: string;
@@ -6,6 +7,22 @@ interface HealthStatus {
   timestamp: string;
 }
 
+interface FileStats {
+  count: number;
+  totalSize: number;
+}
+
+interface Stats {
+  records: number;
+  redisKeys: number;
+  redisMemory: string;
+  identities: number;
+  files: FileStats | null;
+  udlUsers: number | null;
+  sweptAt: number;
+  sweeping: boolean;
+}
+
 interface WatcherStatus {
   id: string;
   path: string;
@@ -22,13 +39,6 @@ interface WatchersResponse {
   count: number;
 }
 
-interface ServiceInfo {
-  name: string;
-  api: string;
-  capabilities: string[];
-  timestamp: number;
-}
-
 const cardStyle: React.CSSProperties = {
   background: '#16213e',
   borderRadius: '8px',
@@ -38,53 +48,110 @@ const cardStyle: React.CSSProperties = {
 
 const gridStyle: React.CSSProperties = {
   display: 'grid',
-  gridTemplateColumns: 'repeat(auto-fit, minmax(300px, 1fr))',
+  // 200px, not 220: five tiles must fit one row inside the 1200px container
+  // (1136 content - 4x16 gap = 1072 / 5 = 214 each) before wrapping.
+  gridTemplateColumns: 'repeat(auto-fit, minmax(200px, 1fr))',
   gap: '1rem',
+  marginBottom: '1rem',
 };
 
 const statStyle: React.CSSProperties = {
   fontSize: '2rem',
   fontWeight: 'bold',
   color: '#4ade80',
+  lineHeight: 1.2,
 };
 
+const labelStyle: React.CSSProperties = {
+  marginBottom: '0.75rem',
+  color: '#888',
+  fontSize: '0.85rem',
+  textTransform: 'uppercase',
+  letterSpacing: '0.04em',
+};
+
+const noteStyle: React.CSSProperties = {
+  color: '#6b7a99',
+  fontSize: '0.8rem',
+  marginTop: '0.4rem',
+};
+
+const numberFmt = new Intl.NumberFormat();
+
+function formatCount(n: number | null | undefined): string {
+  return n === null || n === undefined ? '—' : numberFmt.format(n);
+}
+
+// Binary units: this counts bytes on disk, and every other tool the operator
+// compares against (du, docker, the mount page) reports GiB.
+function formatBytes(bytes: number | null | undefined): string {
+  if (bytes === null || bytes === undefined) return '—';
+  const units = ['B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB'];
+  let value = bytes;
+  let unit = 0;
+  while (value >= 1024 && unit < units.length - 1) {
+    value /= 1024;
+    unit++;
+  }
+  return `${value.toFixed(value >= 100 || unit === 0 ? 0 : 1)} ${units[unit]}`;
+}
+
+function Tile({
+  label,
+  value,
+  note,
+  pending,
+}: {
+  label: string;
+  value: string;
+  note?: string;
+  pending?: boolean;
+}) {
+  return (
+    <div style={cardStyle}>
+      <div style={labelStyle}>{label}</div>
+      <div style={{ ...statStyle, color: pending ? '#6b7a99' : statStyle.color }}>
+        {value}
+      </div>
+      {note && <div style={noteStyle}>{note}</div>}
+    </div>
+  );
+}
+
 export default function Dashboard() {
   const [health, setHealth] = useState<HealthStatus | null>(null);
+  const [stats, setStats] = useState<Stats | null>(null);
   const [watchersData, setWatchersData] = useState<WatchersResponse | null>(null);
-  const [services, setServices] = useState<ServiceInfo[]>([]);
   const [error, setError] = useState<string | null>(null);
 
   useEffect(() => {
+    let cancelled = false;
+
     const fetchData = async () => {
-      try {
-        // Fetch health
-        const healthRes = await fetch('/health');
-        if (healthRes.ok) {
-          setHealth(await healthRes.json());
-        }
+      // Settled, not all: one dead endpoint must not blank every tile.
+      const [healthRes, statsRes, watchersRes] = await Promise.allSettled([
+        getJSON<HealthStatus>('/health'),
+        getJSON<Stats>('/api/stats'),
+        getJSON<WatchersResponse>('/api/watchers'),
+      ]);
+      if (cancelled) return;
 
-        // Fetch watchers status
-        const watchersRes = await fetch('/api/watchers');
-        if (watchersRes.ok) {
-          setWatchersData(await watchersRes.json());
-        }
+      if (healthRes.status === 'fulfilled') setHealth(healthRes.value);
+      if (statsRes.status === 'fulfilled') setStats(statsRes.value);
+      if (watchersRes.status === 'fulfilled') setWatchersData(watchersRes.value);
 
-        // Fetch services
-        const servicesRes = await fetch('/services');
-        if (servicesRes.ok) {
-          const data = await servicesRes.json();
-          setServices(data.services || []);
-        }
-
-        setError(null);
-      } catch (err) {
-        setError(String(err));
-      }
+      const failures = [healthRes, statsRes, watchersRes]
+        .filter((r): r is PromiseRejectedResult => r.status === 'rejected')
+        .map((r) => String(r.reason?.message ?? r.reason));
+      setError(failures.length ? failures.join(' · ') : null);
     };
 
     fetchData();
     const interval = setInterval(fetchData, 5000);
-    return () => clearInterval(interval);
+    return () => {
+      cancelled = true;
+      clearInterval(interval);
+    };
   }, []);
 
   const handleTriggerScan = async () => {
@@ -95,49 +162,102 @@ export default function Dashboard() {
     }
   };
 
-  // Aggregate watcher stats
-  const totalFiles = watchersData?.watchers.reduce((sum, w) => sum + w.fileCount, 0) || 0;
-  const isScanning = watchersData?.watchers.some(w => w.isScanning) || false;
-  const activeWatchers = watchersData?.watchers.filter(w => w.active).length || 0;
-  const lastScan = watchersData?.watchers.reduce((max, w) => Math.max(max, w.lastScan || 0), 0) || 0;
+  const isScanning = watchersData?.watchers.some((w) => w.isScanning) || false;
+  const activeWatchers = watchersData?.watchers.filter((w) => w.active).length || 0;
+  const lastScan =
+    watchersData?.watchers.reduce((max, w) => Math.max(max, w.lastScan || 0), 0) || 0;
+
+  // Records we hold metadata for but have no local file: gateway/cid-rooted
+  // entries, plus anything whose file went away. The interesting number on a
+  // client box, where it should be most of them.
+  const fileless =
+    stats && stats.files ? Math.max(0, stats.records - stats.files.count) : null;
+
+  const sweepPending = !!stats && !stats.files;
+  const sweptNote = (() => {
+    if (!stats) return undefined;
+    if (sweepPending) return stats.sweeping ? 'scanning…' : 'not scanned yet';
+    if (stats.sweeping) return 'refreshing…';
+    if (stats.sweptAt) return `as of ${new Date(stats.sweptAt).toLocaleTimeString()}`;
+    return undefined;
+  })();
 
   return (
-    <div style={{ padding: '2rem', maxWidth: '1200px', margin: '0 auto' }}>
+    <div style={{ padding: '2rem', maxWidth: '1200px', margin: '0 auto', overflowY: 'auto', height: '100%' }}>
       <h1 style={{ marginBottom: '2rem' }}>meta-core Dashboard</h1>
 
       {error && (
         <div style={{ ...cardStyle, background: '#4a1a1a', color: '#f87171' }}>
-          Error: {error}
+          {error}
         </div>
       )}
 
       <div style={gridStyle}>
-        {/* Health Card */}
+        <Tile
+          label="Files discovered"
+          value={formatCount(stats?.files?.count)}
+          note={sweptNote}
+          pending={sweepPending}
+        />
+        <Tile
+          label="Library size"
+          value={formatBytes(stats?.files?.totalSize)}
+          note={sweptNote}
+          pending={sweepPending}
+        />
+        <Tile
+          label="Metadata entries"
+          value={formatCount(stats?.records)}
+          note={
+            fileless === null
+              ? 'records in the index'
+              : `${formatCount(fileless)} with no local file`
+          }
+        />
+        <Tile
+          label="Store keys"
+          value={formatCount(stats?.redisKeys)}
+          note={stats?.redisMemory ? `${stats.redisMemory} on disk` : undefined}
+        />
+        <Tile
+          label="Identities"
+          value={formatCount(stats?.identities)}
+          note={
+            stats?.udlUsers !== null && stats?.udlUsers !== undefined
+              ? `${formatCount(stats.udlUsers)} with user data`
+              : 'signing accounts'
+          }
+        />
+      </div>
+
+      <div style={{ ...gridStyle, gridTemplateColumns: 'repeat(auto-fit, minmax(300px, 1fr))' }}>
         <div style={cardStyle}>
-          <h3 style={{ marginBottom: '1rem', color: '#888' }}>Service Health</h3>
+          <div style={labelStyle}>Service health</div>
           {health ? (
             <>
               <div style={statStyle}>
                 {health.status === 'ok' ? 'Healthy' : health.status}
               </div>
-              <p>Redis: {health.redis ? 'Connected' : 'Disconnected'}</p>
+              <p style={noteStyle}>
+                Metadata store: {health.redis ? 'Open' : 'Unavailable'}
+              </p>
             </>
           ) : (
-            <p>Loading...</p>
+            <p style={noteStyle}>Loading…</p>
           )}
         </div>
 
-        {/* Watchers Status Card */}
         <div style={cardStyle}>
-          <h3 style={{ marginBottom: '1rem', color: '#888' }}>File Watchers</h3>
+          <div style={labelStyle}>File watchers</div>
           {watchersData ? (
             <>
-              <div style={statStyle}>{totalFiles}</div>
-              <p>Files discovered</p>
-              <p>Watchers: {activeWatchers} active / {watchersData.count} total</p>
-              <p>Status: {isScanning ? 'Scanning...' : 'Idle'}</p>
+              <div style={statStyle}>
+                {activeWatchers} / {watchersData.count}
+              </div>
+              <p style={noteStyle}>active watchers</p>
+              <p style={noteStyle}>Status: {isScanning ? 'Scanning…' : 'Idle'}</p>
               {lastScan > 0 && (
-                <p>Last scan: {new Date(lastScan).toLocaleString()}</p>
+                <p style={noteStyle}>Last scan: {new Date(lastScan).toLocaleString()}</p>
               )}
               <button
                 onClick={handleTriggerScan}
@@ -155,27 +275,7 @@ export default function Dashboard() {
               </button>
             </>
           ) : (
-            <p>Loading...</p>
-          )}
-        </div>
-
-        {/* Services Card */}
-        <div style={cardStyle}>
-          <h3 style={{ marginBottom: '1rem', color: '#888' }}>Connected Services</h3>
-          <div style={statStyle}>{services.length}</div>
-          <p>Services registered</p>
-          {services.length > 0 && (
-            <ul style={{ marginTop: '1rem', paddingLeft: '1.5rem' }}>
-              {services.map((svc) => (
-                <li key={svc.name} style={{ marginBottom: '0.5rem' }}>
-                  <strong>{svc.name}</strong>
-                  <br />
-                  <span style={{ color: '#888', fontSize: '0.9rem' }}>
-                    {svc.capabilities?.join(', ') || 'No capabilities'}
-                  </span>
-                </li>
-              ))}
-            </ul>
+            <p style={noteStyle}>Loading…</p>
           )}
         </div>
       </div>

dashboard/src/pages/Identity.tsx

@@ -1,21 +1,74 @@
-import { useEffect, useState } from 'react';
+import { useEffect, useRef, useState } from 'react';
 
-// Status returned by GET /api/identity. Private key is never present here —
-// it is shown exactly once at generation time (see GeneratedKeyPanel).
-interface IdentityStatus {
-  hasIdentity: boolean;
-  uid?: string;
-  curve?: string;
-  createdAt?: number;
-}
+import {
+  INSECURE_CONTEXT_MESSAGE,
+  canSign,
+  proveOwnership,
+  uidFromSecretKey,
+  type IdentityAction,
+} from '../lib/sign';
 
-interface GeneratedKey {
+// Admin console for meta-core's account keystore.
+//
+// meta-core stores one secp256k1 keypair per file under
+// {META_CORE_PATH}/identity/accounts/<uid>.json and has NO notion of a current
+// user — which account is "you" is decided by whichever client signs in
+// (meta-watch). So this page lists accounts; it never speaks of an active one.
+//
+// The private key is returned by exactly two calls: POST /api/identity/generate
+// (once, at creation) and POST /api/identity/reveal (on demand, for an account
+// that already exists). Both land in the same exclusive SecretKeyPanel.
+//
+// Reveal and remove both require the account's own secret key, entered here and
+// used to sign a one-shot challenge locally — the key itself is never sent. So
+// this page can enumerate and create, but it holds no authority over an
+// existing account that its operator does not already have the key for. There
+// is deliberately no admin override: on this node the private key *is* the
+// account.
+
+interface Account {
   uid: string;
   curve: string;
   createdAt: number;
-  privateKeyHex: string;
 }
 
+// What one account holds in the User Data Layer. Absent from
+// /api/udl/users/stats means zero, not unknown.
+interface Stats {
+  records: number;
+  cids: number;
+  keys: number;
+}
+
+// A secret on screen. Carries no createdAt: /api/identity/reveal answers with
+// {uid, curve, privateKeyHex} only.
+interface SecretKeyView {
+  uid: string;
+  privateKeyHex: string;
+  kind: 'generated' | 'revealed';
+}
+
+// Which row has an open confirmation, and for what. One discriminated value
+// rather than a pair of ids, so at most one confirm panel can ever be open.
+interface Pending {
+  uid: string;
+  kind: 'remove' | 'reveal';
+}
+
+// Both confirmable operations map to a server-side action name, and the
+// challenge is bound to it: a challenge minted to reveal a key cannot delete
+// the account. Keeping the mapping in one place stops the two drifting.
+const ACTION_FOR: Record<Pending['kind'], IdentityAction> = {
+  reveal: 'reveal',
+  remove: 'delete',
+};
+
+// meta-watch's sentinel cell for profile records: display name and avatar are
+// about the *user*, not a content file, so they live at (uid, "self", ...).
+// meta-core stores them opaquely and knows nothing of the convention.
+const PROFILE_CID = 'self';
+const PROFILE_NAME_KEY = 'profile:name';
+
 const cardStyle: React.CSSProperties = {
   background: '#16213e',
   borderRadius: '8px',
@@ -59,6 +112,21 @@ const monoStyle: React.CSSProperties = {
   borderRadius: '4px',
 };
 
+const dangerPanelStyle: React.CSSProperties = {
+  background: '#1f0a0a',
+  border: '1px solid #7f1d1d',
+  padding: '0.75rem 1rem',
+  borderRadius: '4px',
+  marginTop: '0.75rem',
+};
+
+const errorTextStyle: React.CSSProperties = {
+  color: '#f87171',
+  background: '#1f0a0a',
+  padding: '0.5rem 0.75rem',
+  borderRadius: '4px',
+};
+
 function formatCreatedAt(unixSec?: number): string {
   if (!unixSec) return '';
   try {
@@ -79,25 +147,165 @@ async function errorMessage(res: Response, fallback: string): Promise<string> {
   return `${fallback} (HTTP ${res.status})`;
 }
 
-function GeneratedKeyPanel({ data, onDismiss }: { data: GeneratedKey; onDismiss: () => void }) {
-  const [copied, setCopied] = useState(false);
-  const copy = async () => {
+// Copy text, falling back to selecting the element that displays it.
+//
+// The fallback is load-bearing, not politeness: the dashboard is served over
+// plain HTTP, where navigator.clipboard is undefined — without it the copy
+// buttons do nothing at all on a real deployment.
+async function copyToClipboard(text: string, fallbackElementId: string): Promise<void> {
   try {
-      await navigator.clipboard.writeText(data.privateKeyHex);
-      setCopied(true);
-      setTimeout(() => setCopied(false), 2000);
+    await navigator.clipboard.writeText(text);
   } catch {
-      // Clipboard API blocked (non-HTTPS context, etc.) — fall back to selection.
     const sel = window.getSelection();
-      const range = document.createRange();
-      const el = document.getElementById('mm-privkey-box');
+    const el = document.getElementById(fallbackElementId);
     if (sel && el) {
+      const range = document.createRange();
       range.selectNodeContents(el);
       sel.removeAllRanges();
       sel.addRange(range);
     }
   }
+}
+
+async function fetchAccounts(): Promise<Account[]> {
+  const res = await fetch('/api/identity/accounts');
+  if (!res.ok) throw new Error(await errorMessage(res, 'Failed to load accounts'));
+  const data = (await res.json()) as { accounts?: Account[] };
+  // Backend order is CreatedAt ascending then uid (identity.List) — stable, so
+  // render it as given rather than re-sorting here.
+  return data.accounts ?? [];
+}
+
+// Resolve an account's display name from the User Data Layer, or null.
+//
+// Never throws and never reports an error upward: a name is decoration on top
+// of the uid, and the account list must render identically whether the store is up
+// (identity itself is file-backed, the UDL is not). The name is also *unsigned*
+// — meta-core stores the plaintext beside the signed record and verifies
+// nothing — so the uid stays on screen as the real identity, and the length cap
+// bounds what a hostile writer can do to the layout.
+async function fetchDisplayName(uid: string): Promise<string | null> {
+  const url =
+    `/api/udl/record?uid=${encodeURIComponent(uid)}` +
+    `&cid=${encodeURIComponent(PROFILE_CID)}` +
+    `&key=${encodeURIComponent(PROFILE_NAME_KEY)}`;
+  try {
+    const res = await fetch(url);
+    if (!res.ok) return null; // 503 when storage is down, 500, …
+    const data = (await res.json()) as { exists?: boolean; value?: unknown };
+    // Key off `value`, not `exists`: clearing a name writes a tombstone, which
+    // leaves the cell existing with no plaintext. Private-tier cells look the
+    // same, which is exactly right — there is nothing to show for either.
+    if (typeof data.value !== 'string') return null;
+    const name = data.value.trim();
+    return name ? name.slice(0, 64) : null;
+  } catch {
+    return null;
+  }
+}
+
+// How much each account holds. One call for the whole page, not one per row:
+// meta-core answers it from a keyspace SCAN (there is no per-user cid index),
+// so per-row calls would walk the keyspace once per account.
+//
+// Never throws, for the same reason fetchDisplayName does not: the counts are
+// context on top of the uid, and the list must render identically when the store is
+// down — accounts are file-backed, their data is not.
+//
+// Returns null on failure rather than an empty map. The difference is
+// load-bearing: an empty map renders as "no stored data" against every account,
+// which inside a delete confirmation is a false statement about what is at
+// stake. Unknown has to look like unknown.
+async function fetchStats(): Promise<Record<string, Stats> | null> {
+  try {
+    const res = await fetch('/api/udl/users/stats');
+    if (!res.ok) return null;
+    const data = (await res.json()) as { users?: Record<string, Stats> };
+    return data.users ?? {};
+  } catch {
+    return null;
+  }
+}
+
+// The secret-key box shared by the reveal and remove confirmations.
+//
+// Separate from the surrounding panel so both operations ask the same way, and
+// so the key lives in this component's state rather than the page's — it is
+// discarded with the panel instead of lingering in a parent that outlives it.
+function SecretKeyConfirm({
+  label,
+  actionLabel,
+  busy,
+  onConfirm,
+  onCancel,
+}: {
+  label: string;
+  actionLabel: string;
+  busy: boolean;
+  onConfirm: (secretKeyHex: string) => void;
+  onCancel: () => void;
+}) {
+  const [secret, setSecret] = useState('');
+  const signable = canSign();
+  // Derived locally, purely to tell the operator they have the wrong key before
+  // they hit the button. The server would refuse either way.
+  const derived = secret.trim() ? uidFromSecretKey(secret) : null;
+  const mismatch = Boolean(secret.trim() && derived && derived !== label);
+
+  return (
+    <form
+      onSubmit={(e) => {
+        e.preventDefault();
+        onConfirm(secret.trim());
+      }}
+    >
+      <p style={{ color: '#fecaca', margin: '0 0 0.5rem' }}>
+        Paste this account's secret key to prove it is yours. It is used to sign a one-time
+        challenge <em>in this browser</em> and is never sent to the server.
+      </p>
+      {!signable && <p style={errorTextStyle}>{INSECURE_CONTEXT_MESSAGE}</p>}
+      <input
+        style={inputStyle}
+        type="password"
+        autoComplete="off"
+        placeholder="64 hex characters"
+        value={secret}
+        onChange={(e) => setSecret(e.target.value)}
+        disabled={busy || !signable}
+        autoFocus
+      />
+      {mismatch && (
+        <p style={{ ...errorTextStyle, marginTop: 0 }}>
+          That key belongs to a different account ({derived}).
+        </p>
+      )}
+      <button
+        type="submit"
+        style={dangerButtonStyle}
+        disabled={busy || !signable || !secret.trim() || mismatch}
+      >
+        {busy ? 'Verifying…' : actionLabel}
+      </button>
+      <button type="button" style={buttonStyle} onClick={onCancel} disabled={busy}>
+        Cancel
+      </button>
+    </form>
+  );
+}
+
+// The one place a private key is ever displayed. Rendered exclusively (the
+// account list is hidden while it is open) so the "save it now" contract of a
+// freshly generated key is not competing with anything, and so the hardcoded
+// element id below stays unique.
+function SecretKeyPanel({ data, onDismiss }: { data: SecretKeyView; onDismiss: () => void }) {
+  const [copied, setCopied] = useState(false);
+
+  const copy = async () => {
+    await copyToClipboard(data.privateKeyHex, 'mm-privkey-box');
+    setCopied(true);
+    setTimeout(() => setCopied(false), 2000);
   };
+
   return (
     <div style={{ ...cardStyle, border: '2px solid #dc2626' }}>
       <div
@@ -109,9 +317,19 @@ function GeneratedKeyPanel({ data, onDismiss }: { data: GeneratedKey; onDismiss:
           marginBottom: '1rem',
         }}
       >
+        {data.kind === 'generated' ? (
+          <>
             <strong>This private key is shown ONCE.</strong> Save it now in a password manager.
-        It will never be displayed again — there is no recovery path. Losing it means losing access
-        to every record signed under this identity.
+            You can ask for it again later with <em>Reveal private key</em>, but only for as long
+            as this account exists on this node — delete it and the key is gone for good.
+          </>
+        ) : (
+          <>
+            <strong>This is the live private key for an existing account.</strong> Anyone holding
+            it can sign as this uid forever, on any machine. There is no revocation and no
+            rotation. Do not paste it into chat, tickets or screenshots.
+          </>
+        )}
       </div>
       <p style={{ color: '#9ca3af', margin: '0 0 0.5rem' }}>uid (public):</p>
       <div style={monoStyle}>{data.uid}</div>
@@ -124,36 +342,40 @@ function GeneratedKeyPanel({ data, onDismiss }: { data: GeneratedKey; onDismiss:
           {copied ? 'Copied' : 'Copy private key'}
         </button>
         <button style={dangerButtonStyle} onClick={onDismiss}>
-          I have saved it
+          {data.kind === 'generated' ? 'I have saved it' : 'Done — hide it'}
         </button>
       </div>
     </div>
   );
 }
 
-function NoIdentityPanel({
+// Create / import. Always available, not just on an empty keystore: this is an
+// admin console, so adding an account to a populated node has to be possible.
+function NewAccountPanel({
   onGenerated,
   onImported,
 }: {
-  onGenerated: (g: GeneratedKey) => void;
+  onGenerated: (s: SecretKeyView) => void;
   onImported: () => void;
 }) {
   const [busy, setBusy] = useState(false);
   const [importing, setImporting] = useState(false);
   const [importHex, setImportHex] = useState('');
   const [error, setError] = useState<string | null>(null);
+  const [notice, setNotice] = useState<string | null>(null);
 
   const generate = async () => {
     setBusy(true);
     setError(null);
+    setNotice(null);
     try {
       const res = await fetch('/api/identity/generate', { method: 'POST' });
       if (!res.ok) {
         setError(await errorMessage(res, 'Generate failed'));
         return;
       }
-      const data = (await res.json()) as GeneratedKey;
-      onGenerated(data);
+      const data = (await res.json()) as { uid: string; privateKeyHex: string };
+      onGenerated({ uid: data.uid, privateKeyHex: data.privateKeyHex, kind: 'generated' });
     } catch (e) {
       setError(`Generate failed: ${e instanceof Error ? e.message : String(e)}`);
     } finally {
@@ -165,6 +387,7 @@ function NoIdentityPanel({
     e.preventDefault();
     setBusy(true);
     setError(null);
+    setNotice(null);
     try {
       const res = await fetch('/api/identity/import', {
         method: 'POST',
@@ -175,6 +398,15 @@ function NoIdentityPanel({
         setError(await errorMessage(res, 'Import failed'));
         return;
       }
+      // Import is idempotent — presenting the key IS the proof of ownership, so
+      // a key this node already holds is a success, not a conflict. `created`
+      // only decides the wording.
+      const data = (await res.json()) as { created?: boolean };
+      setNotice(
+        data.created
+          ? 'Imported — a new account was added to this keystore.'
+          : 'That key was already in this keystore; nothing changed.'
+      );
       setImportHex('');
       setImporting(false);
       onImported();
@@ -187,15 +419,16 @@ function NoIdentityPanel({
 
   return (
     <div style={cardStyle}>
-      <h3 style={{ marginTop: 0 }}>No identity yet</h3>
-      <p style={{ color: '#9ca3af' }}>
-        The User Data Layer needs a signing key for your ratings, watch progress, and "liked" flags
-        to be attributed to you across devices. Nothing happens automatically — generate one below,
-        or import a key you already have.
+      <h3 style={{ marginTop: 0 }}>Add an account</h3>
+      <p style={{ color: '#9ca3af', marginTop: 0 }}>
+        Generating mints a fresh secp256k1 keypair here. Importing adds a key created elsewhere —
+        it is also how an existing account is moved onto this node, so importing a key the
+        keystore already holds succeeds and changes nothing.
       </p>
-      {error && (
-        <p style={{ color: '#f87171', background: '#1f0a0a', padding: '0.5rem 0.75rem', borderRadius: '4px' }}>
-          {error}
+      {error && <p style={errorTextStyle}>{error}</p>}
+      {notice && (
+        <p style={{ color: '#9ca3af', background: '#0a0a18', padding: '0.5rem 0.75rem', borderRadius: '4px' }}>
+          {notice}
         </p>
       )}
       <div>
@@ -235,73 +468,156 @@ function NoIdentityPanel({
   );
 }
 
-function HasIdentityPanel({ status, onReplace }: { status: IdentityStatus; onReplace: () => void }) {
-  const [confirming, setConfirming] = useState(false);
-  const [busy, setBusy] = useState(false);
-  const [error, setError] = useState<string | null>(null);
+function AccountCard({
+  account,
+  name,
+  stats,
+  busy,
+  disabled,
+  pending,
+  error,
+  onAsk,
+  onCancel,
+  onReveal,
+  onRemove,
+}: {
+  account: Account;
+  name?: string;
+  // undefined means "counted, and it holds nothing"; null means "could not be
+  // counted". The two must not read the same on a confirmation screen.
+  stats?: Stats | null;
+  busy: boolean;
+  disabled: boolean;
+  pending: Pending | null;
+  error: string | null;
+  onAsk: (p: Pending) => void;
+  onCancel: () => void;
+  onReveal: (uid: string, secretKeyHex: string) => void;
+  onRemove: (uid: string, secretKeyHex: string) => void;
+}) {
+  const [copied, setCopied] = useState(false);
+  const uidBoxId = `mm-uid-${account.uid}`;
+  const label = name ?? account.uid;
+  const counted = stats !== null;
+  const records = stats?.records ?? 0;
+  const titles = stats?.cids ?? 0;
 
-  const remove = async () => {
-    setBusy(true);
-    setError(null);
-    try {
-      const res = await fetch('/api/identity?confirm=true', { method: 'DELETE' });
-      if (!res.ok && res.status !== 204) {
-        setError(await errorMessage(res, 'Delete failed'));
-        return;
-      }
-      onReplace();
-    } catch (e) {
-      setError(`Delete failed: ${e instanceof Error ? e.message : String(e)}`);
-    } finally {
-      setBusy(false);
-      setConfirming(false);
-    }
+  const copyUid = async () => {
+    await copyToClipboard(account.uid, uidBoxId);
+    setCopied(true);
+    setTimeout(() => setCopied(false), 2000);
   };
 
   return (
     <div style={cardStyle}>
-      <h3 style={{ marginTop: 0 }}>Active identity</h3>
-      <p style={{ color: '#9ca3af', margin: '0 0 0.5rem' }}>uid:</p>
-      <div style={monoStyle}>{status.uid}</div>
-      <p style={{ color: '#888', marginTop: '1rem' }}>
-        Curve: {status.curve} · Created: {formatCreatedAt(status.createdAt)}
+      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'flex-start', gap: '1rem' }}>
+        <div style={{ minWidth: 0, flex: 1 }}>
+          <h3 style={{ margin: '0 0 0.5rem', color: name ? '#fff' : '#888' }}>
+            {name ?? 'Unnamed account'}
+          </h3>
+          <div id={uidBoxId} style={monoStyle}>
+            {account.uid}
+          </div>
+          <p style={{ color: '#888', margin: '0.75rem 0 0', fontSize: '0.85rem' }}>
+            Curve: {account.curve} · Created: {formatCreatedAt(account.createdAt)}
           </p>
-      <p style={{ color: '#9ca3af', fontSize: '0.85rem' }}>
-        The private key lives at <code>/meta-core/identity/identity.json</code> on this volume and
-        is never returned through the API after generation. Other services on this stack (e.g.
-        meta-watch) sign records by calling <code>POST /api/identity/sign</code>.
+          <p style={{ color: '#888', margin: '0.25rem 0 0', fontSize: '0.85rem' }}>
+            {/* An account that has never been used legitimately holds nothing, so
+                zero is a real answer — but only once the count actually ran. */}
+            {!counted
+              ? 'Stored data: could not be counted (storage unavailable)'
+              : records === 0
+                ? 'No stored data'
+                : `${records.toLocaleString()} stored ${records === 1 ? 'record' : 'records'}` +
+                  ` across ${titles.toLocaleString()} ${titles === 1 ? 'title' : 'titles'}`}
           </p>
-      {error && (
-        <p style={{ color: '#f87171', background: '#1f0a0a', padding: '0.5rem 0.75rem', borderRadius: '4px' }}>
-          {error}
-        </p>
-      )}
-      {!confirming ? (
-        <button style={dangerButtonStyle} onClick={() => setConfirming(true)} disabled={busy}>
-          Replace identity
+        </div>
+        <div style={{ display: 'flex', flexDirection: 'column', gap: '0.5rem', flexShrink: 0 }}>
+          <button style={{ ...buttonStyle, marginRight: 0 }} onClick={copyUid} disabled={disabled}>
+            {copied ? 'Copied' : 'Copy uid'}
           </button>
-      ) : (
-        <div
-          style={{
-            background: '#1f0a0a',
-            border: '1px solid #7f1d1d',
-            padding: '0.75rem 1rem',
-            borderRadius: '4px',
-            marginTop: '0.5rem',
-          }}
+          <button
+            style={{ ...dangerButtonStyle, marginRight: 0 }}
+            onClick={() => onAsk({ uid: account.uid, kind: 'reveal' })}
+            disabled={disabled}
           >
+            Reveal private key
+          </button>
+          <button
+            style={{ ...dangerButtonStyle, marginRight: 0 }}
+            onClick={() => onAsk({ uid: account.uid, kind: 'remove' })}
+            disabled={disabled}
+          >
+            Remove
+          </button>
+        </div>
+      </div>
+
+      {error && <p style={{ ...errorTextStyle, marginBottom: 0 }}>{error}</p>}
+
+      {pending?.uid === account.uid && pending.kind === 'reveal' && (
+        <div style={dangerPanelStyle}>
           <p style={{ color: '#fecaca', marginTop: 0 }}>
-            Replacing the identity deletes the current keypair from disk. Records signed by the
-            current uid will keep verifying for anyone who has them cached, but this node will no
-            longer be able to write under that uid. <strong>Make sure you have backed up the key
-            first.</strong>
+            Show the private key for <strong>{label}</strong>?
           </p>
-          <button style={dangerButtonStyle} onClick={remove} disabled={busy}>
-            {busy ? 'Deleting…' : 'Yes, delete identity'}
-          </button>
-          <button style={buttonStyle} onClick={() => setConfirming(false)} disabled={busy}>
-            Cancel
-          </button>
+          <p style={{ color: '#fecaca', marginTop: 0 }}>
+            The key <em>is</em> the account. Anyone who copies it can sign records as this uid on
+            any machine, forever — there is no way to revoke or rotate it afterwards. Because
+            proving ownership already requires the key, this only confirms that the copy this node
+            holds matches yours.
+          </p>
+          <SecretKeyConfirm
+            label={account.uid}
+            actionLabel="Show the private key"
+            busy={busy}
+            onConfirm={(secret) => onReveal(account.uid, secret)}
+            onCancel={onCancel}
+          />
+        </div>
+      )}
+
+      {pending?.uid === account.uid && pending.kind === 'remove' && (
+        <div style={dangerPanelStyle}>
+          <p style={{ color: '#fecaca', marginTop: 0 }}>
+            Remove <strong>{label}</strong> from this node?
+          </p>
+          <ul style={{ color: '#fecaca', paddingLeft: '1.2rem', margin: '0 0 0.75rem' }}>
+            <li>
+              <strong>The key is gone for good.</strong> The uid <em>is</em> the public key, and
+              the private half exists only in this node's keystore. If nobody saved it, nothing —
+              not you, not meta-core — can ever sign as this uid again. Reveal and copy it first
+              if there is any doubt.
+            </li>
+            <li>
+              <strong>Nothing is retracted.</strong> Records already signed under this uid keep
+              verifying on every peer that replicated them. Deleting a key is not a recall.
+            </li>
+            <li>
+              <strong>Its data is destroyed, not orphaned.</strong>{' '}
+              {!counted
+                ? 'This account\u2019s records could not be counted because storage is unavailable — ' +
+                  'so meta-core will refuse this delete rather than remove the key and strand them.'
+                : records === 0
+                  ? 'This account holds no User Data Layer records, so there is nothing to purge.'
+                  : `All ${records.toLocaleString()} User Data Layer ${
+                      records === 1 ? 'record' : 'records'
+                    } — likes, ratings, watch progress across ${titles.toLocaleString()} ${
+                      titles === 1 ? 'title' : 'titles'
+                    } — are permanently deleted from the metadata store, along with every index that names this uid.`}{' '}
+              This cannot be undone and there is no backup.
+            </li>
+            <li>
+              <strong>This signs nobody out elsewhere.</strong> Any device that holds this key
+              still holds it, and can import it back here at any time.
+            </li>
+          </ul>
+          <SecretKeyConfirm
+            label={account.uid}
+            actionLabel="Remove this account and all its data"
+            busy={busy}
+            onConfirm={(secret) => onRemove(account.uid, secret)}
+            onCancel={onCancel}
+          />
         </div>
       )}
     </div>
@@ -309,67 +625,235 @@ function HasIdentityPanel({ status, onReplace }: { status: IdentityStatus; onRep
 }
 
 export default function Identity() {
-  const [status, setStatus] = useState<IdentityStatus | null>(null);
-  const [generated, setGenerated] = useState<GeneratedKey | null>(null);
+  const [accounts, setAccounts] = useState<Account[] | null>(null);
+  const [names, setNames] = useState<Record<string, string>>({});
+  const [stats, setStats] = useState<Record<string, Stats> | null>({});
+  const [notice, setNotice] = useState<string | null>(null);
   const [loading, setLoading] = useState(true);
   const [fetchError, setFetchError] = useState<string | null>(null);
+  const [secret, setSecret] = useState<SecretKeyView | null>(null);
+  const [pending, setPending] = useState<Pending | null>(null);
+  const [busyUid, setBusyUid] = useState<string | null>(null);
+  const [rowError, setRowError] = useState<{ uid: string; message: string } | null>(null);
+
+  // Bumped per refresh so a slow response from a superseded load cannot
+  // overwrite a newer one. The page does not poll (unlike the rest of the
+  // dashboard) — a key list has no business changing under the cursor.
+  const reqGen = useRef(0);
 
   const refresh = async () => {
+    const gen = ++reqGen.current;
     setLoading(true);
     setFetchError(null);
+    let list: Account[];
     try {
-      const res = await fetch('/api/identity');
-      if (!res.ok) {
-        setFetchError(await errorMessage(res, 'Failed to load identity status'));
+      list = await fetchAccounts();
+    } catch (e) {
+      if (gen !== reqGen.current) return;
+      setFetchError(e instanceof Error ? e.message : String(e));
+      setLoading(false);
       return;
     }
-      setStatus((await res.json()) as IdentityStatus);
-    } catch (e) {
-      setFetchError(`Failed to load identity status: ${e instanceof Error ? e.message : String(e)}`);
-    } finally {
+    if (gen !== reqGen.current) return;
+    // Render the list before resolving names, so a down store delays nothing.
+    setAccounts(list);
     setLoading(false);
-    }
+
+    // Names and counts both come after the list is on screen, and neither can
+    // fail the page: a down store costs decoration, not the account list.
+    const [settled, counts] = await Promise.all([
+      Promise.allSettled(list.map((a) => fetchDisplayName(a.uid))),
+      fetchStats(),
+    ]);
+    if (gen !== reqGen.current) return;
+    const next: Record<string, string> = {};
+    settled.forEach((r, i) => {
+      if (r.status === 'fulfilled' && r.value) next[list[i].uid] = r.value;
+    });
+    // Replace rather than merge, so a removed account's name and counts go with
+    // it instead of lingering against a uid that no longer exists.
+    setNames(next);
+    setStats(counts);
   };
 
   useEffect(() => {
     refresh();
   }, []);
 
+  const reveal = async (uid: string, secretKeyHex: string) => {
+    setBusyUid(uid);
+    setRowError(null);
+    try {
+      const proof = await proveOwnership(uid, ACTION_FOR.reveal, secretKeyHex);
+      // POST with a body rather than ?uid=, so neither the target nor the
+      // signature reaches the proxy's access log. The handler accepts the uid
+      // either way; the proof must be in the body.
+      const res = await fetch('/api/identity/reveal', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ confirm: true, uid, ...proof }),
+      });
+      if (!res.ok) {
+        setRowError({ uid, message: await errorMessage(res, 'Reveal failed') });
+        return;
+      }
+      const data = (await res.json()) as { uid: string; privateKeyHex: string };
+      setPending(null);
+      setSecret({ uid: data.uid, privateKeyHex: data.privateKeyHex, kind: 'revealed' });
+    } catch (e) {
+      setRowError({ uid, message: `Reveal failed: ${e instanceof Error ? e.message : String(e)}` });
+    } finally {
+      setBusyUid(null);
+    }
+  };
+
+  const remove = async (uid: string, secretKeyHex: string) => {
+    setBusyUid(uid);
+    setRowError(null);
+    setNotice(null);
+    try {
+      const proof = await proveOwnership(uid, ACTION_FOR.remove, secretKeyHex);
+      // The uid is mandatory: the signature authorises one specific account, so
+      // the backend refuses an unqualified delete rather than guess a target.
+      const res = await fetch('/api/identity', {
+        method: 'DELETE',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ confirm: true, uid, ...proof }),
+      });
+      if (!res.ok) {
+        setRowError({ uid, message: await errorMessage(res, 'Remove failed') });
+        return;
+      }
+      // Report what the purge actually removed. "Account removed" on its own
+      // would not distinguish a clean delete from one that stranded the data.
+      const data = (await res.json().catch(() => ({}))) as { purged?: Stats };
+      const purged = data.purged;
+      setNotice(
+        purged && purged.records > 0
+          ? `Account removed. Purged ${purged.records.toLocaleString()} User Data Layer ` +
+            `${purged.records === 1 ? 'record' : 'records'} across ` +
+            `${purged.cids.toLocaleString()} ${purged.cids === 1 ? 'title' : 'titles'}.`
+          : 'Account removed. It held no User Data Layer records.'
+      );
+      setPending(null);
+      await refresh();
+    } catch (e) {
+      setRowError({ uid, message: `Remove failed: ${e instanceof Error ? e.message : String(e)}` });
+    } finally {
+      setBusyUid(null);
+    }
+  };
+
+  const dismissSecret = () => {
+    setSecret(null);
+    refresh();
+  };
+
+  const ask = (p: Pending) => {
+    setRowError(null);
+    setNotice(null);
+    setPending(p);
+  };
+
+  const showList = !loading && !fetchError && !secret;
+
   return (
+    // App.tsx's content area is `overflow: hidden`, so every page owns its own
+    // scrolling (Files.tsx does the same). Without this the account list is
+    // simply clipped at the viewport with no scrollbar — invisible on a node
+    // with two accounts, and a dead end on one with fifteen.
+    //
+    // The scroller is the outer element and the padding lives inside it, so the
+    // scrollbar sits at the edge of the content area rather than floating in
+    // 2rem of whitespace, and `margin: 0 auto` still centres the column.
+    <div style={{ height: '100%', overflowY: 'auto', minHeight: 0 }}>
     <div style={{ padding: '2rem', maxWidth: '900px', margin: '0 auto' }}>
-      <h1>Identity</h1>
+      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+        <h1 style={{ marginBottom: 0 }}>Identity</h1>
+        <button style={{ ...buttonStyle, marginRight: 0 }} onClick={refresh} disabled={loading}>
+          {loading ? 'Loading…' : 'Refresh'}
+        </button>
+      </div>
       <p style={{ color: '#9ca3af' }}>
-        Signing key for the User Data Layer (per-user ratings, progress, "liked" flags). One
-        identity per node. The same key on another device makes that device count as "you".
+        Every signing key in this node's keystore. meta-core has no "current user" — it stores
+        accounts, and which one is <em>you</em> is decided by whichever client signs in (e.g.
+        meta-watch). Keys live one JSON file per account under{' '}
+        <code>{'{META_CORE_PATH}'}/identity/accounts/&lt;uid&gt;.json</code>, and are used to sign
+        User Data Layer records (ratings, watch progress, "liked" flags).
       </p>
 
+      <div style={{ ...dangerPanelStyle, marginTop: 0, marginBottom: '1rem' }}>
+        <p style={{ color: '#fecaca', margin: 0 }}>
+          <strong>The key is the only authority.</strong> Revealing or removing an account requires
+          that account's secret key, entered here and used to sign a one-time challenge in your
+          browser — there is no admin override, and holding this page is not one. Listing and
+          creating accounts are still open to anything that can reach this API, so the perimeter in
+          front of this port is what keeps the roster private.
+        </p>
+        <p style={{ color: '#fecaca', margin: '0.5rem 0 0' }}>
+          What this does <em>not</em> defend against: anyone with filesystem access to{' '}
+          <code>{'{META_CORE_PATH}'}/identity/accounts/</code> reads every private key directly.
+          The keys are stored in plaintext, matching the trust model of the rest of{' '}
+          <code>/meta-core</code>.
+        </p>
+      </div>
+
+      {notice && (
+        <div style={{ ...cardStyle, border: '1px solid #0f3460' }}>
+          <p style={{ color: '#9ca3af', margin: 0 }}>{notice}</p>
+        </div>
+      )}
+
       {loading && <div style={cardStyle}>Loading…</div>}
+
       {fetchError && (
         <div style={{ ...cardStyle, border: '1px solid #7f1d1d' }}>
-          <p style={{ color: '#f87171', margin: 0 }}>{fetchError}</p>
+          <p style={{ color: '#f87171', margin: '0 0 1rem' }}>{fetchError}</p>
           <button style={buttonStyle} onClick={refresh}>
             Retry
           </button>
         </div>
       )}
 
-      {!loading && !fetchError && generated && (
-        <GeneratedKeyPanel
-          data={generated}
-          onDismiss={() => {
-            setGenerated(null);
-            refresh();
-          }}
+      {!loading && !fetchError && secret && <SecretKeyPanel data={secret} onDismiss={dismissSecret} />}
+
+      {showList && (
+        <>
+          <NewAccountPanel onGenerated={(s) => setSecret(s)} onImported={refresh} />
+
+          <h2 style={{ fontSize: '1.1rem', color: '#9ca3af', margin: '1.5rem 0 1rem' }}>
+            Accounts ({accounts?.length ?? 0})
+          </h2>
+
+          {accounts && accounts.length === 0 && (
+            <div style={cardStyle}>
+              <p style={{ color: '#9ca3af', margin: 0 }}>
+                No accounts in this keystore. Accounts are normally created by a client when
+                someone signs up; use <em>Add an account</em> above if you are bootstrapping this
+                node.
+              </p>
+            </div>
+          )}
+
+          {accounts?.map((a) => (
+            <AccountCard
+              key={a.uid}
+              account={a}
+              name={names[a.uid]}
+              stats={stats === null ? null : stats[a.uid]}
+              busy={busyUid === a.uid}
+              disabled={busyUid !== null}
+              pending={pending}
+              error={rowError?.uid === a.uid ? rowError.message : null}
+              onAsk={ask}
+              onCancel={() => setPending(null)}
+              onReveal={reveal}
+              onRemove={remove}
             />
+          ))}
+        </>
       )}
-
-      {!loading && !fetchError && !generated && status && !status.hasIdentity && (
-        <NoIdentityPanel onGenerated={(g) => setGenerated(g)} onImported={refresh} />
-      )}
-
-      {!loading && !fetchError && !generated && status && status.hasIdentity && (
-        <HasIdentityPanel status={status} onReplace={refresh} />
-      )}
+    </div>
     </div>
   );
 }

docker/entrypoint.sh

@@ -9,8 +9,7 @@ set -e
 
 # Create required directories
 mkdir -p /meta-core/locks
-mkdir -p /meta-core/db/redis
-mkdir -p /meta-core/services
+mkdir -p /meta-core/db
 mkdir -p /meta-core/mounts/errors
 mkdir -p /files
 mkdir -p /var/log/supervisor

docker/leader-election.sh

@@ -2,9 +2,14 @@
 # =============================================================================
 # Leader Election Script for meta-core
 #
-# Uses flock for leader election. Only the leader runs the full application
-# stack (supervisord with Redis, meta-core, nginx, rclone, mount-watcher).
-# Followers remain dormant, periodically retrying to acquire the lock.
+# The flock here is a MUTEX, not service discovery. It is the only thing
+# stopping two containers that mount the same /meta-core volume from putting
+# two writers on one database file (/meta-core/db/meta-core.db). Sibling
+# services no longer read anything from this directory — they locate meta-core
+# over UDP (beacon v2, see docs/project-architecture/beacon-v2.md), so the
+# kv-leader.info file
+# this script used to publish is gone. Keep the lock; it costs nothing and the
+# corruption it prevents is unrecoverable.
 #
 # Environment variables:
 #   META_CORE_PATH         - Path to meta-core data directory (default: /meta-core)
@@ -20,7 +25,6 @@ META_CORE_HTTP_PORT="${META_CORE_HTTP_PORT:-9000}"
 ELECTION_RETRY_SECS="${ELECTION_RETRY_SECS:-5}"
 
 LOCK_FILE="${META_CORE_PATH}/locks/kv-leader.lock"
-INFO_FILE="${META_CORE_PATH}/locks/kv-leader.info"
 SUPERVISORD_CONF="/etc/supervisor/conf.d/supervisord.conf"
 
 # Get the container's IP address
@@ -40,35 +44,13 @@ get_local_ip() {
     echo "$ip"
 }
 
-# Write leader info file (plain text API URL)
-write_leader_info() {
-    local ip=$(get_local_ip)
-    local api_url="http://${ip}:${META_CORE_HTTP_PORT}"
-
-    # Write atomically using temp file + rename
-    local temp_file="${INFO_FILE}.tmp"
-    echo "$api_url" > "$temp_file"
-    mv "$temp_file" "$INFO_FILE"
-
-    echo "[election] Wrote leader info: $api_url"
-}
-
-# Clean up leader info file on shutdown
-cleanup() {
-    echo "[election] Cleaning up..."
-    rm -f "$INFO_FILE"
-    exit 0
-}
-
 # Set up signal handlers for graceful shutdown
-trap cleanup SIGTERM SIGINT
 
 # Ensure lock directory exists
 mkdir -p "$(dirname "$LOCK_FILE")"
 
 echo "[election] Starting leader election..."
 echo "[election] Lock file: $LOCK_FILE"
-echo "[election] Info file: $INFO_FILE"
 
 # Open lock file for flock (file descriptor 200)
 exec 200>"$LOCK_FILE"
@@ -79,9 +61,6 @@ while true; do
     if flock -n 200; then
         echo "[election] Acquired flock - transitioning to LEADER"
 
-        # Write leader info before starting services
-        write_leader_info
-
         # exec supervisord - replaces this process
         # When supervisord exits, the flock is released automatically
         echo "[election] Starting supervisord..."

docker/nginx.conf

@@ -123,14 +123,10 @@ http {
         # =========================================================================
         # Service discovery
         # =========================================================================
-        location /services {
-            proxy_pass http://meta-core-api/services;
-            proxy_http_version 1.1;
-            proxy_set_header Host $host;
-        }
-
-        location /services/ {
-            proxy_pass http://meta-core-api/services/;
+        # meta-discovery v1 neighbours (supersedes /services, which stays
+        # while consumers migrate).
+        location /neighbors {
+            proxy_pass http://meta-core-api/neighbors;
             proxy_http_version 1.1;
             proxy_set_header Host $host;
         }

docker/supervisord.conf

@@ -16,26 +16,13 @@ serverurl=unix:///var/run/supervisor.sock
 supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface
 
 # =============================================================================
-# Redis: Key-value store (managed by supervisord, started before meta-core)
-# Previously spawned by Go code, now managed by bash-based leader election
-# =============================================================================
-[program:redis]
-command=/usr/bin/redis-server --port %(ENV_REDIS_PORT)s --bind 0.0.0.0 --protected-mode no --dir /meta-core/db/redis --appendonly yes --appendfilename appendonly.aof --dbfilename dump.rdb --save 60 1 --loglevel warning --notify-keyspace-events Kg$
-priority=1
-autostart=true
-autorestart=true
-stdout_logfile=/dev/stdout
-stdout_logfile_maxbytes=0
-stderr_logfile=/dev/stderr
-stderr_logfile_maxbytes=0
-startsecs=2
-
-# =============================================================================
-# meta-core: HTTP API, Mount API, File Watcher (connects to local Redis)
+# meta-core: HTTP API, Mount API, File Watcher, metadata store (embedded SQLite)
 # =============================================================================
 [program:meta-core]
 command=/usr/local/bin/meta-core
 priority=10
+; Room to finish in-flight writes and checkpoint the WAL on shutdown.
+stopwaitsecs=60
 autostart=true
 autorestart=true
 stdout_logfile=/dev/stdout
@@ -50,7 +37,6 @@ environment=
     SERVICE_VERSION="%(ENV_SERVICE_VERSION)s",
     META_CORE_HTTP_PORT="%(ENV_META_CORE_HTTP_PORT)s",
     META_CORE_HTTP_HOST="%(ENV_META_CORE_HTTP_HOST)s",
-    REDIS_PORT="%(ENV_REDIS_PORT)s",
     WATCH_INTERVAL_MS="%(ENV_WATCH_INTERVAL_MS)s",
     API_PORT="80",
     BASE_URL="%(ENV_BASE_URL)s"

docs/api-mediated-access.md

@@ -9,6 +9,16 @@ on [uuid-rooted-metadata.md](uuid-rooted-metadata.md), which assumes
 meta-core is the single writer to the metadata keyspace — an assumption
 that's now actually enforced rather than aspirational.
 
+> **2026-10: meta-core no longer uses Redis at all.** Its store is now an
+> embedded SQLite file (`/meta-core/db/meta-core.db`, see
+> [metadata-storage-structure.md](metadata-storage-structure.md)) and the
+> `file:events` / `meta:events` streams are rows of that store. The lockdown
+> below is now structural — there is no database port anywhere — and the
+> SSE wire contract was kept byte-for-byte, so no consumer changed. The
+> rest of this doc is the design record of the Redis-era lockdown; the
+> sections that describe *current* behaviour (SSE retention, reconnect,
+> error handling) have been updated in place.
+
 See "Implementation outcome" at the bottom for the delta between this doc's
 plan and what shipped (notably the write-path CID resolution and the
 dual-root migration sweep, which weren't in the original plan but turned
@@ -85,7 +95,7 @@ we don't fully control.
 ```
 
 **The single-writer rule.** meta-core has exclusive write authority over
-the `file:*`, `cid:*`, `file:__index__`, and `meta-core:*` keyspaces. No
+the `file:*`, `cid:*`, `file:__index__` (now `idx:*`), and `meta-core:*` keyspaces. No
 other service can write — not because of an honoured convention, but
 because they can't reach Redis at all.
 
@@ -243,6 +253,25 @@ After PR A, the cursor contract is **"durable across meta-core restart
 and bounded by `MAXLEN ~ N`"** — matching what consumers already assume
 when they persist a Last-Event-ID.
 
+**Current backing store (since 2026-10).** The streams are rows of
+meta-core's SQLite kv table — `ev:<stream>/<ms13>-<seq10>` → JSON of the
+entry's fields, plus a high-water mark `evhwm:<stream>` that seeds the next
+ID (so a `ClearStream` reset never reissues an ID an old cursor treats as
+seen). The contract above holds unchanged:
+
+- Entries persist across restart (they are in the database file).
+- Retention is ~100k entries per stream, trimmed every 10k appends.
+- IDs keep the Redis `<ms>-<seq>` form, so cursors persisted by meta-sort /
+  meta-share / meta-stremio before the switch still compare.
+- `meta:events` entries (`{type: set|del, key, ts}`) are appended by the
+  storage engine **in the same transaction** as the `file:` key change —
+  `del` only when the key existed, `set` even for an unchanged value. The
+  Redis keyspace-notification hop (PSUBSCRIBE in `MetaPublisher`), which
+  could drop events when it lagged, is gone.
+- The boot-time republish of every field into `meta:events` is kept
+  (meta-fuse rebuilds its VFS only by replaying from `0-0`), batched 5k
+  events per transaction.
+
 ### Heartbeats
 
 Server writes an SSE comment line (`:keep-alive\n\n`) every 30 seconds
@@ -254,10 +283,13 @@ per the SSE spec.
 
 Per the SSE spec the client (or `EventSource`) auto-reconnects after a
 network error, sending `Last-Event-ID`. The server resumes from the next
-entry after that ID by translating to Redis Stream `XREAD … STREAMS file:events <id>`.
+entry after that ID (a range read of the stream's rows; under Redis this
+was `XREAD … STREAMS file:events <id>`). With no `Last-Event-ID` the stream
+starts at the head, resolved once at connect; `0` / `0-0` go through the
+gap path and replay from the beginning.
 
-**Gap handling.** If the requested ID has been trimmed out of the Redis
-Stream by retention, the server emits one synthetic event before resuming
+**Gap handling.** If the requested ID is older than the oldest retained
+entry, the server emits one synthetic event before resuming
 from the oldest available entry:
 
 ```
@@ -271,9 +303,10 @@ react. Consumers that don't care ignore it.
 
 ### Error handling
 
-- **Redis unreachable on connect**: 503 with `Retry-After: 5`.
-- **Redis fails mid-stream**: close the SSE connection. Client reconnects
-  with `Last-Event-ID`; the cycle resumes when Redis recovers.
+- **Store unavailable on connect**: 503 with `Retry-After: 5`.
+- **Store read fails mid-stream**: close the SSE connection. Client
+  reconnects with `Last-Event-ID`; the cycle resumes when meta-core is back
+  (a meta-core restart is the common case — SSE clients just reconnect).
 - **Client disconnects**: handler goroutine exits cleanly; no per-client
   state on meta-core.
 
@@ -307,7 +340,8 @@ inside-only until a concrete external consumer appears.
 ### Implementation footprint
 
 The SSE handler itself is ~80 lines of Go in meta-core: one handler per
-stream, each running an `XREAD … BLOCK 30s` loop and writing
+stream, each running a read-after-cursor loop (an `XREAD … BLOCK 30s` loop
+in the Redis era) and writing
 SSE-formatted lines to the response. Go's `net/http` natively supports
 streaming responses with `http.Flusher.Flush()`. Standard SSE clients
 exist for every language we use: Node `eventsource`, Rust
@@ -562,11 +596,11 @@ metacore-app produces a connection refused. The lock is real.
 | Reads from `file:*` direct? | Forbidden by network topology | Same lock, same reason |
 | Event streams direct? | No — mediated through SSE | Kubernetes-style. Costs one HTTP hop; buys schema evolution + threat-model fit |
 | Enforcement mechanism? | Network isolation (primary) + docs + code review (secondary) | No ACLs, no proxy, no lint |
-| Backing store for streams? | Redis Streams (unchanged) | SSE wraps it; could be swapped later without consumer impact |
+| Backing store for streams? | Redis Streams at the time; SQLite kv rows since 2026-10 | SSE wraps it; the 2026-10 swap proved it — no consumer changed |
 | Consumer groups / horizontal scale? | Not supported via SSE | Not needed today; revisit if scale ever requires it |
 | Storage portability? | Not a goal but a free side-effect | Will not be exercised in alpha |
 | **Canonical write API path?** | **`/meta/{hash}` family** | Has GET/PUT/**PATCH**/DELETE plus `/_add/{key}` and per-property `{key:.*}` operations. `PATCH` calls `MergeMetadataFlat` — matches the partial-update semantics PR B needs. `/api/metadata/{hashId}` stays as the editor-internal surface (no PATCH, no per-property routes) but is not the migration target. |
-| **SSE event-id contract?** | **Opaque to consumers** | Today it's the Redis Stream entry ID (`<ms>-<seq>`); consumers MUST treat as opaque so the backing store can be swapped without breaking the wire contract. Documented in the SSE endpoint comment and in this doc. |
+| **SSE event-id contract?** | **Opaque to consumers** | It is `<ms>-<seq>` (the Redis Stream entry form, kept after the 2026-10 SQLite switch); consumers MUST treat as opaque so the backing store can be swapped without breaking the wire contract. Documented in the SSE endpoint comment and in this doc. |
 | **Typed error envelope?** | **`{error, message, retryable}` with stable `error` slug** | See "Error envelope" subsection below. |
 | **Plugin direct-Redis risk?** | **Confirmed: no plugin uses Redis directly** | Grep across `packages/plugins/` for `ioredis` / `redis.createClient` / `new Redis()` returned empty. Plugins POST results back to meta-sort via `/api/plugins/callback`; meta-sort then writes. PR B picks up the plugin write path transparently. |
 | **meta-sort non-`file:*` writes?** | **Confirmed: none in production** | Full audit of `kvClient.*` callers in `packages/meta-sort/packages/meta-sort-core/src/` shows only: `setMetadataFlat`, `deleteMetadataFlat`, `getMetadataFlat`, `getMetadata`, `getAllHashIds`, `health`, plus the `file:events` stream consumer (`initStreamConsumer` / `startStreamConsumer` / `processPendingEntries`). The generic `kv.set(key, value)` / `kv.setProperty(key, value)` methods on the interface exist for plugin sandboxes and tests but are not invoked by production code with non-`file:*` keys. PR B + PR C cover the full meta-sort surface. |
@@ -591,7 +625,7 @@ Stable `error` slugs the client should switch on:
 | `unknown_root` | 404 | no | The hashId / UUID doesn't exist. Caller probably has a stale reference. |
 | `unknown_cid` | 404 | no | The CID isn't in the reverse index. No retry helps. |
 | `schema_violation` | 400 | no | Body shape rejected (missing required field, invalid value). Caller bug. |
-| `storage_unavailable` | 503 | yes | Redis transient. Caller should retry with backoff. |
+| `storage_unavailable` | 503 | yes | Store transient (Redis at the time; the embedded SQLite store since 2026-10). Caller should retry with backoff. |
 | `internal` | 500 | yes (cautiously) | Unhandled server-side error. Retry once; escalate if persistent. |
 
 **Implemented.** Every 4xx/5xx response across `internal/api`,
@@ -709,7 +743,9 @@ contract violation."
    One-shot fixer for already-stranded entries: walks every UUID's
    `midhash256` field to build the orphan index, merges each stranded
    `file:<midhash>/*` into the matching UUID via `MergeMetadataFlat`,
-   deletes the stranded root, and re-points the alias.
+   deletes the stranded root, and re-points the alias. *Removed in
+   2026-10* with the SQLite switch, together with the other one-shot Redis
+   migrations; it had been run on watch.nsl.sh before the migration.
 
 Verified on the dev stack: 48 stranded entries were reunited; the
 editor now shows every file with its full plugin metadata under one

docs/meta-core-architecture.md

@@ -3,14 +3,15 @@
 ## Document Purpose
 
 This document describes the architectural design of **meta-core**, the
-standalone container that owns Redis, the leader-info file, the HTTP+SSE
+standalone container that owns the metadata store (an embedded SQLite
+file; Redis until 2026-10), the leader-info file, the HTTP+SSE
 metadata surface, and a WebDAV file server. It covers the leader gate,
 storage data model, API design, the SSE event surface, and the integration
 contract with other MetaMesh services.
 
-For the on-disk Redis layout, see
+For the on-disk key layout, see
 [metadata-storage-structure.md](metadata-storage-structure.md). For the
-external-access design (Redis lockdown, SSE wire contract, auth rules),
+external-access design (store lockdown, SSE wire contract, auth rules),
 see [api-mediated-access.md](api-mediated-access.md). For the UUID-rooted
 storage rationale, see [uuid-rooted-metadata.md](uuid-rooted-metadata.md).
 
@@ -31,14 +32,15 @@ view of file metadata:
 
 meta-core sits below all of these as the single owner of:
 
-1. **Redis** — the metadata store and event source.
+1. **The metadata store** — an embedded SQLite file
+   (`/meta-core/db/meta-core.db`) holding metadata and the event streams.
 2. **The leader-info file** — the one place services look to discover meta-core's URLs.
 3. **The HTTP+SSE surface** — the only way external services touch the data plane.
 4. **A WebDAV server** — file access for plugins and other services.
 
 ### Core design principle
 
-> External services never speak Redis. Every read, write, and event flows
+> External services never touch the store. Every read, write, and event flows
 > through meta-core's HTTP+SSE surface.
 
 This is the contract that PR D of [api-mediated-access.md](api-mediated-access.md)
@@ -53,8 +55,8 @@ landed and that the rest of this document assumes.
 meta-core runs as a dedicated container (`metacore-app`). The dev compose
 runs a single instance; the legacy multi-instance topology (sibling
 followers) was deprecated. The flock primitive is retained as the
-correctness anchor — it guarantees that at most one process owns Redis and
-the writable state under `/meta-core`.
+correctness anchor — it guarantees that at most one process writes the
+database file and the writable state under `/meta-core`.
 
 ```
 ┌────────────────────────────────────────────────────────────────────────┐
@@ -62,17 +64,17 @@ the writable state under `/meta-core`.
 │                                                                        │
 │  supervisord                                                           │
 │   ├─ leader-election.sh   (flock → write kv-leader.info → exec self)   │
-│   ├─ redis-server         (AOF + RDB on /meta-core/db/redis)           │
 │   ├─ nginx                (TLS termination, proxy_cache for /webdav)   │
 │   ├─ rclone rcd           (mount daemon)                               │
 │   ├─ mount-watcher.sh     (rclone mount lifecycle)                     │
 │   └─ meta-core (Go) ──►   HTTP + SSE + WebDAV on :9000                 │
+│                           + embedded SQLite (db/meta-core.db)          │
 └────────────────────────────────────────────────────────────────────────┘
                                     │
        ┌────────────────────────────┴────────────────────────────┐
        │  /meta-core (shared volume)                             │
        │    locks/kv-leader.{lock,info}                          │
-       │    db/redis/                                            │
+       │    db/meta-core.db (+ -wal, -shm)                       │
        │    services/*.json                                      │
        │    mounts/{mounts.json, errors/}                        │
        │    watchers.json                                        │
@@ -152,7 +154,7 @@ Container startup
        ▼
 ┌──────────────────────────────┐
 │ supervisord starts:          │
-│   redis → nginx → rclone →   │
+│   nginx → rclone →           │
 │   meta-core Go binary        │
 └──────────────────────────────┘
 ```
@@ -167,10 +169,11 @@ gate wins. Therefore:
   local hostname + IP + config and returns it on demand. There are no
   `OnBecomeLeader` / `OnBecomeFollower` / `OnLeaderLost` callbacks; those
   states do not exist inside the Go process.
-- `LeaderLockInfo.RedisUrl` is intentionally empty in the response from
-  `/urls` — see `internal/leader/election.go:82`. PR D of
-  api-mediated-access.md removed direct Redis exposure; consumers route
-  metadata I/O through meta-core's HTTP API and SSE event streams.
+- `LeaderLockInfo.RedisUrl` is always empty in the response from
+  `/urls` (kept for wire compatibility). PR D of
+  api-mediated-access.md removed direct Redis exposure, and since 2026-10
+  there is no Redis at all; consumers route metadata I/O through
+  meta-core's HTTP API and SSE event streams.
 
 ### Lock-info file
 
@@ -192,18 +195,18 @@ Other services read this file, then call `GET /urls` for full discovery
   `metacore-app` is provisioned, its bash loop will acquire on next tick.
   The dev compose runs a single instance; failover is "restart the
   container."
-- **Redis crash inside the container** → supervisord restarts redis. The
-  Go binary's connect loop retries up to 30 times (1s delay) at startup;
-  at steady state, individual operations fail and clients retry.
+- **The store is in-process** — there is no separate database process to
+  crash. A meta-core crash is a process restart; SQLite's WAL recovers the
+  last committed transaction on reopen.
 
 ---
 
 ## Schema-Version Gate
 
 Before serving any traffic, `cmd/meta-core/main.go:54-61` calls
-`storage.EnsureSchemaVersion`. The sentinel lives in Redis at
+`storage.EnsureSchemaVersion`. The sentinel lives in the store at
 `meta-core:schema-version` (`internal/storage/schema_version.go`). The
-gate refuses to boot when the existing Redis layout predates the
+gate refuses to boot when the existing store layout predates the
 UUID-rooted schema, so legacy `file:midhash256:*` data can't leak into
 the current code paths. In alpha there is no automated migration —
 operators wipe with `pnpm run clean:all` and restart.
@@ -216,20 +219,20 @@ operators wipe with `pnpm run clean:all` and restart.
 
 ```
 ┌────────────────────────────────────────────────────────────────────┐
-│                       METADATA  (Redis)                            │
+│                 METADATA  (embedded SQLite, kv table)              │
 │                                                                    │
 │  Root: opaque UUIDv7 (Crockford Base32; ULID layout, 26 chars)     │
 │  Storage: flat string keys                                         │
 │           file:<uuid>/<property>           → string value          │
 │           file:<uuid>/cids/<bareCid>       → "true" (key-set)      │
-│           file:<uuid>/duplicates           → SET of paths          │
+│           dup:<uuid>/<path>                → "" (one per path)     │
 │                                                                    │
 │  No stored canonical_cid — derived by rank on read.                │
 │                                                                    │
-│  Aliases (reverse index, one Redis STRING each):                   │
+│  Aliases (reverse index, one key each):                            │
 │           cid:<bareCid>                    → <uuid>                │
 │                                                                    │
-│  Index:   file:__index__                   → SET of all UUIDs      │
+│  Index:   idx:roots/<uuid>                 → "" (one per root)     │
 │                                                                    │
 │  Mintable without a local file (remote / deleted entries OK).      │
 │  Resolvable by any registered CID in O(1).                         │
@@ -276,9 +279,8 @@ Bootstrap / discovery
   GET  /status
   GET  /leader
   GET  /urls
-  GET  /services         (alias: /api/services)
-  GET  /services/{name}
-  GET  /services/cleanup/stats
+  GET  /neighbors        (alias: /api/neighbors)
+  GET  /api/stats
 
 Metadata (primary surface for other services)
   GET    /meta
@@ -301,6 +303,7 @@ CID-addressed (public, auth-bypassed at the perimeter)
 
 Editor / KV / schema / snapshot
   GET /api/metadata/hash-ids
+  GET /api/files/tuples
   GET /api/metadata/list
   POST /api/metadata/search
   POST /api/metadata/batch
@@ -317,7 +320,7 @@ Editor / KV / schema / snapshot
   POST /api/snapshot/import
   POST /api/snapshot/wipe
 
-SSE event streams (HTTP-mirror of Redis Streams)
+SSE event streams (HTTP-mirror of the store's event streams)
   GET /api/events/files
   GET /api/events/meta
 
@@ -337,8 +340,10 @@ Watchers
   POST /api/watchers/{scan-all,reset-all}
   (deprecated: /api/scan/trigger, /api/scan/status — see watcher/handlers.go:32)
 
-Admin
-  POST /api/admin/migrate-dual-roots
+(The one-shot Redis-era admin migrations — `/api/admin/migrate-dual-roots`,
+`migrate-domain-screen`, `migrate-user-cids`, `sweep-literature-echoes` —
+were removed with the 2026-10 SQLite switch; they had been run once on
+watch.nsl.sh beforehand.)
 
 WebDAV
   /webdav/...   (GET, PUT, DELETE, MKCOL, COPY, MOVE, PROPFIND)
@@ -366,12 +371,16 @@ See `docs/api-mediated-access.md` "Auth" for the rationale.
 ### SSE event streams — wire contract
 
 `/api/events/files` and `/api/events/meta` are SSE mirrors of the
-`file:events` and `meta:events` Redis Streams. The contract
+`file:events` and `meta:events` streams, stored as `ev:<stream>/…` rows of
+the kv table (`internal/kv/stream.go`). The contract
 (`internal/api/sse_events.go`):
 
-- One SSE event per Redis Stream entry.
-- `id:` is the opaque `<ms>-<seq>` Redis Stream entry ID — clients echo
-  it back via `Last-Event-ID` on reconnect.
+- One SSE event per stream entry.
+- `id:` is the opaque `<ms>-<seq>` entry ID (the Redis Stream form, kept so
+  cursors persisted before the 2026-10 switch still compare) — clients echo
+  it back via `Last-Event-ID` on reconnect. Without `Last-Event-ID` the
+  stream starts at the head (resolved once at connect); `0` / `0-0` replay
+  from the beginning.
 - `event:` is the `type` field of the underlying entry.
 - `data:` is the JSON of the rest of the entry.
 - Heartbeats: SSE comment `:keep-alive\n\n` every 30s of silence.
@@ -380,9 +389,9 @@ See `docs/api-mediated-access.md` "Auth" for the rationale.
   `event: gap` payload before resuming from the oldest available entry.
 
 External services use SSE with `Last-Event-ID` as the resume primitive.
-A Redis consumer-group (XREADGROUP / XACK) exists *internally* — the
-`MetaPublisher` uses one to drain keyspace notifications — but it is not
-the external contract.
+`meta:events` entries are appended by the storage engine in the same
+transaction as the change they describe; the Redis-era keyspace-notification
+hop through `MetaPublisher` is gone.
 
 ### WebDAV URLs
 
@@ -412,7 +421,7 @@ WebDAV caching is handled by nginx's `proxy_cache` (see
 | Single binary | Static compilation |
 | Low resource | ~10-20 MB resident |
 | HTTP server | stdlib `net/http` + gorilla/mux |
-| Redis client | go-redis |
+| Metadata store | embedded SQLite via `modernc.org/sqlite` (pure Go, CGO off) |
 | WebDAV | `golang.org/x/net/webdav` |
 
 ### Repo layout
@@ -425,12 +434,13 @@ packages/meta-core/
 │   ├── cid/                      CID parsing + algorithm ranking
 │   ├── config/                   env-driven configuration
 │   ├── discovery/                service registry + dead-service cleaner
-│   ├── events/                   meta:events stream publisher
+│   ├── events/                   boot-time meta:events republish
+│   ├── kv/                       SQLite kv engine + event streams
 │   ├── leader/                   LeaderInfoProvider (no election logic)
 │   ├── mounts/                   rclone mount manager + handlers + stats
 │   ├── schema/                   live per-field schema indexer
 │   ├── snapshot/                 snapshot export / import / wipe
-│   ├── storage/                  Redis wrapper + UUID + CID reverse index + schema gate
+│   ├── storage/                  flat-key records + search + UUID + CID reverse index + schema gate
 │   ├── watcher/                  scanner + dispatcher + midhash + state
 │   ├── watchers/                 polling-based watcher configs
 │   └── webdav/                   /webdav/* handler
@@ -451,8 +461,8 @@ packages/meta-core/
 ```
 1. Load configuration from environment
 2. Build LeaderInfoProvider          (no election; bash gate already won)
-3. Connect to local Redis            (retry up to 30× / 1s)
-4. EnsureSchemaVersion               (abort if Redis layout is stale)
+3. Open the SQLite store             (META_CORE_DB_PATH or /meta-core/db/meta-core.db)
+4. EnsureSchemaVersion               (abort if the store layout is stale)
 5. Start service discovery + dead-service cleaner
 6. NewServer + Server.Start          (boots watcher, mounts, WebDAV, API)
 7. On first connection: start MetaPublisher + schema Indexer,
@@ -463,9 +473,9 @@ packages/meta-core/
 
 ### Process management
 
-Redis is not spawned by the Go binary; supervisord starts it before
-meta-core (`docker/supervisord.conf`). The Go binary connects to
-`localhost:6379` and retries until Redis is reachable.
+There is no database process: the store is embedded in the Go binary
+(`docker/supervisord.conf` runs meta-core, nginx and rclone). Until
+2026-10 supervisord also ran `redis-server` on `localhost:6379`.
 
 ---
 
@@ -473,15 +483,16 @@ meta-core (`docker/supervisord.conf`). The Go binary connects to
 
 ### Container restart
 
-Supervisord restarts crashed processes (meta-core, redis, nginx, rclone)
+Supervisord restarts crashed processes (meta-core, nginx, rclone)
 individually. The bash flock is held by supervisord's process tree, so
 internal crashes don't trigger re-election.
 
-### Redis crash
+### Store durability
 
-Supervisord restarts redis. The Go binary's connect retry handles the
-window. Persistence is RDB + AOF on the `/meta-core` volume, so no data is
-lost across restarts.
+The SQLite file runs in WAL mode with `synchronous=NORMAL`: every
+committed transaction survives a meta-core process crash. A record write — fields, root index, CID aliases,
+FTS row and its events — is one transaction, so a crash never leaves a
+half-written record.
 
 ### Container crash
 
@@ -514,7 +525,10 @@ via `/health`; metadata I/O and SSE event streams stop.
 | `SERVICE_VERSION` | `1.0.0` | Reported in `/status`. |
 | `API_PORT` | `8180` | External port baked into `baseUrl`. |
 | `BASE_URL` | _empty_ | Overrides constructed `baseUrl` (HTTPS perimeter). |
-| `REDIS_PORT` | `6379` | Local Redis port. |
+| `META_CORE_DB_PATH` | `<META_CORE_PATH>/db/meta-core.db` | SQLite database file. Dev stacks set `/meta-core-db/meta-core.db` (named volume — SQLite WAL is unsafe on the 9p `/meta-core` bind of Windows dev boxes). |
+| `META_CORE_DB_CACHE_MB` | `64` | Page cache of the writer connection. |
+| `META_CORE_DB_READER_CACHE_MB` | `16` | Page cache per reader connection. |
+| `META_CORE_DB_READERS` | `8` | Reader connection pool size. |
 | `META_CORE_HTTP_PORT` | `9000` | Go HTTP+SSE+WebDAV port. |
 | `META_CORE_HTTP_HOST` | `0.0.0.0` | HTTP bind address. |
 | `HEALTH_CHECK_INTERVAL_MS` | `5000` | Internal health-loop cadence. |
@@ -533,7 +547,7 @@ via `/health`; metadata I/O and SSE event streams stop.
 |---|---|
 | `locks/kv-leader.lock` | Flock target. |
 | `locks/kv-leader.info` | Leader API URL (plaintext). |
-| `db/redis/{dump.rdb, appendonly.aof}` | Redis persistence. |
+| `db/meta-core.db` (+ `-wal`, `-shm`) | Metadata store (SQLite). Replaced `db/redis/` in 2026-10. |
 | `services/*.json` | Service registry. |
 | `mounts/mounts.json` | rclone mount configuration. |
 | `mounts/errors/{id}.error` | Mount error logs. |
@@ -549,5 +563,5 @@ and file access for MetaMesh into one container with a typed HTTP+SSE
 surface. The bash flock gate guarantees single-leader semantics without
 an external consensus system. UUID-rooted storage with CID aliasing
 treats all content hashes symmetrically and makes any-CID resolution
-O(1). API-mediated access ensures no other service ever needs to speak
-Redis.
+a single lookup. API-mediated access ensures no other service ever touches
+the store.

docs/metadata-storage-structure.md

@@ -1,6 +1,6 @@
-# Redis Metadata Storage Structure
+# Metadata Storage Structure
 
-How meta-core lays out file metadata in Redis. This document covers the
+How meta-core lays out file metadata in its store. This document covers the
 on-disk shape (UUID-rooted flat string keys, CID reverse index,
 per-root sets) and the schema-version gate. It does **not** enumerate
 field semantics — that's the job of the repo-root
@@ -12,40 +12,80 @@ reverse index), see [`uuid-rooted-metadata.md`](uuid-rooted-metadata.md).
 For the external-access contract (HTTP-only, SSE for events), see
 [`api-mediated-access.md`](api-mediated-access.md).
 
+> **Storage engine (since 2026-10): an embedded SQLite file, not Redis.**
+> Until 2026-10 these keys lived in a Redis server spawned inside the
+> container. They now live in one string→string table of an embedded SQLite
+> database (pure-Go driver `modernc.org/sqlite`, CGO off). The **key names
+> did not change** — only the Redis *types* that some bookkeeping used (SETs,
+> HASHes, Streams) were flattened into plain keys, listed below. Holding
+> everything in RAM had cost ~6.6 GB on watch.nsl.sh's 169k records (Redis
+> plus the API's in-memory search copy) and caused repeated OOM kills.
+
 ## Quick summary
 
+- **One table**: `kv(k TEXT PRIMARY KEY, v TEXT NOT NULL) WITHOUT ROWID`,
+  schema-free — a new metadata field is just a new key, never a migration.
+  File: `/meta-core/db/meta-core.db` (override `META_CORE_DB_PATH`), WAL
+  mode, `synchronous=NORMAL`.
 - **Roots are UUIDv7** encoded as 26-char Crockford Base32 (ULID layout),
   not content hashes. Examples in this doc use the placeholder
   `01JKR8XW5T4QMV7AHNJ2DEFGHK`.
-- **Properties are flat Redis STRING keys**, one per leaf:
-  `file:<uuid>/<property/path>` → string value. *Not* Redis Hashes.
+- **Properties are flat string keys**, one per leaf:
+  `file:<uuid>/<property/path>` → string value. A record is exactly the
+  key range `[file:<uuid>/, file:<uuid>0)` — there is no per-record field
+  list.
 - **CIDs are reverse-index aliases**: `cid:<bareCid>` → `<uuid>`
-  (a Redis STRING per known CID; no algorithm prefix — the multicodec
+  (one key per known CID; no algorithm prefix — the multicodec
   already carries it).
-- **Per-root sets**: `file:<uuid>/cids/<bareCid>` (a *key-set*: one STRING
-  `"true"` per known CID, midhash included), `file:<uuid>/duplicates`
-  (alternate paths with the same content), plus `file:__index__` (every UUID).
+- **Per-root sets**: `file:<uuid>/cids/<bareCid>` (a *key-set*: one key
+  `"true"` per known CID, midhash included), `dup:<uuid>/<path>` (alternate
+  paths with the same content), plus `idx:roots/<uuid>` (every UUID).
   There is **no stored `canonical_cid`** — it is derived by rank on read.
 - **A schema-version sentinel** (`meta-core:schema-version`) refuses to
   boot against legacy data.
 
-Implementation lives in `internal/storage/client.go`,
-`internal/storage/cid_resolution.go`, `internal/storage/uuid.go`, and
-`internal/storage/schema_version.go`.
+Implementation lives in `internal/kv/kv.go` (engine),
+`internal/kv/stream.go` (event streams), `internal/storage/client.go`,
+`internal/storage/search.go`, `internal/storage/cid_resolution.go`,
+`internal/storage/uuid.go`, and `internal/storage/schema_version.go`.
 
 ## Key structure
 
+Everything is one string→string table. The full layout:
+
+| Key | Value | Notes |
+|---|---|---|
+| `file:<rid>/<field>` | field value | a record property — the **only** thing under `file:` |
+| `cid:<cid>` | `<rid>` | reverse index |
+| `meta-core:schema-version` | `"2"` | schema gate |
+| `idx:roots/<rid>` | `""` | set of every root (was the Redis SET `file:__index__`) |
+| `idx:fts/<rid>` | FTS rowid | the record's row in the FTS table |
+| `dup:<rid>/<path>` | `""` | a duplicate path (was the SET `file:<rid>/duplicates`) |
+| `udl:rec:<uid>/<cid>/<key>` | JSON `{record,version,ts,value?}` | User Data Layer entry (was a HASH) |
+| `udl:idx:…<set>\x1f<member>` | `""` | UDL index sets, one key per member |
+| `ev:<stream>/<ms13>-<seq10>` | JSON of the entry's fields | `meta:events` / `file:events` entries (were Redis Streams) |
+| `evhwm:<stream>` | last issued ID | stream high-water mark |
+| `btmagnet:*`, `searchcov:*`, `nzb:*` | — | written by other services via `/api/kv/value`; unchanged |
+
+Keeping bookkeeping **out of `file:`** is load-bearing: the `file:` range is
+exactly the records, so the field index covers only real fields and every
+change under `file:` is a real field change worth publishing on
+`meta:events`. The per-record `file:<rid>/__fields__` SET and the
+`file:__dirty__` set of the Redis era no longer exist. Roots are split from
+the field at the **first** `/`, so CID-rooted and UUID-rooted records both
+parse.
+
 ### Roots
 
 ```
-file:<uuid>/<property/path>   →   Redis STRING (always)
+file:<uuid>/<property/path>   →   string (always)
 ```
 
 UUIDs are produced by `storage.NewUUID()` (`internal/storage/uuid.go`):
 UUIDv7 → 26-char Crockford Base32 (skips I/L/O/U; ULID-compatible). The
-time-sortable prefix lets you `KEYS file:01JKR8*` to find roots minted
-in a given window, which restored some of the debug-ability lost when
-midhash256 stopped being the root.
+time-sortable prefix means roots minted in a given window sort together
+(`k >= 'file:01JKR8' AND k < 'file:01JKR9'`), which restored some of the
+debug-ability lost when midhash256 stopped being the root.
 
 Properties use `/` as the path separator. Nested objects in source code
 are flattened to flat keys on write and reconstructed on read. Examples:
@@ -62,7 +102,7 @@ file:01JKR8XW5T4QMV7AHNJ2DEFGHK/tmdb/poster                       = "bafkreih...
 
 ### Reverse-index aliases (CIDs)
 
-Every CID known for a file is registered as its own Redis STRING, keyed by
+Every CID known for a file is registered as its own key, keyed by
 the **bare CID** — no algorithm prefix. A CIDv1 already encodes its hash
 function in the multicodec, so naming it again in the key would be
 redundant (and would let the same digest be indexed under two spellings):
@@ -78,13 +118,12 @@ cid:bafkreih5kapbjzq...   →   01JKR8XW5T4QMV7AHNJ2DEFGHK
 cid:bagacbabaec7v3...     →   01JKR8XW5T4QMV7AHNJ2DEFGHK
 ```
 
-The reverse index makes `GET /api/meta/<cid>` an O(1) lookup for any
+The reverse index makes `GET /api/meta/<cid>` a primary-key lookup for any
 registered CID, independent of which hash algorithm — there is no primary.
-The auto-alias hook (`maybeAddAliasFromFieldLocked` in
-`internal/storage/cid_resolution.go`, called from `SetProperty`,
-`SetMetadataFlat` and `MergeMetadataFlat`) registers the alias for any
-field whose name starts with `cids/`, so writers emit key-set members
-without knowing the reverse index exists.
+The record write path (`writeFieldsTx` in `internal/storage/client.go`, used
+by `SetProperty`, `SetMetadataFlat` and `MergeMetadataFlat`) registers the
+alias for any field whose name starts with `cids/`, in the same transaction,
+so writers emit key-set members without knowing the reverse index exists.
 
 > ⚠ The hook matches **only** the `cids/` prefix. A legacy `cid_*` or
 > `midhash256` *named* field written to a root is stored verbatim and is
@@ -95,12 +134,13 @@ without knowing the reverse index exists.
 ### Per-root sets
 
 ```
-file:<uuid>/cids/<bareCid>    →   STRING "true" — one key per known CID (a key-set, not a Redis SET)
-file:<uuid>/duplicates        →   Redis SET of alternate paths with same content
+file:<uuid>/cids/<bareCid>    →   "true" — one key per known CID (a key-set)
+dup:<uuid>/<path>             →   ""     — one key per alternate path with same content
 ```
 
-`cids` is a **key-set**: one flat `file:<uuid>/cids/<cid>` STRING per member,
-which keeps it conflict-free to merge across peers (a SET would not be).
+`cids` is a **key-set**: one flat `file:<uuid>/cids/<cid>` key per member,
+which keeps it conflict-free to merge across peers (a single set-valued
+field would not be).
 The record's own address (the midhash) is just the `0x1000` member — it has
 no separate field.
 
@@ -114,61 +154,88 @@ was removed with the flat `cid_*` keys.
 ### Global index
 
 ```
-file:__index__   →   Redis SET of all UUIDs
+idx:roots/<uuid>   →   ""   (one key per root; was the Redis SET file:__index__)
 ```
 
-`internal/storage/client.go::GetAllHashIDs` reads this set to enumerate
-every file without scanning the keyspace.
+`internal/storage/client.go::GetAllHashIDs` range-reads `idx:roots/` to
+enumerate every file without scanning the records.
 
-```bash
-SMEMBERS file:__index__         # all UUIDs
-SCARD    file:__index__         # total file count
-SISMEMBER file:__index__ <uuid>
-```
+### Search structures (derived)
+
+Two derived structures are maintained on top of `kv`, in the same
+transaction as every record write. Both are rebuildable from the kv rows and
+never authoritative (`internal/storage/search.go`):
+
+- **`kv_field`** — a partial expression index
+  `ON kv(lower(substr(k,instr(k,'/')+1)), lower(v)) WHERE k>='file:' AND k<'file;' AND instr(k,'/')>0`.
+  It answers "which records have field F with a value like V" for **any**
+  field, including ones invented tomorrow — the index is over the key itself.
+- **`fts`** — an FTS5 trigram table `fts(rid UNINDEXED, hay)` holding one row
+  per record: its search haystack plus its rid (`idx:fts/<rid>` points at the
+  row). Trigrams make every 3+ character substring indexable.
+
+`POST /api/metadata/search` uses SQL to build a superset of candidates, then
+verifies each with the unchanged Go matchers (`recordMatchesFilter`,
+`matchAllTokens`), so semantics are identical to the old in-memory index.
+Results still come in hashID order and are fresh immediately (no refresh
+lag). This replaced the API's in-memory `searchIndex` (60 s refresh, ~30 KB
+RAM per record).
 
 ### Schema-version sentinel
 
 ```
-meta-core:schema-version   →   STRING (currently "2")
+meta-core:schema-version   →   string (currently "2")
 ```
 
 Set at first boot, checked on every subsequent boot
 (`internal/storage/schema_version.go`). If the sentinel is missing but
-`file:__index__` is non-empty, the gate refuses to boot (legacy data).
+the root index is non-empty, the gate refuses to boot (legacy data).
 If the sentinel is present but doesn't match `SchemaVersion`, the gate
 also refuses to boot. Alpha-stage policy: operators wipe and restart;
 there is no automated migration.
 
-## Why flat STRING keys?
+## Why flat string keys?
 
-The store does not use Redis Hashes. The reasons are:
+The store keeps one flat key per leaf rather than a document or a
+per-record row. The reasons are:
 
-1. **Field-level keyspace notifications.** Redis publishes
-   `__keyspace@0__:<key>` on every SET/DEL of a STRING key. With Hashes
-   you'd only get one notification on the hash itself. meta-core's
-   `MetaPublisher` (`internal/events/meta_publisher.go`) consumes these
-   notifications and publishes structured events to the `meta:events`
-   Redis Stream.
-2. **Selective updates without read-modify-write.** A plugin writing
+1. **Schema-free.** A plugin inventing a field writes a new key; nothing
+   declares it, and the table never needs a migration. The field index
+   covers it automatically.
+2. **Conflict-free merging across peers.** Key-sets (`cids/<cid>`, and the
+   flat fields in general) merge by union of keys — no read-modify-write of
+   a shared value, nothing to reconcile.
+3. **Selective updates without read-modify-write.** A plugin writing
    `tmdb/poster` doesn't have to read the rest of the document.
-3. **Compatibility with the CID alias hooks.** Field writes can trigger
-   alias-maintenance work in `SetProperty` without the plugin caring.
+4. **Compatibility with the CID alias hooks.** Field writes can trigger
+   alias-maintenance work in the write path without the plugin caring.
+
+(Under Redis there was a fourth reason — field-level keyspace notifications
+fed `meta:events`. That is obsolete: events are now written by the storage
+engine itself, see [Event streams](#event-streams).)
 
 ## Reads and writes
 
+All writes go through **one writer goroutine** with group commit: concurrent
+writes share one SQLite transaction, each under its own SAVEPOINT so a
+failure rolls back alone. A record write — fields + root index + CID aliases
++ FTS row + events — is atomic. (Measured ~835 records/s with 16 concurrent
+writers of 40-field records.) Reads use a separate connection pool and see
+the last committed state.
+
 The Go API in `internal/storage/client.go`:
 
 | Method | Behaviour |
 |---|---|
-| `GetMetadataFlat(uuid)` | `SCAN` for `file:<uuid>/*`, `MGET` the values, return `map[string]string`. |
-| `SetMetadataFlat(uuid, m)` | Pipeline `SET` per field; `SADD file:__index__`; auto-register an alias for every `cids/<cid>` member. |
+| `GetMetadataFlat(uuid)` | Range-read `[file:<uuid>/, file:<uuid>0)`, return `map[string]string`. |
+| `SetMetadataFlat(uuid, m)` | Put each field; add `idx:roots/<uuid>`; auto-register an alias for every `cids/<cid>` member; refresh the FTS row. One transaction. |
 | `MergeMetadataFlat(uuid, m)` | Like `SetMetadataFlat` but doesn't pre-clear; used by `PATCH /meta/{hash}`. |
-| `GetProperty(uuid, field)` | `GET file:<uuid>/<field>`. |
-| `SetProperty(uuid, field, value)` | `SET file:<uuid>/<field>`; auto-register alias if the field is a CID. |
-| `DeleteRoot(uuid)` | `SCAN` + `DEL` for `file:<uuid>/*`, unmap every reverse-index entry. |
+| `GetProperty(uuid, field)` | Get `file:<uuid>/<field>`. |
+| `SetProperty(uuid, field, value)` | Put `file:<uuid>/<field>`; auto-register alias if the field is a CID. |
+| `DeleteRoot(uuid)` | Delete the `file:<uuid>/` range, its duplicates, search row and index membership; unmap every reverse-index entry. |
 | `Mint(filePath, size, mtimeNano)` | `NewUUID()` + write `filePath/sizeByte/mtimeNano` + add to index. |
 | `AddAlias(uuid, "<bareCid>")` | Set `cid:<bareCid>` → `<uuid>` and the key-set member `file:<uuid>/cids/<bareCid>` = `"true"`. Nothing to reconcile — canonical is derived on read. |
-| `ResolveRoot("<bareCid>")` | `GET cid:<bareCid>` → uuid (returns the input unchanged if it is already a UUID root). |
+| `ResolveRoot("<bareCid>")` | Get `cid:<bareCid>` → uuid (returns the input unchanged if it is already a UUID root). |
 | `GetMetadataDocument(uuid)` | Flat fields + `cids` hoisted to an array + `canonical_cid` **derived** by `cid.Better` rank + `duplicates`. Backs `GET /api/meta/{cid}`. |
 
 ## Reconstruction (flat → nested)
@@ -196,7 +263,7 @@ Rules:
 
 ## Plugin contribution flow
 
-Plugins don't talk to Redis. They write metadata via meta-core's HTTP
+Plugins don't talk to the store directly. They write metadata via meta-core's HTTP
 API (`PUT /meta/{hash}/{key...}` or `PATCH /meta/{hash}`). Each plugin
 writes under a prefix:
 
@@ -215,12 +282,24 @@ deliberately does not duplicate that registry — it would drift.
 
 ## Event streams
 
-Two Redis Streams are produced inside meta-core:
+Two event streams are kept inside the store, as rows
+`ev:<stream>/<ms13>-<seq10>` (zero-padded so key order is ID order) plus a
+high-water mark `evhwm:<stream>` (`internal/kv/stream.go`):
 
 | Stream | Producer | Contents |
 |---|---|---|
 | `file:events` | `internal/watcher` dispatcher | `add` / `change` / `delete` / `rename` / `reset` events for files on the `/files` volume. |
-| `meta:events` | `internal/events.MetaPublisher` | Field-level metadata mutations derived from Redis keyspace notifications. |
+| `meta:events` | the storage engine (`internal/kv`) | `{type: set\|del, key, ts}` for every Put/Delete of a `file:` key, appended **in the same transaction** as the change. |
+
+`del` is emitted only when the key existed; `set` is emitted even for an
+unchanged value (Redis semantics, kept). Retention is ~100k entries,
+trimmed every 10k appends. At boot `MetaPublisher`
+(`internal/events/meta_publisher.go`) still republishes every field into
+`meta:events` (meta-fuse rebuilds its VFS only by replaying from `0-0`),
+batched 5k events per transaction.
+
+The Redis-era path — keyspace notifications drained by `MetaPublisher`
+through a PSUBSCRIBE / consumer-group hop — is gone (2026-10).
 
 External consumers do **not** read these streams directly. They subscribe
 via SSE:
@@ -228,51 +307,50 @@ via SSE:
 - `GET /api/events/files` — mirror of `file:events`
 - `GET /api/events/meta` — mirror of `meta:events`
 
-The SSE wire contract uses `Last-Event-ID` for resume (the opaque
-`<ms>-<seq>` Redis Stream entry ID). Heartbeats are SSE comments
+The SSE wire contract uses `Last-Event-ID` for resume. IDs keep the Redis
+`<ms>-<seq>` form so cursors persisted by meta-sort / meta-share /
+meta-stremio across the switch still compare. Heartbeats are SSE comments
 (`:keep-alive\n\n`) every 30s of silence. If retention has trimmed past
 a client's cursor, the handler emits one `event: gap` payload before
 resuming. See `internal/api/sse_events.go` and
 [`api-mediated-access.md`](api-mediated-access.md) for the full
 contract.
 
-Internally, meta-core uses a Redis consumer group (XREADGROUP / XACK)
-inside `MetaPublisher` to drain keyspace notifications, but this is not
-the external surface — external services use SSE.
-
 ## Debugging
 
-```bash
-# Roots
-docker exec metacore-app redis-cli SMEMBERS 'file:__index__'
-docker exec metacore-app redis-cli SCARD    'file:__index__'
-docker exec metacore-app redis-cli SRANDMEMBER 'file:__index__'
+The database path is `/meta-core/db/meta-core.db` in the image default and
+on the store app; dev stacks use `/meta-core-db/meta-core.db` (a named
+volume — the `/meta-core` bind is 9p on Windows dev boxes, where SQLite WAL
+is unsafe). Always open it **read-only**; writes must go through the API.
 
-# Full document for one root (flat scan)
-docker exec metacore-app redis-cli --scan --pattern 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/*'
+```bash
+DB=/meta-core/db/meta-core.db      # dev stack: /meta-core-db/meta-core.db
+Q() { docker exec metacore-app sqlite3 -readonly "$DB" "$1"; }
+
+# Roots
+Q "SELECT count(*) FROM kv WHERE k >= 'idx:roots/' AND k < 'idx:roots0'"
+Q "SELECT substr(k,11) FROM kv WHERE k >= 'idx:roots/' AND k < 'idx:roots0' LIMIT 10"
+
+# Full document for one root
+Q "SELECT k,v FROM kv WHERE k >= 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/' AND k < 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK0'"
 
 # One property
-docker exec metacore-app redis-cli GET 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/fileinfo/duration'
-
-# Confirm keys are STRING (not HASH)
-docker exec metacore-app redis-cli TYPE 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/filePath'
-# string
+Q "SELECT v FROM kv WHERE k = 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/fileinfo/duration'"
 
 # Reverse-index lookup (bare CID — no algorithm prefix)
-docker exec metacore-app redis-cli GET 'cid:bafkreih...'      # → uuid
+Q "SELECT v FROM kv WHERE k = 'cid:bafkreih...'"                   # → uuid
 
-# The cids key-set (one STRING per member, NOT a Redis SET — SMEMBERS won't work)
-docker exec metacore-app redis-cli --scan --pattern 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/cids/*'
+# The cids key-set
+Q "SELECT k FROM kv WHERE k >= 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/cids/' AND k < 'file:01JKR8XW5T4QMV7AHNJ2DEFGHK/cids0'"
 
 # canonical_cid is NOT stored. Derive it via the API instead:
 curl -k https://metacore-dev.localhost:8083/api/meta/<cid> | jq '.canonical_cid, .cids'
 
 # Schema-version sentinel
-docker exec metacore-app redis-cli GET 'meta-core:schema-version'
+Q "SELECT v FROM kv WHERE k = 'meta-core:schema-version'"
 
 # Streams (server-side; external consumers should use SSE)
-docker exec metacore-app redis-cli XRANGE 'file:events' - + COUNT 10
-docker exec metacore-app redis-cli XRANGE 'meta:events' - + COUNT 10
+Q "SELECT k,v FROM kv WHERE k >= 'ev:meta:events/' AND k < 'ev:meta:events0' ORDER BY k DESC LIMIT 10"
 
 # HTTP equivalents — preferred
 curl -k 'https://metacore-dev.localhost:8083/api/meta/<cid>'      # CID → document
@@ -286,12 +364,14 @@ curl -k 'https://metacore-dev.localhost:8083/api/kv/info'         # KV stats
 
 | Component | Path |
 |---|---|
-| Redis client + flat-key ops | `internal/storage/client.go` |
+| Storage engine (SQLite kv table, writer, group commit) | `internal/kv/kv.go` |
+| Event streams as kv rows | `internal/kv/stream.go` |
+| Flat-key record ops | `internal/storage/client.go` |
+| Search (field index + FTS) | `internal/storage/search.go` |
 | UUIDv7 minting | `internal/storage/uuid.go` |
-| CID reverse index + aliases + canonical-CID reconciliation | `internal/storage/cid_resolution.go` |
+| CID reverse index + aliases + canonical-CID derivation | `internal/storage/cid_resolution.go` |
 | Schema-version gate | `internal/storage/schema_version.go` |
-| Dual-root migration (legacy clean-up) | `internal/storage/dual_root_migration.go` |
-| Keyspace-notification → `meta:events` publisher | `internal/events/meta_publisher.go` |
+| Boot-time `meta:events` republish | `internal/events/meta_publisher.go` |
 | Watcher → `file:events` dispatcher | `internal/watcher/dispatcher.go` |
 | SSE event mirror | `internal/api/sse_events.go` |
 | Field semantics (authoritative registry) | [`/METADATA_KEYS.md`](../../../METADATA_KEYS.md) |

docs/uuid-rooted-metadata.md

@@ -20,6 +20,12 @@
 >    `cid:<bareCid>` → uuid. A CIDv1's multicodec already names its hash
 >    function, so the `<algo>:` prefix was redundant.
 >
+> 3. **The store is no longer Redis (2026-10).** The same keys now live in
+>    one string→string table of an embedded SQLite file; Redis SETs became
+>    one key per member (`file:__index__` → `idx:roots/<uuid>`,
+>    `file:<uuid>/duplicates` → `dup:<uuid>/<path>`). Redis types named
+>    below are the shape at the time.
+>
 > Text below that references either shape describes the *proposal*, not the
 > code. The rank ordering and everything else did ship as written.
 
@@ -135,7 +141,7 @@ sole writer is meta-core itself:
 | Key | Type (as shipped) | Purpose |
 |-----|------|---------|
 | `cids/<bareCid>` | STRING `"true"` — a *key-set*, one key per member | All CIDs known for this file, midhash included. Mirror of the `cid:*` reverse index. Source of truth for delete-time GC. **Proposed as a Redis SET of `<algo>:<value>` tokens; shipped as a key-set of bare CIDs** — a key-set merges conflict-free across peers and the multicodec already names the algorithm. |
-| `duplicates` | Redis SET | Additional file paths whose content matches this entry. One UUID = one set of metadata; multiple physical files may share that content. Consumed by meta-dup. |
+| `duplicates` | Redis SET at the time; since 2026-10 one `dup:<uuid>/<path>` key per path | Additional file paths whose content matches this entry. One UUID = one set of metadata; multiple physical files may share that content. Consumed by meta-dup. |
 | ~~`canonical_cid`~~ | *(not stored)* | **Dropped.** Was to hold the externally-presented CID. Now derived on read by ranking the `cids` members; surfaced only on `GET /api/meta/{cid}`. |
 
 Existing meta-core-owned fields (`filePath`, `size`, `mtime`, `midhash256`)
@@ -148,7 +154,8 @@ for using sets where they're the right structure.~~ **Reversed for `cids`.**
 The all-strings convention won: `cids` ships as flat `cids/<cid>` STRING keys
 so that two peers merging the same record can never disagree about set
 membership. `duplicates` remained a Redis SET (it is leader-local and never
-merged across peers).
+merged across peers) until the 2026-10 SQLite switch, which flattened it to
+`dup:<uuid>/<path>` keys.
 
 ### Canonical CID selection
 

editor/src/api/snapshotApi.ts

@@ -81,7 +81,7 @@ export class SnapshotAPI {
   }
 
   /**
-   * Wipe Redis metadata. Pass scope=metadata.
+   * Wipe all stored metadata. Pass scope=metadata.
    */
   static async wipe(scope: 'metadata'): Promise<WipeResult> {
     const response = await fetch(`${API_BASE}/wipe?scope=${scope}`, {

editor/src/components/SnapshotPanel.tsx

@@ -43,7 +43,7 @@ export function SnapshotPanel() {
 
   const runWipe = async () => {
     const ok = window.confirm(
-      'This deletes ALL metadata in Redis. Files on disk are not touched, but every manual ' +
+      'This deletes ALL stored metadata. Files on disk are not touched, but every manual ' +
         'edit you made via this editor will be lost. Continue?'
     );
     if (!ok) return;

go.mod

@@ -1,21 +1,25 @@
 module github.com/metazla/meta-core
 
-go 1.21
+go 1.26.0
 
 require (
-	github.com/alicebob/miniredis/v2 v2.31.1
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.1
 	github.com/google/uuid v1.6.0
 	github.com/gorilla/mux v1.8.1
 	github.com/mr-tron/base58 v1.3.0
-	github.com/redis/go-redis/v9 v9.4.0
 	golang.org/x/crypto v0.31.0
 	golang.org/x/net v0.21.0
+	modernc.org/sqlite v1.60.1
 )
 
 require (
-	github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a // indirect
-	github.com/cespare/xxhash/v2 v2.2.0 // indirect
-	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
-	github.com/yuin/gopher-lua v1.1.0 // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/mattn/go-isatty v0.0.24 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	modernc.org/libc v1.77.1 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.12.1 // indirect
 )
+
+require golang.org/x/sys v0.48.0

go.sum

@@ -1,36 +1,62 @@
-github.com/DmitriyVTitov/size v1.5.0/go.mod h1:le6rNI4CoLQV1b9gzp1+3d7hMAD/uu2QcJ+aYbNgiU0=
-github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a h1:HbKu58rmZpUGpz5+4FfNmIU+FmZg2P3Xaj2v2bfNWmk=
-github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a/go.mod h1:SGnFV6hVsYE877CKEZ6tDNTjaSXYUk6QqoIK6PrAtcc=
-github.com/alicebob/miniredis/v2 v2.31.1 h1:7XAt0uUg3DtwEKW5ZAGa+K7FZV2DdKQo5K/6TTnfX8Y=
-github.com/alicebob/miniredis/v2 v2.31.1/go.mod h1:UB/T2Uztp7MlFSDakaX1sTXUv5CASoprx0wulRT6HBg=
-github.com/bsm/ginkgo/v2 v2.12.0 h1:Ny8MWAHyOepLGlLKYmXG4IEkioBysk6GpaRTLC8zwWs=
-github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
-github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
-github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
-github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
-github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
-github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
-github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
-github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/decred/dcrd/crypto/blake256 v1.1.0 h1:zPMNGQCm0g4QTY27fOCorQW7EryeQ/U0x++OzVrdms8=
 github.com/decred/dcrd/crypto/blake256 v1.1.0/go.mod h1:2OfgNZ5wDpcsFmHmCK5gZTPcCXqlm2ArzUIkw9czNJo=
 github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.1 h1:5RVFMOWjMyRy8cARdy79nAmgYw3hK/4HUq48LQ6Wwqo=
 github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.1/go.mod h1:ZXNYxsqcloTdSy/rNShjYzMhyjf0LaoftYK0p+A3h40=
-github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
-github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
-github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
+github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
+github.com/google/pprof v0.0.0-20260802141513-ef3492d7dac3 h1:LMLX+LgTNWpfvCBdFebv6EsYotImrt/Ppc5cXIriCSo=
+github.com/google/pprof v0.0.0-20260802141513-ef3492d7dac3/go.mod h1:jl5iWTm0/hd5PjEYEOuwAJ57L/CibdZfrqZ5XA5GrCk=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
 github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
+github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
+github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
+github.com/mattn/go-isatty v0.0.24 h1:tGZZoVgT/KiqK1c8ocVLeDS8BSWMRd47J3Lbz7vsReI=
+github.com/mattn/go-isatty v0.0.24/go.mod h1:nMCL3Zebbrt45jsMDgnfIwz6ydEQApk5oEI3HqDio6A=
 github.com/mr-tron/base58 v1.3.0 h1:K6Y13R2h+dku0wOqKtecgRnBUBPrZzLZy5aIj8lCcJI=
 github.com/mr-tron/base58 v1.3.0/go.mod h1:2BuubE67DCSWwVfx37JWNG8emOC0sHEU4/HpcYgCLX8=
-github.com/redis/go-redis/v9 v9.4.0 h1:Yzoz33UZw9I/mFhx4MNrB6Fk+XHO1VukNcCa1+lwyKk=
-github.com/redis/go-redis/v9 v9.4.0/go.mod h1:hdY0cQFCN4fnSYT6TkisLufl/4W5UIXyv0b/CLO2V2M=
-github.com/yuin/gopher-lua v1.1.0 h1:BojcDhfyDWgU2f2TOzYK/g5p2gxMrku8oupLDqlnSqE=
-github.com/yuin/gopher-lua v1.1.0/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
+github.com/ncruces/go-strftime v1.0.0 h1:HMFp8mLCTPp341M/ZnA4qaf7ZlsbTc+miZjCLOFAw7w=
+github.com/ncruces/go-strftime v1.0.0/go.mod h1:Fwc5htZGVVkseilnfgOVb9mKy6w1naJmn9CehxcKcls=
+github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
+github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
 golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
 golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
+golang.org/x/mod v0.41.0 h1:qJmnOUb4YB+FsEuM3HcWucdZASCPGhsX6uljO6pog0c=
+golang.org/x/mod v0.41.0/go.mod h1:Ek9pY8RKWXwsWvd3rQiHYtMqkjSUV+s1Rj7j4H5Ur6o=
 golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
 golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
-golang.org/x/sys v0.0.0-20190204203706-41f3e6584952/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sync v0.23.0 h1:KameEIfc1IkluZyXWLn39Wd4tURc6GbCiISGiZm2bQk=
+golang.org/x/sync v0.23.0/go.mod h1:sUUOizhqBxiL6pEWpqNLUiaJn1ShEbZ6BBqskPbjZm0=
+golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
+golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
+golang.org/x/tools v0.50.0 h1:c2ifzfcuY7L90lZ2aKd8S4K2NpASF08SZx9ZuJkHmSU=
+golang.org/x/tools v0.50.0/go.mod h1:7ulVMw3831Mwi5EZD6RomGyffr4VFjuNYXf2BbCEAV0=
+modernc.org/cc/v4 v4.29.7 h1:q+NXGJ0bK3b4TXFYQQVr9pYETGnmwFWkrUzJnMya/Tg=
+modernc.org/cc/v4 v4.29.7/go.mod h1:OnovgIhbbMXMu1aISnJ0wvVD1KnW+cAUJkIrAWh+kVI=
+modernc.org/ccgo/v4 v4.36.1 h1:ZNIUZAryN0UgnJwtyxrdEzcFc3yD4Cu4AzjfPXsLsIE=
+modernc.org/ccgo/v4 v4.36.1/go.mod h1:rrtGc2QkS239nYb/mQNuBMyjq3/y3ZXWbBjPoV3wqzA=
+modernc.org/fileutil v1.4.0 h1:j6ZzNTftVS054gi281TyLjHPp6CPHr2KCxEXjEbD6SM=
+modernc.org/fileutil v1.4.0/go.mod h1:EqdKFDxiByqxLk8ozOxObDSfcVOv/54xDs/DUHdvCUU=
+modernc.org/gc/v2 v2.6.5 h1:nyqdV8q46KvTpZlsw66kWqwXRHdjIlJOhG6kxiV/9xI=
+modernc.org/gc/v2 v2.6.5/go.mod h1:YgIahr1ypgfe7chRuJi2gD7DBQiKSLMPgBQe9oIiito=
+modernc.org/gc/v3 v3.1.5 h1:21ldfPfRYE31Tb7B3mwAK8gy1AxP4+dKjrOQPfqakoc=
+modernc.org/gc/v3 v3.1.5/go.mod h1:HFK/6AGESC7Ex+EZJhJ2Gni6cTaYpSMmU/cT9RmlfYY=
+modernc.org/goabi0 v0.2.0 h1:HvEowk7LxcPd0eq6mVOAEMai46V+i7Jrj13t4AzuNks=
+modernc.org/goabi0 v0.2.0/go.mod h1:CEFRnnJhKvWT1c1JTI3Avm+tgOWbkOu5oPA8eH8LnMI=
+modernc.org/libc v1.77.1 h1:Ct8j47QtiZ1Enj2DtFXQtUqrPCAjdCmPjtCuvrYQ0Hs=
+modernc.org/libc v1.77.1/go.mod h1:87/pZ4L6nD1zqW4nItuS12YO7hN1igAah34xjnQo/W0=
+modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=
+modernc.org/mathutil v1.7.1/go.mod h1:4p5IwJITfppl0G4sUEDtCr4DthTaT47/N3aT6MhfgJg=
+modernc.org/memory v1.12.1 h1:nFMiWrpStgZczNl6XI9GnIk/rWhYIyHGUaR04pGbp9g=
+modernc.org/memory v1.12.1/go.mod h1:/JP4VbVC+K5sU2wZi9bHoq2MAkCnrt2r98UGeSK7Mjw=
+modernc.org/opt v0.2.0 h1:tGyef5ApycA7FSEOMraay9SaTk5zmbx7Tu+cJs4QKZg=
+modernc.org/opt v0.2.0/go.mod h1:03fq9lsNfvkYSfxrfUhZCWPk1lm4cq4N+Bh//bEtgns=
+modernc.org/sortutil v1.2.1 h1:+xyoGf15mM3NMlPDnFqrteY07klSFxLElE2PVuWIJ7w=
+modernc.org/sortutil v1.2.1/go.mod h1:7ZI3a3REbai7gzCLcotuw9AC4VZVpYMjDzETGsSMqJE=
+modernc.org/sqlite v1.60.1 h1:/blz53O951KWFOso4QQvEs/Fq6cDBKLtMVrYNSeJVKw=
+modernc.org/sqlite v1.60.1/go.mod h1:1dIoEagfDE72QytD5scH1lxARtaUgKgHC/NuApA27r0=
+modernc.org/strutil v1.2.1 h1:UneZBkQA+DX2Rp35KcM69cSsNES9ly8mQWD71HKlOA0=
+modernc.org/strutil v1.2.1/go.mod h1:EHkiggD70koQxjVdSBM3JKM7k6L0FbGE5eymy9i3B9A=
+modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=
+modernc.org/token v1.1.0/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=

internal/api/admin_migrate.go

@@ -1,30 +0,0 @@
-package api
-
-import (
-	"net/http"
-)
-
-// handleMigrateDualRoots triggers the one-shot sweep that re-unifies
-// stranded midhash-rooted entries into their UUID roots. See
-// storage.MigrateDualRoots for the data-flow detail and
-// docs/api-mediated-access.md for the bug background.
-//
-// Returns {fixed: N} on success. Safe to call repeatedly — entries already
-// migrated are skipped on the next pass.
-func (s *Server) handleMigrateDualRoots(w http.ResponseWriter, r *http.Request) {
-	if !s.storage.IsConnected() {
-		writeError(w, http.StatusServiceUnavailable, "storage not connected")
-		return
-	}
-
-	fixed, err := s.storage.MigrateDualRootsWithTimeout()
-	if err != nil {
-		writeError(w, http.StatusInternalServerError, err.Error())
-		return
-	}
-
-	writeJSON(w, http.StatusOK, map[string]interface{}{
-		"success": true,
-		"fixed":   fixed,
-	})
-}

internal/api/files_register.go

@@ -0,0 +1,132 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/metazla/meta-core/internal/watcher"
+)
+
+// registerFileRequest is the body of POST /api/files/register.
+type registerFileRequest struct {
+	// Path relative to FILES_PATH, e.g. "plugin/subtitles/ab12….eng.srt".
+	Path string `json:"path"`
+}
+
+type registerFileResponse struct {
+	Root    string `json:"root"`
+	CID     string `json:"cid"`
+	Created bool   `json:"created"`
+	Path    string `json:"path"`
+	Size    int64  `json:"size"`
+}
+
+// pluginRelPath normalises a FILES_PATH-relative path and refuses anything
+// outside plugin/. Plugin output is the only tree a service may register this
+// way: /files/watch is the user's library and belongs to the watcher.
+func pluginRelPath(raw string) (string, bool) {
+	p := strings.TrimPrefix(filepath.ToSlash(strings.TrimSpace(raw)), "/")
+	if p == "" {
+		return "", false
+	}
+	for _, seg := range strings.Split(p, "/") {
+		if seg == ".." {
+			return "", false
+		}
+	}
+	clean := path.Clean(p)
+	if !strings.HasPrefix(clean, "plugin/") || clean == "plugin/" {
+		return "", false
+	}
+	return clean, true
+}
+
+// handleRegisterFile handles POST /api/files/register.
+//
+// Does for ONE file what the watcher does for every file it scans: midhash256
+// it, mint a root carrying filePath/sizeByte/mtimeNano, register the
+// cid:<midhash> alias, and append a file:events entry so meta-share's
+// ipfs_seed chunks, seeds and provides it.
+//
+// It exists for cores that run with ENABLE_FILE_WATCHER=false (a meta-watch
+// client box). Without it, bytes written under /files/plugin over WebDAV are
+// never resolvable by CID and never reach the swarm. Idempotent: the same
+// content at the same path returns the existing root with created=false.
+func (s *Server) handleRegisterFile(w http.ResponseWriter, r *http.Request) {
+	if s.storage == nil || !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+
+	var req registerFileRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	rel, ok := pluginRelPath(req.Path)
+	if !ok {
+		writeError(w, http.StatusBadRequest, "path must be a file under plugin/")
+		return
+	}
+
+	fullPath := filepath.Join(s.config.FilesPath, filepath.FromSlash(rel))
+	absFiles, _ := filepath.Abs(filepath.Join(s.config.FilesPath, "plugin"))
+	absFull, _ := filepath.Abs(fullPath)
+	if !strings.HasPrefix(absFull, absFiles+string(filepath.Separator)) {
+		writeError(w, http.StatusBadRequest, "path must be a file under plugin/")
+		return
+	}
+
+	info, err := os.Stat(fullPath)
+	if err != nil {
+		writeError(w, http.StatusNotFound, "file not found")
+		return
+	}
+	if info.IsDir() {
+		writeError(w, http.StatusBadRequest, "path is a directory, not a file")
+		return
+	}
+
+	midhash, err := watcher.ComputeMidHash256(fullPath, info.Size())
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to hash file")
+		return
+	}
+
+	root, created, err := s.storage.RegisterFileTuple(fullPath, info.Size(), info.ModTime().UnixNano(), midhash)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	if created {
+		ev := watcher.FileEvent{
+			Type:       watcher.EventTypeAdd,
+			Path:       rel,
+			Size:       info.Size(),
+			MidHash256: midhash,
+			Timestamp:  watcher.NowMS(),
+		}
+		if err := watcher.PublishEvent(s.storage, ev); err != nil {
+			// The record is written and resolvable; only seeding is late.
+			writeError(w, http.StatusInternalServerError, "registered, but file event not published: "+err.Error())
+			return
+		}
+	}
+
+	status := http.StatusOK
+	if created {
+		status = http.StatusCreated
+	}
+	writeJSON(w, status, registerFileResponse{
+		Root:    root,
+		CID:     midhash,
+		Created: created,
+		Path:    rel,
+		Size:    info.Size(),
+	})
+}

internal/api/files_register_test.go

@@ -0,0 +1,135 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/metazla/meta-core/internal/config"
+)
+
+// newRegisterTestServer wires handleRegisterFile to a temp store and a temp
+// FILES_PATH. Built directly, not through NewServer, so no watcher runs —
+// which is exactly the configuration this route exists for.
+func newRegisterTestServer(t *testing.T) (*Server, string) {
+	t.Helper()
+	files := t.TempDir()
+	return &Server{storage: newTestStorage(t), config: &config.Config{FilesPath: files}}, files
+}
+
+func writeFixture(t *testing.T, files, rel, body string) string {
+	t.Helper()
+	full := filepath.Join(files, filepath.FromSlash(rel))
+	if err := os.MkdirAll(filepath.Dir(full), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(full, []byte(body), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	return full
+}
+
+func postRegister(t *testing.T, s *Server, path string) (int, registerFileResponse) {
+	t.Helper()
+	body, _ := json.Marshal(registerFileRequest{Path: path})
+	req := httptest.NewRequest(http.MethodPost, "/api/files/register", strings.NewReader(string(body)))
+	rr := httptest.NewRecorder()
+	s.handleRegisterFile(rr, req)
+	var resp registerFileResponse
+	_ = json.Unmarshal(rr.Body.Bytes(), &resp)
+	return rr.Code, resp
+}
+
+func streamLen(t *testing.T, s *Server) int {
+	t.Helper()
+	n, err := s.storage.GetStreamLength("file:events")
+	if err != nil {
+		t.Fatalf("stream length: %v", err)
+	}
+	return int(n)
+}
+
+// The whole point of the route: with the watcher off, a file written under
+// plugin/ becomes a record resolvable by its midhash, and meta-share hears
+// about it on file:events.
+func TestRegisterFile_MintsAliasAndPublishesEvent(t *testing.T) {
+	s, files := newRegisterTestServer(t)
+	rel := "plugin/subtitles/ab12cd34.eng.srt"
+	full := writeFixture(t, files, rel, "1\n00:00:01,000 --> 00:00:02,000\nHello\n")
+
+	code, resp := postRegister(t, s, rel)
+	if code != http.StatusCreated || !resp.Created {
+		t.Fatalf("want 201 created, got %d %+v", code, resp)
+	}
+	if !strings.HasPrefix(resp.CID, "b") || resp.Root == "" {
+		t.Fatalf("want a multibase cid and a root, got %+v", resp)
+	}
+
+	root, err := s.storage.GetByCID(resp.CID)
+	if err != nil || root != resp.Root {
+		t.Fatalf("cid alias must resolve to the root: got %q err=%v, want %q", root, err, resp.Root)
+	}
+	if fp, _ := s.storage.GetProperty(resp.Root, "filePath"); fp != full {
+		t.Fatalf("filePath = %q, want %q", fp, full)
+	}
+
+	entries, err := s.storage.XRevRange("file:events", "+", "-", 0)
+	if err != nil || len(entries) != 1 {
+		t.Fatalf("want exactly one file:events entry, got %d err=%v", len(entries), err)
+	}
+	if vals := entries[0].Values; vals["midhash256"] != resp.CID || vals["path"] != rel {
+		t.Fatalf("event must carry the midhash and the relative path, got %v", vals)
+	}
+}
+
+// Re-uploading the same subtitle is a no-op: same root, no second event (which
+// would make meta-share re-chunk and re-provide the file).
+func TestRegisterFile_IsIdempotent(t *testing.T) {
+	s, files := newRegisterTestServer(t)
+	rel := "plugin/subtitles/same.eng.srt"
+	writeFixture(t, files, rel, "same bytes")
+
+	_, first := postRegister(t, s, rel)
+	code, second := postRegister(t, s, rel)
+	if code != http.StatusOK || second.Created {
+		t.Fatalf("second register must be 200 created=false, got %d %+v", code, second)
+	}
+	if second.Root != first.Root || second.CID != first.CID {
+		t.Fatalf("second register must return the same record: %+v vs %+v", second, first)
+	}
+	if n := streamLen(t, s); n != 1 {
+		t.Fatalf("an idempotent re-register must not publish again, stream has %d", n)
+	}
+}
+
+// Only plugin output may be registered here. /files/watch is the user's
+// library and belongs to the watcher; traversal must not escape either.
+func TestRegisterFile_RejectsPathsOutsidePlugin(t *testing.T) {
+	s, files := newRegisterTestServer(t)
+	writeFixture(t, files, "watch/movie.mkv", "x")
+	for _, p := range []string{
+		"", "plugin", "plugin/", "watch/movie.mkv", "/watch/movie.mkv",
+		"plugin/../watch/movie.mkv", "../etc/passwd", "plugin/../../etc/passwd",
+	} {
+		if code, _ := postRegister(t, s, p); code != http.StatusBadRequest {
+			t.Errorf("path %q: want 400, got %d", p, code)
+		}
+	}
+}
+
+func TestRegisterFile_MissingFileAndDirectory(t *testing.T) {
+	s, files := newRegisterTestServer(t)
+	if code, _ := postRegister(t, s, "plugin/subtitles/nope.srt"); code != http.StatusNotFound {
+		t.Errorf("missing file: want 404, got %d", code)
+	}
+	if err := os.MkdirAll(filepath.Join(files, "plugin", "subtitles", "dir"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if code, _ := postRegister(t, s, "plugin/subtitles/dir"); code != http.StatusBadRequest {
+		t.Errorf("directory: want 400, got %d", code)
+	}
+}

internal/api/files_tuples.go

@@ -0,0 +1,74 @@
+package api
+
+import "net/http"
+
+// fileTupleJSON is one file-backed root on the wire.
+type fileTupleJSON struct {
+	HashID    string `json:"hashId"`
+	FilePath  string `json:"filePath"`
+	SizeByte  int64  `json:"sizeByte"`
+	MtimeNano int64  `json:"mtimeNano"`
+}
+
+// FileTuplesResponse is the body of GET /api/files/tuples.
+//
+// Files is a pointer so the summary form can omit it while the full form
+// always carries it — an empty library is `"files": []`, never an absent key,
+// which a client could mistake for a meta-core that lacks the rows.
+type FileTuplesResponse struct {
+	Files     *[]fileTupleJSON `json:"files,omitempty"`
+	Count     int              `json:"count"`
+	TotalSize int64            `json:"totalSize"`
+}
+
+// handleGetFileTuples handles GET /api/files/tuples.
+//
+// Lists the FILE-BACKED roots — records carrying filePath, sizeByte and
+// mtimeNano, i.e. what the watcher or /api/files/register minted — with their
+// sizes, plus the count and total. Gateway / cid-rooted records carry no file
+// and are not included; neither is a locator record that only merged a cache
+// file's metadata (it has no mtimeNano).
+//
+// It exists so a client never walks every hashId to answer "how many files,
+// how big": GetTuplesForAllFiles reads the three fields for every root in
+// chunked MGETs server-side (~250 round-trips for 82k roots, no SCAN), where
+// the client-side equivalent was one HTTP request per record.
+//
+// ?summary=1 omits the rows and returns only {count, totalSize}.
+func (s *Server) handleGetFileTuples(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+
+	tuples, err := s.storage.GetTuplesForAllFiles()
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	summary := r.URL.Query().Get("summary")
+	withRows := summary == "" || summary == "0" || summary == "false"
+
+	resp := FileTuplesResponse{Count: len(tuples)}
+	var rows []fileTupleJSON
+	if withRows {
+		rows = make([]fileTupleJSON, 0, len(tuples))
+	}
+	for _, t := range tuples {
+		resp.TotalSize += t.Size
+		if withRows {
+			rows = append(rows, fileTupleJSON{
+				HashID:    t.HashID,
+				FilePath:  t.FilePath,
+				SizeByte:  t.Size,
+				MtimeNano: t.MtimeNano,
+			})
+		}
+	}
+	if withRows {
+		resp.Files = &rows
+	}
+
+	writeJSON(w, http.StatusOK, resp)
+}

internal/api/files_tuples_test.go

@@ -0,0 +1,108 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"sort"
+	"testing"
+
+	"github.com/metazla/meta-core/internal/storage"
+)
+
+func newFileTuplesTestServer(t *testing.T) (*Server, *storage.Client) {
+	t.Helper()
+	c := newTestStorage(t)
+	return &Server{storage: c}, c
+}
+
+func getFileTuples(t *testing.T, s *Server, query string) (int, FileTuplesResponse) {
+	t.Helper()
+	req := httptest.NewRequest(http.MethodGet, "/api/files/tuples"+query, nil)
+	rr := httptest.NewRecorder()
+	s.handleGetFileTuples(rr, req)
+	var resp FileTuplesResponse
+	_ = json.Unmarshal(rr.Body.Bytes(), &resp)
+	return rr.Code, resp
+}
+
+func mustMint(t *testing.T, c *storage.Client, path string, size, mtime int64) string {
+	t.Helper()
+	id, err := c.Mint(path, size, mtime)
+	if err != nil {
+		t.Fatalf("mint %s: %v", path, err)
+	}
+	return id
+}
+
+// Only records that are actually files count: a gateway record and a record
+// that merely carries a path + size (no mtimeNano) are both left out.
+func TestFileTuples_OnlyFileBackedRoots(t *testing.T) {
+	s, c := newFileTuplesTestServer(t)
+	a := mustMint(t, c, "/files/watch/a.mkv", 1000, 1)
+	b := mustMint(t, c, "/files/watch/b.mkv", 2500, 2)
+	if err := c.SetMetadataFlat("bagcsgatewayrecord", map[string]string{"title": "Some Release"}); err != nil {
+		t.Fatal(err)
+	}
+	if err := c.SetMetadataFlat("01partialroot", map[string]string{"filePath": "/files/cache/x.mkv", "sizeByte": "999"}); err != nil {
+		t.Fatal(err)
+	}
+
+	code, resp := getFileTuples(t, s, "")
+	if code != http.StatusOK {
+		t.Fatalf("want 200, got %d", code)
+	}
+	if resp.Count != 2 || resp.TotalSize != 3500 {
+		t.Fatalf("want count 2 / totalSize 3500, got %d / %d", resp.Count, resp.TotalSize)
+	}
+	if resp.Files == nil || len(*resp.Files) != 2 {
+		t.Fatalf("want 2 rows, got %+v", resp.Files)
+	}
+	got := []string{(*resp.Files)[0].HashID, (*resp.Files)[1].HashID}
+	want := []string{a, b}
+	sort.Strings(got)
+	sort.Strings(want)
+	if got[0] != want[0] || got[1] != want[1] {
+		t.Fatalf("want roots %v, got %v", want, got)
+	}
+}
+
+func TestFileTuples_SummaryOmitsRows(t *testing.T) {
+	s, c := newFileTuplesTestServer(t)
+	mustMint(t, c, "/files/watch/a.mkv", 1000, 1)
+	mustMint(t, c, "/files/watch/b.mkv", 2500, 2)
+
+	code, resp := getFileTuples(t, s, "?summary=1")
+	if code != http.StatusOK {
+		t.Fatalf("want 200, got %d", code)
+	}
+	if resp.Files != nil {
+		t.Fatalf("summary must omit rows, got %d", len(*resp.Files))
+	}
+	if resp.Count != 2 || resp.TotalSize != 3500 {
+		t.Fatalf("want count 2 / totalSize 3500, got %d / %d", resp.Count, resp.TotalSize)
+	}
+}
+
+// An empty library still carries "files": [] — clients treat an absent key as
+// "this meta-core cannot list files", so it must not disappear when empty.
+func TestFileTuples_EmptyLibraryKeepsFilesKey(t *testing.T) {
+	s, _ := newFileTuplesTestServer(t)
+
+	code, resp := getFileTuples(t, s, "")
+	if code != http.StatusOK {
+		t.Fatalf("want 200, got %d", code)
+	}
+	if resp.Files == nil || len(*resp.Files) != 0 || resp.Count != 0 {
+		t.Fatalf("want an empty files array and count 0, got %+v", resp)
+	}
+}
+
+func TestFileTuples_StorageNotConnected(t *testing.T) {
+	s := &Server{storage: storage.NewClient()}
+
+	code, _ := getFileTuples(t, s, "")
+	if code != http.StatusServiceUnavailable {
+		t.Fatalf("want 503, got %d", code)
+	}
+}

internal/api/handlers.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/metazla/meta-core/internal/leader"
+	"github.com/metazla/meta-core/internal/meshdisco"
 )
 
 // contentTypeByExt maps file extensions to MIME types
@@ -547,62 +548,49 @@ func (s *Server) handleGetFileByCID(w http.ResponseWriter, r *http.Request) {
 	http.ServeContent(w, r, fileInfo.Name(), fileInfo.ModTime(), file)
 }
 
-// handleListServices handles GET /services and GET /api/services
-// Supports optional ?current=<service-name> query parameter
-func (s *Server) handleListServices(w http.ResponseWriter, r *http.Request) {
-	services, err := s.discovery.DiscoverAll()
-	if err != nil {
-		writeError(w, http.StatusInternalServerError, err.Error())
-		return
-	}
-
+// handleListNeighbors handles GET /neighbors and GET /api/neighbors.
+//
+// Beacon v2 (docs/project-architecture/beacon-v2.md). The list is this node's
+// in-memory view of the UDP group, so it works across stacks that share a
+// network but no volume. Instances of one name collapse to the most recent
+// (one row per service, the nav menu's shape); `?all=1` returns every
+// instance, `?cap=<pattern>` keeps only nodes with a matching capability.
+func (s *Server) handleListNeighbors(w http.ResponseWriter, r *http.Request) {
 	response := map[string]interface{}{
-		"services": services,
-		"count":    len(services),
-	}
-
-	// Add 'current' field if query parameter is provided
-	current := r.URL.Query().Get("current")
-	if current != "" {
-		response["current"] = current
+		"current":   s.config.ServiceName,
+		"neighbors": []interface{}{},
+		"count":     0,
 	}
 
+	if s.mesh == nil {
+		// Discovery off or failed to bind. Report empty rather than 503 —
+		// the nav is decoration and callers already treat [] as "hide".
+		response["enabled"] = false
 		writeJSON(w, http.StatusOK, response)
-}
-
-// handleGetService handles GET /services/{name}
-func (s *Server) handleGetService(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
-	name := vars["name"]
-
-	if name == "" {
-		writeError(w, http.StatusBadRequest, "service name is required")
 		return
 	}
 
-	service, err := s.discovery.Discover(name)
-	if err != nil {
-		writeError(w, http.StatusInternalServerError, err.Error())
-		return
+	var list []meshdisco.Neighbor
+	if r.URL.Query().Get("all") != "" {
+		list = s.mesh.Neighbors()
+	} else {
+		list = s.mesh.NeighborsByName()
+	}
+	if pattern := r.URL.Query().Get("cap"); pattern != "" {
+		kept := list[:0]
+		for _, nb := range list {
+			if nb.Matches(pattern) {
+				kept = append(kept, nb)
+			}
+		}
+		list = kept
 	}
 
-	if service == nil {
-		writeError(w, http.StatusNotFound, "service not found")
-		return
-	}
-
-	writeJSON(w, http.StatusOK, service)
-}
-
-// handleCleanupStats handles GET /services/cleanup/stats
-func (s *Server) handleCleanupStats(w http.ResponseWriter, r *http.Request) {
-	if s.cleaner == nil {
-		writeError(w, http.StatusServiceUnavailable, "cleaner not initialized")
-		return
-	}
-
-	stats := s.cleaner.Stats()
-	writeJSON(w, http.StatusOK, stats)
+	response["enabled"] = true
+	response["neighbors"] = list
+	response["count"] = len(list)
+	response["self"] = s.mesh.Self()
+	writeJSON(w, http.StatusOK, response)
 }
 
 // writeJSON writes a JSON response

internal/api/handlers_identity.go

@@ -3,10 +3,14 @@ package api
 import (
 	"encoding/base64"
 	"encoding/json"
+	"errors"
+	"log"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"github.com/metazla/meta-core/internal/identity"
+	"github.com/metazla/meta-core/internal/storage"
 )
 
 // identityStatusResponse is the shape of GET /api/identity. The private key
@@ -58,12 +62,40 @@ type identityImportResponse struct {
 	Created bool `json:"created"`
 }
 
-// identityRevealRequest asks for an existing account's private key back. The
-// key was shown once at generate; without a way to see it again, a client with
-// a real sign-out has no recovery path for a user who never saved it.
+// identityChallengeRequest asks for a one-shot challenge to sign.
+type identityChallengeRequest struct {
+	UID    string `json:"uid"`
+	Action string `json:"action"`
+}
+
+type identityChallengeResponse struct {
+	Challenge string `json:"challenge"`
+	ExpiresAt int64  `json:"expiresAt"`
+}
+
+// identityProof is the proof-of-possession carried by reveal and delete: the
+// challenge text as issued, and a signature over it by the account's key.
+//
+// The signature is produced by whoever holds the key — the browser, locally.
+// It is NOT obtainable from POST /api/identity/sign, which refuses any payload
+// in the challenge domain; that refusal is what makes this proof mean
+// something on a node that stores every private key in plaintext.
+type identityProof struct {
+	Challenge string `json:"challenge"`
+	Signature string `json:"signature"`
+}
+
+// identityRevealRequest asks for an existing account's private key back.
+//
+// Gated on proof-of-possession, which makes it a "does this node hold the same
+// key I do" check rather than the recovery path it once was. That is the
+// deliberate consequence of the rule this file enforces: the private key, and
+// nothing else, is authority over the account. An operator with root on the box
+// can still read the file; an operator with only the API cannot.
 type identityRevealRequest struct {
 	Confirm bool   `json:"confirm"`
 	UID     string `json:"uid"`
+	identityProof
 }
 
 type identityRevealResponse struct {
@@ -75,6 +107,15 @@ type identityRevealResponse struct {
 type identityDeleteRequest struct {
 	Confirm bool   `json:"confirm"`
 	UID     string `json:"uid"`
+	identityProof
+}
+
+// identityDeleteResponse reports what the delete actually removed. The purge
+// counts are the point: "account removed" alone leaves the caller unable to
+// tell a clean removal from one that silently stranded a decade of ratings.
+type identityDeleteResponse struct {
+	UID    string               `json:"uid"`
+	Purged storage.UDLUserStats `json:"purged"`
 }
 
 type identitySignRequest struct {
@@ -88,6 +129,41 @@ type identitySignResponse struct {
 	SigB64 string `json:"sigB64"`
 }
 
+// identitySignBatchRequest signs many payloads under one account in one call.
+//
+// Exists because a User Data Layer write signs exactly one record, and the bulk
+// verbs above it ("mark this whole series seen") produce one record per episode:
+// a 300-episode show is 300 sequential sign round trips through
+// meta-watch -> meta-search -> here, which dominates the operation. The private
+// key still never leaves this process; only the transport is batched.
+type identitySignBatchRequest struct {
+	// PayloadsB64 are the canonical byte strings to sign, in order. The
+	// response's signatures line up index-for-index.
+	PayloadsB64 []string `json:"payloadsB64"`
+	// UID selects which account signs — same optional single-identity
+	// back-compat as identitySignRequest.
+	UID string `json:"uid,omitempty"`
+}
+
+type identitySignBatchResponse struct {
+	SigsB64 []string `json:"sigsB64"`
+}
+
+// maxSignBatch bounds one batch. A signature is cheap but not free, and the
+// request holds the account lock for its duration; a caller with more than this
+// should page. Sized well above the longest real series (Supernatural, 327).
+const maxSignBatch = 1000
+
+// reservedPayloadMessage explains the one refusal the signing endpoints make.
+//
+// This is the load-bearing half of proof-of-possession on a node that holds
+// every private key: without it, a caller wanting to delete someone else's
+// account just asks meta-core to sign the challenge for them, and the gate on
+// reveal/delete becomes a formality. See identity.ChallengeDomain.
+const reservedPayloadMessage = "payload is in the reserved account-authorisation domain (" +
+	identity.ChallengeDomain + "…); meta-core will not sign one. " +
+	"Signing a challenge is what proves you hold the key, so it must be done where the key is."
+
 type identityAEADKeyResponse struct {
 	AEADKeyB64 string `json:"aeadKeyB64"`
 }
@@ -217,23 +293,105 @@ func (s *Server) handleIdentityImport(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
-// handleIdentityReveal returns an existing account's private key. Deliberately
-// POST + explicit confirm (never a bare GET) so it cannot be triggered by a
-// link or an image tag, and so it reads as the deliberate act it is. The
-// endpoint is auth-gated at the perimeter like the rest of /api/identity/*.
-func (s *Server) handleIdentityReveal(w http.ResponseWriter, r *http.Request) {
-	var body identityRevealRequest
-	_ = json.NewDecoder(r.Body).Decode(&body)
-	if !body.Confirm && r.URL.Query().Get("confirm") != "true" {
-		writeErrorSlug(w, http.StatusBadRequest, "confirm_required",
-			"revealing a private key requires {\"confirm\": true} or ?confirm=true", false)
+// handleIdentityChallenge issues the one-shot text a client signs to prove it
+// holds an account's private key.
+//
+// Unauthenticated by design: a challenge is useless without the key, and
+// GET /api/identity/accounts already publishes every uid, so refusing to mint
+// one for an unknown caller would protect nothing. Requiring the account to
+// exist is for a clear error, not secrecy.
+func (s *Server) handleIdentityChallenge(w http.ResponseWriter, r *http.Request) {
+	var body identityChallengeRequest
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
 		return
 	}
 	uid := strings.TrimSpace(body.UID)
+	if uid == "" {
+		writeErrorSlug(w, http.StatusBadRequest, "uid_required", "uid is required", false)
+		return
+	}
+	action := identity.Action(strings.TrimSpace(body.Action))
+	if !identity.ValidAction(action) {
+		writeErrorSlug(w, http.StatusBadRequest, "bad_action",
+			`action must be "reveal" or "delete"`, false)
+		return
+	}
+	if !identity.ExistsByUID(s.config.IdentityAccountsDir(), uid) {
+		writeErrorSlug(w, http.StatusNotFound, "no_identity", "no identity for the given uid", false)
+		return
+	}
+	text, expires, err := s.challenges.Issue(uid, action)
+	if err != nil {
+		if errors.Is(err, identity.ErrChallengeFull) {
+			writeErrorSlug(w, http.StatusServiceUnavailable, "challenges_full", err.Error(), true)
+			return
+		}
+		writeErrorSlug(w, http.StatusBadRequest, "bad_uid", err.Error(), false)
+		return
+	}
+	writeJSON(w, http.StatusOK, identityChallengeResponse{
+		Challenge: text,
+		ExpiresAt: expires.Unix(),
+	})
+}
+
+// requireProof resolves the target account and verifies the caller's
+// proof-of-possession for `action`. status == 0 means the proof held.
+//
+// The uid is mandatory here, unlike elsewhere in this file: the old "sole
+// account" fallback would have this pick a target the signature does not name,
+// and a proof that authorises an unnamed account authorises the wrong one as
+// soon as a second profile exists.
+func (s *Server) requireProof(uid string, proof identityProof, action identity.Action) (
+	id *identity.Identity, status int, slug, msg string,
+) {
+	uid = strings.TrimSpace(uid)
+	if uid == "" {
+		return nil, http.StatusBadRequest, "uid_required",
+			"uid is required: the signature authorises one specific account"
+	}
+	if proof.Challenge == "" || proof.Signature == "" {
+		return nil, http.StatusUnauthorized, "signature_required",
+			"this operation requires proof you hold the account's private key: " +
+				"POST /api/identity/challenge, sign the returned text, and resend it as {challenge, signature}"
+	}
+	sig, err := base64.StdEncoding.DecodeString(proof.Signature)
+	if err != nil {
+		return nil, http.StatusBadRequest, "bad_signature", "signature is not valid base64"
+	}
+	// Resolve before redeeming so a request naming a missing account does not
+	// burn a challenge it could not have used anyway.
+	id, status, slug, msg = s.resolveAccount(uid)
+	if status != 0 {
+		return nil, status, slug, msg
+	}
+	// Redeem first, verify second: the challenge is single-use either way, so a
+	// wrong signature costs the attacker a fresh round trip per guess rather
+	// than letting them grind one challenge offline against the same nonce.
+	if err := s.challenges.Redeem(proof.Challenge, uid, action); err != nil {
+		return nil, http.StatusUnauthorized, "bad_challenge", err.Error()
+	}
+	if err := identity.Verify(uid, []byte(proof.Challenge), sig); err != nil {
+		return nil, http.StatusUnauthorized, "bad_signature", err.Error()
+	}
+	return id, 0, "", ""
+}
+
+// handleIdentityReveal returns an existing account's private key to a caller
+// that proves it already holds that key.
+//
+// Deliberately POST (never a bare GET) so it cannot be triggered by a link or
+// an image tag. The proof is what actually guards it: before this gate existed,
+// anything that could reach the port could read every private key on the node.
+func (s *Server) handleIdentityReveal(w http.ResponseWriter, r *http.Request) {
+	var body identityRevealRequest
+	_ = json.NewDecoder(r.Body).Decode(&body)
+	uid := strings.TrimSpace(body.UID)
 	if uid == "" {
 		uid = strings.TrimSpace(r.URL.Query().Get("uid"))
 	}
-	id, status, slug, msg := s.resolveAccount(uid)
+	id, status, slug, msg := s.requireProof(uid, body.identityProof, identity.ActionReveal)
 	if status != 0 {
 		writeErrorSlug(w, status, slug, msg, false)
 		return
@@ -245,46 +403,62 @@ func (s *Server) handleIdentityReveal(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// handleIdentityDelete removes one account and everything it wrote.
+//
+// Two things happen, in this order and no other:
+//
+//  1. the account's User Data Layer rows are purged (cells plus every index
+//     that names the uid, including the cid-scoped ones shared with other
+//     accounts);
+//  2. the keypair file is removed.
+//
+// Purge-then-delete so a failure never strands data: if the purge errors the
+// key is still on disk, the account still exists, and the caller can retry.
+// The reverse order would leave rows nobody can ever attribute, reach or
+// rewrite — the orphaning this endpoint exists to prevent.
+//
+// What deletion still does NOT do, and cannot: records already signed under
+// this uid and replicated to other peers keep verifying there. Removing a key
+// is not a recall.
 func (s *Server) handleIdentityDelete(w http.ResponseWriter, r *http.Request) {
 	var body identityDeleteRequest
-	// Tolerate empty body — confirm flag in a query param is also acceptable
-	// for shells where sending a JSON body with DELETE is awkward.
+	// Tolerate an empty body so the uid may ride in the query — meta-watch's
+	// proxy puts it there. The proof itself must be in the body: a signature in
+	// a URL ends up in every access log between here and the browser.
 	_ = json.NewDecoder(r.Body).Decode(&body)
-	if !body.Confirm && r.URL.Query().Get("confirm") != "true" {
-		writeErrorSlug(w, http.StatusBadRequest, "confirm_required",
-			"identity deletion requires {\"confirm\": true} or ?confirm=true", false)
-		return
-	}
-	dir := s.config.IdentityAccountsDir()
 	uid := strings.TrimSpace(body.UID)
 	if uid == "" {
 		uid = strings.TrimSpace(r.URL.Query().Get("uid"))
 	}
-	if uid == "" {
-		// Back-compat: with no uid, delete the sole account. Ambiguous (and so
-		// refused) once more than one account exists.
-		list, err := identity.List(dir)
+	id, status, slug, msg := s.requireProof(uid, body.identityProof, identity.ActionDelete)
+	if status != 0 {
+		writeErrorSlug(w, status, slug, msg, false)
+		return
+	}
+
+	// A purge needs storage. Refusing here — rather than deleting the key and
+	// reporting the purge as "0 records" — is the difference between a retry
+	// and permanent orphaned data: once the key is gone the account cannot be
+	// named for a second attempt through this API.
+	if !s.storage.IsConnected() {
+		writeErrorSlug(w, http.StatusServiceUnavailable, "storage_unavailable",
+			"storage is not connected; refusing to delete the key while its data cannot be purged", true)
+		return
+	}
+	purged, err := s.storage.UDLPurgeUser(id.UID)
 	if err != nil {
-			writeError(w, http.StatusInternalServerError, err.Error())
+		writeErrorSlug(w, http.StatusInternalServerError, "purge_failed",
+			"could not purge this account's data; the account was NOT deleted: "+err.Error(), true)
 		return
 	}
-		switch len(list) {
-		case 0:
-			w.WriteHeader(http.StatusNoContent) // idempotent
-			return
-		case 1:
-			uid = list[0].UID
-		default:
-			writeErrorSlug(w, http.StatusBadRequest, "uid_required",
-				"multiple accounts exist; specify uid to delete", false)
+
+	if err := identity.DeleteByUID(s.config.IdentityAccountsDir(), id.UID); err != nil {
+		writeErrorSlug(w, http.StatusInternalServerError, "delete_failed", err.Error(), false)
 		return
 	}
-	}
-	if err := identity.DeleteByUID(dir, uid); err != nil {
-		writeError(w, http.StatusInternalServerError, err.Error())
-		return
-	}
-	w.WriteHeader(http.StatusNoContent)
+	log.Printf("[API] Deleted account %s and purged %d User Data Layer records across %d cids",
+		id.UID, purged.Records, purged.Cids)
+	writeJSON(w, http.StatusOK, identityDeleteResponse{UID: id.UID, Purged: purged})
 }
 
 func (s *Server) handleIdentitySign(w http.ResponseWriter, r *http.Request) {
@@ -307,6 +481,10 @@ func (s *Server) handleIdentitySign(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusBadRequest, "bytesB64 is not valid base64")
 		return
 	}
+	if identity.IsChallengePayload(raw) {
+		writeErrorSlug(w, http.StatusForbidden, "reserved_payload", reservedPayloadMessage, false)
+		return
+	}
 	sig, err := identity.Sign(id, raw)
 	if err != nil {
 		writeError(w, http.StatusInternalServerError, err.Error())
@@ -317,6 +495,58 @@ func (s *Server) handleIdentitySign(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// handleIdentitySignBatch signs every payload in the request under one account.
+//
+// All-or-nothing: a single bad base64 or signing failure fails the whole
+// request rather than returning a short array. The caller pairs signatures with
+// records by index, so a partial response would silently misalign them — and a
+// misaligned signature verifies against the wrong record, which is worse than
+// an error.
+func (s *Server) handleIdentitySignBatch(w http.ResponseWriter, r *http.Request) {
+	var body identitySignBatchRequest
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	uid := body.UID
+	if strings.TrimSpace(uid) == "" {
+		uid = r.URL.Query().Get("uid")
+	}
+	if len(body.PayloadsB64) == 0 {
+		writeError(w, http.StatusBadRequest, "payloadsB64 is required")
+		return
+	}
+	if len(body.PayloadsB64) > maxSignBatch {
+		writeError(w, http.StatusBadRequest, "too many payloads in one batch")
+		return
+	}
+	id, status, slug, msg := s.resolveAccount(uid)
+	if status != 0 {
+		writeErrorSlug(w, status, slug, msg, false)
+		return
+	}
+	sigs := make([]string, 0, len(body.PayloadsB64))
+	for i, p := range body.PayloadsB64 {
+		raw, err := base64.StdEncoding.DecodeString(p)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "payloadsB64["+strconv.Itoa(i)+"] is not valid base64")
+			return
+		}
+		if identity.IsChallengePayload(raw) {
+			writeErrorSlug(w, http.StatusForbidden, "reserved_payload",
+				"payloadsB64["+strconv.Itoa(i)+"]: "+reservedPayloadMessage, false)
+			return
+		}
+		sig, err := identity.Sign(id, raw)
+		if err != nil {
+			writeError(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+		sigs = append(sigs, base64.StdEncoding.EncodeToString(sig))
+	}
+	writeJSON(w, http.StatusOK, identitySignBatchResponse{SigsB64: sigs})
+}
+
 func (s *Server) handleIdentityAEADKey(w http.ResponseWriter, r *http.Request) {
 	id, status, slug, msg := s.resolveAccount(r.URL.Query().Get("uid"))
 	if status != 0 {

internal/api/identity_gate_test.go

@@ -0,0 +1,250 @@
+package api
+
+// End-to-end exercise of the account gate against a live router + a temp store:
+// generate -> write UDL rows -> stats -> challenge -> sign -> delete -> verify
+// both the key and every row are gone. Deliberately drives the real HTTP
+// handlers rather than the packages beneath them, because the bugs that matter
+// here (a challenge accepted for the wrong action, a purge that runs after the
+// key is gone) live in the wiring.
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gorilla/mux"
+	"github.com/metazla/meta-core/internal/config"
+	"github.com/metazla/meta-core/internal/identity"
+)
+
+func newTestServer(t *testing.T) *Server {
+	t.Helper()
+	stor := newTestStorage(t)
+
+	s := &Server{
+		config:     &config.Config{MetaCorePath: t.TempDir()},
+		storage:    stor,
+		challenges: identity.NewChallengeStore(),
+		router:     mux.NewRouter(),
+	}
+	s.setupIdentityTestRoutes()
+	return s
+}
+
+// Only the routes under test, so this does not depend on every other subsystem
+// booting.
+func (s *Server) setupIdentityTestRoutes() {
+	s.router.HandleFunc("/api/identity/accounts", s.handleIdentityAccounts).Methods("GET")
+	s.router.HandleFunc("/api/identity/challenge", s.handleIdentityChallenge).Methods("POST")
+	s.router.HandleFunc("/api/identity/generate", s.handleIdentityGenerate).Methods("POST")
+	s.router.HandleFunc("/api/identity/reveal", s.handleIdentityReveal).Methods("POST")
+	s.router.HandleFunc("/api/identity", s.handleIdentityDelete).Methods("DELETE")
+	s.router.HandleFunc("/api/identity/sign", s.handleIdentitySign).Methods("POST")
+	s.router.HandleFunc("/api/udl/users/stats", s.handleUDLUserStats).Methods("GET")
+}
+
+func do(t *testing.T, s *Server, method, path string, body any) (*httptest.ResponseRecorder, map[string]any) {
+	t.Helper()
+	var rdr *bytes.Reader
+	if body != nil {
+		b, _ := json.Marshal(body)
+		rdr = bytes.NewReader(b)
+	} else {
+		rdr = bytes.NewReader(nil)
+	}
+	req := httptest.NewRequest(method, path, rdr)
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	s.router.ServeHTTP(rec, req)
+	out := map[string]any{}
+	_ = json.Unmarshal(rec.Body.Bytes(), &out)
+	return rec, out
+}
+
+// signAs produces the proof a browser would, from the raw key.
+func signAs(t *testing.T, privHex, challenge string) map[string]any {
+	t.Helper()
+	raw, err := hex.DecodeString(privHex)
+	if err != nil {
+		t.Fatalf("decode key: %v", err)
+	}
+	id, err := identity.Import(hex.EncodeToString(raw))
+	if err != nil {
+		t.Fatalf("import: %v", err)
+	}
+	sig, err := identity.Sign(id, []byte(challenge))
+	if err != nil {
+		t.Fatalf("sign: %v", err)
+	}
+	return map[string]any{
+		"challenge": challenge,
+		"signature": base64.StdEncoding.EncodeToString(sig),
+	}
+}
+
+func TestE2E_DeleteRequiresProofAndPurgesEverything(t *testing.T) {
+	s := newTestServer(t)
+
+	rec, gen := do(t, s, "POST", "/api/identity/generate", nil)
+	if rec.Code != http.StatusCreated {
+		t.Fatalf("generate: %d %s", rec.Code, rec.Body)
+	}
+	uid := gen["uid"].(string)
+	priv := gen["privateKeyHex"].(string)
+
+	// Some data to lose.
+	for _, cell := range [][2]string{{"cidA", "like"}, {"cidA", "rating"}, {"cidB", "seek"}} {
+		if ok, err := s.storage.UDLUpsertIfNewer(uid, cell[0], cell[1], 1, 100, "rec", "", false, false); err != nil || !ok {
+			t.Fatalf("seed: %v", err)
+		}
+	}
+
+	// The count the UI shows in the confirmation.
+	rec, stats := do(t, s, "GET", "/api/udl/users/stats", nil)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("stats: %d %s", rec.Code, rec.Body)
+	}
+	users := stats["users"].(map[string]any)
+	mine := users[uid].(map[string]any)
+	if mine["records"].(float64) != 3 || mine["cids"].(float64) != 2 {
+		t.Fatalf("stats = %v, want 3 records / 2 cids", mine)
+	}
+
+	// Unsigned delete must be refused, and must not have touched anything.
+	rec, body := do(t, s, "DELETE", "/api/identity", map[string]any{"uid": uid, "confirm": true})
+	if rec.Code != http.StatusUnauthorized || body["error"] != "signature_required" {
+		t.Fatalf("unsigned delete = %d %v, want 401 signature_required", rec.Code, body)
+	}
+	if !identity.ExistsByUID(s.config.IdentityAccountsDir(), uid) {
+		t.Fatal("a refused delete removed the key anyway")
+	}
+
+	// meta-core must refuse to sign the caller's authorisation for them —
+	// without this the gate is decoration on a node holding every key.
+	ch, _, err := s.challenges.Issue(uid, identity.ActionDelete)
+	if err != nil {
+		t.Fatalf("issue: %v", err)
+	}
+	rec, body = do(t, s, "POST", "/api/identity/sign", map[string]any{
+		"uid":      uid,
+		"bytesB64": base64.StdEncoding.EncodeToString([]byte(ch)),
+	})
+	if rec.Code != http.StatusForbidden || body["error"] != "reserved_payload" {
+		t.Fatalf("sign of a challenge = %d %v, want 403 reserved_payload", rec.Code, body)
+	}
+
+	// A challenge minted for reveal must not authorise a delete.
+	rec, chBody := do(t, s, "POST", "/api/identity/challenge", map[string]any{"uid": uid, "action": "reveal"})
+	if rec.Code != http.StatusOK {
+		t.Fatalf("challenge: %d %s", rec.Code, rec.Body)
+	}
+	proof := signAs(t, priv, chBody["challenge"].(string))
+	req := map[string]any{"uid": uid, "confirm": true}
+	for k, v := range proof {
+		req[k] = v
+	}
+	rec, body = do(t, s, "DELETE", "/api/identity", req)
+	if rec.Code != http.StatusUnauthorized {
+		t.Fatalf("reveal challenge used for delete = %d %v, want 401", rec.Code, body)
+	}
+
+	// The real thing.
+	rec, chBody = do(t, s, "POST", "/api/identity/challenge", map[string]any{"uid": uid, "action": "delete"})
+	if rec.Code != http.StatusOK {
+		t.Fatalf("challenge: %d %s", rec.Code, rec.Body)
+	}
+	proof = signAs(t, priv, chBody["challenge"].(string))
+	req = map[string]any{"uid": uid, "confirm": true}
+	for k, v := range proof {
+		req[k] = v
+	}
+	rec, body = do(t, s, "DELETE", "/api/identity", req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("signed delete = %d %s", rec.Code, rec.Body)
+	}
+	purged := body["purged"].(map[string]any)
+	if purged["records"].(float64) != 3 || purged["cids"].(float64) != 2 {
+		t.Fatalf("purged = %v, want 3 records / 2 cids", purged)
+	}
+
+	// Key gone.
+	if identity.ExistsByUID(s.config.IdentityAccountsDir(), uid) {
+		t.Fatal("the account file survived the delete")
+	}
+	// Data gone — the orphaning this whole change exists to prevent.
+	after, err := s.storage.UDLAllUserStats()
+	if err != nil {
+		t.Fatalf("stats after: %v", err)
+	}
+	if got, present := after[uid]; present {
+		t.Fatalf("deleted account still holds %+v", got)
+	}
+	for _, cid := range []string{"cidA", "cidB"} {
+		uids, err := s.storage.UDLCidUsers(cid)
+		if err != nil {
+			t.Fatalf("cid users: %v", err)
+		}
+		if len(uids) != 0 {
+			t.Fatalf("%s still names %v after the purge", cid, uids)
+		}
+	}
+
+	// The challenge is single-use, so replaying the same proof does nothing.
+	rec, _ = do(t, s, "DELETE", "/api/identity", req)
+	if rec.Code == http.StatusOK {
+		t.Fatal("a replayed proof must not succeed")
+	}
+}
+
+func TestE2E_RevealRequiresProof(t *testing.T) {
+	s := newTestServer(t)
+	_, gen := do(t, s, "POST", "/api/identity/generate", nil)
+	uid := gen["uid"].(string)
+	priv := gen["privateKeyHex"].(string)
+
+	rec, body := do(t, s, "POST", "/api/identity/reveal", map[string]any{"uid": uid, "confirm": true})
+	if rec.Code != http.StatusUnauthorized || body["error"] != "signature_required" {
+		t.Fatalf("unsigned reveal = %d %v, want 401 signature_required", rec.Code, body)
+	}
+
+	_, chBody := do(t, s, "POST", "/api/identity/challenge", map[string]any{"uid": uid, "action": "reveal"})
+	proof := signAs(t, priv, chBody["challenge"].(string))
+	req := map[string]any{"uid": uid, "confirm": true}
+	for k, v := range proof {
+		req[k] = v
+	}
+	rec, body = do(t, s, "POST", "/api/identity/reveal", req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("signed reveal = %d %s", rec.Code, rec.Body)
+	}
+	if body["privateKeyHex"] != priv {
+		t.Fatal("reveal returned a different key than generate did")
+	}
+}
+
+// Another account's key must not authorise this one, even with a challenge
+// minted for the right uid and action.
+func TestE2E_AnotherAccountsKeyIsRefused(t *testing.T) {
+	s := newTestServer(t)
+	_, alice := do(t, s, "POST", "/api/identity/generate", nil)
+	_, mallory := do(t, s, "POST", "/api/identity/generate", nil)
+
+	uid := alice["uid"].(string)
+	_, chBody := do(t, s, "POST", "/api/identity/challenge", map[string]any{"uid": uid, "action": "delete"})
+	proof := signAs(t, mallory["privateKeyHex"].(string), chBody["challenge"].(string))
+	req := map[string]any{"uid": uid, "confirm": true}
+	for k, v := range proof {
+		req[k] = v
+	}
+	rec, body := do(t, s, "DELETE", "/api/identity", req)
+	if rec.Code != http.StatusUnauthorized || body["error"] != "bad_signature" {
+		t.Fatalf("mallory deleting alice = %d %v, want 401 bad_signature", rec.Code, body)
+	}
+	if !identity.ExistsByUID(s.config.IdentityAccountsDir(), uid) {
+		t.Fatal("alice's account was deleted by mallory's signature")
+	}
+}

internal/api/metadata.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"net/http"
 	"strconv"
-	"strings"
 
 	"github.com/gorilla/mux"
 )
@@ -39,6 +38,36 @@ type MetadataSearchRequest struct {
 	Property      string `json:"property,omitempty"`
 	PropertyValue string `json:"propertyValue,omitempty"`
 	Limit         int    `json:"limit,omitempty"`
+
+	// Filters is the structured form: AND across entries, OR within an
+	// entry's Values. Narrowed in SQL through the field index alongside the
+	// free-text Query, then verified per record (see serveIndexedSearch), so an
+	// id-anchored lookup costs an index probe rather than a read per record.
+	//
+	// Property/PropertyValue is the single-filter legacy shape and folds into
+	// this list (see normalizedFilters) with Exact=false, preserving its
+	// substring semantics byte-for-byte.
+	Filters []MetadataFilter `json:"filters,omitempty"`
+}
+
+// MetadataFilter is one structured constraint on a record.
+//
+// A record satisfies it when ANY of Values matches, and a search result must
+// satisfy EVERY filter (OR within, AND across). An entry with no usable value
+// constrains nothing — same rule the gateway's `genres_filter_matches` uses, so
+// a caller that lowers an empty filter doesn't accidentally empty the result.
+type MetadataFilter struct {
+	// Property is the field name, WITHOUT a key-set suffix: `genres`, not
+	// `genres/Action`. Both storage shapes are probed — see recordMatchesFilter.
+	Property string `json:"property"`
+	// Values are OR'd. Compared case-insensitively.
+	Values []string `json:"values,omitempty"`
+	// Exact selects CSV-exact comparison (the semantics meta-gateway's
+	// `any_csv_value_matches` applies at its own Layer-B re-filter) over
+	// substring containment. Callers doing identity lookups want this: with a
+	// result limit, a substring match on `tmdbid=1405` also admits `21405` and
+	// can crowd the real matches out of the page.
+	Exact bool `json:"exact,omitempty"`
 }
 
 // MetadataSearchResult is a single search result
@@ -415,65 +444,17 @@ func (s *Server) handleSearchMetadata(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Free-text query: served from the in-memory search index (search_index.go)
-	// so we match in memory instead of doing a SCAN+MGET Redis round-trip per
-	// record (that was 40s+ over ~72k records). Full metadata is fetched only
-	// for the <=limit matches.
-	if req.Query != "" && req.Property == "" {
+	// Everything else — free text, structured filters, both, or neither
+	// (which returns the first `limit`) — is served from the store's derived
+	// search indexes (search_index.go → storage.Search).
+	//
+	// There is deliberately no second path. The property branch used to fall
+	// through to a `GetAllHashIDs` + per-record `GetMetadataFlat` scan, which
+	// is what made an id-anchored lookup 3.63s over ~20k records (vs 10ms for
+	// the free-text branch on the same corpus) and kept meta-core out of the
+	// gateway's anchored search path entirely. The index already holds every
+	// field of every record, so that scan was re-reading data it had in hand.
 	s.serveIndexedSearch(w, req)
-		return
-	}
-
-	// Property filter (rare) or empty query (returns the first `limit`): the
-	// legacy scan. Empty query only fetches `limit` records; property search is
-	// low-volume and not on the hot search path.
-	allHashIDs, err := s.storage.GetAllHashIDs()
-	if err != nil {
-		writeError(w, http.StatusInternalServerError, err.Error())
-		return
-	}
-
-	var results []MetadataSearchResult
-	total := len(allHashIDs)
-
-	for _, hashID := range allHashIDs {
-		if len(results) >= req.Limit {
-			break
-		}
-
-		metadata, err := s.storage.GetMetadataFlat(hashID)
-		if err != nil || metadata == nil {
-			continue
-		}
-
-		matches := false
-
-		// Property search
-		if req.Property != "" && req.PropertyValue != "" {
-			value, ok := metadata[req.Property]
-			if ok && strings.Contains(strings.ToLower(value), strings.ToLower(req.PropertyValue)) {
-				matches = true
-			}
-		}
-
-		// If no query or property filter, return all
-		if req.Query == "" && req.Property == "" {
-			matches = true
-		}
-
-		if matches {
-			results = append(results, MetadataSearchResult{
-				HashID:   hashID,
-				Metadata: metadata,
-			})
-		}
-	}
-
-	writeJSON(w, http.StatusOK, MetadataSearchResponse{
-		Results: results,
-		Count:   len(results),
-		Total:   total,
-	})
 }
 
 // handleBatchUpdate handles POST /api/metadata/batch

internal/api/schema_handlers.go

@@ -3,10 +3,10 @@ package api
 import (
 	"encoding/json"
 	"net/http"
-	"time"
 )
 
-// handleSchemaGet returns the live per-field schema derived from meta:events.
+// handleSchemaGet returns the per-field schema (recomputed from the store every
+// few minutes; see schema.Indexer).
 func (s *Server) handleSchemaGet(w http.ResponseWriter, r *http.Request) {
 	if s.schemaIndexer == nil {
 		http.Error(w, "schema indexer not running", http.StatusServiceUnavailable)
@@ -17,29 +17,26 @@ func (s *Server) handleSchemaGet(w http.ResponseWriter, r *http.Request) {
 	_ = json.NewEncoder(w).Encode(snap)
 }
 
-// handleSchemaRescan re-emits a set event for every existing property via the
-// meta publisher, waits for the indexer to drain, and returns the refreshed
-// schema. Equivalent to a full SCAN-based rebuild without locking Redis.
+// handleSchemaRescan recomputes the schema from a full scan of the store and
+// returns it. It no longer republishes every property into meta:events — the
+// indexer reads the store itself — so a rescan floods no consumer.
 func (s *Server) handleSchemaRescan(w http.ResponseWriter, r *http.Request) {
 	if s.schemaIndexer == nil {
 		http.Error(w, "schema indexer not running", http.StatusServiceUnavailable)
 		return
 	}
 
-	count, err := s.RepublishMetadata()
+	snap, err := s.schemaIndexer.Rebuild(r.Context())
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-
-	s.schemaIndexer.WaitForDrain(10 * time.Second)
-
-	snap := s.schemaIndexer.Snapshot()
-	snap.Source = "rescan"
+	out := *snap
+	out.Source = "rescan"
 
 	w.Header().Set("Content-Type", "application/json")
 	_ = json.NewEncoder(w).Encode(map[string]any{
-		"published_events": count,
-		"schema":           snap,
+		"published_events": 0,
+		"schema":           &out,
 	})
 }

internal/api/search_filter_test.go

@@ -0,0 +1,211 @@
+package api
+
+import "testing"
+
+// Tests for the structured-filter matcher that lets meta-core answer an
+// id-anchored query from the in-memory search index (search_index.go).
+//
+// Why this matters beyond "filters work": meta-core is a *coarse pre-filter*
+// for meta-gateway, which re-evaluates every record it emits through its own
+// `query_eval::record_matches`. So the property that has to hold is that this
+// matcher stays a SUPERSET of that one — it may admit records the gateway will
+// drop, but it must never drop a record the gateway would have kept. Every
+// case below is written from that angle:
+//
+//   - key-set fields (`genres/Action`) must match a `genres:action` filter, or
+//     card-tier records vanish from a genre-scoped query;
+//   - a missing field fails CLOSED, matching record_matches;
+//   - an empty/unusable filter constrains NOTHING, so a caller that lowers a
+//     blank filter gets its results rather than an empty page.
+
+func f(property string, exact bool, values ...string) MetadataFilter {
+	return MetadataFilter{Property: property, Values: values, Exact: exact}
+}
+
+func TestRecordMatchesFilter(t *testing.T) {
+	fields := map[string]string{
+		"fileType":               "video",
+		"videoType":              "tv,anime",
+		"tmdbid":                 "1405",
+		"genres/Action":          "true",
+		"genres/Science Fiction": "true",
+		"source/gateway:nyaa.si": "true",
+		"categories/XXX":         "true",
+		"retracted":              "false",
+	}
+
+	cases := []struct {
+		name   string
+		filter MetadataFilter
+		want   bool
+	}{
+		// Flat scalar.
+		{"flat exact hit", f("fileType", true, "video"), true},
+		{"flat exact miss", f("fileType", true, "audio"), false},
+		{"flat exact is case-insensitive", f("fileType", true, "VIDEO"), true},
+
+		// csv-set field: each comma piece is compared independently.
+		{"csv member hit", f("videoType", true, "anime"), true},
+		{"csv member miss", f("videoType", true, "movie"), false},
+
+		// Exact vs contains — the reason Exact exists. A substring match on an
+		// identity field admits neighbours and, under a result limit, crowds
+		// the real matches off the page.
+		{"contains admits a superstring", f("tmdbid", false, "140"), true},
+		{"exact rejects a superstring", f("tmdbid", true, "140"), false},
+		{"exact accepts the whole value", f("tmdbid", true, "1405"), true},
+
+		// Key-set shape. The stored member is verbatim (`genres/Action`) while
+		// query values arrive lowercased, so the case-insensitive sweep is what
+		// makes a genre-scoped row work at all.
+		{"key-set exact casing", f("genres", true, "Action"), true},
+		{"key-set lowercased query", f("genres", true, "action"), true},
+		{"key-set with a space", f("genres", true, "science fiction"), true},
+		{"key-set miss", f("genres", true, "horror"), false},
+		{"key-set label containing a colon", f("source", true, "gateway:nyaa.si"), true},
+
+		// OR within one filter's values.
+		{"or hits on the second value", f("fileType", true, "audio", "video"), true},
+		{"or misses on all values", f("fileType", true, "audio", "image"), false},
+
+		// Fail-closed on an absent field — mirrors record_matches, and is what
+		// keeps a filtered query from returning unrelated records.
+		{"absent field fails closed", f("imdbid", true, "tt0903747"), false},
+
+		// A filter that constrains nothing must not empty the result.
+		{"no values constrains nothing", f("fileType", true), true},
+		{"blank value constrains nothing", f("fileType", true, "  "), true},
+		{"no property constrains nothing", f("", true, "video"), true},
+
+		// A FLAT field whose value happens to be "false" is still a value, and
+		// an exact filter for it matches. Only the key-set arm treats "false"
+		// as non-membership (pinned in the test below).
+		{"flat field valued false still matches", f("retracted", true, "false"), true},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := recordMatchesFilter(fields, &tc.filter); got != tc.want {
+				t.Fatalf("recordMatchesFilter(%+v) = %v, want %v", tc.filter, got, tc.want)
+			}
+		})
+	}
+}
+
+// `retracted = "false"` is a flat field, not a key-set member, so the flat arm
+// legitimately matches the literal string "false". The key-set arm is what must
+// treat it as non-membership — pinned separately so the two arms don't get
+// conflated if either is refactored.
+func TestFalseyKeySetMemberIsNotMembership(t *testing.T) {
+	fields := map[string]string{"genres/Action": "false", "genres/Drama": "0"}
+	for _, v := range []string{"Action", "Drama"} {
+		filter := f("genres", true, v)
+		if recordMatchesFilter(fields, &filter) {
+			t.Fatalf("genres/%s with a falsey value must not assert membership", v)
+		}
+	}
+}
+
+func TestRecordMatchesFiltersIsAndAcrossEntries(t *testing.T) {
+	fields := map[string]string{"fileType": "video", "season": "2"}
+
+	all := []MetadataFilter{f("fileType", true, "video"), f("season", true, "2")}
+	if !recordMatchesFilters(fields, all) {
+		t.Fatal("a record satisfying every filter must match")
+	}
+
+	one := []MetadataFilter{f("fileType", true, "video"), f("season", true, "3")}
+	if recordMatchesFilters(fields, one) {
+		t.Fatal("filters are AND across entries — one miss must reject the record")
+	}
+
+	if !recordMatchesFilters(fields, nil) {
+		t.Fatal("no filters must match everything")
+	}
+}
+
+// The legacy Property/PropertyValue pair keeps its substring semantics: it is
+// the shape existing callers already use, and tightening it silently would
+// change results for them. New callers pass Filters and opt into Exact.
+func TestNormalizedFiltersFoldsTheLegacyPair(t *testing.T) {
+	got := normalizedFilters(MetadataSearchRequest{Property: "tmdbid", PropertyValue: "1405"})
+	if len(got) != 1 {
+		t.Fatalf("legacy pair must fold into exactly one filter, got %d", len(got))
+	}
+	if got[0].Property != "tmdbid" || len(got[0].Values) != 1 || got[0].Values[0] != "1405" {
+		t.Fatalf("legacy pair folded incorrectly: %+v", got[0])
+	}
+	if got[0].Exact {
+		t.Fatal("the legacy pair must stay substring (Exact=false) for compatibility")
+	}
+
+	// A half-specified pair is not a filter — it must not become one that
+	// matches nothing and empties the response.
+	if n := len(normalizedFilters(MetadataSearchRequest{Property: "tmdbid"})); n != 0 {
+		t.Fatalf("a property with no value must not fold into a filter, got %d", n)
+	}
+	if n := len(normalizedFilters(MetadataSearchRequest{PropertyValue: "1405"})); n != 0 {
+		t.Fatalf("a value with no property must not fold into a filter, got %d", n)
+	}
+
+	both := normalizedFilters(MetadataSearchRequest{
+		Property:      "tmdbid",
+		PropertyValue: "1405",
+		Filters:       []MetadataFilter{f("fileType", true, "video")},
+	})
+	if len(both) != 2 {
+		t.Fatalf("the legacy pair must be appended to explicit filters, got %d", len(both))
+	}
+}
+
+// The acceptance bar for routing the anchored path through the index: a
+// full-miss filtered sweep over a realistic corpus must stay in the same class
+// as the free-text branch (measured 10 ms over 19 622 live records), not the
+// legacy per-record Redis scan it replaces (measured 3.63 s over the same
+// corpus). Full-miss is the worst case — the loop cannot short-circuit on the
+// result limit, so every record is evaluated.
+//
+// Run: go test ./internal/api/ -bench BenchmarkFilterSweep -benchtime 10x
+func BenchmarkFilterSweep(b *testing.B) {
+	const records = 20000
+	corpus := make([]map[string]string, records)
+	for i := range corpus {
+		corpus[i] = map[string]string{
+			"title":                  "Some Release",
+			"fileType":               "video",
+			"videoType":              "tv",
+			"tmdbid":                 "1405",
+			"season":                 "2",
+			"genres/Action":          "true",
+			"genres/Drama":           "true",
+			"source/gateway:nyaa.si": "true",
+			"categories/TV/Anime":    "true",
+			"indexer":                "nyaa.si",
+			"fileName":               "some.release.s02e05.mkv",
+			"description/eng":        "text",
+			"poster":                 "bafy",
+			"sizeByte":               "123456789",
+			"contentKind":            "episode",
+			"anchoredBy/tmdb:1405":   "true",
+		}
+	}
+	// A miss on the identity field: the shape an id-anchored gateway query
+	// takes, and the one that must not degrade.
+	filters := []MetadataFilter{
+		f("tmdbid", true, "999999"),
+		f("fileType", true, "video"),
+		f("genres", true, "action"),
+	}
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		hits := 0
+		for _, fields := range corpus {
+			if recordMatchesFilters(fields, filters) {
+				hits++
+			}
+		}
+		if hits != 0 {
+			b.Fatalf("expected a full miss, got %d hits", hits)
+		}
+	}
+}

internal/api/search_index.go

@@ -1,100 +1,59 @@
 package api
 
 import (
-	"log"
 	"net/http"
 	"strings"
-	"sync"
-	"sync/atomic"
-	"time"
 
 	"github.com/metazla/meta-core/internal/storage"
 )
 
-// searchIndexRefreshInterval is how often the in-memory search index is rebuilt
-// from Redis in the background. Records ingest continuously, so a newly stored
-// record becomes searchable within one interval; the rebuild is a single
-// batched bulk read (storage.GetSearchIndexTuples), off the request path.
-const searchIndexRefreshInterval = 60 * time.Second
-
-// searchIndex is an in-memory snapshot of every record's search haystack
-// (hashID + lowercased searchable fields), rebuilt periodically from Redis. It
-// exists so POST /api/metadata/search matches in memory (string ops over a
-// slice) instead of doing a SCAN+MGET Redis round-trip per record — the latter
-// took 40s+ over ~72k records and made a live parallel search path unusable.
-type searchIndex struct {
-	mu     sync.RWMutex
-	tuples []storage.SearchTuple
-	ready  atomic.Bool
-}
-
-// snapshot returns the current tuples slice and whether the index has built at
-// least once. The refresh swaps in a fresh slice under the write lock (never
-// mutates in place), so the returned slice is safe to read lock-free.
-func (idx *searchIndex) snapshot() ([]storage.SearchTuple, bool) {
-	idx.mu.RLock()
-	defer idx.mu.RUnlock()
-	return idx.tuples, idx.ready.Load()
-}
-
-// refresh rebuilds the index from Redis once (a batched bulk read).
-func (idx *searchIndex) refresh(stor *storage.Client) {
-	if stor == nil || !stor.IsConnected() {
-		return
-	}
-	tuples, err := stor.GetSearchIndexTuples()
-	if err != nil {
-		log.Printf("[API] search index refresh failed: %v", err)
-		return
-	}
-	idx.mu.Lock()
-	idx.tuples = tuples
-	idx.mu.Unlock()
-	idx.ready.Store(true)
-}
-
-// runRefreshLoop builds the index immediately, then rebuilds on a ticker for the
-// process lifetime.
-func (idx *searchIndex) runRefreshLoop(stor *storage.Client) {
-	idx.refresh(stor)
-	ticker := time.NewTicker(searchIndexRefreshInterval)
-	defer ticker.Stop()
-	for range ticker.C {
-		idx.refresh(stor)
-	}
-}
-
-// serveIndexedSearch answers a free-text (non-property) query from the in-memory
-// index: token-AND match against each record's haystack (or a whole-query hashID
-// substring, preserving the legacy behaviour), then fetch full metadata for only
-// the <=limit matches. No Redis round-trip per scanned record.
+// serveIndexedSearch answers a search from the database's derived indexes
+// (storage.Search): SQL narrows to a superset of candidates through the field
+// expression index and the FTS5 trigram table, then every candidate is checked
+// here with the exact matchers below — a token-AND match against the record's
+// haystack (or a whole-query hashID substring, preserving the legacy
+// behaviour) AND every structured filter.
+//
+// Until 2026-10 this ran against an in-memory copy of every record, rebuilt
+// from Redis; that copy cost ~30 KB of RAM per record (5.1 GB on watch.nsl.sh)
+// and is gone. The matchers did not change, so neither did the semantics.
+//
+// This is the ONLY search path. Free text, filters, both, or neither all land
+// here; only the `hashId` exact-match branch in handleSearchMetadata bypasses it.
 func (s *Server) serveIndexedSearch(w http.ResponseWriter, req MetadataSearchRequest) {
-	tuples, ready := s.search.snapshot()
-	if !ready {
-		// First call before the background build finished: warm inline with the
-		// efficient batched read (seconds), never the per-record SCAN fallback.
-		s.search.refresh(s.storage)
-		tuples, _ = s.search.snapshot()
-	}
 	tokens := strings.Fields(strings.ToLower(req.Query))
 	queryLower := strings.ToLower(req.Query)
-	results := make([]MetadataSearchResult, 0, req.Limit)
-	for _, t := range tuples {
-		if len(results) >= req.Limit {
-			break
+	filters := normalizedFilters(req)
+
+	narrow := make([]storage.SearchFilter, 0, len(filters))
+	for _, f := range filters {
+		narrow = append(narrow, storage.SearchFilter{Property: f.Property, Values: f.Values})
 	}
-		if !matchAllTokens(t.Haystack, tokens) &&
-			!strings.Contains(strings.ToLower(t.HashID), queryLower) {
-			continue
+	hits, err := s.storage.Search(req.Query, narrow, req.Limit, func(hashID string, fields map[string]string) bool {
+		if req.Query != "" &&
+			!matchAllTokens(storage.Haystack(fields), tokens) &&
+			!strings.Contains(strings.ToLower(hashID), queryLower) {
+			return false
 		}
-		// Full metadata is cached in the index — return it straight from memory,
-		// no Redis round-trip per result.
-		results = append(results, MetadataSearchResult{HashID: t.HashID, Metadata: t.Fields})
+		return recordMatchesFilters(fields, filters)
+	})
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "search failed: "+err.Error())
+		return
+	}
+	total, err := s.storage.CountRoots()
+	if err != nil {
+		total = 0
+	}
+
+	results := make([]MetadataSearchResult, 0, len(hits))
+	for _, h := range hits {
+		results = append(results, MetadataSearchResult{HashID: h.HashID, Metadata: h.Fields})
 	}
 	writeJSON(w, http.StatusOK, MetadataSearchResponse{
 		Results: results,
 		Count:   len(results),
-		Total:   len(tuples),
+		Total:   int(total),
 	})
 }
 
@@ -108,3 +67,114 @@ func matchAllTokens(haystack string, tokens []string) bool {
 	}
 	return true
 }
+
+// normalizedFilters returns the request's structured filters with the legacy
+// Property/PropertyValue pair folded in as one more entry.
+//
+// The legacy pair keeps Exact=false so its long-standing substring semantics
+// are unchanged for existing callers; new callers pass Filters and choose.
+func normalizedFilters(req MetadataSearchRequest) []MetadataFilter {
+	if req.Property == "" || req.PropertyValue == "" {
+		return req.Filters
+	}
+	out := make([]MetadataFilter, 0, len(req.Filters)+1)
+	out = append(out, req.Filters...)
+	return append(out, MetadataFilter{
+		Property: req.Property,
+		Values:   []string{req.PropertyValue},
+	})
+}
+
+// recordMatchesFilters reports whether fields satisfies every filter (AND).
+func recordMatchesFilters(fields map[string]string, filters []MetadataFilter) bool {
+	for i := range filters {
+		if !recordMatchesFilter(fields, &filters[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// recordMatchesFilter reports whether fields satisfies one filter (OR within
+// its values), probing BOTH storage shapes a field can take:
+//
+//   - a flat scalar/csv-set field — `fileType = "video"`, `videoType = "tv,anime"`;
+//   - a key-set member — `genres/Action = "true"`, `source/gateway:nyaa.si = "true"`
+//     (METADATA_KEYS "How the store is shaped").
+//
+// Probing both is what lets one filter shape serve the whole vocabulary. The
+// gateway needs a `genres:action` filter to find a record whose genre lives in
+// the key `genres/Action`, and a `fileType:video` filter to find one whose value
+// lives in the field `fileType` — without meta-core knowing which fields are
+// key-sets. It also means this stays a SUPERSET of the gateway's own
+// `record_matches`, which is the contract: meta-core pre-filters, the gateway
+// re-filters authoritatively.
+//
+// A filter with no usable value constrains nothing (matches). A filter whose
+// field is absent fails closed, matching `record_matches`.
+func recordMatchesFilter(fields map[string]string, f *MetadataFilter) bool {
+	values := make([]string, 0, len(f.Values))
+	for _, v := range f.Values {
+		if v = strings.TrimSpace(v); v != "" {
+			values = append(values, v)
+		}
+	}
+	if f.Property == "" || len(values) == 0 {
+		return true
+	}
+
+	// Key-set shape: `<property>/<value>` present and truthy. Try the exact
+	// key first — that hits whenever the caller's casing matches what was
+	// written, which is the common case and costs one map probe.
+	for _, v := range values {
+		if isTruthyMember(fields[f.Property+"/"+v]) {
+			return true
+		}
+	}
+	// Members are written verbatim (`genres/Action`) while query values arrive
+	// lowercased, so fall back to one case-insensitive sweep. Single pass over
+	// the record's fields for ALL values, not one pass per value.
+	wanted := make(map[string]struct{}, len(values))
+	for _, v := range values {
+		wanted[strings.ToLower(v)] = struct{}{}
+	}
+	prefix := strings.ToLower(f.Property) + "/"
+	for k, val := range fields {
+		if len(k) <= len(prefix) || !strings.EqualFold(k[:len(prefix)], prefix) {
+			continue
+		}
+		if _, ok := wanted[strings.ToLower(k[len(prefix):])]; ok && isTruthyMember(val) {
+			return true
+		}
+	}
+
+	// Flat shape: the field's own value, split on `,` for csv-set fields.
+	fieldValue, ok := fields[f.Property]
+	if !ok {
+		return false
+	}
+	for _, piece := range strings.Split(fieldValue, ",") {
+		piece = strings.TrimSpace(piece)
+		if piece == "" {
+			continue
+		}
+		for _, v := range values {
+			if f.Exact {
+				if strings.EqualFold(piece, v) {
+					return true
+				}
+			} else if strings.Contains(strings.ToLower(piece), strings.ToLower(v)) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// isTruthyMember reports whether a key-set member's value asserts membership.
+// Mirrors the gateway's `is_truthy_member`: presence with a non-empty,
+// non-"false"/"0" value.
+func isTruthyMember(v string) bool {
+	v = strings.TrimSpace(strings.ToLower(v))
+	return v != "" && v != "false" && v != "0"
+}

internal/api/server.go

@@ -9,10 +9,10 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/metazla/meta-core/internal/config"
-	"github.com/metazla/meta-core/internal/discovery"
 	"github.com/metazla/meta-core/internal/events"
 	"github.com/metazla/meta-core/internal/identity"
 	"github.com/metazla/meta-core/internal/leader"
+	"github.com/metazla/meta-core/internal/meshdisco"
 	"github.com/metazla/meta-core/internal/mounts"
 	"github.com/metazla/meta-core/internal/schema"
 	"github.com/metazla/meta-core/internal/storage"
@@ -25,8 +25,6 @@ import (
 type Server struct {
 	config            *config.Config
 	leaderProvider    *leader.LeaderInfoProvider
-	discovery         *discovery.Service
-	cleaner           *discovery.Cleaner
 	storage           *storage.Client
 	mountsManager     *mounts.Manager
 	mountsHandlers    *mounts.Handlers
@@ -41,34 +39,46 @@ type Server struct {
 	metaPublisher     *events.MetaPublisher
 	schemaIndexer     *schema.Indexer
 	webdavHandler     *webdav.Handler
-	search            *searchIndex
+	// challenges backs proof-of-possession on reveal/delete. In-process, so a
+	// restart invalidates the ones in flight — see identity/challenge.go.
+	challenges *identity.ChallengeStore
+	// mesh is the UDP discovery node (beacon v2). nil when discovery
+	// is disabled or failed to bind, in which case /api/neighbors reports an
+	// empty list rather than erroring — a dashboard nav is decoration and
+	// must not take the API down with it.
+	mesh   *meshdisco.Node
 	router *mux.Router
 	server *http.Server
+	// stats caches the keyspace-walk half of GET /api/stats so a polling
+	// dashboard never puts a multi-second store walk on the request path.
+	stats *statsCache
+}
+
+// SetMeshNode attaches the UDP discovery node. Separate from NewServer so the
+// server's constructor signature (and its tests) stay untouched.
+func (s *Server) SetMeshNode(n *meshdisco.Node) {
+	s.mesh = n
 }
 
 // NewServer creates a new API server
 func NewServer(
 	cfg *config.Config,
 	leaderProvider *leader.LeaderInfoProvider,
-	disc *discovery.Service,
-	cleaner *discovery.Cleaner,
 	stor *storage.Client,
 ) *Server {
 	s := &Server{
 		config:         cfg,
 		leaderProvider: leaderProvider,
-		discovery:      disc,
-		cleaner:        cleaner,
 		storage:        stor,
-		search:         &searchIndex{},
 		router:         mux.NewRouter(),
+		stats:          &statsCache{},
 	}
 
 	// Initialize file watcher/scanner and dispatcher
 	var scanFunc mounts.ScanFunc
 	if cfg.EnableFileWatcher {
 		s.watcherDispatcher = watcher.NewDispatcher()
-		// Wire storage client for Redis Stream publishing
+		// Wire storage client for file:events publishing
 		if stor != nil {
 			s.watcherDispatcher.SetStorageClient(stor)
 		}
@@ -78,7 +88,7 @@ func NewServer(
 		} else {
 			s.fileWatcher = fileWatcher
 			// Wire storage so the watcher can persist (path,size,mtime,cid)
-			// tuples to Redis as it computes midhashes.
+			// tuples to the store as it computes midhashes.
 			if stor != nil {
 				fileWatcher.SetStorageClient(stor)
 			}
@@ -100,7 +110,7 @@ func NewServer(
 				// Pass republish callback to handlers (handles nil metaPublisher case)
 				s.watchersHandlers = watchers.NewHandlers(watchersManager, s.watchersPoller, s.RepublishMetadata)
 
-				// Hydrate the in-memory state registry from Redis tuples so
+				// Hydrate the in-memory state registry from stored tuples so
 				// the first scan tick after boot can skip ComputeMidHash256
 				// for files whose (size, mtime) match.
 				configs := watchersManager.List()
@@ -111,7 +121,7 @@ func NewServer(
 				if loaded, skipped, err := s.fileWatcher.HydrateStateFromStorage(roots); err != nil {
 					log.Printf("[API] Warning: failed to hydrate watcher state: %v", err)
 				} else {
-					log.Printf("[API] Hydrated watcher state from Redis: %d files loaded, %d skipped (no matching watcher root)", loaded, skipped)
+					log.Printf("[API] Hydrated watcher state from the store: %d files loaded, %d skipped (no matching watcher root)", loaded, skipped)
 				}
 			}
 		}
@@ -139,6 +149,8 @@ func NewServer(
 	// Initialize WebDAV handler (caching is handled by nginx proxy_cache)
 	s.webdavHandler = webdav.NewHandler(cfg)
 
+	s.challenges = identity.NewChallengeStore()
+
 	// One-time migration: fold a pre-multi-account identity.json into the
 	// per-account keystore so existing single-identity hosts keep their uid.
 	if migrated, err := identity.MigrateLegacy(cfg.IdentityFilePath(), cfg.IdentityAccountsDir()); err != nil {
@@ -159,6 +171,10 @@ func (s *Server) setupRoutes() {
 	s.router.HandleFunc("/leader", s.handleLeader).Methods("GET")
 	s.router.HandleFunc("/urls", s.handleURLs).Methods("GET")
 
+	// Dashboard headline counters in one request. Cheap half live, keyspace
+	// walks served from a background-refreshed cache — see stats.go.
+	s.router.HandleFunc("/api/stats", s.handleStats).Methods("GET")
+
 	// Metadata Editor API routes (must be before /meta/{hash} routes)
 	s.router.HandleFunc("/api/metadata/hash-ids", s.handleGetHashIds).Methods("GET")
 	s.router.HandleFunc("/api/metadata/list", s.handleListMetadata).Methods("GET")
@@ -170,11 +186,13 @@ func (s *Server) setupRoutes() {
 	// at the perimeter — do NOT add to nginx-hash-lock unauth bypass.
 	s.router.HandleFunc("/api/identity", s.handleIdentityGet).Methods("GET")
 	s.router.HandleFunc("/api/identity/accounts", s.handleIdentityAccounts).Methods("GET")
+	s.router.HandleFunc("/api/identity/challenge", s.handleIdentityChallenge).Methods("POST")
 	s.router.HandleFunc("/api/identity/generate", s.handleIdentityGenerate).Methods("POST")
 	s.router.HandleFunc("/api/identity/import", s.handleIdentityImport).Methods("POST")
 	s.router.HandleFunc("/api/identity/reveal", s.handleIdentityReveal).Methods("POST")
 	s.router.HandleFunc("/api/identity", s.handleIdentityDelete).Methods("DELETE")
 	s.router.HandleFunc("/api/identity/sign", s.handleIdentitySign).Methods("POST")
+	s.router.HandleFunc("/api/identity/sign-batch", s.handleIdentitySignBatch).Methods("POST")
 	s.router.HandleFunc("/api/identity/aead-key", s.handleIdentityAEADKey).Methods("GET")
 
 	// Snapshot (export / import / wipe)
@@ -206,10 +224,14 @@ func (s *Server) setupRoutes() {
 	// Continue Watching, ratings, profile). See internal/api/udl.go.
 	s.router.HandleFunc("/api/udl/record", s.handleUDLRecordGet).Methods("GET")
 	s.router.HandleFunc("/api/udl/record", s.handleUDLRecordPut).Methods("PUT")
+	s.router.HandleFunc("/api/udl/records", s.handleUDLRecordsPut).Methods("PUT")
 	s.router.HandleFunc("/api/udl/user/{uid}/key/{key}", s.handleUDLUserKey).Methods("GET")
 	s.router.HandleFunc("/api/udl/user/{uid}/cid/{cid}", s.handleUDLUserCid).Methods("GET")
+	s.router.HandleFunc("/api/udl/user/{uid}/all", s.handleUDLUserAll).Methods("GET")
+	s.router.HandleFunc("/api/udl/user/{uid}/count", s.handleUDLUserCount).Methods("GET")
 	s.router.HandleFunc("/api/udl/cid/{cid}/users", s.handleUDLCidUsers).Methods("GET")
 	s.router.HandleFunc("/api/udl/cid/{cid}/aggregate", s.handleUDLAggregate).Methods("GET")
+	s.router.HandleFunc("/api/udl/users/stats", s.handleUDLUserStats).Methods("GET")
 
 	// Metadata operations - base endpoints
 	s.router.HandleFunc("/meta/{hash}", s.handleGetMeta).Methods("GET")
@@ -234,30 +256,31 @@ func (s *Server) setupRoutes() {
 	s.router.HandleFunc("/api/file/{cid}/info", s.handleGetFileByCIDInfo).Methods("GET")
 	s.router.HandleFunc("/file/{cid}", s.handleGetFileByCID).Methods("GET")
 	s.router.HandleFunc("/file/cid", s.handleComputeFileCID).Methods("POST")
+	// Register one file under /files/plugin by midhash — the watcher's
+	// mint + alias + file:events path for a single file. Registered
+	// unconditionally: it exists for boxes whose watcher is OFF.
+	s.router.HandleFunc("/api/files/register", s.handleRegisterFile).Methods("POST")
+	// File-backed roots (filePath+sizeByte+mtimeNano) with sizes, batched
+	// server-side, so clients answer "how many files, how big" without one
+	// read per hashId. ?summary=1 returns only {count, totalSize}.
+	s.router.HandleFunc("/api/files/tuples", s.handleGetFileTuples).Methods("GET")
 
 	// Public metadata-by-CID resolver. Reverse-index lookup → full document.
 	// Auth-bypassed alongside /api/file/{cid} so meta-share peers can query
 	// without going through Authelia.
 	s.router.HandleFunc("/api/meta/{cid}", s.handleGetMetaByCID).Methods("GET")
 
-	// Admin: reunify stranded midhash-rooted entries into their UUID roots
-	// (the dual-root pattern caused by historical writes that bypassed CID
-	// resolution).
-	s.router.HandleFunc("/api/admin/migrate-dual-roots", s.handleMigrateDualRoots).Methods("POST")
-
-	// SSE event streams. Mediated mirror of the Redis Streams; consumers
-	// reach them over HTTP instead of touching Redis directly. Auth-bypass
+	// SSE event streams. The only way consumers see meta-core's change
+	// streams — they never touch the database. Auth-bypass
 	// applies but exposure should be inside-only (do NOT proxy through
 	// Caddy publicly). See docs/api-mediated-access.md "Auth".
 	s.router.HandleFunc("/api/events/files", s.handleEventsFiles).Methods("GET")
 	s.router.HandleFunc("/api/events/meta", s.handleEventsMeta).Methods("GET")
 
-	// Service discovery
-	// Both /services and /api/services are supported for consistency with other services
-	s.router.HandleFunc("/services", s.handleListServices).Methods("GET")
-	s.router.HandleFunc("/api/services", s.handleListServices).Methods("GET")
-	s.router.HandleFunc("/services/cleanup/stats", s.handleCleanupStats).Methods("GET")
-	s.router.HandleFunc("/services/{name}", s.handleGetService).Methods("GET")
+	// beacon v2: neighbours heard over UDP. Supersedes /api/services,
+	// which is still served above while consumers migrate.
+	s.router.HandleFunc("/neighbors", s.handleListNeighbors).Methods("GET")
+	s.router.HandleFunc("/api/neighbors", s.handleListNeighbors).Methods("GET")
 
 	// Mount management routes (if manager initialized)
 	if s.mountsHandlers != nil {
@@ -326,31 +349,33 @@ func (s *Server) Start() error {
 		s.mountStatsPoller.Start()
 	}
 
-	// Build + periodically refresh the in-memory search index so
-	// POST /api/metadata/search matches in memory instead of a Redis
-	// round-trip per record (see search_index.go).
-	if s.storage != nil {
-		go s.search.runRefreshLoop(s.storage)
-	}
-
-	// Start meta publisher (if storage is connected)
-	// Publishes keyspace notifications to meta:events stream
+	// Start meta publisher (if storage is connected). Live change events are
+	// written by the storage engine itself; the publisher owns the bulk
+	// republish below.
 	if s.storage != nil && s.storage.IsConnected() {
-		s.metaPublisher = events.NewMetaPublisher(s.storage.GetRedisClient())
+		s.metaPublisher = events.NewMetaPublisher(s.storage)
 		if err := s.metaPublisher.Start(); err != nil {
 			log.Printf("[API] Warning: failed to start meta publisher: %v", err)
 		} else {
-			// Schema indexer consumes the same stream to derive a live
-			// per-field schema (type/hint/breakdown). Start it before the
-			// republish flood so it captures the bootstrap events.
-			s.schemaIndexer = schema.NewIndexer(s.storage.GetRedisClient(), s.storage.GetPrefix())
+			// Schema indexer: per-field schema (type/hint/breakdown) from a
+			// periodic scan of the store.
+			s.schemaIndexer = schema.NewIndexer(s.storage.Store())
 			if err := s.schemaIndexer.Start(); err != nil {
 				log.Printf("[API] Warning: failed to start schema indexer: %v", err)
 				s.schemaIndexer = nil
 			}
 
-			// Republish events for all existing metadata
+			// Republish events for all existing metadata. Consumers that
+			// rebuild by replaying meta:events from the beginning (meta-fuse)
+			// depend on it.
 			go func() {
+				started := time.Now()
+				if n, err := s.storage.RebuildSearchIfEmpty(); err != nil {
+					log.Printf("[API] Warning: search row rebuild failed: %v", err)
+				} else if n > 0 {
+					log.Printf("[API] Rebuilt search rows for %d records in %s", n, time.Since(started).Round(time.Millisecond))
+				}
+
 				count, err := s.RepublishMetadata()
 				if err != nil {
 					log.Printf("[API] Warning: failed to republish metadata on startup: %v", err)

internal/api/snapshot.go

@@ -103,7 +103,7 @@ func (s *Server) handleSnapshotImport(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, result)
 }
 
-// handleSnapshotWipe clears Redis metadata.
+// handleSnapshotWipe clears all stored metadata.
 // POST /api/snapshot/wipe?scope=metadata
 func (s *Server) handleSnapshotWipe(w http.ResponseWriter, r *http.Request) {
 	if !s.storage.IsConnected() {

internal/api/sse_events.go

@@ -3,7 +3,6 @@ package api
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"log"
 	"net/http"
@@ -11,15 +10,17 @@ import (
 	"strings"
 	"time"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
-// SSE event stream endpoints for the file:events and meta:events Redis Streams.
+// SSE event stream endpoints for the file:events and meta:events streams.
 //
 // Wire contract (see docs/api-mediated-access.md):
-//   - One SSE event per Redis Stream entry.
-//   - `id:` is the opaque Redis Stream entry ID (`<ms>-<seq>`); consumers
-//     MUST treat it as a black-box string they echo back via Last-Event-ID.
+//   - One SSE event per stream entry.
+//   - `id:` is the opaque stream entry ID (`<ms>-<seq>`, the Redis Streams
+//     form, kept across the move to SQLite so cursors consumers persisted to
+//     disk still compare correctly); consumers MUST treat it as a black-box
+//     string they echo back via Last-Event-ID.
 //   - `event:` is the `type` field from the underlying entry.
 //   - `data:` is the JSON-encoded rest of the entry (all fields except `type`).
 //   - Heartbeats are SSE comment lines (`:keep-alive\n\n`) every 30s of silence.
@@ -30,30 +31,30 @@ import (
 const (
 	sseHeartbeatInterval = 30 * time.Second
 
-	// sseReadBlock controls how long each XREAD blocks before returning.
+	// sseReadBlock controls how long each read waits for new entries.
 	// Much shorter than sseHeartbeatInterval so the handler stays responsive
 	// to client disconnects and the heartbeat check runs frequently enough
 	// that the keep-alive fires within a few seconds of its nominal cadence.
 	sseReadBlock = 2 * time.Second
 
-	// sseReadCount caps how many entries one XREAD returns. Small enough
+	// sseReadCount caps how many entries one read returns. Small enough
 	// to keep per-flush memory low, large enough to drain bursts cheaply.
 	sseReadCount = 100
 )
 
-// handleEventsFiles streams the file:events Redis Stream as SSE.
+// handleEventsFiles streams the file:events stream as SSE.
 func (s *Server) handleEventsFiles(w http.ResponseWriter, r *http.Request) {
 	s.streamSSE(w, r, "file:events")
 }
 
-// handleEventsMeta streams the meta:events Redis Stream as SSE.
+// handleEventsMeta streams the meta:events stream as SSE.
 func (s *Server) handleEventsMeta(w http.ResponseWriter, r *http.Request) {
 	s.streamSSE(w, r, "meta:events")
 }
 
-// streamSSE is the shared SSE pump shared by both endpoints. One handler per
-// stream — there is no fan-out; each subscriber holds its own XREAD loop.
-// That's fine at our scale (≤20 subscribers; one per consumer service).
+// streamSSE is the SSE pump shared by both endpoints. Each subscriber reads
+// the stream itself and sleeps on the store's commit broadcast between reads —
+// fine at our scale (≤20 subscribers; one per consumer service).
 func (s *Server) streamSSE(w http.ResponseWriter, r *http.Request, stream string) {
 	if !s.storage.IsConnected() {
 		w.Header().Set("Retry-After", "5")
@@ -89,14 +90,14 @@ func (s *Server) streamSSE(w http.ResponseWriter, r *http.Request, stream string
 	w.WriteHeader(http.StatusOK)
 	flusher.Flush()
 
-	client := s.storage.GetRedisClient()
-	if client == nil {
+	store := s.storage.Store()
+	if store == nil {
 		// Storage was just disconnected — close cleanly.
 		return
 	}
 
 	ctx := r.Context()
-	cursor := resolveStartCursor(ctx, client, stream, r.Header.Get("Last-Event-ID"), w, flusher)
+	cursor := resolveStartCursor(ctx, store, stream, r.Header.Get("Last-Event-ID"), w, flusher)
 
 	lastWrite := time.Now()
 	for {
@@ -104,37 +105,34 @@ func (s *Server) streamSSE(w http.ResponseWriter, r *http.Request, stream string
 			return
 		}
 
-		// Bounded BLOCK lets us re-check ctx and emit heartbeats. The
-		// context's deadline isn't propagated into XREAD's BLOCK arg —
-		// that's a poll-style timeout on Redis itself — so we keep BLOCK
-		// short.
-		readCtx, cancel := context.WithTimeout(ctx, sseReadBlock+2*time.Second)
-		result, err := client.XRead(readCtx, &redis.XReadArgs{
-			Streams: []string{stream, cursor},
-			Block:   sseReadBlock,
-			Count:   sseReadCount,
-		}).Result()
-		cancel()
-
+		// Take the wake-up channel BEFORE reading, so an append landing
+		// between the read and the wait still wakes us.
+		wake := store.Wait(stream)
+		entries, err := store.ReadAfter(ctx, stream, cursor, sseReadCount)
 		if err != nil {
-			// redis.Nil = BLOCK timeout with no entries. Anything else
-			// while the client is still connected is a real failure.
-			if errors.Is(err, redis.Nil) || isContextTimeout(err) {
-				// fall through to heartbeat check
-			} else if errors.Is(err, context.Canceled) || ctx.Err() != nil {
-				return
-			} else {
-				log.Printf("[SSE %s] XREAD error: %v", stream, err)
+			if ctx.Err() != nil {
 				return
 			}
+			log.Printf("[SSE %s] read error: %v", stream, err)
+			return
 		}
 
-		for _, str := range result {
-			for _, msg := range str.Messages {
-				writeSSEEntry(w, flusher, msg)
-				cursor = msg.ID
+		for _, e := range entries {
+			writeSSEEntry(w, flusher, e)
+			cursor = e.ID
 			lastWrite = time.Now()
 		}
+
+		if len(entries) == 0 {
+			timer := time.NewTimer(sseReadBlock)
+			select {
+			case <-ctx.Done():
+				timer.Stop()
+				return
+			case <-wake:
+			case <-timer.C:
+			}
+			timer.Stop()
 		}
 
 		// Heartbeat if quiet for >= the interval. Comment line; SSE
@@ -150,38 +148,44 @@ func (s *Server) streamSSE(w http.ResponseWriter, r *http.Request, stream string
 }
 
 // resolveStartCursor decides where to start reading.
-//   - No Last-Event-ID → start at "$" (only new entries).
+//   - No Last-Event-ID → the stream's last issued ID, resolved ONCE here (only
+//     entries appended from now on). Redis' "$" was re-resolved on every
+//     XREAD, which dropped anything appended between two reads.
 //   - Last-Event-ID provided AND still in stream → resume from it.
 //   - Last-Event-ID provided BUT trimmed → emit one synthetic `gap` event
 //     and resume from the oldest available entry's predecessor "0", so the
-//     next XREAD picks up everything still in the stream.
+//     next read picks up everything still in the stream.
 //
-// The "still in stream" check is cheap: one XRANGE for the first entry.
-func resolveStartCursor(ctx context.Context, client *redis.Client, stream, lastID string, w http.ResponseWriter, flusher http.Flusher) string {
-	if lastID == "" {
-		return "$"
-	}
-
-	// One-entry XRANGE to find the oldest ID currently in the stream.
+// The "still in stream" check is cheap: one read of the first entry.
+func resolveStartCursor(ctx context.Context, store *kv.Store, stream, lastID string, w http.ResponseWriter, flusher http.Flusher) string {
 	xCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
 	defer cancel()
-	entries, err := client.XRangeN(xCtx, stream, "-", "+", 1).Result()
+
+	if lastID == "" {
+		head, err := store.LastID(xCtx, stream)
+		if err != nil {
+			log.Printf("[SSE %s] head lookup failed: %v (starting from the beginning)", stream, err)
+			return "0"
+		}
+		return head
+	}
+
+	oldestEntry, ok, err := store.Oldest(xCtx, stream)
 	if err != nil {
 		// Treat any error as "stream not available right now" and resume
-		// from the cursor — XREAD will either find it or block until new
-		// entries arrive.
-		log.Printf("[SSE %s] XRANGE probe failed: %v (resuming from cursor)", stream, err)
+		// from the cursor — the read either finds it or waits for new entries.
+		log.Printf("[SSE %s] oldest-entry probe failed: %v (resuming from cursor)", stream, err)
 		return lastID
 	}
 
-	if len(entries) == 0 {
+	if !ok {
 		// Stream is empty. Cursor may be from a previous incarnation; safest
-		// is to resume from the cursor — XREAD against an empty stream
-		// returns nothing and blocks until new entries arrive.
+		// is to resume from the cursor — reading an empty stream returns
+		// nothing and waits until new entries arrive.
 		return lastID
 	}
 
-	oldest := entries[0].ID
+	oldest := oldestEntry.ID
 	if compareStreamIDs(lastID, oldest) >= 0 {
 		// Cursor is at or past the oldest — fine to resume.
 		return lastID
@@ -197,39 +201,35 @@ func resolveStartCursor(ctx context.Context, client *redis.Client, stream, lastI
 	fmt.Fprintf(w, "event: gap\ndata: %s\n\n", string(payload))
 	flusher.Flush()
 
-	// Return "0" so the next XREAD picks up entries starting from the
+	// Return "0" so the next read picks up entries starting from the
 	// stream's true minimum — including `oldest` itself.
 	return "0"
 }
 
-// writeSSEEntry serialises one Redis Stream entry as an SSE event.
+// writeSSEEntry serialises one stream entry as an SSE event.
 //
 // `event:` comes from the entry's `type` field (no prefix munging). `data:`
-// is a JSON object containing all OTHER fields. Field values from the Redis
-// stream are interface{} (typically strings); we encode whatever the stream
-// holds.
-func writeSSEEntry(w http.ResponseWriter, flusher http.Flusher, msg redis.XMessage) {
+// is a JSON object containing all OTHER fields.
+func writeSSEEntry(w http.ResponseWriter, flusher http.Flusher, e kv.Entry) {
 	eventType := "message"
-	data := make(map[string]interface{}, len(msg.Values))
-	for k, v := range msg.Values {
+	data := make(map[string]string, len(e.Values))
+	for k, v := range e.Values {
 		if k == "type" {
-			if s, ok := v.(string); ok {
-				eventType = s
+			eventType = v
 			continue
 		}
-		}
 		data[k] = v
 	}
 
 	payload, err := json.Marshal(data)
 	if err != nil {
-		log.Printf("[SSE] failed to marshal entry %s: %v", msg.ID, err)
+		log.Printf("[SSE] failed to marshal entry %s: %v", e.ID, err)
 		return
 	}
 
 	// Spec: each event ends with a blank line. id/event/data lines are
 	// terminated with single \n.
-	fmt.Fprintf(w, "id: %s\n", msg.ID)
+	fmt.Fprintf(w, "id: %s\n", e.ID)
 	fmt.Fprintf(w, "event: %s\n", eventType)
 	fmt.Fprintf(w, "data: %s\n\n", string(payload))
 	flusher.Flush()
@@ -263,18 +263,3 @@ func parseStreamID(id string) (int64, int64) {
 	}
 	return ms, seq
 }
-
-// isContextTimeout returns true for the context deadline error wrapped by
-// go-redis when XREAD's read context fires. We treat it the same as
-// redis.Nil — i.e. an empty poll cycle, not a fatal error.
-func isContextTimeout(err error) bool {
-	if err == nil {
-		return false
-	}
-	if errors.Is(err, context.DeadlineExceeded) {
-		return true
-	}
-	// go-redis sometimes wraps this in its own error type. String match is
-	// a safety net.
-	return strings.Contains(err.Error(), "context deadline exceeded")
-}

internal/api/stats.go

@@ -0,0 +1,166 @@
+package api
+
+import (
+	"log"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/metazla/meta-core/internal/identity"
+)
+
+// statsSweepTTL is how long a keyspace-walk result stays good. The walk is
+// never on the request path (see statsCache), so this only controls how stale
+// the library tiles may look, not how slow the endpoint is.
+const statsSweepTTL = 60 * time.Second
+
+// fileStatsJSON is the file-backed half of the library: the roots that carry
+// filePath+sizeByte+mtimeNano. Gateway / cid-rooted records have no file on
+// disk and are counted in Records, not here — the gap between the two numbers
+// is exactly "metadata we hold for files we do not have".
+type fileStatsJSON struct {
+	Count     int   `json:"count"`
+	TotalSize int64 `json:"totalSize"`
+}
+
+// StatsResponse is the body of GET /api/stats — every headline number the
+// dashboard shows, in one request.
+//
+// Deliberately split by cost. Records/RedisKeys/RedisMemory/Identities are
+// cheap (an index range count, a cached row count, a file stat) plus a
+// directory listing, recomputed on every call. The `redis*` JSON names
+// predate the move to SQLite and are kept for dashboard compatibility:
+// redisKeys is the store's row count, redisMemory its on-disk size. Files and UDLUsers need a keyspace walk — ~0.5s for the file
+// tuples and ~3s for the UDL SCAN on an 88k-record box — so they are served
+// from a background-refreshed cache and are null until the first sweep lands.
+type StatsResponse struct {
+	Records     int64          `json:"records"`
+	RedisKeys   int64          `json:"redisKeys"`
+	RedisMemory string         `json:"redisMemory"`
+	Identities  int            `json:"identities"`
+	Files       *fileStatsJSON `json:"files"`
+	UDLUsers    *int           `json:"udlUsers"`
+	// SweptAt is when the cached half was computed (unix ms), 0 if never.
+	SweptAt int64 `json:"sweptAt"`
+	// Sweeping reports that a refresh is in flight, so the UI can show the
+	// cached numbers as provisional instead of pretending they are live.
+	Sweeping bool `json:"sweeping"`
+}
+
+// statsCache holds the expensive half of /api/stats.
+//
+// Why a cache and not just "compute it": the dashboard polls. A multi-second store walk
+// per tick, per open tab, is a self-inflicted outage on a box that is also
+// serving playback — the same shape as meta-sort's /api/stats full sweep. So
+// the handler NEVER waits on a walk: it returns whatever the last sweep
+// produced and kicks off a new one if the old one is stale. `running` makes
+// that single-flight, so ten tabs cost one walk.
+type statsCache struct {
+	mu       sync.Mutex
+	files    *fileStatsJSON
+	udlUsers *int
+	sweptAt  time.Time
+	running  bool
+}
+
+// snapshot returns the cached values and whether a refresh is in flight.
+func (c *statsCache) snapshot() (*fileStatsJSON, *int, time.Time, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.files, c.udlUsers, c.sweptAt, c.running
+}
+
+// refreshIfStale starts a background sweep unless one is already running or
+// the last result is still fresh. Returns true if it started one.
+func (c *statsCache) refreshIfStale(sweep func() (*fileStatsJSON, *int)) bool {
+	c.mu.Lock()
+	if c.running || time.Since(c.sweptAt) < statsSweepTTL {
+		c.mu.Unlock()
+		return false
+	}
+	c.running = true
+	c.mu.Unlock()
+
+	go func() {
+		files, udl := sweep()
+		c.mu.Lock()
+		defer c.mu.Unlock()
+		c.running = false
+		// A failed sweep leaves the previous numbers in place rather than
+		// blanking the tiles; sweptAt still advances so a hard-failing walk
+		// (store down) does not spin once per poll.
+		c.sweptAt = time.Now()
+		if files != nil {
+			c.files = files
+		}
+		if udl != nil {
+			c.udlUsers = udl
+		}
+	}()
+	return true
+}
+
+// handleStats handles GET /api/stats.
+func (s *Server) handleStats(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+
+	resp := StatsResponse{}
+
+	if n, err := s.storage.CountRoots(); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	} else {
+		resp.Records = n
+	}
+	if n, err := s.storage.CountKeys(); err == nil {
+		resp.RedisKeys = n
+	}
+	if mem, err := s.storage.GetMemoryInfo(); err == nil {
+		resp.RedisMemory = mem
+	} else {
+		resp.RedisMemory = "N/A"
+	}
+	if list, err := identity.List(s.config.IdentityAccountsDir()); err == nil {
+		resp.Identities = len(list)
+	}
+
+	s.stats.refreshIfStale(s.sweepStats)
+	files, udl, sweptAt, sweeping := s.stats.snapshot()
+	resp.Files = files
+	resp.UDLUsers = udl
+	resp.Sweeping = sweeping
+	if !sweptAt.IsZero() {
+		resp.SweptAt = sweptAt.UnixMilli()
+	}
+
+	writeJSON(w, http.StatusOK, resp)
+}
+
+// sweepStats runs the two keyspace walks behind the cached tiles. Called off
+// the request path only. A failing half returns nil so the other half still
+// lands.
+func (s *Server) sweepStats() (*fileStatsJSON, *int) {
+	var files *fileStatsJSON
+	if tuples, err := s.storage.GetTuplesForAllFiles(); err != nil {
+		log.Printf("[API] stats: file tuple sweep failed: %v", err)
+	} else {
+		fs := fileStatsJSON{Count: len(tuples)}
+		for _, t := range tuples {
+			fs.TotalSize += t.Size
+		}
+		files = &fs
+	}
+
+	var udl *int
+	if stats, err := s.storage.UDLAllUserStats(); err != nil {
+		log.Printf("[API] stats: UDL user sweep failed: %v", err)
+	} else {
+		n := len(stats)
+		udl = &n
+	}
+
+	return files, udl
+}

internal/api/storage_helper_test.go

@@ -0,0 +1,19 @@
+package api
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/metazla/meta-core/internal/storage"
+)
+
+// newTestStorage opens a fresh metadata store in the test's temp dir.
+func newTestStorage(t *testing.T) *storage.Client {
+	t.Helper()
+	c := storage.NewClient()
+	if err := c.Connect(filepath.Join(t.TempDir(), "meta-core.db")); err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	t.Cleanup(func() { _ = c.Close() })
+	return c
+}

internal/api/udl.go

@@ -7,15 +7,17 @@ package api
 // meta-watch's local op-log. Records arrive already signed (and, for
 // private-tier keys, already encrypted) as opaque base64 CBOR blobs; meta-core
 // version-gates and indexes them but never inspects the crypto. See
-// internal/storage/udl.go for the Redis model.
+// internal/storage/udl.go for the key model.
 
 import (
 	"encoding/json"
 	"math"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"github.com/gorilla/mux"
+	"github.com/metazla/meta-core/internal/storage"
 )
 
 // UDLPutRequest is the body of PUT /api/udl/record.
@@ -42,12 +44,50 @@ type UDLPutResponse struct {
 	Accepted bool `json:"accepted"`
 }
 
+// UDLPutBatchRequest is the body of PUT /api/udl/records — many cells, one
+// request. Each entry is exactly a UDLPutRequest, so a client can build the
+// same signed record for either endpoint.
+type UDLPutBatchRequest struct {
+	Records []UDLPutRequest `json:"records"`
+}
+
+// UDLPutBatchResult is one cell's outcome. Accepted=false with an empty Error
+// means the write was stale (the single-record endpoint's 409), which in a
+// batch is an ordinary outcome rather than a failure.
+type UDLPutBatchResult struct {
+	Key      string `json:"key"`
+	Accepted bool   `json:"accepted"`
+	Error    string `json:"error,omitempty"`
+}
+
+// UDLPutBatchResponse mirrors the request order index-for-index.
+type UDLPutBatchResponse struct {
+	Results []UDLPutBatchResult `json:"results"`
+}
+
+// maxUDLBatch bounds one batch. Each record is a store write while the
+// request is held open; sized to match the sign batch on the other side of the
+// same operation (see maxSignBatch).
+const maxUDLBatch = 1000
+
 // UDLRecordResponse is the response of GET /api/udl/record.
 type UDLRecordResponse struct {
 	Record  string `json:"record"`
 	Version int64  `json:"version"`
 	Ts      int64  `json:"ts"`
 	Exists  bool   `json:"exists"`
+	// Value is the plaintext JSON scalar stored beside the opaque record, and
+	// is present only for PUBLIC-tier keys (like, rating, profile:name,
+	// profile:avatar). json.RawMessage rather than string because the field is
+	// generic over keys — a bool for `like`, a number for `rating`, a string
+	// for a profile name (see aggregatePublicValues) — and because it is the
+	// exact type UDLPutRequest.Value uses, so a value written through PUT reads
+	// back byte-identical.
+	//
+	// Absent, never null, when there is no plaintext: private-tier cells,
+	// tombstones and never-written cells must not read as an empty public
+	// value. Readers key off presence, not `exists`.
+	Value *json.RawMessage `json:"value,omitempty"`
 }
 
 // UDLAggregate mirrors meta-watch's Aggregate wire shape exactly (snake_case
@@ -79,12 +119,20 @@ func (s *Server) handleUDLRecordGet(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusInternalServerError, err.Error())
 		return
 	}
-	writeJSON(w, http.StatusOK, UDLRecordResponse{
+	resp := UDLRecordResponse{
 		Record:  cell.Record,
 		Version: cell.Version,
 		Ts:      cell.Ts,
 		Exists:  exists,
-	})
+	}
+	// json.Valid guards the encoder: a malformed `value` hash field (hand-edited
+	// the store, a future writer bug) would otherwise fail mid-encode and emit a
+	// truncated body instead of a readable error.
+	if exists && cell.HasValue && json.Valid([]byte(cell.Value)) {
+		raw := json.RawMessage(cell.Value)
+		resp.Value = &raw
+	}
+	writeJSON(w, http.StatusOK, resp)
 }
 
 // handleUDLRecordPut handles PUT /api/udl/record. Version-gated: a stale write
@@ -124,6 +172,64 @@ func (s *Server) handleUDLRecordPut(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, UDLPutResponse{Accepted: true})
 }
 
+// handleUDLRecordsPut handles PUT /api/udl/records — the batch form of
+// handleUDLRecordPut.
+//
+// Exists for the bulk verbs above this layer ("mark this whole series seen"),
+// where one user action produces one cell per episode. Each cell still goes
+// through the same version-gated Lua upsert, so the CRDT semantics are
+// identical — this batches the transport only.
+//
+// **Not transactional, and deliberately not 409.** A per-record `accepted` flag
+// replaces the single-record conflict status: in a batch, one stale cell is a
+// normal outcome (another device already marked that episode) and must not fail
+// the 299 cells beside it. Callers read the array, not the status code.
+func (s *Server) handleUDLRecordsPut(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+	var req UDLPutBatchRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if len(req.Records) == 0 {
+		writeError(w, http.StatusBadRequest, "records is required")
+		return
+	}
+	if len(req.Records) > maxUDLBatch {
+		writeError(w, http.StatusBadRequest, "too many records in one batch")
+		return
+	}
+	results := make([]UDLPutBatchResult, 0, len(req.Records))
+	for _, rec := range req.Records {
+		if rec.Uid == "" || rec.Cid == "" || rec.Key == "" || rec.Record == "" {
+			results = append(results, UDLPutBatchResult{
+				Key:   rec.Key,
+				Error: "uid, cid, key and record are required",
+			})
+			continue
+		}
+		publicValue := ""
+		hasValue := false
+		if rec.Value != nil {
+			publicValue = string(*rec.Value)
+			hasValue = true
+		}
+		accepted, err := s.storage.UDLUpsertIfNewer(rec.Uid, rec.Cid, rec.Key, rec.Version, rec.Ts, rec.Record, publicValue, hasValue, rec.Tombstone)
+		if err != nil {
+			// A storage error is per-record here rather than fatal for the whole
+			// batch: the cells already written stay written, and reporting which
+			// ones failed lets the caller retry exactly those.
+			results = append(results, UDLPutBatchResult{Key: rec.Key, Error: err.Error()})
+			continue
+		}
+		results = append(results, UDLPutBatchResult{Key: rec.Key, Accepted: accepted})
+	}
+	writeJSON(w, http.StatusOK, UDLPutBatchResponse{Results: results})
+}
+
 // handleUDLUserKey handles GET /api/udl/user/{uid}/key/{key}
 // (active_for_user_key — My List, Continue Watching).
 func (s *Server) handleUDLUserKey(w http.ResponseWriter, r *http.Request) {
@@ -166,6 +272,75 @@ func (s *Server) handleUDLUserCid(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]interface{}{"entries": entries})
 }
 
+// handleUDLUserAll handles GET /api/udl/user/{uid}/all?after=<cid>&limit=<n>
+// — every record a uid owns, for cross-instance profile recovery.
+//
+// The other user-scoped reads answer a question with one coordinate already
+// known. Recovery knows only the uid: a box that has just imported a secret key
+// has no idea which cids or keys the profile ever touched, so it needs the
+// whole set or it gets nothing.
+//
+// Paged on a cid boundary — `nextCid` empty means the export is complete. The
+// response is opaque signed records, exactly as stored; whoever consumes it is
+// responsible for verifying each one before trusting it (meta-core has never
+// held the account key and cannot verify on anyone's behalf).
+func (s *Server) handleUDLUserAll(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+	uid := mux.Vars(r)["uid"]
+	if uid == "" {
+		writeError(w, http.StatusBadRequest, "uid is required")
+		return
+	}
+	limit := maxUDLBatch
+	if v := r.URL.Query().Get("limit"); v != "" {
+		n, err := strconv.Atoi(v)
+		if err != nil || n <= 0 {
+			writeError(w, http.StatusBadRequest, "limit must be a positive integer")
+			return
+		}
+		if n < limit {
+			limit = n
+		}
+	}
+	entries, nextCid, err := s.storage.UDLAllForUser(uid, r.URL.Query().Get("after"), limit)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]interface{}{
+		"entries": entries,
+		"nextCid": nextCid,
+	})
+}
+
+// handleUDLUserCount handles GET /api/udl/user/{uid}/count — how many cids a
+// uid holds records for.
+//
+// Exists so a gateway mirror can enforce a per-profile quota without walking
+// anything: 32 random bytes are a valid uid, so an unbounded mirror is a
+// disk-fill DoS that needs no account. A quota check that itself cost a scan
+// would just move the denial of service one layer up.
+func (s *Server) handleUDLUserCount(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+	uid := mux.Vars(r)["uid"]
+	if uid == "" {
+		writeError(w, http.StatusBadRequest, "uid is required")
+		return
+	}
+	n, err := s.storage.UDLCountUserCids(uid)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]interface{}{"cids": n})
+}
+
 // handleUDLCidUsers handles GET /api/udl/cid/{cid}/users (uids_for_cid).
 func (s *Server) handleUDLCidUsers(w http.ResponseWriter, r *http.Request) {
 	if !s.storage.IsConnected() {
@@ -245,3 +420,35 @@ func aggregatePublicValues(key string, values []string) UDLAggregate {
 	}
 	return agg
 }
+
+// udlUserStatsResponse is the shape of GET /api/udl/users/stats.
+type udlUserStatsResponse struct {
+	// Users maps uid -> counts. Accounts holding nothing are absent rather than
+	// present with zeroes; a caller rendering a list treats "missing" as 0.
+	Users map[string]storage.UDLUserStats `json:"users"`
+}
+
+// handleUDLUserStats handles GET /api/udl/users/stats — how much every account
+// holds, in one keyspace walk.
+//
+// Bulk rather than per-uid because the only caller is the accounts page, which
+// needs a number for every row: the counts come from a SCAN (there is no
+// per-user cid index — see storage/udl_admin.go), and MATCH filters without
+// indexing, so N per-uid calls would walk the whole keyspace N times.
+//
+// Deliberately not on the critical path of anything. It is an admin read whose
+// cost grows with the keyspace, so callers should fetch it after rendering,
+// never before.
+func (s *Server) handleUDLUserStats(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeErrorSlug(w, http.StatusServiceUnavailable, "storage_unavailable",
+			"storage not connected", true)
+		return
+	}
+	stats, err := s.storage.UDLAllUserStats()
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, udlUserStatsResponse{Users: stats})
+}

internal/api/udl_test.go

@@ -0,0 +1,216 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+// newUDLTestServer returns a Server wired to an in-memory Redis.
+//
+// The struct is built directly rather than through NewServer: NewServer boots
+// the file watcher, mounts manager, watchers poller and WebDAV handler, none of
+// which the UDL handlers touch — they use s.storage and nothing else.
+func newUDLTestServer(t *testing.T) *Server {
+	t.Helper()
+	return &Server{storage: newTestStorage(t)}
+}
+
+// getRecord drives handleUDLRecordGet and decodes the body into raw JSON
+// fields, so a test can assert on the *encoding* of `value` (is it a quoted
+// string? is the key there at all?) rather than on what a typed struct would
+// have coerced it into.
+func getRecord(t *testing.T, s *Server, uid, cid, key string) (int, map[string]json.RawMessage) {
+	t.Helper()
+
+	req := httptest.NewRequest(http.MethodGet, "/api/udl/record?uid="+uid+"&cid="+cid+"&key="+key, nil)
+	rr := httptest.NewRecorder()
+	s.handleUDLRecordGet(rr, req)
+
+	var body map[string]json.RawMessage
+	if err := json.Unmarshal(rr.Body.Bytes(), &body); err != nil {
+		t.Fatalf("decode response %q: %v", rr.Body.String(), err)
+	}
+	return rr.Code, body
+}
+
+// The plaintext value of a PUBLIC-tier cell must come back over the wire, and
+// come back *as it was written* — a JSON string stays a quoted string, a bool
+// stays a bool.
+//
+// Both halves matter. Without the value at all, the meta-core dashboard can
+// only ever show 44-character base58 uids: display names live in the User Data
+// Layer as the public cell (uid, "self", "profile:name"), and the plaintext
+// sits in Redis where the storage layer has always read it — the handler just
+// used to drop it. And the type has to stay json.RawMessage: this endpoint is
+// generic over keys, so a `*string` would mangle `like` (bool) and `rating`
+// (number) while looking correct for names.
+func TestUDLRecordGet_ReturnsPublicValue(t *testing.T) {
+	s := newUDLTestServer(t)
+
+	const uid = "zAlice"
+	if ok, err := s.storage.UDLUpsertIfNewer(uid, "self", "profile:name", 1, 100, "cmVj", `"Ada Lovelace"`, true, false); err != nil || !ok {
+		t.Fatalf("seed name: ok=%v err=%v", ok, err)
+	}
+	if ok, err := s.storage.UDLUpsertIfNewer(uid, "bagcsaaa", "like", 1, 100, "cmVj", `true`, true, false); err != nil || !ok {
+		t.Fatalf("seed like: ok=%v err=%v", ok, err)
+	}
+
+	code, body := getRecord(t, s, uid, "self", "profile:name")
+	if code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", code)
+	}
+	if got := string(body["value"]); got != `"Ada Lovelace"` {
+		t.Fatalf("value = %s, want a quoted JSON string", got)
+	}
+	var name string
+	if err := json.Unmarshal(body["value"], &name); err != nil || name != "Ada Lovelace" {
+		t.Fatalf("value should unmarshal to the plain name, got %q err=%v", name, err)
+	}
+
+	// A boolean key survives unquoted — the assertion a *string field fails.
+	if _, body = getRecord(t, s, uid, "bagcsaaa", "like"); string(body["value"]) != "true" {
+		t.Fatalf("like value = %s, want the bare JSON literal true", body["value"])
+	}
+}
+
+// A cell with no plaintext must omit `value` entirely rather than send null.
+//
+// That is the shape of every private-tier key (seek, watched, card, localpath —
+// their real value rides encrypted inside the opaque record) and of every
+// tombstone. A reader keys off presence: "there is no plaintext here" and "the
+// plaintext is null" are different facts, and a name cleared by its owner
+// leaves the cell existing with no value, which must not read as a name.
+func TestUDLRecordGet_OmitsValueForPrivateCell(t *testing.T) {
+	s := newUDLTestServer(t)
+
+	const uid = "zBob"
+	if ok, err := s.storage.UDLUpsertIfNewer(uid, "bagcsaaa", "seek", 1, 100, "ZW5jcnlwdGVk", "", false, false); err != nil || !ok {
+		t.Fatalf("seed private cell: ok=%v err=%v", ok, err)
+	}
+
+	code, body := getRecord(t, s, uid, "bagcsaaa", "seek")
+	if code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", code)
+	}
+	if _, ok := body["value"]; ok {
+		t.Fatalf("private cell must omit `value`, got %s", body["value"])
+	}
+	if string(body["exists"]) != "true" {
+		t.Fatalf("exists = %s, want true", body["exists"])
+	}
+}
+
+// A cell that was never written answers 200 with exists:false and no value —
+// not a 404, and not an empty-string value that would render as a blank name.
+func TestUDLRecordGet_MissingCellHasNoValue(t *testing.T) {
+	s := newUDLTestServer(t)
+
+	code, body := getRecord(t, s, "zNobody", "self", "profile:name")
+	if code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", code)
+	}
+	if string(body["exists"]) != "false" {
+		t.Fatalf("exists = %s, want false", body["exists"])
+	}
+	if _, ok := body["value"]; ok {
+		t.Fatalf("missing cell must omit `value`, got %s", body["value"])
+	}
+}
+
+// putRecords drives handleUDLRecordsPut with a raw JSON body and decodes the
+// per-record results.
+func putRecords(t *testing.T, s *Server, body string) (int, UDLPutBatchResponse) {
+	t.Helper()
+
+	req := httptest.NewRequest(http.MethodPut, "/api/udl/records", strings.NewReader(body))
+	rr := httptest.NewRecorder()
+	s.handleUDLRecordsPut(rr, req)
+
+	var out UDLPutBatchResponse
+	if rr.Code == http.StatusOK {
+		if err := json.Unmarshal(rr.Body.Bytes(), &out); err != nil {
+			t.Fatalf("decode response %q: %v", rr.Body.String(), err)
+		}
+	}
+	return rr.Code, out
+}
+
+// **The load-bearing property of the batch endpoint: one stale cell does not
+// fail the batch.**
+//
+// The single-record PUT answers a stale version with 409, which is right when
+// the caller wrote one thing. In a batch it would be wrong: bulk verbs ("mark
+// this whole series seen") routinely include episodes another device already
+// marked, and 409-ing there would abandon every cell after it. So staleness is
+// reported per record as accepted:false, with 200 on the request itself.
+func TestUDLRecordsPut_StaleCellDoesNotFailTheBatch(t *testing.T) {
+	s := newUDLTestServer(t)
+
+	const uid = "zCarol"
+	const cid = "bagdsaaaseries"
+	// Seed s01e01 at version 4 — the batch below tries to write it at 2.
+	if ok, err := s.storage.UDLUpsertIfNewer(uid, cid, "seen:s01e01", 4, 100, "b2xk", "", false, false); err != nil || !ok {
+		t.Fatalf("seed: ok=%v err=%v", ok, err)
+	}
+
+	code, out := putRecords(t, s, `{"records":[
+		{"uid":"`+uid+`","cid":"`+cid+`","key":"seen:s01e01","version":2,"ts":200,"record":"c3RhbGU"},
+		{"uid":"`+uid+`","cid":"`+cid+`","key":"seen:s01e02","version":1,"ts":200,"record":"ZnJlc2g"}
+	]}`)
+
+	if code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 — a stale cell is an outcome, not an error", code)
+	}
+	if len(out.Results) != 2 {
+		t.Fatalf("results = %d, want 2 (one per record, in order)", len(out.Results))
+	}
+	if out.Results[0].Accepted || out.Results[0].Error != "" {
+		t.Fatalf("stale cell = %+v, want accepted:false with no error", out.Results[0])
+	}
+	if !out.Results[1].Accepted {
+		t.Fatalf("fresh cell = %+v, want accepted:true", out.Results[1])
+	}
+
+	// The fresh cell really landed, and the stale one did not overwrite.
+	if _, body := getRecord(t, s, uid, cid, "seen:s01e02"); string(body["exists"]) != "true" {
+		t.Fatalf("s01e02 was not written")
+	}
+	if _, body := getRecord(t, s, uid, cid, "seen:s01e01"); string(body["version"]) != "4" {
+		t.Fatalf("s01e01 version = %s, want 4 (the stale write must not apply)", body["version"])
+	}
+}
+
+// A malformed record is reported in its own slot rather than rejecting the
+// request, for the same reason: the caller retries that cell, not the batch.
+func TestUDLRecordsPut_ReportsBadRecordPerSlot(t *testing.T) {
+	s := newUDLTestServer(t)
+
+	code, out := putRecords(t, s, `{"records":[
+		{"uid":"zDan","cid":"bagdsaaa","key":"","version":1,"ts":1,"record":"eA"},
+		{"uid":"zDan","cid":"bagdsaaa","key":"seen:s01e01","version":1,"ts":1,"record":"eA"}
+	]}`)
+
+	if code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", code)
+	}
+	if out.Results[0].Error == "" {
+		t.Fatalf("record with no key must report an error, got %+v", out.Results[0])
+	}
+	if !out.Results[1].Accepted {
+		t.Fatalf("the valid record beside it must still land, got %+v", out.Results[1])
+	}
+}
+
+// An empty batch is a client bug, not a no-op: it almost always means the
+// caller built its record list wrong, and answering 200 with an empty array
+// would hide that.
+func TestUDLRecordsPut_RejectsEmptyBatch(t *testing.T) {
+	s := newUDLTestServer(t)
+
+	if code, _ := putRecords(t, s, `{"records":[]}`); code != http.StatusBadRequest {
+		t.Fatalf("status = %d, want 400", code)
+	}
+}

internal/cid/card.go

@@ -0,0 +1,92 @@
+package cid
+
+import (
+	"encoding/base32"
+	"encoding/binary"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+)
+
+// DecodeCard recovers the (source, id) pair a card locator (CodeCard, 0x1007)
+// wraps. Wire form:
+//
+//	0x01 ‖ varint(0x1007) ‖ 0x00 (identity mh) ‖ varint(len(digest)) ‖ digest
+//	digest = varint(len(source)) ‖ source ‖ id        (both UTF-8)
+//
+// Decode stops at the multihash code because ranking needs nothing past it;
+// reading *which work* a card addresses needs the digest too, so this is the
+// one place in Go that walks the whole thing.
+//
+// ⚠ Mirror of meta-read `card_cid::decode` and of meta-feeder-sdk
+// `compute_card_cid`. The vectors in card_test.go are pinned literals copied
+// from meta-read, not round-trips, so a drift on either side fails a test
+// instead of silently reading a different work out of the same CID.
+//
+// Identity multihash only: a 0x1007 CID carrying any other multihash is not
+// something anyone mints, and reading its digest as (source, id) would be
+// reading hash bytes as text. Bytes past the declared digest length are
+// ignored, as meta-read does.
+func DecodeCard(cidStr string) (source, id string, err error) {
+	if len(cidStr) < 2 || cidStr[0] != 'b' {
+		return "", "", fmt.Errorf("cid %q: not a multibase base32 CIDv1", cidStr)
+	}
+	raw, err := base32.StdEncoding.WithPadding(base32.NoPadding).DecodeString(strings.ToUpper(cidStr[1:]))
+	if err != nil {
+		return "", "", fmt.Errorf("cid %q: base32 decode: %w", cidStr, err)
+	}
+
+	next := func(buf []byte, what string) (uint64, []byte, error) {
+		v, n := binary.Uvarint(buf)
+		if n <= 0 {
+			return 0, nil, fmt.Errorf("cid %q: bad %s varint", cidStr, what)
+		}
+		return v, buf[n:], nil
+	}
+
+	version, raw, err := next(raw, "version")
+	if err != nil {
+		return "", "", err
+	}
+	if version != 1 {
+		return "", "", fmt.Errorf("cid %q: unsupported CID version %d", cidStr, version)
+	}
+	codec, raw, err := next(raw, "codec")
+	if err != nil {
+		return "", "", err
+	}
+	if codec != CodeCard {
+		return "", "", fmt.Errorf("cid %q: codec 0x%x is not a card locator", cidStr, codec)
+	}
+	mh, raw, err := next(raw, "multihash-code")
+	if err != nil {
+		return "", "", err
+	}
+	if mh != 0 {
+		return "", "", fmt.Errorf("cid %q: card locator with non-identity multihash 0x%x", cidStr, mh)
+	}
+	digestLen, raw, err := next(raw, "digest-length")
+	if err != nil {
+		return "", "", err
+	}
+	if digestLen > uint64(len(raw)) {
+		return "", "", fmt.Errorf("cid %q: digest truncated", cidStr)
+	}
+	digest := raw[:digestLen]
+
+	sourceLen, rest, err := next(digest, "source-length")
+	if err != nil {
+		return "", "", err
+	}
+	if sourceLen > uint64(len(rest)) {
+		return "", "", fmt.Errorf("cid %q: source truncated", cidStr)
+	}
+	source, id = string(rest[:sourceLen]), string(rest[sourceLen:])
+	if source == "" || id == "" {
+		return "", "", fmt.Errorf("cid %q: empty source or id", cidStr)
+	}
+	if !utf8.ValidString(source) || !utf8.ValidString(id) {
+		return "", "", fmt.Errorf("cid %q: source or id is not UTF-8", cidStr)
+	}
+	return source, id, nil
+}

internal/cid/card_test.go

@@ -0,0 +1,71 @@
+package cid
+
+import (
+	"encoding/base32"
+	"encoding/binary"
+	"strings"
+	"testing"
+)
+
+// Pinned from meta-read `src/card_cid.rs` / meta-feeder-sdk `compute_card_cid`
+// — literals, not round-trips (see DecodeCard).
+const (
+	goldenAnilistCard  = "bagdsaaaua5qw42lmnfzxi3lbnztwcorrga2tonzy"
+	goldenMangadexCard = "bagdsaabybrwwc3thmfsgk6bon5zgol3nmfxgoyjpmiygenzsgftgmlldgm4dqljugq4dmllbmeygmlldgjrdaytcgmzdcnjrgi"
+)
+
+// wireCID builds a CIDv1 from raw parts so the negative cases below can vary
+// one field at a time.
+func wireCID(codec, mh uint64, digest []byte) string {
+	buf := []byte{0x01}
+	buf = binary.AppendUvarint(buf, codec)
+	buf = binary.AppendUvarint(buf, mh)
+	buf = binary.AppendUvarint(buf, uint64(len(digest)))
+	buf = append(buf, digest...)
+	return "b" + strings.ToLower(base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(buf))
+}
+
+func cardDigest(source, id string) []byte {
+	d := binary.AppendUvarint(nil, uint64(len(source)))
+	d = append(d, source...)
+	return append(d, id...)
+}
+
+func TestDecodeCard_GoldenVectors(t *testing.T) {
+	for _, tc := range []struct {
+		cid, source, id string
+	}{
+		{goldenAnilistCard, "anilist", "manga:105778"},
+		{goldenMangadexCard, "mangadex.org", "/manga/b0b721ff-c388-4486-aa0f-c2b0bb321512"},
+	} {
+		source, id, err := DecodeCard(tc.cid)
+		if err != nil {
+			t.Fatalf("DecodeCard(%s): %v", tc.cid, err)
+		}
+		if source != tc.source || id != tc.id {
+			t.Errorf("DecodeCard(%s) = (%q, %q), want (%q, %q)", tc.cid, source, id, tc.source, tc.id)
+		}
+		// The test encoder must agree with the pinned literal, or the negative
+		// cases below are testing a different wire format.
+		if got := wireCID(CodeCard, 0, cardDigest(tc.source, tc.id)); got != tc.cid {
+			t.Errorf("wireCID(%q, %q) = %s, want %s", tc.source, tc.id, got, tc.cid)
+		}
+	}
+}
+
+func TestDecodeCard_RejectsEverythingElse(t *testing.T) {
+	for name, s := range map[string]string{
+		"url locator codec":      wireCID(CodeURL, 0, cardDigest("anilist", "1")),
+		"non-identity multihash": wireCID(CodeCard, CodeSha256, cardDigest("anilist", "1")),
+		"empty id":               wireCID(CodeCard, 0, cardDigest("anilist", "")),
+		"source past digest":     wireCID(CodeCard, 0, []byte{0x20, 'a'}),
+		"not a CID":              "title:berserk",
+		"CIDv0":                  "QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG",
+		"truncated":              goldenAnilistCard[:12],
+		"empty":                  "",
+	} {
+		if source, id, err := DecodeCard(s); err == nil {
+			t.Errorf("%s: DecodeCard(%q) = (%q, %q), want error", name, s, source, id)
+		}
+	}
+}

internal/cid/cid-rank-vectors.json

@@ -22,7 +22,7 @@
     "25": "nzb-posting - content-derived (Message-ID set digest), but not itself fetchable",
     "20": "BitTorrent infohashes - swarm interop",
     "10": "midhash256 - the record address",
-    "5": "opaque locators (nzb-release, url, card) - never outrank a real digest",
+    "5": "opaque locators (nzb-release, url, card, yt-video, ext-play) - never outrank a real digest",
     "0": "weak/unknown digests, unparseable input"
   },
   "tieBreak": "lexicographically smaller cid wins",
@@ -116,6 +116,30 @@
       "rank": 5,
       "note": "codec 0x1007 + IDENTITY multihash 0x00, digest = varint(len(source)) || source || id — here (\"tmdb\",\"tv:95479\"). Same codec-slot rule as nzb-release/url: match on the CODEC, never the mh. The limit case of the family — the only CID in MetaMesh with NO bytes behind it anywhere, ever: it addresses a *work* (a series, a film), not a file, so the byte path 404s by design and bitswap never offers it (seeding is gated on sha2-256). Tier 5 is load-bearing for the planned cross-source merge: one card record may carry BOTH a TMDB and a MyAnimeList locator, and if a real card body is ever added (see card-tier-search.md §4.3) its sha2-256 must win the canonical election over both locators without any addressing change. Ranking it 0 instead would still lose to a digest, but would put the implementations back out of agreement — which is the exact failure this fixture exists to prevent."
     },
+    {
+      "name": "yt-video-locator",
+      "cid": "bagecaaarav3gszdfn42ein3vgvfumn2tka4a",
+      "rank": 5,
+      "note": "codec 0x1008 + IDENTITY multihash 0x00, digest = varint(len(kind)) || kind || id — here (\"video\",\"4D7u5KF7SP8\"). DELEGATED PLAYBACK: the limit case beyond card. A card addresses a work with no bytes anywhere; this addresses a *rendition* whose bytes exist but are permanently someone else's — an external player renders it, nothing is transported, seeded or content-addressed. Framing is byte-identical to card (0x1007) on purpose, so each implementation extends the parser it already wrote. Same codec-slot rule: match on the CODEC, never the mh (identity 0x00 would fall through and score 0). Tier 5 is load-bearing for the on-ramp: a delegated reference and a real archived copy can sit on ONE record, and that sha2-256 must win the canonical election over this locator with no addressing change. NOTE the byte path must REFUSE this (400), not 404 — see docs/cid-formats.md §7.4."
+    },
+    {
+      "name": "ext-play-locator",
+      "cid": "bagesaabenb2hi4dthixs6zlymfwxa3dffzrgc3temnqw24bomnxw2l3bnrrhk3jppa",
+      "rank": 5,
+      "note": "codec 0x1009 + IDENTITY multihash 0x00, digest = the verbatim UTF-8 URL. WIRE-IDENTICAL to url (0x1006) apart from the codec, and that difference is the entire contract: 0x1006 means 'fetch these bytes once and seed them', 0x1009 means 'open this in a browser, there are no bytes for us'. A decoder that matched on SHAPE rather than on the codec slot would see an identity multihash wrapping an http(s) URL, take the 0x1006 path, fetch a watch/Bandcamp page, chunk it, seed the HTML and link that content CID onto the record AS THE FILE — the MSR1 poisoning shape, except permanent and replicated. Same tier/reasoning as the rest of the locator family."
+    },
+    {
+      "name": "provider-file-locator",
+      "cid": "bagfcaaa2bvxxazloon2we5djorwgk43gnfwgkorxga3dcobtgq",
+      "rank": 5,
+      "note": "codec 0x100A + IDENTITY multihash 0x00, digest = varint(len(source)) || source || id - here (\"opensubtitles\",\"file:7061834\"). The GENERIC fetchable locator: one codec for every provider whose bytes are fetched the same way; the provider is inside the digest. Framing byte-identical to card (0x1007), but the byte path RESOLVES it (via source's fetch tier) instead of 404ing. Same codec-slot rule as the rest of the family: match on the CODEC, never the mh (identity 0x00 would fall through and score 0). Tier 5: once the fetched bytes' sha2-256 is linked onto the record it wins the canonical election with no addressing change."
+    },
+    {
+      "name": "provider-file-tachiyomi",
+      "cid": "bagfcaabebf2gcy3inf4w63ljnvwhu332gnvw423po42hg33ug4zdeytdonrtk4bsnq",
+      "rank": 5,
+      "note": "provider-file (0x100A) under the second registered source, (\"tachiyomi\", base32lower(sha256(\"https://www.mangakakalot.gg/manga/ragna-crimson/chapter-94\"))[..26] = \"mlzoz3knkow4sot722bcsc5p2l\"). A comic chapter, minted by meta-feeder-suwayomi from the chapter's address ON ITS SITE - never the Suwayomi host/port/row ids - so every box mints this same cid; redeemed into one CBZ. Same rank as any provider-file (rank ignores source); the vector proves the digest bytes (cid-formats.md section 8.3)."
+    },
     {
       "name": "sha1",
       "cid": "baeircff3eqvxxaqqot2lt242stkdtk3gq4c2vra",

internal/cid/rank.go

@@ -58,6 +58,31 @@ const (
 	// one record, and a real digest added later still wins the election.
 	CodeCard = 0x1007 // custom — identity-multihash CID wrapping a card (work) id
 
+	// CodeYtVideo and CodeExtPlay are the DELEGATED-PLAYBACK locators — the
+	// limit case beyond CodeCard. A card addresses a work with no bytes
+	// anywhere; these address a *rendition* whose bytes exist but are
+	// permanently someone else's: an external player renders the media, nothing
+	// is transported, seeded or content-addressed.
+	//
+	// They rank on the CODEC like the rest of the family — their multihash is
+	// identity (0x00), so a rank that dispatched on the multihash would see 0x00,
+	// fall through and silently score 0. That is the exact drift that once made
+	// meta-share and meta-search elect different canonical CIDs for one record.
+	//
+	// Tier 5 is also what keeps the on-ramp safe: a delegated reference and a
+	// real CID can sit on one record, and if the media is ever archived to the
+	// mesh its sha2-256 wins the canonical election with no addressing change.
+	CodeYtVideo = 0x1008 // custom — identity-multihash CID wrapping a YouTube (kind, id)
+	CodeExtPlay = 0x1009 // custom — identity-multihash CID wrapping a URL to OPEN, never fetch
+
+	// CodeProviderFile is the FETCHABLE twin of CodeExtPlay: a provider-held
+	// file addressed as varint(len(source))‖source‖id — ("opensubtitles",
+	// "file:7061834"). Framing is byte-identical to CodeCard; only the byte
+	// path differs (it redeems the id through that source's feeder instead of
+	// 404ing). Same codec-slot rule and same tier: once the fetched bytes'
+	// sha2-256 is linked onto the record it wins with no addressing change.
+	CodeProviderFile = 0x100A // custom — identity-multihash CID wrapping a (source, id) provider file
+
 	// CodeNzbPosting is the INVERSE trap of the two above: its multihash is a
 	// REAL sha2-256 digest (over the normalised, sorted article Message-ID
 	// set of a Usenet posting we scanned ourselves — never a locator, no
@@ -165,7 +190,8 @@ func Rank(cidStr string) int {
 	}
 	// Opaque locators. Codec-only: their multihash is identity (0x00), so
 	// there is nothing to match on the mh side.
-	if codec == CodeNzbRelease || codec == CodeURL || codec == CodeCard {
+	if codec == CodeNzbRelease || codec == CodeURL || codec == CodeCard ||
+		codec == CodeYtVideo || codec == CodeExtPlay || codec == CodeProviderFile {
 		return RankLocator
 	}
 	// nzb-posting: codec-only, checked BEFORE the mh switch below — its

internal/config/config.go

@@ -19,8 +19,8 @@ type Config struct {
 	BaseURL        string // Base URL for stable service discovery
 	PublicURL      string // Browser-facing URL for the service-bar nav; overrides BaseURL when set (e.g. a debug-direct port with no Caddy in front)
 
-	// Redis configuration
-	RedisPort int // Redis port (default: 6379)
+	// Storage configuration
+	DBPathOverride string // META_CORE_DB_PATH; empty = <MetaCorePath>/db/meta-core.db
 
 	// HTTP API configuration
 	HTTPPort int    // HTTP API port (default: 9000)
@@ -40,6 +40,14 @@ type Config struct {
 
 	// Mount configuration
 	MountsDir string // Path to mounts configuration (default: /meta-core/mounts)
+
+	// UDP discovery (beacon v2). Replaces the file-based registry that used
+	// to live under /meta-core/services; see
+	// docs/project-architecture/beacon-v2.md.
+	EnableUDPDiscovery  bool   // Advertise + listen on the multicast group (default: true)
+	DiscoveryGroup      string // BEACON_GROUP: IPv4 multicast group (default: 239.255.99.1)
+	DiscoveryPort       int    // BEACON_PORT: UDP port (default: 9099)
+	DiscoveryIntervalMS int    // BEACON_INTERVAL_MS: unsolicited advertise interval (default: 10000)
 }
 
 // Load creates a Config from environment variables
@@ -52,7 +60,7 @@ func Load() *Config {
 		APIPort:                getEnvInt("API_PORT", 8180),
 		BaseURL:                getEnv("BASE_URL", ""),
 		PublicURL:              getEnv("META_CORE_PUBLIC_URL", ""),
-		RedisPort:             getEnvInt("REDIS_PORT", 6379),
+		DBPathOverride:         getEnv("META_CORE_DB_PATH", ""),
 		HTTPPort:               getEnvInt("META_CORE_HTTP_PORT", 9000),
 		HTTPHost:               getEnv("META_CORE_HTTP_HOST", "0.0.0.0"),
 		HealthCheckIntervalMS:  getEnvInt("HEALTH_CHECK_INTERVAL_MS", 5000),
@@ -63,6 +71,10 @@ func Load() *Config {
 		WatchIntervalMS:        getEnvInt("WATCH_INTERVAL_MS", 1000),
 		DebounceMS:             getEnvInt("DEBOUNCE_MS", 30000),
 		EnableFileWatcher:      getEnvBool("ENABLE_FILE_WATCHER", true),
+		EnableUDPDiscovery:     getEnvBool("ENABLE_UDP_DISCOVERY", true),
+		DiscoveryGroup:         getEnv("BEACON_GROUP", "239.255.99.1"),
+		DiscoveryPort:          getEnvInt("BEACON_PORT", 9099),
+		DiscoveryIntervalMS:    getEnvInt("BEACON_INTERVAL_MS", 10000),
 	}
 
 	// Set mounts directory
@@ -71,24 +83,20 @@ func Load() *Config {
 	return cfg
 }
 
-// LockFilePath returns the path to the leader lock file
+// LockFilePath returns the path to the database-volume mutex (one meta-core
+// per database file). Held by
+// docker/leader-election.sh; nothing reads it, and it is NOT service
+// discovery — see docs/project-architecture/beacon-v2.md.
 func (c *Config) LockFilePath() string {
 	return c.MetaCorePath + "/locks/kv-leader.lock"
 }
 
-// InfoFilePath returns the path to the leader info file
-func (c *Config) InfoFilePath() string {
-	return c.MetaCorePath + "/locks/kv-leader.info"
+// DBPath returns the path of meta-core's SQLite database file.
+func (c *Config) DBPath() string {
+	if c.DBPathOverride != "" {
+		return c.DBPathOverride
 	}
-
-// RedisDataDir returns the path to Redis data directory
-func (c *Config) RedisDataDir() string {
-	return c.MetaCorePath + "/db/redis"
-}
-
-// ServicesDir returns the path to services directory
-func (c *Config) ServicesDir() string {
-	return c.MetaCorePath + "/services"
+	return c.MetaCorePath + "/db/meta-core.db"
 }
 
 // MountsFilePath returns the path to the mounts configuration file

internal/discovery/cleaner.go

@@ -1,196 +0,0 @@
-package discovery
-
-import (
-	"encoding/json"
-	"log"
-	"os"
-	"path/filepath"
-	"sync"
-	"time"
-
-	"github.com/metazla/meta-core/internal/config"
-)
-
-// CleanupStats holds statistics about the cleanup process
-type CleanupStats struct {
-	LastRunTime     string `json:"lastRunTime,omitempty"`
-	ServicesRemoved int    `json:"servicesRemoved"`
-	TotalRuns       int    `json:"totalRuns"`
-	Errors          int    `json:"errors"`
-}
-
-// Cleaner handles periodic cleanup of dead service registration files
-type Cleaner struct {
-	config      *config.Config
-	servicesDir string
-	ownFile     string // Our own service file (never delete)
-
-	stats    CleanupStats
-	stopChan chan struct{}
-	wg       sync.WaitGroup
-	mu       sync.RWMutex
-}
-
-// NewCleaner creates a new service cleaner
-func NewCleaner(cfg *config.Config) *Cleaner {
-	hostname, _ := os.Hostname()
-	return &Cleaner{
-		config:      cfg,
-		servicesDir: cfg.ServicesDir(),
-		ownFile:     filepath.Join(cfg.ServicesDir(), cfg.ServiceName+"-"+hostname+".json"),
-		stopChan:    make(chan struct{}),
-	}
-}
-
-// Start begins the cleanup loop
-func (c *Cleaner) Start() error {
-	log.Printf("[Cleaner] Starting dead service cleanup (interval: %dms, threshold: %dms)",
-		c.config.CleanupIntervalMS, c.config.DeadServiceThresholdMS)
-
-	c.wg.Add(1)
-	go c.cleanupLoop()
-
-	return nil
-}
-
-// Stop stops the cleanup loop
-func (c *Cleaner) Stop() error {
-	log.Println("[Cleaner] Stopping dead service cleanup...")
-	close(c.stopChan)
-	c.wg.Wait()
-	return nil
-}
-
-// cleanupLoop runs the periodic cleanup
-func (c *Cleaner) cleanupLoop() {
-	defer c.wg.Done()
-
-	// Run an initial cleanup shortly after starting
-	initialDelay := time.NewTimer(30 * time.Second)
-	select {
-	case <-c.stopChan:
-		initialDelay.Stop()
-		return
-	case <-initialDelay.C:
-		c.runCleanup()
-	}
-
-	ticker := time.NewTicker(time.Duration(c.config.CleanupIntervalMS) * time.Millisecond)
-	defer ticker.Stop()
-
-	for {
-		select {
-		case <-c.stopChan:
-			return
-		case <-ticker.C:
-			c.runCleanup()
-		}
-	}
-}
-
-// runCleanup scans the services directory and removes dead services
-func (c *Cleaner) runCleanup() {
-	c.mu.Lock()
-	c.stats.TotalRuns++
-	c.stats.LastRunTime = time.Now().UTC().Format(time.RFC3339)
-	c.mu.Unlock()
-
-	entries, err := os.ReadDir(c.servicesDir)
-	if err != nil {
-		if !os.IsNotExist(err) {
-			log.Printf("[Cleaner] Failed to read services directory: %v", err)
-			c.mu.Lock()
-			c.stats.Errors++
-			c.mu.Unlock()
-		}
-		return
-	}
-
-	threshold := time.Duration(c.config.DeadServiceThresholdMS) * time.Millisecond
-	removedCount := 0
-
-	for _, entry := range entries {
-		if entry.IsDir() || filepath.Ext(entry.Name()) != ".json" {
-			continue
-		}
-
-		filePath := filepath.Join(c.servicesDir, entry.Name())
-
-		// Never delete our own service file
-		if filePath == c.ownFile {
-			continue
-		}
-
-		// Check if service is dead
-		isDead, serviceName, age := c.isServiceDead(filePath, threshold)
-		if isDead {
-			if err := os.Remove(filePath); err != nil {
-				log.Printf("[Cleaner] Failed to remove dead service file %s: %v", entry.Name(), err)
-				c.mu.Lock()
-				c.stats.Errors++
-				c.mu.Unlock()
-			} else {
-				ageMinutes := age.Minutes()
-				log.Printf("[Cleaner] Removed dead service: %s (last heartbeat: %.1f minutes ago)", serviceName, ageMinutes)
-				removedCount++
-			}
-		}
-	}
-
-	if removedCount > 0 {
-		c.mu.Lock()
-		c.stats.ServicesRemoved += removedCount
-		c.mu.Unlock()
-		log.Printf("[Cleaner] Cleanup complete: removed %d dead service(s)", removedCount)
-	}
-}
-
-// isServiceDead checks if a service file represents a dead service
-// Returns: isDead, serviceName, age since last heartbeat
-func (c *Cleaner) isServiceDead(filePath string, threshold time.Duration) (bool, string, time.Duration) {
-	data, err := os.ReadFile(filePath)
-	if err != nil {
-		// Can't read file - treat as dead to clean up corrupted files
-		log.Printf("[Cleaner] Cannot read service file %s: %v (treating as dead)", filepath.Base(filePath), err)
-		return true, filepath.Base(filePath), threshold
-	}
-
-	var info ServiceInfo
-	if err := json.Unmarshal(data, &info); err != nil {
-		// Corrupted JSON - skip rather than delete (might be recoverable)
-		log.Printf("[Cleaner] Skipping corrupted service file %s: %v", filepath.Base(filePath), err)
-		return false, "", 0
-	}
-
-	// Parse last heartbeat timestamp
-	if info.LastHeartbeat == "" {
-		// No heartbeat timestamp - treat as dead
-		return true, info.Name, threshold
-	}
-
-	lastHeartbeat, err := time.Parse(time.RFC3339, info.LastHeartbeat)
-	if err != nil {
-		// Invalid timestamp - treat as dead
-		log.Printf("[Cleaner] Invalid timestamp in service file %s: %v (treating as dead)", filepath.Base(filePath), err)
-		return true, info.Name, threshold
-	}
-
-	age := time.Since(lastHeartbeat)
-	if age > threshold {
-		return true, info.Name, age
-	}
-
-	return false, info.Name, age
-}
-
-// Stats returns a copy of the current cleanup statistics
-func (c *Cleaner) Stats() CleanupStats {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	return CleanupStats{
-		LastRunTime:     c.stats.LastRunTime,
-		ServicesRemoved: c.stats.ServicesRemoved,
-		TotalRuns:       c.stats.TotalRuns,
-		Errors:          c.stats.Errors,
-	}
-}

internal/discovery/service.go

@@ -1,286 +0,0 @@
-package discovery
-
-import (
-	"encoding/json"
-	"fmt"
-	"log"
-	"net"
-	"os"
-	"path/filepath"
-	"sync"
-	"time"
-
-	"github.com/metazla/meta-core/internal/config"
-)
-
-// ServiceInfo contains simplified service registration data
-// URLs are obtained via the /urls API endpoint
-type ServiceInfo struct {
-	Name          string `json:"name"`
-	Hostname      string `json:"hostname"`
-	BaseUrl       string `json:"baseUrl"`
-	Status        string `json:"status"`
-	LastHeartbeat string `json:"lastHeartbeat"`
-}
-
-// Service handles service registration and discovery
-type Service struct {
-	config      *config.Config
-	servicesDir string
-	serviceFile string
-	info        *ServiceInfo
-	mu          sync.RWMutex
-
-	stopChan chan struct{}
-	wg       sync.WaitGroup
-}
-
-// NewService creates a new service discovery instance
-func NewService(cfg *config.Config) *Service {
-	hostname, _ := os.Hostname()
-	return &Service{
-		config:      cfg,
-		servicesDir: cfg.ServicesDir(),
-		serviceFile: filepath.Join(cfg.ServicesDir(), cfg.ServiceName+"-"+hostname+".json"),
-		stopChan:    make(chan struct{}),
-	}
-}
-
-// Start begins service registration and heartbeat
-func (s *Service) Start() error {
-	log.Printf("[Discovery] Starting service discovery for %s", s.config.ServiceName)
-
-	// Ensure services directory exists
-	if err := os.MkdirAll(s.servicesDir, 0755); err != nil {
-		return fmt.Errorf("failed to create services directory: %w", err)
-	}
-
-	// Build and register service info
-	s.info = s.buildServiceInfo()
-	if err := s.register(); err != nil {
-		return fmt.Errorf("failed to register service: %w", err)
-	}
-
-	// Start heartbeat loop
-	s.wg.Add(1)
-	go s.heartbeatLoop()
-
-	return nil
-}
-
-// Stop stops service discovery and unregisters
-func (s *Service) Stop() error {
-	log.Println("[Discovery] Stopping service discovery...")
-	close(s.stopChan)
-	s.wg.Wait()
-
-	// Unregister by removing service file
-	if err := os.Remove(s.serviceFile); err != nil && !os.IsNotExist(err) {
-		log.Printf("[Discovery] Failed to remove service file: %v", err)
-	}
-
-	return nil
-}
-
-// buildServiceInfo creates the service info for this instance
-func (s *Service) buildServiceInfo() *ServiceInfo {
-	hostname, _ := os.Hostname()
-	ip := getLocalIP()
-
-	// Browser-facing nav URL: prefer META_CORE_PUBLIC_URL (the reachable URL
-	// when there's no Caddy perimeter in front — e.g. a debug-direct port),
-	// then BASE_URL (the Caddy perimeter URL), then the internal IP.
-	var baseUrl string
-	if s.config.PublicURL != "" {
-		baseUrl = s.config.PublicURL
-	} else if s.config.BaseURL != "" {
-		baseUrl = s.config.BaseURL
-	} else {
-		baseUrl = fmt.Sprintf("http://%s:%d", ip, s.config.APIPort)
-	}
-
-	info := &ServiceInfo{
-		Name:          s.config.ServiceName,
-		Hostname:      hostname,
-		BaseUrl:       baseUrl,
-		Status:        "running",
-		LastHeartbeat: time.Now().UTC().Format(time.RFC3339),
-	}
-
-	return info
-}
-
-// register writes service info to file
-func (s *Service) register() error {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	return s.writeServiceInfo(s.info)
-}
-
-// writeServiceInfo atomically writes service info to file
-func (s *Service) writeServiceInfo(info *ServiceInfo) error {
-	tempPath := s.serviceFile + ".tmp"
-
-	data, err := json.MarshalIndent(info, "", "  ")
-	if err != nil {
-		return err
-	}
-
-	if err := os.WriteFile(tempPath, data, 0644); err != nil {
-		return err
-	}
-
-	return os.Rename(tempPath, s.serviceFile)
-}
-
-// heartbeatLoop periodically updates the last heartbeat
-func (s *Service) heartbeatLoop() {
-	defer s.wg.Done()
-
-	ticker := time.NewTicker(time.Duration(s.config.HeartbeatIntervalMS) * time.Millisecond)
-	defer ticker.Stop()
-
-	for {
-		select {
-		case <-s.stopChan:
-			return
-		case <-ticker.C:
-			s.heartbeat()
-		}
-	}
-}
-
-// heartbeat updates the last heartbeat timestamp
-func (s *Service) heartbeat() {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	if s.info == nil {
-		return
-	}
-
-	s.info.LastHeartbeat = time.Now().UTC().Format(time.RFC3339)
-
-	if err := s.writeServiceInfo(s.info); err != nil {
-		log.Printf("[Discovery] Failed to update heartbeat: %v", err)
-	}
-}
-
-// UpdateStatus updates the service status
-func (s *Service) UpdateStatus(status string) error {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	if s.info == nil {
-		return fmt.Errorf("service not registered")
-	}
-
-	s.info.Status = status
-	s.info.LastHeartbeat = time.Now().UTC().Format(time.RFC3339)
-	return s.writeServiceInfo(s.info)
-}
-
-// Discover finds a service by name
-// Looks for files matching pattern: name-*.json (hostname-based naming)
-func (s *Service) Discover(name string) (*ServiceInfo, error) {
-	// First try exact match for backward compatibility
-	exactPath := filepath.Join(s.servicesDir, name+".json")
-	if data, err := os.ReadFile(exactPath); err == nil {
-		var info ServiceInfo
-		if err := json.Unmarshal(data, &info); err == nil {
-			return s.checkStale(&info), nil
-		}
-	}
-
-	// Search for hostname-based files: name-*.json
-	pattern := filepath.Join(s.servicesDir, name+"-*.json")
-	matches, err := filepath.Glob(pattern)
-	if err != nil {
-		return nil, err
-	}
-
-	// Return the first valid service found
-	for _, match := range matches {
-		data, err := os.ReadFile(match)
-		if err != nil {
-			continue
-		}
-
-		var info ServiceInfo
-		if err := json.Unmarshal(data, &info); err != nil {
-			continue
-		}
-
-		return s.checkStale(&info), nil
-	}
-
-	return nil, nil
-}
-
-// checkStale marks a service as stale if heartbeat is too old
-func (s *Service) checkStale(info *ServiceInfo) *ServiceInfo {
-	lastHeartbeat, err := time.Parse(time.RFC3339, info.LastHeartbeat)
-	if err == nil {
-		staleThreshold := time.Duration(s.config.StaleThresholdMS) * time.Millisecond
-		if time.Since(lastHeartbeat) > staleThreshold {
-			info.Status = "stale"
-		}
-	}
-	return info
-}
-
-// DiscoverAll finds all registered services
-func (s *Service) DiscoverAll() ([]*ServiceInfo, error) {
-	entries, err := os.ReadDir(s.servicesDir)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return []*ServiceInfo{}, nil
-		}
-		return nil, err
-	}
-
-	var services []*ServiceInfo
-	for _, entry := range entries {
-		if entry.IsDir() || filepath.Ext(entry.Name()) != ".json" {
-			continue
-		}
-
-		filePath := filepath.Join(s.servicesDir, entry.Name())
-		data, err := os.ReadFile(filePath)
-		if err != nil {
-			log.Printf("[Discovery] Failed to read service file %s: %v", entry.Name(), err)
-			continue
-		}
-
-		var info ServiceInfo
-		if err := json.Unmarshal(data, &info); err != nil {
-			log.Printf("[Discovery] Failed to parse service file %s: %v", entry.Name(), err)
-			continue
-		}
-
-		services = append(services, s.checkStale(&info))
-	}
-
-	return services, nil
-}
-
-// getLocalIP returns the local IP address
-func getLocalIP() string {
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		hostname, _ := os.Hostname()
-		return hostname
-	}
-
-	for _, addr := range addrs {
-		if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
-			if ipnet.IP.To4() != nil {
-				return ipnet.IP.String()
-			}
-		}
-	}
-
-	hostname, _ := os.Hostname()
-	return hostname
-}

internal/events/meta_publisher.go

@@ -1,189 +1,89 @@
 package events
 
 import (
-	"context"
 	"fmt"
 	"log"
-	"strings"
 	"sync"
 	"time"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/storage"
 )
 
 const (
-	// MetaEventsStream is the Redis stream name for metadata events
-	MetaEventsStream = "meta:events"
+	// MetaEventsStream is the stream name for metadata events.
+	MetaEventsStream = storage.MetaEventsStream
 
 	// MetaEventsMaxLen is the approximate cap on stream length. Bounded
 	// retention is a contract requirement for the SSE wire — see
 	// docs/api-mediated-access.md "Backing-store retention and lifecycle".
-	// Cheap (~) trim keeps growth bounded without serialising writes.
-	MetaEventsMaxLen = 100_000
+	MetaEventsMaxLen = storage.MetaEventsMaxLen
 )
 
-// MetaPublisher subscribes to Redis keyspace notifications
-// and publishes metadata change events to the meta:events stream
+// republishBatch is how many events one republish transaction appends —
+// large enough to amortise the commit, small enough that the writer is never
+// held for long.
+const republishBatch = 5_000
+
+// MetaPublisher owns the meta:events stream's bulk republish.
+//
+// Live change events no longer pass through here: under Redis this subscribed
+// to keyspace notifications and copied each into the stream, a hop that could
+// drop events whenever the subscriber lagged. The storage engine now appends
+// the event in the same transaction as the change (internal/kv), so a change
+// and its event commit together.
 type MetaPublisher struct {
-	client  *redis.Client
-	ctx     context.Context
-	cancel  context.CancelFunc
-	wg      sync.WaitGroup
+	client  *storage.Client
 	running bool
 	mu      sync.RWMutex
 }
 
-// NewMetaPublisher creates a new MetaPublisher
-func NewMetaPublisher(client *redis.Client) *MetaPublisher {
-	ctx, cancel := context.WithCancel(context.Background())
-	return &MetaPublisher{
-		client: client,
-		ctx:    ctx,
-		cancel: cancel,
-	}
+// NewMetaPublisher creates a new MetaPublisher.
+func NewMetaPublisher(client *storage.Client) *MetaPublisher {
+	return &MetaPublisher{client: client}
 }
 
-// Start begins subscribing to keyspace notifications.
-//
-// The stream is NOT truncated on startup — the SSE wire contract requires
-// Last-Event-ID resumption to survive a meta-core restart, which means
-// entries must persist across restart. Growth is bounded instead by
-// MAXLEN ~ MetaEventsMaxLen on every XAdd (see publishEvent).
+// Start marks the publisher ready. The stream is NOT truncated on startup —
+// the SSE wire contract requires Last-Event-ID resumption to survive a
+// meta-core restart. Growth is bounded by MetaEventsMaxLen instead.
 func (p *MetaPublisher) Start() error {
 	p.mu.Lock()
-	if p.running {
-		p.mu.Unlock()
-		return nil
-	}
+	defer p.mu.Unlock()
 	p.running = true
-	p.mu.Unlock()
-
-	p.wg.Add(1)
-	go p.subscribeLoop()
-
-	log.Println("[MetaPublisher] Started - listening for keyspace notifications")
+	log.Println("[MetaPublisher] Started")
 	return nil
 }
 
-// Stop stops the publisher
+// Stop stops the publisher.
 func (p *MetaPublisher) Stop() error {
 	p.mu.Lock()
-	if !p.running {
-		p.mu.Unlock()
-		return nil
-	}
+	defer p.mu.Unlock()
 	p.running = false
-	p.mu.Unlock()
-
-	p.cancel()
-	p.wg.Wait()
-
 	log.Println("[MetaPublisher] Stopped")
 	return nil
 }
 
-// IsRunning returns true if the publisher is running
+// IsRunning returns true if the publisher is running.
 func (p *MetaPublisher) IsRunning() bool {
 	p.mu.RLock()
 	defer p.mu.RUnlock()
 	return p.running
 }
 
-// subscribeLoop subscribes to keyspace notifications and publishes events
-func (p *MetaPublisher) subscribeLoop() {
-	defer p.wg.Done()
-
-	// Subscribe to all file:* keyspace events
-	// Pattern: __keyspace@0__:file:*
-	pattern := "__keyspace@0__:file:*"
-	pubsub := p.client.PSubscribe(p.ctx, pattern)
-	defer pubsub.Close()
-
-	log.Printf("[MetaPublisher] Subscribed to pattern: %s", pattern)
-
-	ch := pubsub.Channel()
-	for {
-		select {
-		case <-p.ctx.Done():
-			return
-		case msg := <-ch:
-			if msg == nil {
-				continue
-			}
-			// msg.Channel: __keyspace@0__:file:midhash256:abc123/tmdb
-			// msg.Payload: set, del, expire, etc.
-			p.publishEvent(msg.Channel, msg.Payload)
-		}
-	}
-}
-
-// publishEvent publishes a keyspace event to the meta:events stream
-func (p *MetaPublisher) publishEvent(channel, operation string) {
-	// Extract key from channel: __keyspace@0__:file:xxx/field -> file:xxx/field
-	key := strings.TrimPrefix(channel, "__keyspace@0__:")
-
-	// Skip index key and non-file keys
-	if strings.Contains(key, "__index__") || !strings.HasPrefix(key, "file:") {
-		return
-	}
-
-	// Build event fields
-	fields := map[string]interface{}{
-		"type": operation, // "set", "del", "expire"
-		"key":  key,       // "file:midhash256:abc123/tmdb"
-		"ts":   fmt.Sprintf("%d", time.Now().UnixMilli()),
-	}
-
-	// Approximate MAXLEN trim keeps the stream bounded across restarts
-	// (see Start). Cap is intentionally generous; most consumers reconnect
-	// well within retention.
-	_, err := p.client.XAdd(p.ctx, &redis.XAddArgs{
-		Stream: MetaEventsStream,
-		MaxLen: MetaEventsMaxLen,
-		Approx: true,
-		Values: fields,
-	}).Result()
-
-	if err != nil {
-		log.Printf("[MetaPublisher] Error publishing event: %v", err)
-	}
-}
-
-// publishEventDirect publishes an event directly (not from keyspace notification)
-func (p *MetaPublisher) publishEventDirect(operation, key string) {
-	fields := map[string]interface{}{
-		"type": operation,
-		"key":  key,
-		"ts":   fmt.Sprintf("%d", time.Now().UnixMilli()),
-	}
-
-	_, err := p.client.XAdd(p.ctx, &redis.XAddArgs{
-		Stream: MetaEventsStream,
-		MaxLen: MetaEventsMaxLen,
-		Approx: true,
-		Values: fields,
-	}).Result()
-
-	if err != nil {
-		log.Printf("[MetaPublisher] Error publishing direct event: %v", err)
-	}
-}
-
 // RepublishFunc is a function type for getting metadata that can be republished
 type RepublishFunc func() (hashIDs []string, getMetadata func(hashID string) (map[string]string, error), err error)
 
-// RepublishAllMetadata iterates over all existing file metadata and publishes events
-// This is called on startup and can be triggered via API
+// RepublishAllMetadata publishes a `set` event for every property of every
+// record. Called on startup and via the API.
+//
+// It exists for consumers that rebuild their state by replaying meta:events
+// from the beginning (meta-fuse's VFS does, with initialCursor 0-0) rather
+// than backfilling over HTTP. Appended in bounded batches, each its own
+// transaction, so a multi-million-event republish never holds the writer.
 func (p *MetaPublisher) RepublishAllMetadata(republishFunc RepublishFunc) (int, error) {
-	p.mu.RLock()
-	running := p.running
-	p.mu.RUnlock()
-
-	if !running {
+	if !p.IsRunning() {
 		return 0, fmt.Errorf("publisher not running")
 	}
 
-	// Get all hash IDs and metadata getter
 	hashIDs, getMetadata, err := republishFunc()
 	if err != nil {
 		return 0, fmt.Errorf("failed to get hash IDs: %w", err)
@@ -191,22 +91,39 @@ func (p *MetaPublisher) RepublishAllMetadata(republishFunc RepublishFunc) (int,
 
 	log.Printf("[MetaPublisher] Republishing events for %d files...", len(hashIDs))
 
-	publishedCount := 0
+	published := 0
+	batch := make([]map[string]string, 0, republishBatch)
+	flush := func() error {
+		if err := p.client.AppendEvents(MetaEventsStream, MetaEventsMaxLen, batch); err != nil {
+			return err
+		}
+		published += len(batch)
+		batch = batch[:0]
+		return nil
+	}
 	for _, hashID := range hashIDs {
-		// Get all properties for this file
 		metadata, err := getMetadata(hashID)
 		if err != nil || metadata == nil {
 			continue
 		}
-
-		// Publish a set event for each property
+		ts := fmt.Sprintf("%d", time.Now().UnixMilli())
 		for property := range metadata {
-			key := fmt.Sprintf("file:%s/%s", hashID, property)
-			p.publishEventDirect("set", key)
-			publishedCount++
+			batch = append(batch, map[string]string{
+				"type": "set",
+				"key":  fmt.Sprintf("file:%s/%s", hashID, property),
+				"ts":   ts,
+			})
+			if len(batch) >= republishBatch {
+				if err := flush(); err != nil {
+					return published, fmt.Errorf("republish: %w", err)
 				}
 			}
+		}
+	}
+	if err := flush(); err != nil {
+		return published, fmt.Errorf("republish: %w", err)
+	}
 
-	log.Printf("[MetaPublisher] Republished %d property events", publishedCount)
-	return publishedCount, nil
+	log.Printf("[MetaPublisher] Republished %d property events", published)
+	return published, nil
 }

internal/identity/challenge.go

@@ -0,0 +1,126 @@
+package identity
+
+// In-memory, single-use challenge store backing proof-of-possession on the
+// account operations that need it (reveal, delete).
+//
+// In memory on purpose: a challenge is worthless once redeemed and worthless
+// once expired, so persisting it would only widen the window in which a leaked
+// one is useful. A meta-core restart invalidates every challenge in flight,
+// which costs a client one retry.
+//
+// Mirrors the sign-in challenge in meta-watch's src/auth.rs, down to the TTL —
+// the browser signs immediately, so seconds is the right order and a narrow
+// window bounds replay if one ever surfaces in a proxy log.
+
+import (
+	"errors"
+	"sync"
+	"time"
+)
+
+// ChallengeTTL is how long an issued challenge stays answerable.
+const ChallengeTTL = 120 * time.Second
+
+// maxChallenges caps the store. An unauthenticated caller can mint challenges
+// for any uid it can name, so the map is attacker-growable; without a ceiling
+// that is a memory-exhaustion lever. At the cap, issuing fails rather than
+// evicting: dropping someone else's live challenge on demand would let an
+// attacker deny sign-outs, which is worse than making them retry.
+const maxChallenges = 4096
+
+var (
+	// ErrChallengeUnknown covers absent, already-redeemed and expired alike.
+	// One error for all three deliberately: distinguishing them tells a prober
+	// whether a challenge string was ever real.
+	ErrChallengeUnknown = errors.New("challenge is unknown, already used, or expired")
+	ErrChallengeFull    = errors.New("too many challenges in flight; try again shortly")
+)
+
+type challengeEntry struct {
+	uid     string
+	action  Action
+	expires time.Time
+}
+
+// ChallengeStore issues and redeems challenges. Safe for concurrent use.
+type ChallengeStore struct {
+	mu      sync.Mutex
+	entries map[string]challengeEntry
+	ttl     time.Duration
+	// now is swappable so the tests can age entries without sleeping.
+	now func() time.Time
+}
+
+func NewChallengeStore() *ChallengeStore {
+	return &ChallengeStore{
+		entries: make(map[string]challengeEntry),
+		ttl:     ChallengeTTL,
+		now:     time.Now,
+	}
+}
+
+// Issue mints a challenge for (uid, action) and remembers it until redeemed or
+// expired. Returns the literal text the client signs and its expiry.
+func (s *ChallengeStore) Issue(uid string, action Action) (string, time.Time, error) {
+	if !validUID(uid) {
+		return "", time.Time{}, errors.New("invalid uid")
+	}
+	if !ValidAction(action) {
+		return "", time.Time{}, errors.New("unknown action")
+	}
+	text, err := NewChallengeText(uid, action)
+	if err != nil {
+		return "", time.Time{}, err
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.sweepLocked()
+	if len(s.entries) >= maxChallenges {
+		return "", time.Time{}, ErrChallengeFull
+	}
+	expires := s.now().Add(s.ttl)
+	s.entries[text] = challengeEntry{uid: uid, action: action, expires: expires}
+	return text, expires, nil
+}
+
+// Redeem consumes a challenge, asserting it was issued for this exact uid and
+// action. Single-use: the entry is dropped on any lookup that finds it, so a
+// mismatched redemption burns the challenge rather than leaving it to be
+// retried against a different account.
+func (s *ChallengeStore) Redeem(text, uid string, action Action) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	entry, ok := s.entries[text]
+	if !ok {
+		return ErrChallengeUnknown
+	}
+	delete(s.entries, text)
+	if s.now().After(entry.expires) {
+		return ErrChallengeUnknown
+	}
+	if entry.uid != uid || entry.action != action {
+		return ErrChallengeUnknown
+	}
+	// Re-read the signed bytes rather than trusting the map key alone: the
+	// signature covers `text`, so `text` is what has to name this uid+action.
+	if !ChallengeMatches(text, uid, action) {
+		return ErrChallengeUnknown
+	}
+	return nil
+}
+
+// sweepLocked drops expired entries. Caller holds the lock.
+//
+// Called only from Issue: with no background goroutine, expiry is enforced
+// lazily on the one path that grows the map, which is exactly where the bound
+// matters.
+func (s *ChallengeStore) sweepLocked() {
+	now := s.now()
+	for text, e := range s.entries {
+		if now.After(e.expires) {
+			delete(s.entries, text)
+		}
+	}
+}

internal/identity/noble_interop_test.go

@@ -0,0 +1,43 @@
+package identity
+
+import (
+	"encoding/base64"
+	"testing"
+)
+
+// A real signature produced by @noble/secp256k1 v3 — the library the dashboard
+// and meta-watch both sign with — pinned as a fixture and verified here.
+//
+// This is the one seam neither side's own tests can cover: Go signs DER, the
+// browser signs 64-byte compact, and every unit test above verifies signatures
+// this package produced itself. If the encodings ever disagree, the gate fails
+// closed in production (nobody can delete their own account) while every other
+// test stays green. Regenerate with:
+//
+//	node -e 'import("@noble/secp256k1").then(async s => { … })'
+//
+// against the same fixed scalar (32 zero bytes with 42 in the last).
+func TestVerify_AcceptsARealNobleV3Signature(t *testing.T) {
+	const (
+		uid       = "ztbJ71eLvfmGXw2ydaSPHavfwjva5Bzadutw2tvYDVFVY"
+		challenge = "metamesh-identity-v1:delete:ztbJ71eLvfmGXw2ydaSPHavfwjva5Bzadutw2tvYDVFVY:deadbeef"
+		sigB64    = "lIiZGL0j9l/w2WXwzwe56cICnusuYdD3oaTuYfFTtNJBR9MolXFPk3014WQeAlvmbX4LfnW+TQz4asqoSwmSAQ=="
+	)
+
+	sig, err := base64.StdEncoding.DecodeString(sigB64)
+	if err != nil {
+		t.Fatalf("decode fixture: %v", err)
+	}
+	if len(sig) != 64 {
+		t.Fatalf("fixture is %d bytes, expected noble's 64-byte compact form", len(sig))
+	}
+	if err := Verify(uid, []byte(challenge), sig); err != nil {
+		t.Fatalf("a genuine browser signature must verify: %v", err)
+	}
+
+	// And the same signature must not verify over a different challenge — a
+	// verifier that ignored the payload would pass the line above too.
+	if err := Verify(uid, []byte(challenge+"x"), sig); err == nil {
+		t.Fatal("the fixture verified over the wrong payload")
+	}
+}

internal/identity/verify.go

@@ -0,0 +1,160 @@
+package identity
+
+// Signature verification against a uid, and the challenge vocabulary that
+// makes a signature mean "I hold this account's private key" rather than
+// "meta-core signed something for me".
+//
+// The asymmetry that motivates this file: meta-core *holds* every private key,
+// so it can sign as anybody. A signature is therefore only proof of possession
+// if the payload is one meta-core refuses to sign on request — hence
+// ChallengeDomain, which POST /api/identity/sign rejects outright. Without that
+// refusal an attacker mints their own authorisation in one extra call and the
+// whole gate is decoration.
+//
+// Verification itself needs no stored state: a uid *is* the public key
+// ("z" + base58btc(33-byte compressed sec1)), so the pubkey is recovered from
+// the uid the caller names. Mirrors `verify_local` / `verify_local_compact` in
+// meta-watch's src/record/sign.rs — same curve, same digest, both signature
+// encodings.
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4/ecdsa"
+	"github.com/mr-tron/base58"
+)
+
+// ChallengeDomain prefixes every byte string that authorises an account
+// operation. POST /api/identity/sign and /sign-batch refuse payloads carrying
+// it, so the only way to produce one is to hold the key yourself.
+//
+// Versioned because it is a wire commitment: changing it invalidates every
+// challenge in flight, which is harmless, but changing it *silently* would let
+// an old-domain payload keep working. Bump it deliberately.
+const ChallengeDomain = "metamesh-identity-v1:"
+
+// Action is the operation a challenge authorises. A challenge minted to reveal
+// a key must not also delete the account, so the action is inside the signed
+// bytes and is re-checked at redemption.
+type Action string
+
+const (
+	ActionReveal Action = "reveal"
+	ActionDelete Action = "delete"
+)
+
+// ValidAction reports whether a is an action a challenge may be issued for.
+func ValidAction(a Action) bool {
+	return a == ActionReveal || a == ActionDelete
+}
+
+// ValidUID exposes the uid shape check to callers outside this package (the
+// API layer, which must reject a hostile uid before it reaches a key-range read
+// pattern or a file path).
+func ValidUID(uid string) bool { return validUID(uid) }
+
+// IsChallengePayload reports whether b is (or claims to be) an account
+// authorisation payload. Used by the signing endpoints to refuse minting one.
+//
+// Deliberately a prefix test on raw bytes rather than a parse: anything that
+// merely *looks* like a challenge is refused, so a malformed or future-version
+// payload fails closed instead of being signed.
+func IsChallengePayload(b []byte) bool {
+	return strings.HasPrefix(string(b), ChallengeDomain)
+}
+
+// PubkeyFromUID recovers the compressed public key a uid encodes.
+func PubkeyFromUID(uid string) (*secp256k1.PublicKey, error) {
+	if !validUID(uid) {
+		return nil, fmt.Errorf("invalid uid: %q", uid)
+	}
+	if !strings.HasPrefix(uid, "z") {
+		return nil, errors.New("uid is not multibase base58btc (missing 'z' prefix)")
+	}
+	raw, err := base58.Decode(uid[1:])
+	if err != nil {
+		return nil, fmt.Errorf("uid is not valid base58: %w", err)
+	}
+	if len(raw) != 33 {
+		return nil, fmt.Errorf("uid decodes to %d bytes, want a 33-byte compressed pubkey", len(raw))
+	}
+	pub, err := secp256k1.ParsePubKey(raw)
+	if err != nil {
+		return nil, fmt.Errorf("uid is not a point on secp256k1: %w", err)
+	}
+	return pub, nil
+}
+
+// Verify checks sig over SHA-256(payload) against the public key inside uid.
+//
+// Accepts both encodings in circulation: DER (what Sign emits, and what User
+// Data Layer records carry) and 64-byte compact r‖s (what the browser emits —
+// noble-secp256k1 v3 dropped DER, and meta-watch's sign-in already sends
+// compact). Rejecting either would break one of the two callers.
+func Verify(uid string, payload, sig []byte) error {
+	pub, err := PubkeyFromUID(uid)
+	if err != nil {
+		return err
+	}
+	parsed, err := parseSignature(sig)
+	if err != nil {
+		return err
+	}
+	digest := sha256.Sum256(payload)
+	if !parsed.Verify(digest[:], pub) {
+		return errors.New("signature does not verify for this uid")
+	}
+	return nil
+}
+
+func parseSignature(sig []byte) (*ecdsa.Signature, error) {
+	if len(sig) == 64 {
+		var r, s secp256k1.ModNScalar
+		// SetByteSlice reports overflow (>= curve order), which is not a valid
+		// scalar. A zero r or s is likewise never produced by a real signer.
+		if r.SetByteSlice(sig[:32]) || r.IsZero() {
+			return nil, errors.New("compact signature has an invalid r")
+		}
+		if s.SetByteSlice(sig[32:]) || s.IsZero() {
+			return nil, errors.New("compact signature has an invalid s")
+		}
+		return ecdsa.NewSignature(&r, &s), nil
+	}
+	parsed, err := ecdsa.ParseDERSignature(sig)
+	if err != nil {
+		return nil, fmt.Errorf("signature is neither 64-byte compact nor valid DER: %w", err)
+	}
+	return parsed, nil
+}
+
+// NewChallengeText mints the literal string a client signs. The uid and action
+// are inside it, so a signature cannot be lifted from one account or operation
+// onto another even if the nonce leaks.
+func NewChallengeText(uid string, action Action) (string, error) {
+	nonce := make([]byte, 32)
+	if _, err := rand.Read(nonce); err != nil {
+		return "", fmt.Errorf("read nonce: %w", err)
+	}
+	return ChallengeDomain + string(action) + ":" + uid + ":" + hex.EncodeToString(nonce), nil
+}
+
+// ChallengeMatches reports whether text is a well-formed challenge for exactly
+// this uid and action. The store already keys on the full text, so this is a
+// belt-and-braces re-read of the signed bytes themselves: it is the signed
+// content, not the lookup key, that a verifier must agree with.
+//
+// Compared in constant time — the text is a bearer secret until redeemed.
+func ChallengeMatches(text, uid string, action Action) bool {
+	want := ChallengeDomain + string(action) + ":" + uid + ":"
+	if len(text) <= len(want) {
+		return false
+	}
+	return subtle.ConstantTimeCompare([]byte(text[:len(want)]), []byte(want)) == 1
+}

internal/identity/verify_test.go

@@ -0,0 +1,278 @@
+package identity
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4/ecdsa"
+)
+
+// The whole gate rests on a uid being the public key: verification consults no
+// stored state, so a signature is checked against the account the caller names
+// rather than against whatever key meta-core happens to hold.
+func TestVerify_AcceptsDERFromOurOwnSigner(t *testing.T) {
+	id, err := Generate()
+	if err != nil {
+		t.Fatalf("generate: %v", err)
+	}
+	payload := []byte(ChallengeDomain + "delete:" + id.UID + ":abcdef")
+
+	sig, err := Sign(id, payload)
+	if err != nil {
+		t.Fatalf("sign: %v", err)
+	}
+	if err := Verify(id.UID, payload, sig); err != nil {
+		t.Fatalf("DER signature from Sign must verify: %v", err)
+	}
+}
+
+// The browser is the signer that matters here, and noble-secp256k1 v3 emits
+// 64-byte compact r‖s — it dropped DER entirely. A verifier that took only DER
+// would reject every real proof while passing this package's own tests.
+func TestVerify_AcceptsCompactAsTheBrowserEmitsIt(t *testing.T) {
+	id, err := Generate()
+	if err != nil {
+		t.Fatalf("generate: %v", err)
+	}
+	payload := []byte("some challenge text")
+
+	raw, _ := hex.DecodeString(id.PrivateKeyHex)
+	priv := secp256k1.PrivKeyFromBytes(raw)
+	digest := sha256.Sum256(payload)
+	der := ecdsa.Sign(priv, digest[:])
+
+	// Re-encode the same signature compactly, the way the browser would.
+	parsed, err := ecdsa.ParseDERSignature(der.Serialize())
+	if err != nil {
+		t.Fatalf("parse own DER: %v", err)
+	}
+	r := parsed.R()
+	sc := parsed.S()
+	compact := make([]byte, 0, 64)
+	rb := r.Bytes()
+	sb := sc.Bytes()
+	compact = append(compact, rb[:]...)
+	compact = append(compact, sb[:]...)
+
+	if err := Verify(id.UID, payload, compact); err != nil {
+		t.Fatalf("compact signature must verify: %v", err)
+	}
+}
+
+func TestVerify_RejectsAnotherAccountsSignature(t *testing.T) {
+	alice, _ := Generate()
+	mallory, _ := Generate()
+	payload := []byte("challenge for alice")
+
+	sig, err := Sign(mallory, payload)
+	if err != nil {
+		t.Fatalf("sign: %v", err)
+	}
+	if err := Verify(alice.UID, payload, sig); err == nil {
+		t.Fatal("a signature by mallory must not verify as alice")
+	}
+}
+
+func TestVerify_RejectsTamperedPayload(t *testing.T) {
+	id, _ := Generate()
+	sig, _ := Sign(id, []byte("delete account A"))
+	if err := Verify(id.UID, []byte("delete account B"), sig); err == nil {
+		t.Fatal("a signature must not verify over different bytes")
+	}
+}
+
+func TestVerify_RejectsGarbageSignatureEncodings(t *testing.T) {
+	id, _ := Generate()
+	for name, sig := range map[string][]byte{
+		"empty":            {},
+		"short":            {1, 2, 3},
+		"zero compact":     make([]byte, 64),
+		"not der":          []byte("this is not a signature at all......."),
+		"63 bytes":         make([]byte, 63),
+		"65 bytes non-der": make([]byte, 65),
+	} {
+		if err := Verify(id.UID, []byte("x"), sig); err == nil {
+			t.Errorf("%s: expected rejection", name)
+		}
+	}
+}
+
+func TestPubkeyFromUID_RejectsMalformedUIDs(t *testing.T) {
+	id, _ := Generate()
+	for name, uid := range map[string]string{
+		"empty":          "",
+		"no z prefix":    id.UID[1:],
+		"truncated":      id.UID[:20],
+		"path traversal": "../../etc/passwd",
+		"with slash":     "z/" + id.UID,
+		"not on curve":   "z" + strings.Repeat("1", 45),
+	} {
+		if _, err := PubkeyFromUID(uid); err == nil {
+			t.Errorf("%s (%q): expected rejection", name, uid)
+		}
+	}
+	if _, err := PubkeyFromUID(id.UID); err != nil {
+		t.Fatalf("a real uid must parse: %v", err)
+	}
+}
+
+// The refusal that makes proof-of-possession mean anything on a node holding
+// every private key. If this ever returns false for a challenge, an attacker
+// asks /api/identity/sign to authorise their own delete.
+func TestIsChallengePayload_CatchesAnythingInTheDomain(t *testing.T) {
+	yes := [][]byte{
+		[]byte(ChallengeDomain),
+		[]byte(ChallengeDomain + "delete:zAlice:beef"),
+		[]byte(ChallengeDomain + "some-future-action:whatever"),
+		[]byte("metamesh-identity-v1:"), // literal, in case the const drifts
+	}
+	for _, b := range yes {
+		if !IsChallengePayload(b) {
+			t.Errorf("must refuse to sign %q", b)
+		}
+	}
+	no := [][]byte{
+		{},
+		[]byte("metamesh-identity-v2:delete:zAlice"), // different domain, not ours to refuse
+		[]byte("a record payload"),
+		[]byte(" " + ChallengeDomain), // not a prefix
+	}
+	for _, b := range no {
+		if IsChallengePayload(b) {
+			t.Errorf("must still sign %q", b)
+		}
+	}
+}
+
+func TestChallengeMatches_TiesTheTextToUIDAndAction(t *testing.T) {
+	text, err := NewChallengeText("zAlice", ActionDelete)
+	if err != nil {
+		t.Fatalf("mint: %v", err)
+	}
+	if !ChallengeMatches(text, "zAlice", ActionDelete) {
+		t.Fatal("its own uid+action must match")
+	}
+	if ChallengeMatches(text, "zBob", ActionDelete) {
+		t.Fatal("another uid must not match")
+	}
+	if ChallengeMatches(text, "zAlice", ActionReveal) {
+		t.Fatal("another action must not match")
+	}
+	// A prefix-only uid must not slip through: "zAlic" is a prefix of "zAlice",
+	// and a naive HasPrefix on the uid alone would accept it.
+	if ChallengeMatches(text, "zAlic", ActionDelete) {
+		t.Fatal("a uid that is a prefix of the real one must not match")
+	}
+}
+
+func TestNewChallengeText_IsUnpredictable(t *testing.T) {
+	seen := make(map[string]struct{}, 64)
+	for i := 0; i < 64; i++ {
+		text, err := NewChallengeText("zAlice", ActionDelete)
+		if err != nil {
+			t.Fatalf("mint: %v", err)
+		}
+		if _, dup := seen[text]; dup {
+			t.Fatal("challenge repeated — the nonce is not random")
+		}
+		seen[text] = struct{}{}
+	}
+}
+
+// --- challenge store --------------------------------------------------------
+
+func TestChallengeStore_RedeemIsSingleUse(t *testing.T) {
+	s := NewChallengeStore()
+	text, _, err := s.Issue("zAlice", ActionDelete)
+	if err != nil {
+		t.Fatalf("issue: %v", err)
+	}
+	if err := s.Redeem(text, "zAlice", ActionDelete); err != nil {
+		t.Fatalf("first redeem: %v", err)
+	}
+	if err := s.Redeem(text, "zAlice", ActionDelete); err == nil {
+		t.Fatal("a challenge must not be redeemable twice — that is replay")
+	}
+}
+
+// A challenge minted to *look at* a key must not delete the account, and one
+// minted for Alice must not act on Bob. Both are inside the signed text, so a
+// store that ignored them would authorise the wrong operation with a perfectly
+// valid signature.
+func TestChallengeStore_RedeemRefusesWrongUIDOrAction(t *testing.T) {
+	s := NewChallengeStore()
+
+	text, _, _ := s.Issue("zAlice", ActionReveal)
+	if err := s.Redeem(text, "zAlice", ActionDelete); err == nil {
+		t.Fatal("a reveal challenge must not authorise a delete")
+	}
+
+	text2, _, _ := s.Issue("zAlice", ActionDelete)
+	if err := s.Redeem(text2, "zBob", ActionDelete); err == nil {
+		t.Fatal("alice's challenge must not authorise deleting bob")
+	}
+}
+
+// A failed redemption still consumes the challenge, so a wrong guess costs a
+// round trip rather than leaving the nonce up for another attempt.
+func TestChallengeStore_FailedRedeemStillBurnsIt(t *testing.T) {
+	s := NewChallengeStore()
+	text, _, _ := s.Issue("zAlice", ActionDelete)
+	_ = s.Redeem(text, "zBob", ActionDelete)
+	if err := s.Redeem(text, "zAlice", ActionDelete); err == nil {
+		t.Fatal("a burnt challenge must stay burnt for its rightful owner too")
+	}
+}
+
+func TestChallengeStore_Expires(t *testing.T) {
+	s := NewChallengeStore()
+	now := time.Unix(1_700_000_000, 0)
+	s.now = func() time.Time { return now }
+
+	text, expires, _ := s.Issue("zAlice", ActionDelete)
+	if !expires.Equal(now.Add(ChallengeTTL)) {
+		t.Fatalf("expiry %v, want %v", expires, now.Add(ChallengeTTL))
+	}
+	now = now.Add(ChallengeTTL + time.Second)
+	if err := s.Redeem(text, "zAlice", ActionDelete); err == nil {
+		t.Fatal("an expired challenge must not redeem")
+	}
+}
+
+// Issuing is unauthenticated, so the map is attacker-growable. The cap is what
+// stops that being a memory-exhaustion lever; expiry sweeping is what stops the
+// cap being reached by honest traffic.
+func TestChallengeStore_CapsInFlightAndSweepsExpired(t *testing.T) {
+	s := NewChallengeStore()
+	now := time.Unix(1_700_000_000, 0)
+	s.now = func() time.Time { return now }
+
+	for i := 0; i < maxChallenges; i++ {
+		if _, _, err := s.Issue("zAlice", ActionDelete); err != nil {
+			t.Fatalf("issue %d: %v", i, err)
+		}
+	}
+	if _, _, err := s.Issue("zAlice", ActionDelete); err == nil {
+		t.Fatal("expected the store to refuse once full")
+	}
+
+	// Once they age out, the next issue sweeps and succeeds again.
+	now = now.Add(ChallengeTTL + time.Second)
+	if _, _, err := s.Issue("zAlice", ActionDelete); err != nil {
+		t.Fatalf("after expiry the store must accept again: %v", err)
+	}
+}
+
+func TestChallengeStore_RefusesInvalidInputs(t *testing.T) {
+	s := NewChallengeStore()
+	if _, _, err := s.Issue("../etc", ActionDelete); err == nil {
+		t.Fatal("a uid that is not uid-shaped must be refused")
+	}
+	if _, _, err := s.Issue("zAlice", Action("sudo")); err == nil {
+		t.Fatal("an unknown action must be refused")
+	}
+}

internal/kv/kv.go

@@ -0,0 +1,713 @@
+// Package kv is meta-core's storage engine: one string→string table in an
+// embedded SQLite file.
+//
+// # Why a key/value table and not a schema
+//
+// meta-core's data model is schema-free on purpose — a record is a set of flat
+// `file:<rid>/<field>` keys, and a new metadata field is just a new key
+// (METADATA_KEYS.md). The engine keeps exactly that model:
+//
+//	CREATE TABLE kv(k TEXT PRIMARY KEY, v TEXT NOT NULL) WITHOUT ROWID
+//
+// is the only table that holds data, and it never needs a migration. What
+// Redis gave us that a bare KV would not — "list a record's fields", "find
+// records by field value", free-text search — comes from the table being
+// *ordered* (a record is a key range) and from two derived structures the
+// storage package maintains on top: an expression index over the field name
+// parsed out of the key, and an FTS5 table. Both are rebuildable from the kv
+// rows and never authoritative.
+//
+// It replaced Redis on 2026-10: holding everything in RAM cost ~6.6 GB on a
+// 169k-record corpus (Redis plus the API's in-memory copy needed to search
+// it), with the OOM kills that implies. The same data is ~2.5 GB on disk here
+// and the working set is a bounded page cache.
+//
+// # Concurrency
+//
+// SQLite allows one writer at a time, so every write goes through one writer
+// goroutine owning one connection. Concurrent Update calls are GROUP-COMMITTED:
+// the writer runs every request waiting at that moment inside one SQLite
+// transaction, each under its own SAVEPOINT (a failing request rolls back
+// alone), and commits once. A commit — writing the dirty pages of the table,
+// the field index and the FTS shadow tables to the WAL — was ~40% of the cost
+// of a record write, so sharing it is what makes concurrent ingest scale.
+//
+// Reads use a separate pool and see the last committed state (WAL). Inside
+// Update, read through the *Tx — the reader pool cannot see uncommitted rows —
+// and never call Update from inside an Update callback (the writer would wait
+// for itself).
+//
+// # Events
+//
+// Redis keyspace notifications are replaced by the transaction itself: every
+// Put/Delete of a key the Options.EventKey predicate selects is appended, in
+// the same transaction, to Options.EventStream as {type: set|del, key, ts}.
+// A change and its event therefore commit together or not at all.
+package kv
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"log"
+	"net/url"
+	"os"
+	"strings"
+	"sync"
+	"time"
+
+	_ "modernc.org/sqlite"
+)
+
+// Options configures a Store.
+type Options struct {
+	// EventStream receives a set/del entry for every changed key EventKey
+	// selects. Empty disables change events.
+	EventStream string
+	// EventMaxLen is the approximate retention of EventStream.
+	EventMaxLen int64
+	// EventKey selects the keys whose changes are published.
+	EventKey func(key string) bool
+	// WriterCacheMB / ReaderCacheMB size SQLite's page cache per connection.
+	WriterCacheMB int
+	ReaderCacheMB int
+	// Readers is the size of the read connection pool.
+	Readers int
+	// Schema is extra DDL run at open (idempotent CREATE … IF NOT EXISTS),
+	// for derived indexes owned by the caller.
+	Schema string
+}
+
+// Store is an open database.
+type Store struct {
+	path string
+	opts Options
+	w    *sql.DB // single connection: the one writer
+	r    *sql.DB // read pool
+
+	streamMu sync.Mutex
+	streams  map[string]*streamState
+
+	// Hot write statements, prepared once on the writer connection: parsing
+	// SQL on every Put was the single largest cost of a record write.
+	stPut, stPutIfAbsent, stDelete, stGet, stInsert *sql.Stmt
+
+	writes    chan *writeReq
+	writeMu   sync.Mutex // held by the writer while a group runs
+	closeOnce sync.Once
+	stopped   chan struct{}
+}
+
+// writeReq is one Update call waiting for the writer.
+type writeReq struct {
+	fn   func(tx *Tx) error
+	done chan error
+}
+
+// maxGroup caps how many requests share one commit, bounding how long the
+// writer holds a transaction open.
+const maxGroup = 128
+
+// Open opens (creating if needed) the database file at path.
+func Open(path string, opts Options) (*Store, error) {
+	if opts.Readers <= 0 {
+		opts.Readers = 8
+	}
+	if opts.WriterCacheMB <= 0 {
+		opts.WriterCacheMB = 64
+	}
+	if opts.ReaderCacheMB <= 0 {
+		opts.ReaderCacheMB = 16
+	}
+	if opts.EventMaxLen <= 0 {
+		opts.EventMaxLen = 100_000
+	}
+
+	w, err := sql.Open("sqlite", dsn(path, opts.WriterCacheMB, false))
+	if err != nil {
+		return nil, fmt.Errorf("open writer: %w", err)
+	}
+	w.SetMaxOpenConns(1)
+	w.SetMaxIdleConns(1)
+	w.SetConnMaxLifetime(0)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	if _, err := w.ExecContext(ctx, `CREATE TABLE IF NOT EXISTS kv(k TEXT PRIMARY KEY, v TEXT NOT NULL) WITHOUT ROWID`); err != nil {
+		w.Close()
+		return nil, fmt.Errorf("create kv: %w", err)
+	}
+	if opts.Schema != "" {
+		// No deadline: on an existing store, the first open after a new index
+		// is added builds it over every row (minutes at millions of keys).
+		// Cancelling that just rolls it back and restarts it on the next boot.
+		started := time.Now()
+		if _, err := w.ExecContext(context.Background(), opts.Schema); err != nil {
+			w.Close()
+			return nil, fmt.Errorf("apply schema: %w", err)
+		}
+		if d := time.Since(started); d > 5*time.Second {
+			log.Printf("[kv] schema applied in %s (indexes built)", d.Round(time.Second))
+		}
+	}
+
+	r, err := sql.Open("sqlite", dsn(path, opts.ReaderCacheMB, true))
+	if err != nil {
+		w.Close()
+		return nil, fmt.Errorf("open readers: %w", err)
+	}
+	r.SetMaxOpenConns(opts.Readers)
+	r.SetMaxIdleConns(opts.Readers)
+
+	st := &Store{path: path, opts: opts, w: w, r: r, streams: make(map[string]*streamState)}
+	// Fresh deadline: the schema step above may legitimately have taken minutes.
+	ctx, cancel = context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	for _, p := range []struct {
+		dst   **sql.Stmt
+		query string
+	}{
+		{&st.stPut, `INSERT INTO kv(k, v) VALUES(?, ?) ON CONFLICT(k) DO UPDATE SET v = excluded.v`},
+		{&st.stPutIfAbsent, `INSERT INTO kv(k, v) VALUES(?, ?) ON CONFLICT(k) DO NOTHING`},
+		{&st.stDelete, `DELETE FROM kv WHERE k = ?`},
+		{&st.stGet, `SELECT v FROM kv WHERE k = ?`},
+		{&st.stInsert, `INSERT INTO kv(k, v) VALUES(?, ?)`},
+	} {
+		if *p.dst, err = w.PrepareContext(ctx, p.query); err != nil {
+			r.Close()
+			w.Close()
+			return nil, fmt.Errorf("prepare: %w", err)
+		}
+	}
+	st.writes = make(chan *writeReq)
+	st.stopped = make(chan struct{})
+	go st.writer()
+	return st, nil
+}
+
+// dsn builds a modernc DSN. WAL + synchronous=NORMAL is the durability class
+// Redis' AOF-everysec gave us: a power loss may drop the last transactions,
+// never corrupt the file.
+func dsn(path string, cacheMB int, readOnly bool) string {
+	q := url.Values{}
+	q.Add("_pragma", "busy_timeout(30000)")
+	q.Add("_pragma", "journal_mode(WAL)")
+	q.Add("_pragma", "synchronous(NORMAL)")
+	q.Add("_pragma", fmt.Sprintf("cache_size(-%d)", cacheMB*1024))
+	q.Add("_pragma", "temp_store(MEMORY)")
+	q.Add("_pragma", "journal_size_limit(268435456)")
+	if readOnly {
+		q.Add("_pragma", "query_only(1)")
+	} else {
+		q.Add("_txlock", "immediate")
+	}
+	return "file:" + path + "?" + q.Encode()
+}
+
+// Close stops the writer and closes both pools, checkpointing the WAL into the
+// main file.
+func (s *Store) Close() error {
+	s.closeOnce.Do(func() { close(s.stopped) })
+	s.writeMu.Lock() // wait for an in-flight group to finish
+	defer s.writeMu.Unlock()
+	_, _ = s.w.Exec(`PRAGMA wal_checkpoint(TRUNCATE)`)
+	return errors.Join(s.r.Close(), s.w.Close())
+}
+
+// Ping reports whether the database answers.
+func (s *Store) Ping(ctx context.Context) error {
+	var one int
+	return s.r.QueryRowContext(ctx, `SELECT 1`).Scan(&one)
+}
+
+// Path is the database file path.
+func (s *Store) Path() string { return s.path }
+
+// DB exposes the read pool for callers that own derived indexes (search). It
+// is read-only (query_only), so it cannot bypass Update.
+func (s *Store) DB() *sql.DB { return s.r }
+
+// FileSize returns the on-disk size of the database plus its WAL.
+func (s *Store) FileSize() int64 {
+	var total int64
+	for _, suffix := range []string{"", "-wal"} {
+		if fi, err := os.Stat(s.path + suffix); err == nil {
+			total += fi.Size()
+		}
+	}
+	return total
+}
+
+// Checkpoint folds the WAL back into the main file. TRUNCATE takes the writer
+// slot and waits for readers, so callers run it when idle.
+func (s *Store) Checkpoint(ctx context.Context) error {
+	_, err := s.w.ExecContext(ctx, `PRAGMA wal_checkpoint(TRUNCATE)`)
+	return err
+}
+
+// KV is one key/value pair.
+type KV struct {
+	K, V string
+}
+
+// Reader is the read surface shared by Store (committed state) and Tx (the
+// transaction's own view). Storage helpers take a Reader so they work both
+// inside and outside a write.
+type Reader interface {
+	Get(ctx context.Context, k string) (string, bool, error)
+	MGet(ctx context.Context, keys []string) (map[string]string, error)
+	Range(ctx context.Context, prefix, after string, limit int) ([]KV, error)
+	Count(ctx context.Context, prefix string) (int64, error)
+}
+
+type queryer interface {
+	QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error)
+	QueryRowContext(ctx context.Context, query string, args ...any) *sql.Row
+}
+
+// PrefixEnd returns the smallest string greater than every string with the
+// given prefix, so [prefix, PrefixEnd(prefix)) is exactly the prefix's range.
+// An empty result means "unbounded".
+func PrefixEnd(prefix string) string {
+	b := []byte(prefix)
+	for i := len(b) - 1; i >= 0; i-- {
+		if b[i] < 0xff {
+			b[i]++
+			return string(b[:i+1])
+		}
+	}
+	return ""
+}
+
+func get(ctx context.Context, q queryer, k string) (string, bool, error) {
+	var v string
+	err := q.QueryRowContext(ctx, `SELECT v FROM kv WHERE k = ?`, k).Scan(&v)
+	if errors.Is(err, sql.ErrNoRows) {
+		return "", false, nil
+	}
+	if err != nil {
+		return "", false, err
+	}
+	return v, true, nil
+}
+
+// mgetBatch stays well under SQLite's default 32766 bound-parameter cap.
+const mgetBatch = 500
+
+func mget(ctx context.Context, q queryer, keys []string) (map[string]string, error) {
+	out := make(map[string]string, len(keys))
+	for start := 0; start < len(keys); start += mgetBatch {
+		end := min(start+mgetBatch, len(keys))
+		chunk := keys[start:end]
+		args := make([]any, len(chunk))
+		for i, k := range chunk {
+			args[i] = k
+		}
+		rows, err := q.QueryContext(ctx, `SELECT k, v FROM kv WHERE k IN (?`+strings.Repeat(",?", len(chunk)-1)+`)`, args...)
+		if err != nil {
+			return nil, err
+		}
+		for rows.Next() {
+			var k, v string
+			if err := rows.Scan(&k, &v); err != nil {
+				rows.Close()
+				return nil, err
+			}
+			out[k] = v
+		}
+		if err := rows.Close(); err != nil {
+			return nil, err
+		}
+	}
+	return out, nil
+}
+
+// rangeQuery returns keys with prefix, strictly after `after` (when non-empty),
+// in key order, at most limit (<= 0 means all).
+func rangeQuery(ctx context.Context, q queryer, prefix, after string, limit int) ([]KV, error) {
+	lo, loOp := prefix, ">="
+	if after != "" && after >= prefix {
+		lo, loOp = after, ">"
+	}
+	query := `SELECT k, v FROM kv WHERE k ` + loOp + ` ?`
+	args := []any{lo}
+	if end := PrefixEnd(prefix); end != "" {
+		query += ` AND k < ?`
+		args = append(args, end)
+	}
+	query += ` ORDER BY k`
+	if limit > 0 {
+		query += ` LIMIT ?`
+		args = append(args, limit)
+	}
+	rows, err := q.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []KV
+	for rows.Next() {
+		var kv KV
+		if err := rows.Scan(&kv.K, &kv.V); err != nil {
+			return nil, err
+		}
+		out = append(out, kv)
+	}
+	return out, rows.Err()
+}
+
+func count(ctx context.Context, q queryer, prefix string) (int64, error) {
+	query := `SELECT count(*) FROM kv WHERE k >= ?`
+	args := []any{prefix}
+	if end := PrefixEnd(prefix); end != "" {
+		query += ` AND k < ?`
+		args = append(args, end)
+	}
+	var n int64
+	err := q.QueryRowContext(ctx, query, args...).Scan(&n)
+	return n, err
+}
+
+// Get returns the committed value of k.
+func (s *Store) Get(ctx context.Context, k string) (string, bool, error) { return get(ctx, s.r, k) }
+
+// MGet returns the committed values of the keys that exist.
+func (s *Store) MGet(ctx context.Context, keys []string) (map[string]string, error) {
+	return mget(ctx, s.r, keys)
+}
+
+// Range returns committed keys under prefix after `after`, in key order.
+func (s *Store) Range(ctx context.Context, prefix, after string, limit int) ([]KV, error) {
+	return rangeQuery(ctx, s.r, prefix, after, limit)
+}
+
+// Count returns how many committed keys sit under prefix.
+func (s *Store) Count(ctx context.Context, prefix string) (int64, error) {
+	return count(ctx, s.r, prefix)
+}
+
+// ScanPrefix walks every committed key under prefix in pages of `page`, each
+// page its own short read so a long walk never pins a WAL snapshot (which
+// would stop checkpoints and let the WAL grow without bound).
+func (s *Store) ScanPrefix(ctx context.Context, prefix string, page int, fn func([]KV) error) error {
+	if page <= 0 {
+		page = 5000
+	}
+	after := ""
+	for {
+		batch, err := rangeQuery(ctx, s.r, prefix, after, page)
+		if err != nil {
+			return err
+		}
+		if len(batch) == 0 {
+			return nil
+		}
+		if err := fn(batch); err != nil {
+			return err
+		}
+		if len(batch) < page {
+			return nil
+		}
+		after = batch[len(batch)-1].K
+	}
+}
+
+// CountAll counts every row. A full scan — callers cache it.
+func (s *Store) CountAll(ctx context.Context) (int64, error) {
+	var n int64
+	err := s.r.QueryRowContext(ctx, `SELECT count(*) FROM kv`).Scan(&n)
+	return n, err
+}
+
+// ErrClosed is returned by Update on a closed store.
+var ErrClosed = errors.New("kv: store closed")
+
+// Update runs fn atomically: its writes (and the change events they publish)
+// commit together or not at all. fn may share a SQLite transaction with other
+// concurrent Updates (group commit) but is isolated from their failures by a
+// savepoint. Never call Update from inside fn.
+//
+// ctx bounds only the wait for the writer. Once fn starts it runs to
+// completion: interrupting a statement inside a shared transaction would roll
+// back every request in the group.
+func (s *Store) Update(ctx context.Context, fn func(tx *Tx) error) error {
+	req := &writeReq{fn: fn, done: make(chan error, 1)}
+	select {
+	case s.writes <- req:
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-s.stopped:
+		return ErrClosed
+	}
+	return <-req.done
+}
+
+// writer is the single goroutine that executes writes.
+func (s *Store) writer() {
+	for {
+		var first *writeReq
+		select {
+		case first = <-s.writes:
+		case <-s.stopped:
+			return
+		}
+		group := []*writeReq{first}
+	drain:
+		for len(group) < maxGroup {
+			select {
+			case r := <-s.writes:
+				group = append(group, r)
+			default:
+				break drain
+			}
+		}
+		s.writeMu.Lock()
+		s.runGroup(group)
+		s.writeMu.Unlock()
+	}
+}
+
+// group is the state shared by the requests of one commit.
+type group struct {
+	tx      *sql.Tx
+	pending map[string]*streamPending
+	stmts   map[*sql.Stmt]*sql.Stmt
+}
+
+func (g *group) snapshot() map[string]streamPending {
+	out := make(map[string]streamPending, len(g.pending))
+	for k, p := range g.pending {
+		out[k] = *p
+	}
+	return out
+}
+
+func (g *group) restore(snap map[string]streamPending) {
+	g.pending = make(map[string]*streamPending, len(snap))
+	for k, p := range snap {
+		p := p
+		g.pending[k] = &p
+	}
+}
+
+func (s *Store) runGroup(reqs []*writeReq) {
+	ctx := context.Background()
+	results := make([]error, len(reqs))
+	fail := func(err error) {
+		for i, r := range reqs {
+			if results[i] == nil {
+				results[i] = err
+			}
+			r.done <- results[i]
+		}
+	}
+
+	sqlTx, err := s.w.BeginTx(ctx, nil)
+	if err != nil {
+		fail(fmt.Errorf("begin: %w", err))
+		return
+	}
+	g := &group{tx: sqlTx}
+	for i, r := range reqs {
+		if _, err := sqlTx.ExecContext(ctx, `SAVEPOINT req`); err != nil {
+			_ = sqlTx.Rollback()
+			fail(fmt.Errorf("savepoint: %w", err))
+			return
+		}
+		snap := g.snapshot()
+		tx := &Tx{ctx: ctx, s: s, g: g}
+		err := r.fn(tx)
+		if err == nil {
+			err = tx.flushEvents()
+		}
+		if err != nil {
+			results[i] = err
+			if _, rbErr := sqlTx.ExecContext(ctx, `ROLLBACK TO req`); rbErr != nil {
+				_ = sqlTx.Rollback()
+				fail(fmt.Errorf("rollback to savepoint: %w (after %v)", rbErr, err))
+				return
+			}
+			g.restore(snap)
+		}
+		if _, err := sqlTx.ExecContext(ctx, `RELEASE req`); err != nil {
+			_ = sqlTx.Rollback()
+			fail(fmt.Errorf("release savepoint: %w", err))
+			return
+		}
+	}
+	if err := (&Tx{ctx: ctx, s: s, g: g}).flushHWM(); err != nil {
+		_ = sqlTx.Rollback()
+		fail(err)
+		return
+	}
+	if err := sqlTx.Commit(); err != nil {
+		fail(fmt.Errorf("commit: %w", err))
+		return
+	}
+	s.afterCommit(g.pending)
+	for i, r := range reqs {
+		r.done <- results[i]
+	}
+}
+
+// Tx is one Update's view of the write transaction. Its reads see its own
+// writes (and those of earlier requests in the same group).
+type Tx struct {
+	ctx    context.Context
+	s      *Store
+	g      *group
+	events []map[string]string
+}
+
+func (t *Tx) sqlTx() *sql.Tx { return t.g.tx }
+
+// stmt binds one of the store's prepared statements to the transaction.
+func (t *Tx) stmt(st *sql.Stmt) *sql.Stmt {
+	if t.g.stmts == nil {
+		t.g.stmts = make(map[*sql.Stmt]*sql.Stmt, 5)
+	}
+	bound := t.g.stmts[st]
+	if bound == nil {
+		bound = t.g.tx.StmtContext(t.ctx, st)
+		t.g.stmts[st] = bound
+	}
+	return bound
+}
+
+// Context is the context the transaction runs under.
+func (t *Tx) Context() context.Context { return t.ctx }
+
+func (t *Tx) Get(ctx context.Context, k string) (string, bool, error) {
+	var v string
+	err := t.stmt(t.s.stGet).QueryRowContext(ctx, k).Scan(&v)
+	if errors.Is(err, sql.ErrNoRows) {
+		return "", false, nil
+	}
+	if err != nil {
+		return "", false, err
+	}
+	return v, true, nil
+}
+func (t *Tx) MGet(ctx context.Context, keys []string) (map[string]string, error) {
+	return mget(ctx, t.sqlTx(), keys)
+}
+func (t *Tx) Range(ctx context.Context, prefix, after string, limit int) ([]KV, error) {
+	return rangeQuery(ctx, t.sqlTx(), prefix, after, limit)
+}
+func (t *Tx) Count(ctx context.Context, prefix string) (int64, error) {
+	return count(ctx, t.sqlTx(), prefix)
+}
+
+// Exec runs a raw statement in the transaction — for the caller's derived
+// tables (FTS), never for kv rows (which would skip events).
+func (t *Tx) Exec(query string, args ...any) (sql.Result, error) {
+	return t.sqlTx().ExecContext(t.ctx, query, args...)
+}
+
+// QueryRow runs a raw single-row query in the transaction.
+func (t *Tx) QueryRow(query string, args ...any) *sql.Row {
+	return t.sqlTx().QueryRowContext(t.ctx, query, args...)
+}
+
+// Put sets k = v. Publishes `set` even when the value is unchanged, as Redis
+// keyspace notifications did.
+func (t *Tx) Put(k, v string) error {
+	if _, err := t.stmt(t.s.stPut).ExecContext(t.ctx, k, v); err != nil {
+		return fmt.Errorf("put %q: %w", k, err)
+	}
+	t.event("set", k)
+	return nil
+}
+
+// PutIfAbsent sets k = v only when k does not exist. Reports whether it wrote.
+// Publishes nothing when the key already existed (nothing changed).
+func (t *Tx) PutIfAbsent(k, v string) (bool, error) {
+	res, err := t.stmt(t.s.stPutIfAbsent).ExecContext(t.ctx, k, v)
+	if err != nil {
+		return false, fmt.Errorf("put %q: %w", k, err)
+	}
+	n, _ := res.RowsAffected()
+	if n > 0 {
+		t.event("set", k)
+	}
+	return n > 0, nil
+}
+
+// Delete removes k. Reports whether it existed; publishes `del` only then,
+// as Redis did.
+func (t *Tx) Delete(k string) (bool, error) {
+	res, err := t.stmt(t.s.stDelete).ExecContext(t.ctx, k)
+	if err != nil {
+		return false, fmt.Errorf("delete %q: %w", k, err)
+	}
+	n, _ := res.RowsAffected()
+	if n > 0 {
+		t.event("del", k)
+	}
+	return n > 0, nil
+}
+
+// DeletePrefix removes up to limit keys under prefix (limit <= 0: all) and
+// returns how many went. Bulk callers loop over separate Updates with a limit
+// so one transaction never grows to millions of rows.
+func (t *Tx) DeletePrefix(prefix string, limit int) (int64, error) {
+	end := PrefixEnd(prefix)
+	sel := `SELECT k FROM kv WHERE k >= ?`
+	args := []any{prefix}
+	if end != "" {
+		sel += ` AND k < ?`
+		args = append(args, end)
+	}
+	if limit > 0 {
+		sel += ` ORDER BY k LIMIT ?`
+		args = append(args, limit)
+	}
+	rows, err := t.sqlTx().QueryContext(t.ctx, `DELETE FROM kv WHERE k IN (`+sel+`) RETURNING k`, args...)
+	if err != nil {
+		return 0, fmt.Errorf("delete prefix %q: %w", prefix, err)
+	}
+	var keys []string
+	for rows.Next() {
+		var k string
+		if err := rows.Scan(&k); err != nil {
+			rows.Close()
+			return 0, err
+		}
+		keys = append(keys, k)
+	}
+	if err := rows.Close(); err != nil {
+		return 0, err
+	}
+	for _, k := range keys {
+		t.event("del", k)
+	}
+	return int64(len(keys)), nil
+}
+
+func (t *Tx) event(op, k string) {
+	if t.s.opts.EventStream == "" || t.s.opts.EventKey == nil || !t.s.opts.EventKey(k) {
+		return
+	}
+	t.events = append(t.events, map[string]string{
+		"type": op,
+		"key":  k,
+		"ts":   fmt.Sprintf("%d", time.Now().UnixMilli()),
+	})
+}
+
+// flushEvents appends the queued change events to the event stream, inside
+// the transaction, right before commit.
+func (t *Tx) flushEvents() error {
+	if len(t.events) == 0 {
+		return nil
+	}
+	evs := t.events
+	t.events = nil
+	for _, e := range evs {
+		if _, err := t.Append(t.s.opts.EventStream, t.s.opts.EventMaxLen, e); err != nil {
+			return err
+		}
+	}
+	return nil
+}

internal/kv/kv_test.go

@@ -0,0 +1,314 @@
+package kv
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func openTest(t *testing.T, path string) *Store {
+	t.Helper()
+	if path == "" {
+		path = filepath.Join(t.TempDir(), "kv.db")
+	}
+	s, err := Open(path, Options{
+		EventStream: "meta:events",
+		EventMaxLen: 100_000,
+		EventKey:    func(k string) bool { return strings.HasPrefix(k, "file:") },
+	})
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	t.Cleanup(func() { _ = s.Close() })
+	return s
+}
+
+func update(t *testing.T, s *Store, fn func(tx *Tx) error) {
+	t.Helper()
+	if err := s.Update(context.Background(), fn); err != nil {
+		t.Fatalf("update: %v", err)
+	}
+}
+
+func events(t *testing.T, s *Store) []Entry {
+	t.Helper()
+	es, err := s.ReadAfter(context.Background(), "meta:events", "0", 0)
+	if err != nil {
+		t.Fatalf("read events: %v", err)
+	}
+	return es
+}
+
+// The replacement for keyspace notifications: a change and its event commit
+// together, with Redis' semantics — `set` even for an unchanged value, `del`
+// only for a key that existed, and nothing for keys outside the event scope.
+func TestChangesPublishEventsWithRedisSemantics(t *testing.T) {
+	s := openTest(t, "")
+	update(t, s, func(tx *Tx) error {
+		_ = tx.Put("file:A/title", "x")
+		_ = tx.Put("file:A/title", "x") // unchanged value still publishes
+		_ = tx.Put("cid:bafk", "A")     // outside the event scope
+		_, _ = tx.Delete("file:A/missing")
+		_, _ = tx.Delete("file:A/title")
+		return nil
+	})
+	got := events(t, s)
+	want := []string{"set file:A/title", "set file:A/title", "del file:A/title"}
+	if len(got) != len(want) {
+		t.Fatalf("events = %+v, want %v", got, want)
+	}
+	for i, e := range got {
+		if e.Values["type"]+" "+e.Values["key"] != want[i] {
+			t.Errorf("event %d = %v, want %q", i, e.Values, want[i])
+		}
+	}
+}
+
+func TestRolledBackChangesPublishNothing(t *testing.T) {
+	s := openTest(t, "")
+	err := s.Update(context.Background(), func(tx *Tx) error {
+		_ = tx.Put("file:A/title", "x")
+		return errors.New("boom")
+	})
+	if err == nil {
+		t.Fatal("want the error back")
+	}
+	if _, ok, _ := s.Get(context.Background(), "file:A/title"); ok {
+		t.Fatal("rolled-back write is visible")
+	}
+	if es := events(t, s); len(es) != 0 {
+		t.Fatalf("rolled-back write published %+v", es)
+	}
+}
+
+func TestDeletePrefixPublishesOneDelPerKey(t *testing.T) {
+	s := openTest(t, "")
+	update(t, s, func(tx *Tx) error {
+		for _, k := range []string{"file:A/a", "file:A/b", "file:AB/c"} {
+			_ = tx.Put(k, "1")
+		}
+		return nil
+	})
+	var n int64
+	update(t, s, func(tx *Tx) error {
+		var err error
+		n, err = tx.DeletePrefix("file:A/", 0)
+		return err
+	})
+	if n != 2 {
+		t.Fatalf("deleted %d, want 2 (file:AB/ is not under file:A/)", n)
+	}
+	es := events(t, s)
+	if dels := es[3:]; len(dels) != 2 || dels[0].Values["type"] != "del" || dels[1].Values["type"] != "del" {
+		t.Fatalf("want two del events, got %+v", es)
+	}
+}
+
+// IDs are Redis-shaped and strictly increasing, within one millisecond and
+// across a reopen — the SSE cursors consumers persist depend on both.
+func TestStreamIDsAreMonotonicAcrossReopen(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "kv.db")
+	s, err := Open(path, Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var ids []string
+	if err := s.Update(context.Background(), func(tx *Tx) error {
+		for i := 0; i < 50; i++ {
+			id, err := tx.Append("file:events", 0, map[string]string{"n": "x"})
+			if err != nil {
+				return err
+			}
+			ids = append(ids, id)
+		}
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	_ = s.Close()
+
+	s2 := openTest(t, path)
+	var after string
+	update(t, s2, func(tx *Tx) error {
+		var err error
+		after, err = tx.Append("file:events", 0, map[string]string{"n": "y"})
+		return err
+	})
+	ids = append(ids, after)
+	for i := 1; i < len(ids); i++ {
+		if !idLess(t, ids[i-1], ids[i]) {
+			t.Fatalf("id %d (%s) does not follow %s", i, ids[i], ids[i-1])
+		}
+	}
+	if !strings.Contains(ids[0], "-") || strings.HasPrefix(ids[0], "0") {
+		t.Fatalf("id %q is not the unpadded <ms>-<seq> form", ids[0])
+	}
+}
+
+func idLess(t *testing.T, a, b string) bool {
+	t.Helper()
+	am, as, err := ParseID(a)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bm, bs, err := ParseID(b)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return am < bm || (am == bm && as < bs)
+}
+
+// The watcher's reset clears file:events. The next ID must still exceed every
+// ID issued before the clear, or a consumer holding an old cursor would skip
+// the reset event.
+func TestClearStreamKeepsTheHighWaterMark(t *testing.T) {
+	s := openTest(t, "")
+	var before, after string
+	update(t, s, func(tx *Tx) error {
+		var err error
+		for i := 0; i < 5; i++ {
+			if before, err = tx.Append("file:events", 0, map[string]string{"type": "add"}); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	update(t, s, func(tx *Tx) error { return tx.ClearStream("file:events") })
+	if n, _ := s.Len(context.Background(), "file:events"); n != 0 {
+		t.Fatalf("len after clear = %d", n)
+	}
+	update(t, s, func(tx *Tx) error {
+		var err error
+		after, err = tx.Append("file:events", 0, map[string]string{"type": "reset"})
+		return err
+	})
+	if !idLess(t, before, after) {
+		t.Fatalf("post-clear id %s does not follow pre-clear %s", after, before)
+	}
+	got, err := s.ReadAfter(context.Background(), "file:events", before, 10)
+	if err != nil || len(got) != 1 || got[0].Values["type"] != "reset" {
+		t.Fatalf("an old cursor must see the reset: %+v err=%v", got, err)
+	}
+}
+
+// MAXLEN ~ semantics across many small transactions (the common case: one
+// event per write).
+func TestStreamTrimsAcrossTransactions(t *testing.T) {
+	defer func(old int64) { trimEvery = old }(trimEvery)
+	trimEvery = 100
+	s := openTest(t, "")
+	const maxLen = 50
+	for i := int64(0); i < 3*trimEvery; i++ {
+		update(t, s, func(tx *Tx) error {
+			_, err := tx.Append("x", maxLen, map[string]string{"i": "1"})
+			return err
+		})
+	}
+	n, err := s.Len(context.Background(), "x")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n > maxLen+trimEvery {
+		t.Fatalf("stream holds %d entries, want <= %d", n, maxLen+trimEvery)
+	}
+	oldest, ok, err := s.Oldest(context.Background(), "x")
+	if err != nil || !ok {
+		t.Fatal(err)
+	}
+	if last, _ := s.LastID(context.Background(), "x"); !idLess(t, oldest.ID, last) {
+		t.Fatalf("oldest %s should precede last %s", oldest.ID, last)
+	}
+}
+
+// A subscriber that took the wake channel before reading is woken by the next
+// commit — the property the SSE pump relies on to not miss an append.
+func TestWaitIsClosedByTheNextCommit(t *testing.T) {
+	s := openTest(t, "")
+	wake := s.Wait("meta:events")
+	update(t, s, func(tx *Tx) error { return tx.Put("file:A/x", "1") })
+	select {
+	case <-wake:
+	case <-time.After(2 * time.Second):
+		t.Fatal("commit did not wake the waiter")
+	}
+}
+
+func TestReadAfterZeroFormsReadFromTheStart(t *testing.T) {
+	s := openTest(t, "")
+	update(t, s, func(tx *Tx) error {
+		_, err := tx.Append("x", 0, map[string]string{"n": "1"})
+		return err
+	})
+	for _, id := range []string{"", "0", "0-0"} {
+		got, err := s.ReadAfter(context.Background(), "x", id, 10)
+		if err != nil || len(got) != 1 {
+			t.Errorf("ReadAfter(%q) = %d entries, err %v; want 1", id, len(got), err)
+		}
+	}
+}
+
+func TestRangeIsExactlyThePrefix(t *testing.T) {
+	s := openTest(t, "")
+	update(t, s, func(tx *Tx) error {
+		for _, k := range []string{"file:A/a", "file:A/b/c", "file:A0", "file:AB/x", "file:A"} {
+			_ = tx.Put(k, "v")
+		}
+		return nil
+	})
+	rows, err := s.Range(context.Background(), "file:A/", "", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rows) != 2 || rows[0].K != "file:A/a" || rows[1].K != "file:A/b/c" {
+		t.Fatalf("range = %+v", rows)
+	}
+}
+
+// Concurrent Updates share commits; a failing one must roll back alone and
+// leave its neighbours' writes and events intact.
+func TestGroupCommitIsolatesFailures(t *testing.T) {
+	s := openTest(t, "")
+	const n = 200
+	errs := make(chan error, n)
+	for i := 0; i < n; i++ {
+		go func(i int) {
+			errs <- s.Update(context.Background(), func(tx *Tx) error {
+				k := fmt.Sprintf("file:R%03d/title", i)
+				if err := tx.Put(k, "x"); err != nil {
+					return err
+				}
+				if i%10 == 0 {
+					return errors.New("fail")
+				}
+				return nil
+			})
+		}(i)
+	}
+	failed := 0
+	for i := 0; i < n; i++ {
+		if <-errs != nil {
+			failed++
+		}
+	}
+	if failed != n/10 {
+		t.Fatalf("failed = %d, want %d", failed, n/10)
+	}
+	rows, _ := s.Range(context.Background(), "file:", "", 0)
+	if len(rows) != n-n/10 {
+		t.Fatalf("committed %d rows, want %d", len(rows), n-n/10)
+	}
+	if es := events(t, s); len(es) != n-n/10 {
+		t.Fatalf("events = %d, want %d (one per committed write, none for failures)", len(es), n-n/10)
+	}
+	for _, r := range rows {
+		var i int
+		fmt.Sscanf(r.K, "file:R%03d/title", &i)
+		if i%10 == 0 {
+			t.Fatalf("failed request's write %s committed", r.K)
+		}
+	}
+}

internal/kv/stream.go

@@ -0,0 +1,356 @@
+package kv
+
+// Append-only event streams, as rows of the kv table.
+//
+// A stream entry is the row
+//
+//	ev:<stream>/<ms:13>-<seq:10>  →  JSON object of the entry's string fields
+//
+// Zero padding makes key order equal ID order, so reading "after an ID" is a
+// plain range read and trimming is a range delete. On the wire IDs are the
+// unpadded Redis form (`1700000000000-0`): meta-sort, meta-share and
+// meta-stremio persist SSE cursors to disk across the Redis → SQLite switch,
+// and those compare as <ms>-<seq> pairs.
+//
+// The last issued ID is kept in `evhwm:<stream>` and updated in the same
+// transaction as the append. That high-water mark, not the newest surviving
+// row, seeds the next ID — so Clear (the watcher's `reset`) never reissues an
+// ID an old cursor would treat as already seen.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Entry is one stream entry.
+type Entry struct {
+	ID     string
+	Values map[string]string
+}
+
+type streamID struct{ ms, seq int64 }
+
+func (id streamID) String() string {
+	return strconv.FormatInt(id.ms, 10) + "-" + strconv.FormatInt(id.seq, 10)
+}
+
+func (id streamID) padded() string { return fmt.Sprintf("%013d-%010d", id.ms, id.seq) }
+
+func (id streamID) less(o streamID) bool {
+	return id.ms < o.ms || (id.ms == o.ms && id.seq < o.seq)
+}
+
+// ParseID parses a Redis-style stream ID. "", "0", "0-0", "-" all parse as the
+// zero ID (before everything). A bare "<ms>" means "<ms>-0".
+func ParseID(s string) (ms, seq int64, err error) {
+	if s == "" || s == "-" || s == "0" {
+		return 0, 0, nil
+	}
+	msPart, seqPart, hasSeq := strings.Cut(s, "-")
+	ms, err = strconv.ParseInt(msPart, 10, 64)
+	if err != nil || ms < 0 {
+		return 0, 0, fmt.Errorf("invalid stream id %q", s)
+	}
+	if hasSeq {
+		seq, err = strconv.ParseInt(seqPart, 10, 64)
+		if err != nil || seq < 0 {
+			return 0, 0, fmt.Errorf("invalid stream id %q", s)
+		}
+	}
+	return ms, seq, nil
+}
+
+func streamPrefix(stream string) string { return "ev:" + stream + "/" }
+func hwmKey(stream string) string       { return "evhwm:" + stream }
+
+// streamState is the in-memory view of a stream's high-water mark plus the
+// broadcast channel subscribers wait on. Updated only after a commit.
+type streamState struct {
+	loaded    bool
+	hwm       streamID
+	sinceTrim int64 // committed appends since the last trim
+	notify    chan struct{}
+}
+
+// streamPending is what a transaction did to one stream, applied to
+// streamState on commit (and discarded on rollback).
+type streamPending struct {
+	hwm        streamID
+	appends    int64
+	trimmed    bool
+	lastTrimAt int64 // value of appends when this transaction last trimmed
+}
+
+func (s *Store) state(stream string) *streamState {
+	st := s.streams[stream]
+	if st == nil {
+		st = &streamState{notify: make(chan struct{})}
+		s.streams[stream] = st
+	}
+	return st
+}
+
+// Wait returns a channel closed by the next commit that appends to stream.
+// Take it BEFORE reading, so an append between the read and the wait is not
+// missed.
+func (s *Store) Wait(stream string) <-chan struct{} {
+	s.streamMu.Lock()
+	defer s.streamMu.Unlock()
+	return s.state(stream).notify
+}
+
+func (s *Store) afterCommit(pending map[string]*streamPending) {
+	if len(pending) == 0 {
+		return
+	}
+	s.streamMu.Lock()
+	defer s.streamMu.Unlock()
+	for name, p := range pending {
+		st := s.state(name)
+		st.loaded = true
+		st.hwm = p.hwm
+		if p.trimmed {
+			st.sinceTrim = p.appends - p.lastTrimAt
+		} else {
+			st.sinceTrim += p.appends
+		}
+		close(st.notify)
+		st.notify = make(chan struct{})
+	}
+}
+
+// hwm returns the stream's last issued ID as seen by this transaction.
+func (t *Tx) hwm(stream string) (streamID, error) {
+	if p := t.g.pending[stream]; p != nil {
+		return p.hwm, nil
+	}
+	t.s.streamMu.Lock()
+	st := t.s.state(stream)
+	loaded, hwm := st.loaded, st.hwm
+	t.s.streamMu.Unlock()
+	if loaded {
+		return hwm, nil
+	}
+	v, ok, err := t.Get(t.ctx, hwmKey(stream))
+	if err != nil {
+		return streamID{}, err
+	}
+	if !ok {
+		return streamID{}, nil
+	}
+	ms, seq, err := ParseID(v)
+	if err != nil {
+		return streamID{}, err
+	}
+	return streamID{ms, seq}, nil
+}
+
+// Append adds an entry to stream and returns its ID. The stream is trimmed to
+// about maxLen entries (maxLen <= 0: unbounded).
+func (t *Tx) Append(stream string, maxLen int64, fields map[string]string) (string, error) {
+	last, err := t.hwm(stream)
+	if err != nil {
+		return "", fmt.Errorf("stream %s hwm: %w", stream, err)
+	}
+	id := streamID{ms: time.Now().UnixMilli()}
+	if !last.less(id) {
+		id = streamID{ms: last.ms, seq: last.seq + 1}
+	}
+	body, err := json.Marshal(fields)
+	if err != nil {
+		return "", err
+	}
+	if _, err := t.stmt(t.s.stInsert).ExecContext(t.ctx, streamPrefix(stream)+id.padded(), string(body)); err != nil {
+		return "", fmt.Errorf("append %s: %w", stream, err)
+	}
+	if t.g.pending == nil {
+		t.g.pending = make(map[string]*streamPending)
+	}
+	p := t.g.pending[stream]
+	if p == nil {
+		p = &streamPending{}
+		t.g.pending[stream] = p
+	}
+	p.hwm = id
+	p.appends++
+	// Trim in steps, not per append: MAXLEN ~ semantics, like the XADD it
+	// replaces. The count spans transactions (most append one event each).
+	if maxLen > 0 {
+		t.s.streamMu.Lock()
+		since := t.s.state(stream).sinceTrim
+		t.s.streamMu.Unlock()
+		if !p.trimmed {
+			since += p.appends
+		} else {
+			since = p.appends - p.lastTrimAt
+		}
+		if since >= trimEvery {
+			if err := t.trim(stream, maxLen); err != nil {
+				return "", err
+			}
+			p.trimmed, p.lastTrimAt = true, p.appends
+		}
+	}
+	return id.String(), nil
+}
+
+// trimEvery is how many appends pass between trims. A trim locates its cut
+// point by walking maxLen entries back from the newest, so it is kept rare;
+// the cost is overshooting maxLen by at most trimEvery entries.
+var trimEvery int64 = 10_000 // var so tests can lower it
+
+func (t *Tx) trim(stream string, maxLen int64) error {
+	prefix := streamPrefix(stream)
+	var cut string
+	err := t.sqlTx().QueryRowContext(t.ctx,
+		`SELECT k FROM kv WHERE k >= ? AND k < ? ORDER BY k DESC LIMIT 1 OFFSET ?`,
+		prefix, PrefixEnd(prefix), maxLen).Scan(&cut)
+	if err != nil {
+		return nil // fewer than maxLen entries (sql.ErrNoRows): nothing to trim
+	}
+	_, err = t.sqlTx().ExecContext(t.ctx, `DELETE FROM kv WHERE k >= ? AND k <= ?`, prefix, cut)
+	return err
+}
+
+// flushHWM persists each touched stream's high-water mark — once per
+// transaction, not per append.
+func (t *Tx) flushHWM() error {
+	for stream, p := range t.g.pending {
+		if _, err := t.stmt(t.s.stPut).ExecContext(t.ctx, hwmKey(stream), p.hwm.String()); err != nil {
+			return fmt.Errorf("stream %s hwm: %w", stream, err)
+		}
+	}
+	return nil
+}
+
+// TrimAll trims stream to maxLen inside the transaction regardless of how many
+// appends this transaction made. Used after an append burst split over many
+// short transactions.
+func (t *Tx) TrimAll(stream string, maxLen int64) error { return t.trim(stream, maxLen) }
+
+// ClearStream deletes every entry of stream, keeping its high-water mark.
+func (t *Tx) ClearStream(stream string) error {
+	prefix := streamPrefix(stream)
+	_, err := t.sqlTx().ExecContext(t.ctx, `DELETE FROM kv WHERE k >= ? AND k < ?`, prefix, PrefixEnd(prefix))
+	return err
+}
+
+func decodeEntry(stream, k, v string) (Entry, error) {
+	padded := strings.TrimPrefix(k, streamPrefix(stream))
+	ms, seq, err := ParseID(padded)
+	if err != nil {
+		return Entry{}, err
+	}
+	var values map[string]string
+	if err := json.Unmarshal([]byte(v), &values); err != nil {
+		return Entry{}, fmt.Errorf("decode %s: %w", k, err)
+	}
+	return Entry{ID: streamID{ms, seq}.String(), Values: values}, nil
+}
+
+func decodeEntries(stream string, rows []KV) ([]Entry, error) {
+	out := make([]Entry, 0, len(rows))
+	for _, kv := range rows {
+		e, err := decodeEntry(stream, kv.K, kv.V)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, e)
+	}
+	return out, nil
+}
+
+// ReadAfter returns up to n entries strictly after id, oldest first. "0",
+// "0-0" and "" read from the beginning.
+func (s *Store) ReadAfter(ctx context.Context, stream, id string, n int) ([]Entry, error) {
+	ms, seq, err := ParseID(id)
+	if err != nil {
+		return nil, err
+	}
+	prefix := streamPrefix(stream)
+	after := ""
+	if ms != 0 || seq != 0 {
+		after = prefix + streamID{ms, seq}.padded()
+	}
+	rows, err := rangeQuery(ctx, s.r, prefix, after, n)
+	if err != nil {
+		return nil, err
+	}
+	return decodeEntries(stream, rows)
+}
+
+// Oldest returns the oldest surviving entry, or ok=false for an empty stream.
+func (s *Store) Oldest(ctx context.Context, stream string) (Entry, bool, error) {
+	rows, err := rangeQuery(ctx, s.r, streamPrefix(stream), "", 1)
+	if err != nil || len(rows) == 0 {
+		return Entry{}, false, err
+	}
+	e, err := decodeEntry(stream, rows[0].K, rows[0].V)
+	return e, err == nil, err
+}
+
+// LastID returns the last ID ever issued on stream ("0-0" if none) — the
+// cursor meaning "only entries appended from now on".
+func (s *Store) LastID(ctx context.Context, stream string) (string, error) {
+	s.streamMu.Lock()
+	st := s.state(stream)
+	loaded, hwm := st.loaded, st.hwm
+	s.streamMu.Unlock()
+	if loaded {
+		return hwm.String(), nil
+	}
+	v, ok, err := s.Get(ctx, hwmKey(stream))
+	if err != nil {
+		return "", err
+	}
+	if !ok {
+		return "0-0", nil
+	}
+	return v, nil
+}
+
+// Len is the number of surviving entries.
+func (s *Store) Len(ctx context.Context, stream string) (int64, error) {
+	return count(ctx, s.r, streamPrefix(stream))
+}
+
+// RevRange returns up to n entries newest first, stopping at (excluding)
+// entries at or before afterID when afterID is non-empty.
+func (s *Store) RevRange(ctx context.Context, stream, afterID string, n int) ([]Entry, error) {
+	prefix := streamPrefix(stream)
+	query := `SELECT k, v FROM kv WHERE k > ? AND k < ? ORDER BY k DESC`
+	lo := prefix
+	if afterID != "" {
+		ms, seq, err := ParseID(afterID)
+		if err != nil {
+			return nil, err
+		}
+		lo = prefix + streamID{ms, seq}.padded()
+	}
+	args := []any{lo, PrefixEnd(prefix)}
+	if n > 0 {
+		query += ` LIMIT ?`
+		args = append(args, n)
+	}
+	rows, err := s.r.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var kvs []KV
+	for rows.Next() {
+		var kv KV
+		if err := rows.Scan(&kv.K, &kv.V); err != nil {
+			return nil, err
+		}
+		kvs = append(kvs, kv)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return decodeEntries(stream, kvs)
+}

internal/meshdisco/node.go

@@ -0,0 +1,439 @@
+package meshdisco
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"sort"
+	"sync"
+	"syscall"
+	"time"
+
+	"golang.org/x/net/ipv4"
+	"golang.org/x/sys/unix"
+)
+
+// Config configures a Node. Payload is a function rather than a value so the
+// advertise is rebuilt from live state on every tick — that is what keeps the
+// advertised core URLs and GET /urls from drifting apart.
+type Config struct {
+	Name     string
+	Instance string
+	Version  string
+
+	Group    string
+	Port     int
+	Interval time.Duration
+
+	// Payload returns this node's status ("starting" / "running") and its
+	// resources. The envelope and NodeInfo are filled in by the Node.
+	Payload func() (status string, resources []Resource)
+}
+
+func (c *Config) applyDefaults() {
+	if c.Group == "" {
+		c.Group = DefaultGroup
+	}
+	if c.Port == 0 {
+		c.Port = DefaultPort
+	}
+	if c.Interval <= 0 {
+		c.Interval = DefaultInterval
+	}
+}
+
+type seen struct {
+	node      NodeInfo
+	resources []Resource
+	addr      string
+	lastSeen  time.Time
+}
+
+// Node is one beacon v2 participant: it advertises its resources, answers
+// probes, and keeps a TTL map of every other node it has heard from.
+type Node struct {
+	cfg   Config
+	group net.IP
+
+	pc     *ipv4.PacketConn
+	closer interface{ Close() error }
+
+	// ifaces are the multicast-capable interfaces we joined and send on.
+	// A container attached to two docker networks (metashare-app on `pcs`
+	// and `metamesh-mesh`, metawatch-* on `metawatch` and `metamesh-mesh`)
+	// has two entries here, and MUST be advertised on both — sending via the
+	// default route alone silently covers only one network.
+	ifaces []net.Interface
+
+	// sendMu serialises SetMulticastInterface + WriteTo, which are a
+	// two-step operation on one shared socket.
+	sendMu sync.Mutex
+
+	mu    sync.RWMutex
+	nodes map[string]*seen
+
+	stopChan chan struct{}
+	stopOnce sync.Once
+	wg       sync.WaitGroup
+}
+
+// New creates a Node. It does not touch the network until Start.
+func New(cfg Config) *Node {
+	cfg.applyDefaults()
+	return &Node{
+		cfg:      cfg,
+		nodes:    make(map[string]*seen),
+		stopChan: make(chan struct{}),
+	}
+}
+
+// Start opens the multicast socket, joins the group on every eligible
+// interface, and begins advertising. A join failure on one interface is logged
+// and skipped rather than fatal — a host that blocks multicast degrades
+// instead of failing to boot.
+func (n *Node) Start() error {
+	n.group = net.ParseIP(n.cfg.Group)
+	if n.group == nil || n.group.To4() == nil {
+		return fmt.Errorf("beacon: invalid multicast group %q", n.cfg.Group)
+	}
+
+	lc := net.ListenConfig{Control: reusePort}
+	conn, err := lc.ListenPacket(context.Background(), "udp4", fmt.Sprintf(":%d", n.cfg.Port))
+	if err != nil {
+		return fmt.Errorf("beacon: listen on :%d: %w", n.cfg.Port, err)
+	}
+	n.closer = conn
+
+	pc := ipv4.NewPacketConn(conn)
+	// TTL 1: link-local only. Discovery never routes off the local segment;
+	// the two-host topology keeps two separate meshes by design.
+	if err := pc.SetMulticastTTL(1); err != nil {
+		log.Printf("[beacon] Warning: could not set multicast TTL: %v", err)
+	}
+	n.pc = pc
+
+	n.ifaces = eligibleInterfaces()
+	if len(n.ifaces) == 0 {
+		log.Println("[beacon] Warning: no multicast-capable interfaces found; discovery will be inert")
+	}
+
+	group := &net.UDPAddr{IP: n.group}
+	joined := 0
+	for i := range n.ifaces {
+		if err := pc.JoinGroup(&n.ifaces[i], group); err != nil {
+			log.Printf("[beacon] Warning: join %s on %s failed: %v", n.cfg.Group, n.ifaces[i].Name, err)
+			continue
+		}
+		joined++
+	}
+	log.Printf("[beacon] Listening on %s:%d as %s/%s (joined %d of %d interfaces)",
+		n.cfg.Group, n.cfg.Port, n.cfg.Name, n.cfg.Instance, joined, len(n.ifaces))
+
+	n.wg.Add(2)
+	go n.readLoop()
+	go n.advertiseLoop()
+
+	return nil
+}
+
+// Stop multicasts a bye — so neighbours drop us immediately instead of
+// waiting out the staleness window — then closes the socket and waits for the
+// loops to exit.
+func (n *Node) Stop() error {
+	var err error
+	n.stopOnce.Do(func() {
+		n.broadcast(Message{Proto: Proto, V: Version, Type: TypeBye, Node: n.nodeInfo("")})
+		close(n.stopChan)
+		if n.closer != nil {
+			err = n.closer.Close()
+		}
+		n.wg.Wait()
+	})
+	return err
+}
+
+// Probe multicasts a probe on every interface. Every node owning a resource
+// matching one of want (every node, when want is empty) replies immediately,
+// so a caller does not have to wait out an interval.
+func (n *Node) Probe(want ...string) {
+	n.broadcast(Message{Proto: Proto, V: Version, Type: TypeProbe, From: n.cfg.Instance, Want: want})
+}
+
+// Neighbors returns every node heard from within the staleness window,
+// sorted by (name, instance). Expired entries are dropped as a side effect —
+// expiry is a read-time concern, so there is no reaper goroutine.
+func (n *Node) Neighbors() []Neighbor {
+	cutoff := time.Now().Add(-n.cfg.Interval * LivenessFactor)
+
+	n.mu.Lock()
+	out := make([]Neighbor, 0, len(n.nodes))
+	for k, s := range n.nodes {
+		if s.lastSeen.Before(cutoff) {
+			delete(n.nodes, k)
+			continue
+		}
+		out = append(out, newNeighbor(s.node, s.resources, s.addr, s.lastSeen))
+	}
+	n.mu.Unlock()
+
+	sort.Slice(out, func(i, j int) bool {
+		if out[i].Name != out[j].Name {
+			return out[i].Name < out[j].Name
+		}
+		return out[i].Instance < out[j].Instance
+	})
+	return out
+}
+
+// NeighborsByName collapses multiple instances of one name down to the most
+// recently seen — the shape the nav menu wants.
+func (n *Node) NeighborsByName() []Neighbor {
+	best := make(map[string]Neighbor)
+	for _, nb := range n.Neighbors() {
+		if cur, ok := best[nb.Name]; !ok || nb.LastSeen > cur.LastSeen {
+			best[nb.Name] = nb
+		}
+	}
+	out := make([]Neighbor, 0, len(best))
+	for _, nb := range best {
+		out = append(out, nb)
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Name < out[j].Name })
+	return out
+}
+
+// Self returns this node as a row, so callers can render themselves without
+// waiting to hear their own multicast echo back.
+func (n *Node) Self() Neighbor {
+	status, resources := n.payload()
+	return newNeighbor(*n.nodeInfo(status), resources, "", time.Now())
+}
+
+func (n *Node) payload() (string, []Resource) {
+	if n.cfg.Payload == nil {
+		return "running", nil
+	}
+	return n.cfg.Payload()
+}
+
+func (n *Node) nodeInfo(status string) *NodeInfo {
+	return &NodeInfo{Name: n.cfg.Name, Instance: n.cfg.Instance, Version: n.cfg.Version, Status: status}
+}
+
+func (n *Node) advertiseMsg() Message {
+	status, resources := n.payload()
+	return Message{Proto: Proto, V: Version, Type: TypeAdvertise, Node: n.nodeInfo(status), Resources: resources}
+}
+
+func (n *Node) readLoop() {
+	defer n.wg.Done()
+	buf := make([]byte, ReadBufferSize)
+
+	for {
+		select {
+		case <-n.stopChan:
+			return
+		default:
+		}
+
+		nRead, _, src, err := n.pc.ReadFrom(buf)
+		if err != nil {
+			select {
+			case <-n.stopChan:
+				return
+			default:
+			}
+			log.Printf("[beacon] Read error: %v", err)
+			continue
+		}
+
+		msg, ok := Parse(buf[:nRead])
+		if !ok {
+			continue // v1 or foreign traffic on the shared group
+		}
+
+		switch msg.Type {
+		case TypeProbe:
+			if msg.From == n.cfg.Instance {
+				continue
+			}
+			ad := n.advertiseMsg()
+			wanted := len(msg.Want) == 0
+			for _, r := range ad.Resources {
+				if r.MatchesAny(msg.Want) {
+					wanted = true
+					break
+				}
+			}
+			if wanted {
+				// Unicast straight back to the prober's source address; its
+				// ephemeral source port is where it is listening.
+				n.send(ad, src)
+			}
+		case TypeAdvertise, TypeBye:
+			// Drop our own multicast echo. Loopback stays enabled so a
+			// single-container test still sees traffic; we filter by identity.
+			if msg.Node.Instance == n.cfg.Instance {
+				continue
+			}
+			n.record(msg, src)
+		}
+	}
+}
+
+func (n *Node) record(msg Message, src net.Addr) {
+	addr := ""
+	if src != nil {
+		if udp, ok := src.(*net.UDPAddr); ok {
+			addr = udp.IP.String()
+		} else {
+			addr = src.String()
+		}
+	}
+
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	if msg.Type == TypeBye {
+		delete(n.nodes, msg.Node.Instance)
+		return
+	}
+	n.nodes[msg.Node.Instance] = &seen{node: *msg.Node, resources: msg.Resources, addr: addr, lastSeen: time.Now()}
+}
+
+func (n *Node) advertiseLoop() {
+	defer n.wg.Done()
+
+	// Advertise immediately, then probe once so the map fills without
+	// waiting a full interval for everyone else's ticker.
+	n.broadcast(n.advertiseMsg())
+	n.Probe()
+
+	ticker := time.NewTicker(n.cfg.Interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-n.stopChan:
+			return
+		case <-ticker.C:
+			n.broadcast(n.advertiseMsg())
+		}
+	}
+}
+
+func encode(msg Message) ([]byte, bool) {
+	body, err := json.Marshal(msg)
+	if err != nil {
+		return nil, false
+	}
+	if len(body) > MaxDatagram {
+		log.Printf("[beacon] Warning: %d-byte datagram exceeds the fragmentation-safe %d", len(body), MaxDatagram)
+	}
+	return body, true
+}
+
+// send unicasts msg to dst (a probe reply).
+func (n *Node) send(msg Message, dst net.Addr) {
+	body, ok := encode(msg)
+	if !ok {
+		return
+	}
+	n.sendMu.Lock()
+	defer n.sendMu.Unlock()
+	if _, err := n.pc.WriteTo(body, nil, dst); err != nil {
+		log.Printf("[beacon] Reply to %s failed: %v", dst, err)
+	}
+}
+
+// broadcast writes one message to the group once per eligible interface.
+// Writing once and letting the routing table choose would reach exactly one
+// network, which is the failure mode this protocol exists to avoid.
+func (n *Node) broadcast(msg Message) {
+	if n.pc == nil {
+		return
+	}
+	body, ok := encode(msg)
+	if !ok {
+		return
+	}
+	dst := &net.UDPAddr{IP: n.group, Port: n.cfg.Port}
+
+	n.sendMu.Lock()
+	defer n.sendMu.Unlock()
+	for i := range n.ifaces {
+		if err := n.pc.SetMulticastInterface(&n.ifaces[i]); err != nil {
+			log.Printf("[beacon] Warning: select interface %s failed: %v", n.ifaces[i].Name, err)
+			continue
+		}
+		if _, err := n.pc.WriteTo(body, nil, dst); err != nil {
+			log.Printf("[beacon] Warning: send on %s failed: %v", n.ifaces[i].Name, err)
+		}
+	}
+}
+
+// eligibleInterfaces returns every up, non-loopback, multicast-capable
+// interface that has an IPv4 address.
+func eligibleInterfaces() []net.Interface {
+	all, err := net.Interfaces()
+	if err != nil {
+		log.Printf("[beacon] Warning: could not enumerate interfaces: %v", err)
+		return nil
+	}
+
+	var out []net.Interface
+	for _, ifi := range all {
+		if ifi.Flags&net.FlagUp == 0 ||
+			ifi.Flags&net.FlagLoopback != 0 ||
+			ifi.Flags&net.FlagMulticast == 0 {
+			continue
+		}
+		addrs, err := ifi.Addrs()
+		if err != nil {
+			continue
+		}
+		for _, a := range addrs {
+			if ipnet, ok := a.(*net.IPNet); ok && ipnet.IP.To4() != nil {
+				out = append(out, ifi)
+				break
+			}
+		}
+	}
+	return out
+}
+
+// reusePort sets SO_REUSEADDR + SO_REUSEPORT so several listeners (a test, a
+// sidecar, a beacon v1 responder in the same netns) can bind 9099 on one host.
+func reusePort(_, _ string, c syscall.RawConn) error {
+	var serr error
+	err := c.Control(func(fd uintptr) {
+		serr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
+		if serr == nil {
+			serr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+		}
+	})
+	if err != nil {
+		return err
+	}
+	return serr
+}
+
+// LocalIPv4 returns this host's first non-loopback IPv4 address, or the
+// hostname when none can be determined. Same fallback the file-based registry
+// used (discovery/service.go), kept identical so announced URLs don't shift.
+func LocalIPv4() string {
+	addrs, err := net.InterfaceAddrs()
+	if err == nil {
+		for _, addr := range addrs {
+			if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+				if ipnet.IP.To4() != nil {
+					return ipnet.IP.String()
+				}
+			}
+		}
+	}
+	host, _ := os.Hostname()
+	return host
+}

internal/meshdisco/proto.go

@@ -0,0 +1,237 @@
+// Package meshdisco implements beacon v2: local resource advertise / discover
+// over UDP multicast (239.255.99.1:9099), the protocol every meta-* service
+// and SDK-hosted plugin uses to find its neighbours.
+//
+// A node advertises Resources, each tagged with capability strings
+// ("metamesh.core", "metamesh.service/meta-sort", "metamesh.transport/nzb@1");
+// consumers keep a live view of everyone else's and filter by capability.
+// meta-core advertises "metamesh.core" carrying its /urls block, which is how
+// services locate it without a shared volume.
+//
+// The wire protocol is documented in docs/project-architecture/beacon-v2.md.
+// Keep this package and that doc in step — the Rust (meta-feeder-sdk),
+// TypeScript and Python implementations are written against the doc.
+package meshdisco
+
+import (
+	"encoding/json"
+	"strings"
+	"time"
+)
+
+const (
+	// Proto and Version form the envelope every v2 message carries. Anything
+	// else on the group (beacon v1, junk) is dropped silently.
+	Proto   = "beacon"
+	Version = 2
+
+	// DefaultGroup / DefaultPort are beacon's endpoint, on purpose: one
+	// well-known place for every kind of local resource. v1 and v2 coexist
+	// because v2 never sends v1's "discovery" / "announce" types.
+	DefaultGroup = "239.255.99.1"
+	DefaultPort  = 9099
+
+	// DefaultInterval is how often an unsolicited advertise is emitted.
+	DefaultInterval = 10 * time.Second
+
+	// LivenessFactor multiplies the interval to get the staleness window.
+	// Expiry is evaluated at read time; there is no reaper.
+	LivenessFactor = 3
+
+	// ReadBufferSize is the receive buffer; MaxDatagram is what a sender
+	// stays under so nothing fragments.
+	ReadBufferSize = 8192
+	MaxDatagram    = 1400
+
+	TypeProbe     = "probe"
+	TypeAdvertise = "advertise"
+	TypeBye       = "bye"
+
+	// CapCore is meta-core's capability; its resource carries Data.urls.
+	CapCore = "metamesh.core"
+	// CapServicePrefix + name is every service's capability.
+	CapServicePrefix = "metamesh.service/"
+	CapAnyService    = "metamesh.service/*"
+)
+
+// URLs mirrors meta-core's GET /urls response (api.URLsResponse) minus
+// redisUrl. It travels as the metamesh.core resource's Data.urls, so a service
+// locates meta-core from the advertise alone.
+type URLs struct {
+	Hostname          string `json:"hostname"`
+	BaseUrl           string `json:"baseUrl"`
+	ApiUrl            string `json:"apiUrl"`
+	WebdavUrl         string `json:"webdavUrl"`
+	WebdavUrlInternal string `json:"webdavUrlInternal"`
+}
+
+// NodeInfo says who is advertising.
+type NodeInfo struct {
+	Name     string `json:"name"`
+	Instance string `json:"instance"`
+	Version  string `json:"version,omitempty"`
+	// Status is "starting" | "running"; absent reads as running.
+	Status string `json:"status,omitempty"`
+}
+
+// Resource is one advertised thing.
+type Resource struct {
+	ID   string   `json:"id"`
+	Caps []string `json:"caps"`
+	// Endpoints: well-known names http, ui, manifest, mcp. A value starting
+	// with "/" is relative to endpoints.http.
+	Endpoints map[string]string `json:"endpoints,omitempty"`
+	Rev       string            `json:"rev,omitempty"`
+	// Binds names the one consumer instance this resource belongs to.
+	Binds string          `json:"binds,omitempty"`
+	Data  json.RawMessage `json:"data,omitempty"`
+}
+
+// Matches reports whether any cap matches pattern.
+func (r Resource) Matches(pattern string) bool {
+	for _, c := range r.Caps {
+		if CapMatches(pattern, c) {
+			return true
+		}
+	}
+	return false
+}
+
+// MatchesAny reports whether any cap matches any pattern; an empty list matches.
+func (r Resource) MatchesAny(patterns []string) bool {
+	if len(patterns) == 0 {
+		return true
+	}
+	for _, p := range patterns {
+		if r.Matches(p) {
+			return true
+		}
+	}
+	return false
+}
+
+// Endpoint returns the named endpoint as an absolute URL.
+func (r Resource) Endpoint(name string) string {
+	v := r.Endpoints[name]
+	if strings.HasPrefix(v, "/") {
+		base := r.Endpoints["http"]
+		if base == "" {
+			return ""
+		}
+		return strings.TrimRight(base, "/") + v
+	}
+	return v
+}
+
+// Message is every v2 datagram.
+type Message struct {
+	Proto     string     `json:"proto"`
+	V         int        `json:"v"`
+	Type      string     `json:"type"`
+	Node      *NodeInfo  `json:"node,omitempty"`
+	Resources []Resource `json:"resources,omitempty"`
+	// From and Want are probe-only.
+	From string   `json:"from,omitempty"`
+	Want []string `json:"want,omitempty"`
+}
+
+// Parse decodes a datagram, returning ok=false for anything that is not a
+// well-formed beacon v2 message (v1 traffic, other versions, unknown types,
+// an advertise/bye without a node).
+func Parse(b []byte) (Message, bool) {
+	var m Message
+	if err := json.Unmarshal(b, &m); err != nil {
+		return m, false
+	}
+	if m.Proto != Proto || m.V != Version {
+		return m, false
+	}
+	switch m.Type {
+	case TypeProbe:
+		return m, true
+	case TypeAdvertise, TypeBye:
+		if m.Node == nil || m.Node.Name == "" || m.Node.Instance == "" {
+			return m, false
+		}
+		return m, true
+	}
+	return m, false
+}
+
+func splitContract(s string) (string, string, bool) {
+	if i := strings.LastIndex(s, "@"); i >= 0 {
+		return s[:i], s[i+1:], true
+	}
+	return s, "", false
+}
+
+// CapMatches reports whether capability cap satisfies pattern:
+// "*" matches everything; an "@N" on the pattern must equal the cap's
+// contract (none on the pattern ignores it); "x/*" matches any variant of x;
+// otherwise the bases must be equal.
+func CapMatches(pattern, cap string) bool {
+	if pattern == "*" {
+		return true
+	}
+	pbase, pc, phas := splitContract(pattern)
+	cbase, cc, chas := splitContract(cap)
+	if phas && (!chas || pc != cc) {
+		return false
+	}
+	if prefix, ok := strings.CutSuffix(pbase, "/*"); ok {
+		rest, ok := strings.CutPrefix(cbase, prefix)
+		return ok && strings.HasPrefix(rest, "/") && len(rest) > 1
+	}
+	return pbase == cbase
+}
+
+// Neighbor is a node heard on the wire, as served by /api/neighbors.
+type Neighbor struct {
+	NodeInfo
+	Resources []Resource `json:"resources"`
+	// Caps flattens every resource's caps, for consumers that just filter.
+	Caps []string `json:"caps"`
+	// BaseUrl is the metamesh.service/* resource's endpoints.ui — kept so
+	// v1-era readers (the nav menu) keep working.
+	BaseUrl string `json:"baseUrl,omitempty"`
+	// Addr is the packet's source address, never a payload claim.
+	Addr string `json:"addr"`
+	// LastSeen is unix seconds.
+	LastSeen float64 `json:"lastSeen"`
+}
+
+// Matches reports whether any resource matches pattern.
+func (n Neighbor) Matches(pattern string) bool {
+	for _, r := range n.Resources {
+		if r.Matches(pattern) {
+			return true
+		}
+	}
+	return false
+}
+
+func newNeighbor(node NodeInfo, resources []Resource, addr string, seen time.Time) Neighbor {
+	nb := Neighbor{
+		NodeInfo:  node,
+		Resources: resources,
+		Caps:      []string{},
+		Addr:      addr,
+		LastSeen:  float64(seen.UnixNano()) / 1e9,
+	}
+	if nb.Resources == nil {
+		nb.Resources = []Resource{}
+	}
+	seenCap := map[string]bool{}
+	for _, r := range resources {
+		for _, c := range r.Caps {
+			if !seenCap[c] {
+				seenCap[c] = true
+				nb.Caps = append(nb.Caps, c)
+			}
+		}
+		if nb.BaseUrl == "" && r.Matches(CapAnyService) {
+			nb.BaseUrl = r.Endpoint("ui")
+		}
+	}
+	return nb
+}

internal/meshdisco/proto_test.go

@@ -0,0 +1,140 @@
+package meshdisco
+
+import (
+	"encoding/json"
+	"net"
+	"testing"
+	"time"
+)
+
+func TestCapMatches(t *testing.T) {
+	cases := []struct {
+		pattern, cap string
+		want         bool
+	}{
+		{"metamesh.transport/*", "metamesh.transport/nzb@1", true},
+		{"metamesh.transport/*", "metamesh.transport/ipfs", true},
+		{"metamesh.transport/*", "metamesh.transport", false},
+		{"metamesh.transport/*", "metamesh.transportx/a", false},
+		{"metamesh.transport/*", "metamesh.transport/", false},
+		{"metamesh.transport/nzb", "metamesh.transport/nzb@2", true},
+		{"metamesh.transport/nzb@2", "metamesh.transport/nzb@2", true},
+		{"metamesh.transport/nzb@2", "metamesh.transport/nzb@1", false},
+		{"metamesh.transport/nzb@2", "metamesh.transport/nzb", false},
+		{"metamesh.transport/*@1", "metamesh.transport/nzb@1", true},
+		{"metamesh.core", "metamesh.core", true},
+		{"metamesh.core", "metamesh.core2", false},
+		{"mcp", "mcp/x", false},
+		{"*", "anything@3", true},
+	}
+	for _, c := range cases {
+		if got := CapMatches(c.pattern, c.cap); got != c.want {
+			t.Errorf("CapMatches(%q, %q) = %v, want %v", c.pattern, c.cap, got, c.want)
+		}
+	}
+}
+
+func TestParseRejectsV1AndForeign(t *testing.T) {
+	for _, raw := range []string{
+		`{"type":"discovery"}`,
+		`{"type":"announce","name":"x","tools":[]}`,
+		`{"v":1,"type":"announce","name":"meta-sort"}`,
+		`{"proto":"beacon","v":3,"type":"probe"}`,
+		`{"proto":"beacon","v":2,"type":"announce"}`,
+		`{"proto":"beacon","v":2,"type":"advertise"}`,
+		"\x00garbage",
+	} {
+		if _, ok := Parse([]byte(raw)); ok {
+			t.Errorf("Parse(%q) accepted", raw)
+		}
+	}
+	if _, ok := Parse([]byte(`{"proto":"beacon","v":2,"type":"probe","want":["metamesh.core"]}`)); !ok {
+		t.Error("valid probe rejected")
+	}
+}
+
+func TestNeighborRowCarriesCapsAndBaseUrl(t *testing.T) {
+	nb := newNeighbor(
+		NodeInfo{Name: "meta-sort", Instance: "metasort-app"},
+		[]Resource{{ID: "service", Caps: []string{"metamesh.service/meta-sort"}, Endpoints: map[string]string{"ui": "https://x"}}},
+		"10.0.0.1", time.Now(),
+	)
+	if nb.BaseUrl != "https://x" || len(nb.Caps) != 1 || !nb.Matches(CapAnyService) {
+		t.Fatalf("unexpected row: %+v", nb)
+	}
+}
+
+// End to end over loopback: a probe with a non-matching want gets no reply;
+// a matching one gets the advertise; advertise then bye updates the view.
+func TestProbeAndRecord(t *testing.T) {
+	port := freePort(t)
+	n := New(Config{
+		Name: "meta-core", Instance: "core-1", Port: port, Interval: time.Hour,
+		Payload: func() (string, []Resource) {
+			return "running", []Resource{{ID: "core", Caps: []string{CapCore}}}
+		},
+	})
+	if err := n.Start(); err != nil {
+		t.Fatal(err)
+	}
+	defer n.Stop()
+
+	c, err := net.ListenUDP("udp4", &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+	dst := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: port}
+	buf := make([]byte, ReadBufferSize)
+
+	send := func(m Message) {
+		b, _ := json.Marshal(m)
+		if _, err := c.WriteToUDP(b, dst); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	send(Message{Proto: Proto, V: Version, Type: TypeProbe, From: "cli", Want: []string{"metamesh.service/*"}})
+	c.SetReadDeadline(time.Now().Add(300 * time.Millisecond))
+	if _, _, err := c.ReadFromUDP(buf); err == nil {
+		t.Fatal("non-matching probe got a reply")
+	}
+
+	send(Message{Proto: Proto, V: Version, Type: TypeProbe, From: "cli", Want: []string{CapCore}})
+	c.SetReadDeadline(time.Now().Add(2 * time.Second))
+	nr, _, err := c.ReadFromUDP(buf)
+	if err != nil {
+		t.Fatalf("matching probe got no reply: %v", err)
+	}
+	if m, ok := Parse(buf[:nr]); !ok || m.Type != TypeAdvertise || m.Node.Instance != "core-1" {
+		t.Fatalf("bad reply: %s", buf[:nr])
+	}
+
+	peer := &NodeInfo{Name: "meta-sort", Instance: "sort-1"}
+	send(Message{Proto: Proto, V: Version, Type: TypeAdvertise, Node: peer,
+		Resources: []Resource{{ID: "service", Caps: []string{"metamesh.service/meta-sort"}}}})
+	waitFor(t, func() bool { return len(n.Neighbors()) == 1 })
+	send(Message{Proto: Proto, V: Version, Type: TypeBye, Node: peer})
+	waitFor(t, func() bool { return len(n.Neighbors()) == 0 })
+}
+
+func freePort(t *testing.T) int {
+	c, err := net.ListenUDP("udp4", &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+	return c.LocalAddr().(*net.UDPAddr).Port
+}
+
+func waitFor(t *testing.T, cond func() bool) {
+	t.Helper()
+	deadline := time.Now().Add(2 * time.Second)
+	for time.Now().Before(deadline) {
+		if cond() {
+			return
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	t.Fatal("condition not reached")
+}

internal/schema/classify.go

@@ -21,7 +21,7 @@ import (
 // (crc32: "bafk3eaqerjhiwhy").
 var cidRegex = regexp.MustCompile(`^(ba[a-z2-7]{14,}|Qm[1-9A-HJ-NP-Za-km-z]{44})$`)
 
-// ClassifyValue returns the (primitive, hint) for a Redis value.
+// ClassifyValue returns the (primitive, hint) for a stored value.
 // exists=false (key missing) and JSON null literal both map to PrimUndefined.
 // Empty string is a valid string.
 func ClassifyValue(value string, exists bool) (Primitive, Hint) {

internal/schema/indexer.go

@@ -6,17 +6,20 @@ import (
 	"regexp"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 
-	"github.com/metazla/meta-core/internal/events"
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
 var langCodeRegex = regexp.MustCompile(`^[a-z]{2,3}$`)
 
-// fieldState is the per-field accumulator. perKey lets us undo a previous
-// contribution when the same Redis key is re-SET or DELed.
+// rebuildInterval is how often the schema is recomputed in the background.
+// It describes the *shape* of the data (which fields exist, their types), which
+// drifts slowly; a few minutes of staleness is invisible to the editor that
+// reads it, and POST /api/schema/rescan recomputes on demand.
+const rebuildInterval = 10 * time.Minute
+
+// fieldState is the per-field accumulator.
 type fieldState struct {
 	counts         map[string]int
 	primitives     map[Primitive]int
@@ -24,12 +27,6 @@ type fieldState struct {
 	typedCount     int
 	undefinedCount int
 	languageKeyed  bool
-	perKey         map[string]labelPair
-}
-
-type labelPair struct {
-	prim Primitive
-	hint Hint
 }
 
 func newFieldState() *fieldState {
@@ -37,19 +34,25 @@ func newFieldState() *fieldState {
 		counts:     make(map[string]int),
 		primitives: make(map[Primitive]int),
 		hintCounts: make(map[Hint]int),
-		perKey:     make(map[string]labelPair),
 	}
 }
 
-// Indexer maintains a live field-schema by consuming meta:events.
+// Indexer maintains the per-field schema by scanning the store.
+//
+// It used to follow meta:events and keep, per field, a map of EVERY record key
+// it had seen (so a re-set or delete could undo that key's contribution). At
+// 6.3M keys that map was ~2 GB of RAM — about half of meta-core's resident
+// memory once the search copy was gone — and it only worked if every event was
+// replayed into it, which is half of why meta-core republished every field on
+// boot. A periodic streaming scan holds one accumulator per FIELD instead and
+// is exact by construction.
 type Indexer struct {
-	client    *redis.Client
-	keyPrefix string
+	store *kv.Store
 
 	mu   sync.RWMutex
-	fields map[string]*fieldState
+	snap *SchemaResponse
 
-	processed uint64 // total events processed since start
+	rebuildMu sync.Mutex
 
 	ctx     context.Context
 	cancel  context.CancelFunc
@@ -58,37 +61,41 @@ type Indexer struct {
 	running bool
 }
 
-// NewIndexer creates an Indexer. keyPrefix should match storage.Client.GetPrefix()
-// so the indexer can build absolute Redis keys for GET calls.
-func NewIndexer(client *redis.Client, keyPrefix string) *Indexer {
+// NewIndexer creates an Indexer over store.
+func NewIndexer(store *kv.Store) *Indexer {
 	ctx, cancel := context.WithCancel(context.Background())
-	return &Indexer{
-		client:    client,
-		keyPrefix: keyPrefix,
-		fields:    make(map[string]*fieldState),
-		ctx:       ctx,
-		cancel:    cancel,
-	}
+	return &Indexer{store: store, ctx: ctx, cancel: cancel}
 }
 
-// Start begins consuming the meta:events stream from the earliest available ID.
+// Start computes the schema in the background now and every rebuildInterval.
 func (i *Indexer) Start() error {
 	i.runMu.Lock()
+	defer i.runMu.Unlock()
 	if i.running {
-		i.runMu.Unlock()
 		return nil
 	}
 	i.running = true
-	i.runMu.Unlock()
-
 	i.wg.Add(1)
-	go i.consumeLoop()
-
-	log.Println("[SchemaIndexer] Started - consuming meta:events stream")
+	go func() {
+		defer i.wg.Done()
+		ticker := time.NewTicker(rebuildInterval)
+		defer ticker.Stop()
+		for {
+			if _, err := i.Rebuild(i.ctx); err != nil && i.ctx.Err() == nil {
+				log.Printf("[SchemaIndexer] rebuild failed: %v", err)
+			}
+			select {
+			case <-i.ctx.Done():
+				return
+			case <-ticker.C:
+			}
+		}
+	}()
+	log.Println("[SchemaIndexer] Started - scanning the store")
 	return nil
 }
 
-// Stop terminates the consumer goroutine.
+// Stop terminates the background rebuilds.
 func (i *Indexer) Stop() error {
 	i.runMu.Lock()
 	if !i.running {
@@ -104,93 +111,55 @@ func (i *Indexer) Stop() error {
 	return nil
 }
 
-// ProcessedCount returns the total number of stream events processed.
-// Used by WaitForDrain to detect when a rescan flood has been absorbed.
-func (i *Indexer) ProcessedCount() uint64 {
-	return atomic.LoadUint64(&i.processed)
-}
+// Rebuild recomputes the schema from every record key and publishes it. One
+// rebuild runs at a time; a concurrent caller waits and gets the fresh result.
+func (i *Indexer) Rebuild(ctx context.Context) (*SchemaResponse, error) {
+	i.rebuildMu.Lock()
+	defer i.rebuildMu.Unlock()
 
-// WaitForDrain blocks until ProcessedCount has been stable for `stableFor` or
-// the timeout elapses. Suitable for use right after RepublishMetadata.
-func (i *Indexer) WaitForDrain(timeout time.Duration) {
-	deadline := time.Now().Add(timeout)
-	last := i.ProcessedCount()
-	stableSince := time.Now()
-	for time.Now().Before(deadline) {
-		time.Sleep(100 * time.Millisecond)
-		now := i.ProcessedCount()
-		if now != last {
-			last = now
-			stableSince = time.Now()
-			continue
-		}
-		if time.Since(stableSince) >= 300*time.Millisecond {
-			return
-		}
-	}
-}
-
-func (i *Indexer) consumeLoop() {
-	defer i.wg.Done()
-	lastID := "0"
-	for {
-		select {
-		case <-i.ctx.Done():
-			return
-		default:
-		}
-
-		res, err := i.client.XRead(i.ctx, &redis.XReadArgs{
-			Streams: []string{events.MetaEventsStream, lastID},
-			Block:   2 * time.Second,
-			Count:   500,
-		}).Result()
-
-		if err != nil {
-			if err == redis.Nil || i.ctx.Err() != nil {
-				continue
-			}
-			log.Printf("[SchemaIndexer] XRead error: %v", err)
-			time.Sleep(1 * time.Second)
-			continue
-		}
-
-		for _, stream := range res {
-			for _, msg := range stream.Messages {
-				lastID = msg.ID
-				i.processEvent(msg.Values)
-				atomic.AddUint64(&i.processed, 1)
-			}
-		}
-	}
-}
-
-func (i *Indexer) processEvent(values map[string]any) {
-	op, _ := values["type"].(string)
-	key, _ := values["key"].(string)
-	if key == "" {
-		return
-	}
-	fieldPath, keyHint, ok := parseFieldPath(key)
+	started := time.Now()
+	fields := make(map[string]*fieldState)
+	err := i.store.ScanPrefix(ctx, "file:", 5000, func(rows []kv.KV) error {
+		for _, row := range rows {
+			fieldPath, keyHint, ok := parseFieldPath(row.K)
 			if !ok {
-		return
+				continue
+			}
+			fs := fields[fieldPath]
+			if fs == nil {
+				fs = newFieldState()
+				fields[fieldPath] = fs
+			}
+			if keyHint != "" {
+				fs.languageKeyed = true
+			}
+			prim, hint := ClassifyValue(row.V, true)
+			incContribution(fs, labelPair{prim: prim, hint: hint})
+		}
+		return ctx.Err()
+	})
+	if err != nil {
+		return nil, err
 	}
 
-	switch op {
-	case "set":
-		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
-		val, err := i.client.Get(ctx, i.keyPrefix+key).Result()
-		cancel()
-		exists := err != redis.Nil
-		if err != nil && err != redis.Nil {
-			// Treat transient errors as "value disappeared" — nothing to record.
-			return
+	snap := &SchemaResponse{
+		Fields:      make(map[string]*FieldSchema, len(fields)),
+		GeneratedAt: time.Now().UTC(),
+		Source:      "scan",
 	}
-		prim, hint := ClassifyValue(val, exists)
-		i.upsert(fieldPath, key, keyHint, prim, hint)
-	case "del", "expire":
-		i.remove(fieldPath, key)
+	for fp, fs := range fields {
+		snap.Fields[fp] = computeFieldSchema(fs)
 	}
+	i.mu.Lock()
+	i.snap = snap
+	i.mu.Unlock()
+	log.Printf("[SchemaIndexer] %d fields from a full scan in %s", len(fields), time.Since(started).Round(time.Millisecond))
+	return snap, nil
+}
+
+type labelPair struct {
+	prim Primitive
+	hint Hint
 }
 
 // parseFieldPath turns "file:<rootID>/<propertyPath>" into the logical field
@@ -222,46 +191,6 @@ func parseFieldPath(key string) (string, KeyHint, bool) {
 	return property, "", true
 }
 
-func (i *Indexer) upsert(fieldPath, redisKey string, keyHint KeyHint, prim Primitive, hint Hint) {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
-	fs, ok := i.fields[fieldPath]
-	if !ok {
-		fs = newFieldState()
-		i.fields[fieldPath] = fs
-	}
-	if keyHint != "" {
-		fs.languageKeyed = true
-	}
-
-	if old, ok := fs.perKey[redisKey]; ok {
-		decContribution(fs, old)
-	}
-
-	fs.perKey[redisKey] = labelPair{prim: prim, hint: hint}
-	incContribution(fs, labelPair{prim: prim, hint: hint})
-}
-
-func (i *Indexer) remove(fieldPath, redisKey string) {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
-	fs, ok := i.fields[fieldPath]
-	if !ok {
-		return
-	}
-	old, ok := fs.perKey[redisKey]
-	if !ok {
-		return
-	}
-	delete(fs.perKey, redisKey)
-	decContribution(fs, old)
-	if len(fs.perKey) == 0 {
-		delete(i.fields, fieldPath)
-	}
-}
-
 func incContribution(fs *fieldState, lp labelPair) {
 	label := breakdownLabel(lp.prim, lp.hint)
 	fs.counts[label]++
@@ -276,43 +205,15 @@ func incContribution(fs *fieldState, lp labelPair) {
 	}
 }
 
-func decContribution(fs *fieldState, lp labelPair) {
-	label := breakdownLabel(lp.prim, lp.hint)
-	fs.counts[label]--
-	if fs.counts[label] <= 0 {
-		delete(fs.counts, label)
-	}
-	if lp.prim == PrimUndefined {
-		fs.undefinedCount--
-		return
-	}
-	fs.typedCount--
-	fs.primitives[lp.prim]--
-	if fs.primitives[lp.prim] <= 0 {
-		delete(fs.primitives, lp.prim)
-	}
-	if lp.hint != "" {
-		fs.hintCounts[lp.hint]--
-		if fs.hintCounts[lp.hint] <= 0 {
-			delete(fs.hintCounts, lp.hint)
-		}
-	}
-}
-
-// Snapshot returns the current schema. Safe to call concurrently with consumption.
+// Snapshot returns the latest computed schema. Before the first scan finishes
+// it is empty with Source "pending".
 func (i *Indexer) Snapshot() *SchemaResponse {
 	i.mu.RLock()
 	defer i.mu.RUnlock()
-
-	out := &SchemaResponse{
-		Fields:      make(map[string]*FieldSchema, len(i.fields)),
-		GeneratedAt: time.Now().UTC(),
-		Source:      "live",
+	if i.snap == nil {
+		return &SchemaResponse{Fields: map[string]*FieldSchema{}, GeneratedAt: time.Now().UTC(), Source: "pending"}
 	}
-	for fp, fs := range i.fields {
-		out.Fields[fp] = computeFieldSchema(fs)
-	}
-	return out
+	return i.snap
 }
 
 func computeFieldSchema(fs *fieldState) *FieldSchema {

internal/schema/indexer_test.go

@@ -0,0 +1,56 @@
+package schema
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"github.com/metazla/meta-core/internal/kv"
+)
+
+func TestRebuildDerivesTypesFromTheStore(t *testing.T) {
+	store, err := kv.Open(filepath.Join(t.TempDir(), "kv.db"), kv.Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer store.Close()
+	if err := store.Update(context.Background(), func(tx *kv.Tx) error {
+		for k, v := range map[string]string{
+			"file:A/sizeByte":   "100",
+			"file:B/sizeByte":   "200",
+			"file:A/title/eng":  "One",
+			"file:B/title/fre":  "Deux",
+			"file:A/mixed":      "1",
+			"file:B/mixed":      "x",
+			"cid:bafknotrecord": "A",
+		} {
+			if err := tx.Put(k, v); err != nil {
+				return err
+			}
+		}
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	ix := NewIndexer(store)
+	if got := ix.Snapshot(); got.Source != "pending" || len(got.Fields) != 0 {
+		t.Fatalf("before a scan: %+v", got)
+	}
+	snap, err := ix.Rebuild(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f := snap.Fields["sizeByte"]; f == nil || f.Type != PrimInt || f.Breakdown["int"] != 2 {
+		t.Fatalf("sizeByte = %+v", f)
+	}
+	if f := snap.Fields["title"]; f == nil || f.KeyHint != KeyHintLanguageCode {
+		t.Fatalf("title = %+v (want language-keyed)", f)
+	}
+	if f := snap.Fields["mixed"]; f == nil || f.Type != PrimMixed {
+		t.Fatalf("mixed = %+v", f)
+	}
+	if len(snap.Fields) != 3 {
+		t.Fatalf("fields = %v (non-record keys must not count)", snap.Fields)
+	}
+}

internal/snapshot/export.go

@@ -24,7 +24,7 @@ type ExportOptions struct {
 	SourceHost string
 }
 
-// Exporter writes snapshot ZIPs from a live Redis store.
+// Exporter writes snapshot ZIPs from the live metadata store.
 type Exporter struct {
 	storage *storage.Client
 }

internal/snapshot/flatten.go

@@ -8,7 +8,7 @@ import (
 	"strings"
 )
 
-// Flat keys use "/" as the separator. Property paths inside Redis are
+// Flat keys use "/" as the separator. Property paths inside the store are
 // stored as e.g. "fileinfo/streamdetails/video/0/codec".
 const flatSep = "/"
 
@@ -33,7 +33,7 @@ func Reconstruct(flat map[string]string) interface{} {
 }
 
 // Flatten is the inverse of Reconstruct: walks a nested value and produces a
-// flat property map whose values are all strings (Redis-ready).
+// flat property map whose values are all strings (store-ready).
 //
 // Arrays become numeric path segments ("genre/0", "genre/1"). Nil/missing
 // values are stored as "" to preserve the field's presence — this matches
@@ -127,7 +127,7 @@ func flattenInto(v interface{}, path string, out map[string]string) {
 		out[path] = ""
 	case map[string]interface{}:
 		if len(t) == 0 && path != "" {
-			// Empty objects don't have a Redis representation; skip.
+			// Empty objects don't have a flat-key representation; skip.
 			return
 		}
 		for k, child := range t {

internal/snapshot/import.go

@@ -73,7 +73,7 @@ type ImportResult struct {
 	PluginOutput *PluginOutputResult `json:"pluginOutput,omitempty"`
 }
 
-// Importer applies snapshot ZIPs to a live Redis store.
+// Importer applies snapshot ZIPs to the live metadata store.
 type Importer struct {
 	storage *storage.Client
 }
@@ -83,7 +83,7 @@ func NewImporter(stor *storage.Client) *Importer {
 }
 
 // Import reads a ZIP from r (which must support io.ReaderAt; callers pass
-// *bytes.Reader after buffering the upload) and applies it to Redis.
+// *bytes.Reader after buffering the upload) and applies it to the store.
 func (i *Importer) Import(r io.ReaderAt, size int64, opts ImportOptions) (*ImportResult, error) {
 	if i.storage == nil || !i.storage.IsConnected() {
 		return nil, fmt.Errorf("storage not connected")

internal/snapshot/wipe.go

@@ -16,7 +16,7 @@ type WipeResult struct {
 	MetadataDeleted int64 `json:"metadataDeleted"`
 }
 
-// Wiper clears metadata from Redis.
+// Wiper clears metadata from the store.
 type Wiper struct {
 	storage *storage.Client
 }

internal/storage/cid_resolution.go

@@ -5,10 +5,9 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
-	"time"
 
 	"github.com/metazla/meta-core/internal/cid"
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
 // This file implements the CID-resolution layer that lives on top of the
@@ -18,7 +17,7 @@ import (
 //     The UUID is an internal implementation detail; the mental model is
 //     "N CIDs → one record of keys→metadata".
 //   - Every known CID for a file is registered as a reverse-index entry:
-//       cid:<bareCid> → <uuid>                (Redis STRING)
+//       cid:<bareCid> → <uuid>
 //     and as a member of the per-root bare-CID key-set:
 //       file:<uuid>/cids/<bareCid> = "true"   (flat key, sentinel value)
 //   - A CID is self-describing: its algorithm is recoverable from the CIDv1
@@ -27,14 +26,13 @@ import (
 //     *derived by rank* from the key-set on read (GetMetadataDocument), never
 //     stored.
 //
-// Auto-alias hooks in SetProperty/SetMetadataFlat/MergeMetadataFlat catch
-// any write of a cids/<cid> field and register the reverse-index entry, so
+// The record write path (writeFieldsTx) catches any write of a cids/<cid>
+// field and registers the reverse-index entry in the same transaction, so
 // writers that just emit the key-set members don't need to know about the
-// reverse index at all. The hook helpers are *Locked — they assume c.mu is
-// already held by the caller, avoiding nested RLock (which can deadlock
-// against a waiting writer).
+// reverse index at all. The helpers here take the caller's *kv.Tx: a write
+// must never open a second transaction (there is one writer connection).
 
-// CIDIndexPrefix is the Redis key prefix for the reverse index. Combined
+// CIDIndexPrefix is the key prefix for the reverse index. Combined
 // with a bare CID, it forms the full key: "cid:bafk…".
 const CIDIndexPrefix = "cid:"
 
@@ -45,110 +43,113 @@ const CIDIndexPrefix = "cid:"
 // reverse-index entries that need cleanup).
 const CIDsKeyPrefix = "cids/"
 
-// DuplicatesField is the per-root SET key holding additional file paths
-// whose content hashes to the same CIDs as this root. The watcher writes
-// here when it sees a new path for content that's already indexed; meta-dup
-// reads from it.
-const DuplicatesField = "duplicates"
-
-// buildCIDIndexKey returns the absolute Redis key for a reverse-index entry.
-// cidStr is a bare multibase CIDv1 ("bafk…").
-func (c *Client) buildCIDIndexKey(cidStr string) string {
-	return c.buildKey(CIDIndexPrefix + cidStr)
-}
+// Duplicate paths — other physical locations whose content hashes to the same
+// CIDs as a root — live as dup:<rid>/<path> = "" (a key-set). The watcher
+// writes one when it sees a new path for content that's already indexed.
 
 // Mint creates a new root with filePath/sizeByte/mtimeNano and registers it
-// in the file index. Returns the new UUID. The caller is expected to follow
+// in the root index. Returns the new UUID. The caller is expected to follow
 // up with AddAlias for at least one CID — a root without any alias is
 // reachable only via the index, which works but defeats the point.
 func (c *Client) Mint(filePath string, size, mtimeNano int64) (string, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return "", fmt.Errorf("not connected")
+	var uuid string
+	err := c.update(func(tx *kv.Tx) error {
+		var err error
+		uuid, err = mintTx(tx, filePath, size, mtimeNano)
+		return err
+	})
+	return uuid, err
 }
 
+func mintTx(tx *kv.Tx, filePath string, size, mtimeNano int64) (string, error) {
 	uuid, err := NewUUID()
 	if err != nil {
 		return "", fmt.Errorf("uuid: %w", err)
 	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	prefix := c.buildKeyPrefix(uuid)
-	pipe := c.client.Pipeline()
-	pipe.Set(ctx, prefix+"filePath", filePath, 0)
-	pipe.Set(ctx, prefix+"sizeByte", strconv.FormatInt(size, 10), 0)
-	pipe.Set(ctx, prefix+"mtimeNano", strconv.FormatInt(mtimeNano, 10), 0)
-	pipe.SAdd(ctx, c.buildIndexKey(), uuid)
-	if _, err := pipe.Exec(ctx); err != nil {
-		return "", fmt.Errorf("mint pipeline: %w", err)
-	}
-	return uuid, nil
+	return uuid, writeFieldsTx(tx, uuid, map[string]string{
+		"filePath":  filePath,
+		"sizeByte":  strconv.FormatInt(size, 10),
+		"mtimeNano": strconv.FormatInt(mtimeNano, 10),
+	})
 }
 
 // AddAlias registers cidStr as a sibling CID of uuid: it writes the reverse
 // index cid:<cidStr> → uuid and the key-set member cids/<cidStr> = "true".
 // Idempotent: registering the same CID twice is a no-op.
 func (c *Client) AddAlias(uuid, cidStr string) error {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return fmt.Errorf("not connected")
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	return c.addAliasLocked(ctx, uuid, cidStr)
-}
-
-// addAliasLocked is the lock-free body of AddAlias. The caller must already
-// hold c.mu (read or write). Split out so the alias-maintenance hooks
-// invoked from SetProperty / SetMetadataFlat / MergeMetadataFlat can reuse
-// the work without re-entering the lock — nested RLock can deadlock against
-// a waiting writer.
-func (c *Client) addAliasLocked(ctx context.Context, uuid, cidStr string) error {
 	if uuid == "" || cidStr == "" {
 		return fmt.Errorf("uuid and cid are required")
 	}
+	return c.update(func(tx *kv.Tx) error {
+		return writeFieldsTx(tx, uuid, map[string]string{CIDsKeyPrefix + cidStr: "true"})
+	})
+}
 
-	keysetKey := c.buildKeyPrefix(uuid) + CIDsKeyPrefix + cidStr
-
+// addAliasTx registers the reverse-index entry for a cids/<cid> member the
+// caller is writing (writeFieldsTx writes the member itself).
+func addAliasTx(tx *kv.Tx, uuid, cidStr string) error {
+	if uuid == "" || cidStr == "" {
+		return fmt.Errorf("uuid and cid are required")
+	}
 	// Self-pointing alias guard. If the caller is trying to register
 	// cid:<cid> → <cid> (i.e. the root IS the cid value), that's the
 	// dual-root failure mode in disguise — it means somebody wrote
 	// /meta/<cid> without first resolving via ResolveRoot. Refuse the alias
-	// write; leave any existing alias alone. Still record the key-set
-	// membership so the field-level write succeeds.
+	// write; leave any existing alias alone. The key-set membership is still
+	// recorded by the caller, so the field-level write succeeds.
 	if uuid == cidStr {
-		return c.client.Set(ctx, keysetKey, "true", 0).Err()
+		return nil
 	}
-
 	// Guard against the dual-root pattern: if cid:<cid> already points at a
-	// DIFFERENT uuid, don't silently overwrite. Leave the existing alias and
-	// just record the key-set membership so it's still discoverable via the
-	// root → cids enumeration.
-	indexKey := c.buildCIDIndexKey(cidStr)
-	existing, err := c.client.Get(ctx, indexKey).Result()
-	if err != nil && err != redis.Nil {
+	// DIFFERENT uuid, don't silently overwrite. Leave the existing alias; the
+	// key-set membership keeps the CID discoverable via root → cids.
+	indexKey := CIDIndexPrefix + cidStr
+	existing, _, err := tx.Get(tx.Context(), indexKey)
+	if err != nil {
 		return fmt.Errorf("read existing alias: %w", err)
 	}
 	if existing != "" && existing != uuid {
-		return c.client.Set(ctx, keysetKey, "true", 0).Err()
+		return nil
+	}
+	if existing == uuid {
+		return nil
+	}
+	return tx.Put(indexKey, uuid)
 }
 
-	pipe := c.client.Pipeline()
-	pipe.Set(ctx, indexKey, uuid, 0)
-	pipe.Set(ctx, keysetKey, "true", 0)
-	if _, err := pipe.Exec(ctx); err != nil {
-		return fmt.Errorf("add alias pipeline: %w", err)
-	}
+// removeAliasTx is the inverse of addAliasTx: it drops the reverse-index
+// entry cid:<cid> → <uuid>. The caller deletes the cids/<cid> key-set member
+// itself (DeleteProperty does both).
+//
+// ⚠ Why this exists. A cids/ member write touches two keys — the flat
+// file:<uuid>/cids/<cid> and this reverse alias — while the delete path once
+// only removed the first. A "deleted" CID therefore still resolved: GET
+// /meta/<cid>, ResolveRoot and GetByCID all kept answering with the record.
+// The asymmetry is not theoretical. meta-share published dag-pb roots computed
+// over RAR volumes and par2 files onto six records on watch.nsl.sh; removing
+// the member was expressible, removing the claim was not, so the false
+// identity survived its own retraction.
+//
+// Guarded, not blind: the alias is removed only when it currently points at
+// THIS uuid. Two records can legitimately race to claim a cid (see the
+// dual-root guard in addAliasTx, which leaves the first writer's alias in
+// place); deleting a member from the loser must not unpick the winner's index.
+func removeAliasTx(tx *kv.Tx, uuid, cidStr string) error {
+	if uuid == "" || cidStr == "" {
 		return nil
 	}
+	indexKey := CIDIndexPrefix + cidStr
+	existing, ok, err := tx.Get(tx.Context(), indexKey)
+	if err != nil {
+		return fmt.Errorf("read existing alias: %w", err)
+	}
+	if !ok || existing != uuid {
+		// Absent, or somebody else owns this alias. Leave it.
+		return nil
+	}
+	_, err = tx.Delete(indexKey)
+	return err
+}
 
 // ResolveRoot maps a hash supplied by a caller (a meta-sort write, an editor
 // lookup, an SSE consumer) to the actual storage root key.
@@ -167,8 +168,8 @@ func (c *Client) addAliasLocked(ctx context.Context, uuid, cidStr string) error
 //   - hash matches a reverse-index entry → return UUID
 //   - otherwise return hash unchanged (legacy / explicit-UUID writes)
 //
-// Errors are converted to "no resolution" — if Redis is down or the lookup
-// fails we let the caller proceed with the bare hash and surface the Redis
+// Errors are converted to "no resolution" — if the store is down or the
+// lookup fails we let the caller proceed with the bare hash and surface the
 // failure on the actual operation.
 func (c *Client) ResolveRoot(hash string) string {
 	if hash == "" {
@@ -185,23 +186,16 @@ func (c *Client) ResolveRoot(hash string) string {
 // when the CID is unknown; the empty string is the "not found" signal rather
 // than a typed error so callers can branch without errors.As.
 func (c *Client) GetByCID(cidStr string) (string, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return "", fmt.Errorf("not connected")
+	s, err := c.kv()
+	if err != nil {
+		return "", err
 	}
 	if cidStr == "" {
 		return "", nil
 	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	ctx, cancel := opCtx()
 	defer cancel()
-
-	uuid, err := c.client.Get(ctx, c.buildCIDIndexKey(cidStr)).Result()
-	if err == redis.Nil {
-		return "", nil
-	}
+	uuid, _, err := s.Get(ctx, CIDIndexPrefix+cidStr)
 	if err != nil {
 		return "", fmt.Errorf("get cid index: %w", err)
 	}
@@ -209,140 +203,49 @@ func (c *Client) GetByCID(cidStr string) (string, error) {
 }
 
 // AddDuplicatePath records that path is another physical location whose
-// content matches uuid. Returns true if path was newly added (not already
-// in the set). The watcher calls this when it sees a file whose midhash
-// matches an existing root but at a different filePath.
+// content matches uuid. Returns true if path was newly added. The watcher
+// calls this when it sees a file whose midhash matches an existing root but
+// at a different filePath.
 func (c *Client) AddDuplicatePath(uuid, path string) (bool, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return false, fmt.Errorf("not connected")
-	}
 	if uuid == "" || path == "" {
 		return false, nil
 	}
+	added := false
+	err := c.update(func(tx *kv.Tx) error {
+		var err error
+		added, err = tx.PutIfAbsent(dupPrefix(uuid)+path, "")
+		return err
+	})
+	return added, err
+}
 
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	added, err := c.client.SAdd(ctx, c.buildKeyPrefix(uuid)+DuplicatesField, path).Result()
+// cidsForRoot returns a root's bare-CID key-set members (cids/ prefix
+// stripped).
+func cidsForRoot(ctx context.Context, r kv.Reader, uuid string) ([]string, error) {
+	prefix := recordPrefix(uuid) + CIDsKeyPrefix
+	rows, err := r.Range(ctx, prefix, "", 0)
 	if err != nil {
-		return false, fmt.Errorf("sadd duplicates: %w", err)
-	}
-	return added > 0, nil
-}
-
-// cidsForRootLocked scans the bare-CID key-set for a root and returns its
-// members (bare CIDs, with the cids/ prefix stripped). Caller must hold c.mu.
-func (c *Client) cidsForRootLocked(ctx context.Context, uuid string) ([]string, error) {
-	prefix := c.buildKeyPrefix(uuid) + CIDsKeyPrefix
-	var out []string
-	var cursor uint64
-	for {
-		keys, next, err := c.client.Scan(ctx, cursor, prefix+"*", 1000).Result()
-		if err != nil {
-			return nil, fmt.Errorf("scan cids: %w", err)
-		}
-		for _, k := range keys {
-			out = append(out, strings.TrimPrefix(k, prefix))
-		}
-		cursor = next
-		if cursor == 0 {
-			break
+		return nil, err
 	}
+	out := make([]string, 0, len(rows))
+	for _, row := range rows {
+		out = append(out, row.K[len(prefix):])
 	}
 	return out, nil
 }
 
 // DeleteRoot removes everything keyed off uuid: every file:<uuid>/* property
 // (including the cids/<cid> key-set), every reverse-index entry for those
-// CIDs, and the index membership. Idempotent — a uuid with no remaining keys
-// is a successful no-op.
+// CIDs, its duplicates, search row and index membership. Idempotent — a uuid
+// with no remaining keys is a successful no-op.
 func (c *Client) DeleteRoot(uuid string) error {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return fmt.Errorf("not connected")
-	}
 	if uuid == "" {
 		return nil
 	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
-	defer cancel()
-
-	prefix := c.buildKeyPrefix(uuid)
-
-	// 1. Read the cids key-set first — once we delete file:<uuid>/* we lose
-	//    the list of reverse-index entries to clean up.
-	cids, err := c.cidsForRootLocked(ctx, uuid)
-	if err != nil {
+	return c.update(func(tx *kv.Tx) error {
+		_, err := deleteRecordTx(tx, uuid)
 		return err
-	}
-
-	// 2. Delete every reverse-index entry in one shot.
-	if len(cids) > 0 {
-		keys := make([]string, 0, len(cids))
-		for _, cidStr := range cids {
-			keys = append(keys, c.buildCIDIndexKey(cidStr))
-		}
-		if err := c.client.Del(ctx, keys...).Err(); err != nil {
-			return fmt.Errorf("del cid index: %w", err)
-		}
-	}
-
-	// 3. Scan and delete every file:<uuid>/* key (cids/<cid> keys included).
-	var cursor uint64
-	for {
-		keys, next, err := c.client.Scan(ctx, cursor, prefix+"*", 1000).Result()
-		if err != nil {
-			return fmt.Errorf("scan root keys: %w", err)
-		}
-		if len(keys) > 0 {
-			if err := c.client.Del(ctx, keys...).Err(); err != nil {
-				return fmt.Errorf("del root keys: %w", err)
-			}
-		}
-		cursor = next
-		if cursor == 0 {
-			break
-		}
-	}
-
-	// 4. Remove from the file index set.
-	if err := c.client.SRem(ctx, c.buildIndexKey(), uuid).Err(); err != nil {
-		return fmt.Errorf("srem index: %w", err)
-	}
-	return nil
-}
-
-// maybeAddAliasFromFieldLocked inspects a (field, value) pair written into a
-// root. If it's a key-set member — field name starts with "cids/" — it
-// registers the implied CID in the reverse index. Writers emit cids/<cid>
-// members without knowing about the reverse index; this hook keeps it in
-// sync transparently.
-//
-// Caller must hold c.mu. Errors are intentionally swallowed at the call site
-// (logged, not returned): an out-of-sync reverse index is recoverable via a
-// sweep, while a failed property write is not.
-func (c *Client) maybeAddAliasFromFieldLocked(ctx context.Context, uuid, field, value string) error {
-	cidStr := cidFromKeysetField(field)
-	if cidStr == "" {
-		return nil
-	}
-	return c.addAliasLocked(ctx, uuid, cidStr)
-}
-
-// maybeAddAliasesFromMetadataLocked bulk-applies maybeAddAliasFromFieldLocked
-// over every entry in a metadata map. Used by SetMetadataFlat /
-// MergeMetadataFlat after the underlying pipeline write succeeds. Caller must
-// hold c.mu.
-func (c *Client) maybeAddAliasesFromMetadataLocked(ctx context.Context, uuid string, metadata map[string]string) {
-	for k := range metadata {
-		_ = c.maybeAddAliasFromFieldLocked(ctx, uuid, k, metadata[k])
-	}
+	})
 }
 
 // cidFromKeysetField returns the bare CID encoded in a cids/<cid> field name,
@@ -372,24 +275,23 @@ type MetadataDocument struct {
 // the duplicates SET. Returns nil if the root has no keys at all (deleted or
 // never existed).
 func (c *Client) GetMetadataDocument(uuid string) (*MetadataDocument, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return nil, fmt.Errorf("not connected")
+	s, err := c.kv()
+	if err != nil {
+		return nil, err
 	}
 	if uuid == "" {
 		return nil, nil
 	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	ctx, cancel := opCtx()
 	defer cancel()
 
-	flat, err := c.getMetadataFlatInternal(ctx, uuid)
+	flat, err := readRecord(ctx, s, uuid)
 	if err != nil {
 		return nil, err
 	}
-	prefix := c.buildKeyPrefix(uuid)
+	if flat == nil {
+		flat = make(map[string]string)
+	}
 
 	// Hoist the cids/<cid> key-set members into a typed array and derive the
 	// canonical CID by rank. The members remain in Flat too — that's how
@@ -409,9 +311,13 @@ func (c *Client) GetMetadataDocument(uuid string) (*MetadataDocument, error) {
 		}
 	}
 
-	dups, err := c.client.SMembers(ctx, prefix+DuplicatesField).Result()
-	if err != nil && err != redis.Nil {
-		return nil, fmt.Errorf("smembers duplicates: %w", err)
+	dupRows, err := s.Range(ctx, dupPrefix(uuid), "", 0)
+	if err != nil {
+		return nil, fmt.Errorf("read duplicates: %w", err)
+	}
+	dups := make([]string, 0, len(dupRows))
+	for _, row := range dupRows {
+		dups = append(dups, row.K[len(dupPrefix(uuid)):])
 	}
 
 	if len(flat) == 0 && len(cids) == 0 && len(dups) == 0 {
@@ -424,3 +330,66 @@ func (c *Client) GetMetadataDocument(uuid string) (*MetadataDocument, error) {
 		Duplicates: dups,
 	}, nil
 }
+
+// RegisterFileTuple records one physical file under its midhash256 CID, the
+// same way the file watcher does for every file it scans: mint a UUID root
+// (filePath/sizeByte/mtimeNano) and write `cids/<midhash>`, whose hook
+// registers the cid:<midhash> reverse alias. Content already known under
+// another path is recorded as a duplicate; the same path just refreshes
+// size/mtime.
+//
+// Returns the root and whether it was newly minted. Shared by the watcher and
+// POST /api/files/register, which is how a box running with the watcher off
+// (a meta-watch client core) still gets files it writes under /files/plugin
+// resolvable by CID.
+func (c *Client) RegisterFileTuple(absPath string, size, mtimeNano int64, midhash string) (string, bool, error) {
+	if midhash == "" {
+		return "", false, fmt.Errorf("midhash is required")
+	}
+	var (
+		uuid   string
+		minted bool
+	)
+	// One transaction: the lookup and the mint cannot interleave with another
+	// registration of the same content, so two concurrent scans of one file
+	// can no longer mint two roots for it.
+	err := c.update(func(tx *kv.Tx) error {
+		ctx := tx.Context()
+		existing, _, err := tx.Get(ctx, CIDIndexPrefix+midhash)
+		if err != nil {
+			return fmt.Errorf("GetByCID(%s): %w", midhash, err)
+		}
+		uuid = existing
+		if uuid == "" {
+			if uuid, err = mintTx(tx, absPath, size, mtimeNano); err != nil {
+				return fmt.Errorf("Mint(%s): %w", absPath, err)
+			}
+			minted = true
+			if err := writeFieldsTx(tx, uuid, map[string]string{CIDsKeyPrefix + midhash: "true"}); err != nil {
+				return fmt.Errorf("cids/%s for %s: %w", midhash, uuid, err)
+			}
+			return nil
+		}
+		current, _, err := tx.Get(ctx, recordPrefix(uuid)+"filePath")
+		if err != nil {
+			return err
+		}
+		if current != absPath {
+			if _, err := tx.PutIfAbsent(dupPrefix(uuid)+absPath, ""); err != nil {
+				return fmt.Errorf("AddDuplicatePath %s @ %s: %w", uuid, absPath, err)
+			}
+			return nil
+		}
+		if err := writeFieldsTx(tx, uuid, map[string]string{
+			"sizeByte":  strconv.FormatInt(size, 10),
+			"mtimeNano": strconv.FormatInt(mtimeNano, 10),
+		}); err != nil {
+			return fmt.Errorf("refresh tuple for %s: %w", uuid, err)
+		}
+		return nil
+	})
+	if err != nil {
+		return "", false, err
+	}
+	return uuid, minted, nil
+}

internal/storage/cid_retraction_test.go

@@ -0,0 +1,159 @@
+package storage
+
+import (
+	"context"
+	"testing"
+)
+
+// Tests for retracting a `cids/<cid>` key-set member (cid_resolution.go's
+// removeAliasTx, reached through DeleteProperty).
+//
+// Why this is worth its own file. Adding a member writes two keys — the flat
+// `file:<uuid>/cids/<cid>` and the reverse alias `cid:<cid>` → `<uuid>`. Until
+// removeAliasLocked (now removeAliasTx) existed, deleting removed only the
+// first, so a retracted CID kept resolving to the record: the member was gone
+// from the document and the claim was not.
+//
+// That asymmetry had a live consequence. meta-share minted dag-pb roots and
+// midhash256s over whatever `archive::pick_media` elected, which on an
+// obfuscated posting was an arbitrary RAR volume or a par2 file. Six records on
+// watch.nsl.sh carry such members. `METADATA_KEYS.md` §2 defines a `cids/`
+// member as a digest of *this record's file* and notes that every member is a
+// reverse index back to the record — so those entries assert that an archive
+// volume is the episode. Retracting one has to remove the assertion, not just
+// the row.
+
+// aliasTarget returns the uuid that cid:<cidStr> currently resolves to, or "".
+func aliasTarget(t *testing.T, c *Client, cidStr string) string {
+	t.Helper()
+	got, _, err := c.Store().Get(context.Background(), CIDIndexPrefix+cidStr)
+	if err != nil {
+		t.Fatalf("get alias: %v", err)
+	}
+	return got
+}
+
+func hasField(t *testing.T, c *Client, hashID, field string) bool {
+	t.Helper()
+	fields, err := c.GetMetadataFlat(hashID)
+	if err != nil {
+		t.Fatalf("read record: %v", err)
+	}
+	_, ok := fields[field]
+	return ok
+}
+
+// The real shape: `…glnrqztt…` is the nzb-release locator whose record published
+// a dag-pb root computed over volume 3 of a 35-volume RAR5 set.
+const (
+	poisonedRoot = "bafybeicicuzdvuztca2hp2g2k7scgr4nnibilzgoppljeprphybqot7v6i"
+	goodMidhash  = "bagacbabaed6uiulnv7tscpxne22eztkjvnxg5almn43dpfecppixarfe7xhlu"
+)
+
+func TestRetractingACidMemberRemovesTheClaimNotJustTheRow(t *testing.T) {
+	withClient(t, func(t *testing.T, c *Client) {
+		const uuid = "01KSBHMTESTRECORD"
+
+		if err := c.SetMetadataFlat(uuid, map[string]string{
+			"cids/" + poisonedRoot: "true",
+			"cids/" + goodMidhash:  "true",
+			"fileType":             "video",
+		}); err != nil {
+			t.Fatalf("seed: %v", err)
+		}
+
+		// All three writes landed, and the CID resolves to the record.
+		if got := aliasTarget(t, c, poisonedRoot); got != uuid {
+			t.Fatalf("alias should point at the record before retraction, got %q", got)
+		}
+		if !hasField(t, c, uuid, "cids/"+poisonedRoot) {
+			t.Fatal("field index should list the member before retraction")
+		}
+		if got := c.ResolveRoot(poisonedRoot); got != uuid {
+			t.Fatalf("ResolveRoot should find the record before retraction, got %q", got)
+		}
+
+		if err := c.DeleteProperty(uuid, "cids/"+poisonedRoot); err != nil {
+			t.Fatalf("DeleteProperty: %v", err)
+		}
+
+		// 1. the flat key
+		if v, ok, _ := c.Store().Get(context.Background(),
+			recordPrefix(uuid)+"cids/"+poisonedRoot); ok {
+			t.Fatalf("flat key should be gone, still %q", v)
+		}
+		// 2. the record read
+		if hasField(t, c, uuid, "cids/"+poisonedRoot) {
+			t.Fatal("record read still lists the retracted member")
+		}
+		// 3. the reverse alias — the one that used to survive
+		if got := aliasTarget(t, c, poisonedRoot); got != "" {
+			t.Fatalf("reverse alias survived retraction, still points at %q", got)
+		}
+		if got := c.ResolveRoot(poisonedRoot); got == uuid {
+			t.Fatal("a retracted cid must not resolve to the record any more")
+		}
+
+		// The siblings are untouched: retraction is surgical, not a purge.
+		if got := aliasTarget(t, c, goodMidhash); got != uuid {
+			t.Fatalf("an unrelated sibling lost its alias, got %q", got)
+		}
+		if !hasField(t, c, uuid, "cids/"+goodMidhash) {
+			t.Fatal("an unrelated sibling lost its field-index entry")
+		}
+		if v, err := c.GetProperty(uuid, "fileType"); err != nil || v != "video" {
+			t.Fatalf("an unrelated field changed: %q %v", v, err)
+		}
+	})
+}
+
+// Two records can race to claim one cid; addAliasLocked leaves the first
+// writer's alias in place. Retracting the loser's member must not unpick the
+// winner's index — which is why removeAliasLocked compares before deleting.
+func TestRetractingDoesNotStealAnotherRecordsAlias(t *testing.T) {
+	withClient(t, func(t *testing.T, c *Client) {
+		const winner = "01KSBHMWINNER"
+		const loser = "01KSBHMLOSER"
+		const shared = "bafybeiaeb2lqi4z3np3q4tarldtyjp2t5lvnoodmtpvpi2tz73azn5td2m"
+
+		if err := c.SetMetadataFlat(winner, map[string]string{"cids/" + shared: "true"}); err != nil {
+			t.Fatalf("seed winner: %v", err)
+		}
+		if err := c.SetMetadataFlat(loser, map[string]string{"cids/" + shared: "true"}); err != nil {
+			t.Fatalf("seed loser: %v", err)
+		}
+		if got := aliasTarget(t, c, shared); got != winner {
+			t.Fatalf("the first writer should own the alias, got %q", got)
+		}
+
+		if err := c.DeleteProperty(loser, "cids/"+shared); err != nil {
+			t.Fatalf("DeleteProperty: %v", err)
+		}
+
+		if got := aliasTarget(t, c, shared); got != winner {
+			t.Fatalf("retracting the loser's member stole the winner's alias, now %q", got)
+		}
+		if hasField(t, c, loser, "cids/"+shared) {
+			t.Fatal("the loser's own member should still be gone")
+		}
+	})
+}
+
+// A non-cids field has no alias to clean up, and the delete must not invent one.
+func TestRetractingAnOrdinaryFieldTouchesNoAlias(t *testing.T) {
+	withClient(t, func(t *testing.T, c *Client) {
+		const uuid = "01KSBHMORDINARY"
+		if err := c.SetMetadataFlat(uuid, map[string]string{
+			"cids/" + goodMidhash: "true",
+			"quality":             "1080p",
+		}); err != nil {
+			t.Fatalf("seed: %v", err)
+		}
+		if err := c.DeleteProperty(uuid, "quality"); err != nil {
+			t.Fatalf("DeleteProperty: %v", err)
+		}
+		if got := aliasTarget(t, c, goodMidhash); got != uuid {
+			t.Fatalf("deleting an ordinary field disturbed a cid alias, got %q", got)
+		}
+	})
+}

internal/storage/clear_test.go

@@ -1,67 +1,74 @@
 package storage
 
 import (
+	"context"
+	"path/filepath"
+	"strings"
 	"testing"
 
-	"github.com/alicebob/miniredis/v2"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
-// newTestClient spins an in-memory Redis and returns a connected Client with
-// the given namespace prefix. The server is torn down with the test.
-func newTestClient(t *testing.T, prefix string) (*Client, *miniredis.Miniredis) {
+// newTestClient opens a fresh database in the test's temp dir.
+func newTestClient(t *testing.T) *Client {
 	t.Helper()
-
-	s := miniredis.RunT(t)
-	c := NewClient(prefix)
-	if err := c.Connect("redis://" + s.Addr()); err != nil {
-		t.Fatalf("connect to miniredis: %v", err)
+	c := NewClient()
+	if err := c.Connect(filepath.Join(t.TempDir(), "meta-core.db")); err != nil {
+		t.Fatalf("connect: %v", err)
 	}
 	t.Cleanup(func() { _ = c.Close() })
-	return c, s
+	return c
+}
+
+// allKeys lists every row (test helper; full scan).
+func allKeys(t *testing.T, c *Client) []string {
+	t.Helper()
+	var keys []string
+	if err := c.Store().ScanPrefix(context.Background(), "", 1000, func(rows []kv.KV) error {
+		for _, r := range rows {
+			keys = append(keys, r.K)
+		}
+		return nil
+	}); err != nil {
+		t.Fatalf("scan: %v", err)
+	}
+	return keys
 }
 
 // TestClearAllMetadata_PurgesCIDReverseIndex is the regression test for the
-// leak: ClearAllMetadata used to delete every file:<root>/* key and the
-// file:__index__ set, but left the cid:<cid> → root reverse-index entries
-// behind. Those stale aliases are not cosmetic — ResolveRoot consults them, so
-// a surviving entry silently redirects a later write into a deleted root.
+// leak: ClearAllMetadata used to delete every record key and the root index,
+// but left the cid:<cid> → root reverse-index entries behind. Those stale
+// aliases are not cosmetic — ResolveRoot consults them, so a surviving entry
+// silently redirects a later write into a deleted root.
 func TestClearAllMetadata_PurgesCIDReverseIndex(t *testing.T) {
-	for _, prefix := range []string{"", "mm:"} {
-		name := "no-prefix"
-		if prefix != "" {
-			name = "prefixed"
-		}
-		t.Run(name, func(t *testing.T) {
-			c, s := newTestClient(t, prefix)
+	c := newTestClient(t)
 
-			// Two records, each with several CID aliases (a midhash plus
-			// siblings) — exactly what the watcher produces.
+	// Two records, each with several CID aliases (a midhash plus siblings) —
+	// exactly what the watcher produces.
 	aliases := map[string][]string{}
 	for i, f := range []string{"watch/a.mkv", "watch/b.mkv"} {
 		uuid, err := c.Mint(f, int64(100+i), int64(1000+i))
 		if err != nil {
 			t.Fatalf("mint: %v", err)
 		}
-				cids := []string{
-					"bafkmid" + uuid,
-					"bafkfull" + uuid,
-				}
+		cids := []string{"bafkmid" + uuid, "bafkfull" + uuid}
 		for _, cidStr := range cids {
 			if err := c.AddAlias(uuid, cidStr); err != nil {
 				t.Fatalf("add alias %s: %v", cidStr, err)
 			}
 		}
+		if _, err := c.AddDuplicatePath(uuid, "watch/copy-"+f); err != nil {
+			t.Fatalf("add duplicate: %v", err)
+		}
 		aliases[uuid] = cids
 	}
 
-			// An entry already orphaned by a previous (buggy) clear: a
-			// reverse-index key whose root no longer exists. The sweep is
-			// expected to collect it too.
-			if err := s.Set(c.buildCIDIndexKey("bafkorphan"), "01OLDDEADROOT"); err != nil {
+	// An entry already orphaned by a previous (buggy) clear: a reverse-index
+	// key whose root no longer exists. The sweep is expected to collect it too.
+	if err := c.SetRawValue(CIDIndexPrefix+"bafkorphan", "01OLDDEADROOT"); err != nil {
 		t.Fatalf("seed orphan: %v", err)
 	}
 
-			// Sanity: the aliases resolve before the clear.
 	for uuid, cids := range aliases {
 		for _, cidStr := range cids {
 			if got := c.ResolveRoot(cidStr); got != uuid {
@@ -74,19 +81,25 @@ func TestClearAllMetadata_PurgesCIDReverseIndex(t *testing.T) {
 	if err != nil {
 		t.Fatalf("ClearAllMetadata: %v", err)
 	}
-			// deletedCount counts files, not keys.
 	if deleted != 2 {
 		t.Errorf("deletedCount = %d, want 2 (files, not keys)", deleted)
 	}
 
-			// No reverse-index key may survive — not for the cleared records,
-			// not the pre-existing orphan.
-			if leaked := s.Keys(); len(leaked) != 0 {
-				t.Errorf("keys survived the clear: %v", leaked)
+	// Nothing record-shaped may survive: not the records, not their aliases,
+	// duplicates or search rows, not the pre-existing orphan. (The event
+	// streams and the schema sentinel are not metadata and stay.)
+	for _, k := range allKeys(t, c) {
+		for _, ns := range []string{recordNS, CIDIndexPrefix, rootsNS, ftsNS, dupNS} {
+			if strings.HasPrefix(k, ns) {
+				t.Errorf("key survived the clear: %q", k)
+			}
+		}
+	}
+	var ftsRows int
+	if err := c.Store().DB().QueryRow(`SELECT count(*) FROM fts`).Scan(&ftsRows); err != nil || ftsRows != 0 {
+		t.Errorf("fts rows after clear = %d (err %v), want 0", ftsRows, err)
 	}
 
-			// And the aliases must no longer resolve: ResolveRoot returns the
-			// hash unchanged when there is no index entry.
 	for _, cids := range aliases {
 		for _, cidStr := range cids {
 			if got := c.ResolveRoot(cidStr); got != cidStr {
@@ -97,15 +110,13 @@ func TestClearAllMetadata_PurgesCIDReverseIndex(t *testing.T) {
 	if got, err := c.GetByCID("bafkorphan"); err != nil || got != "" {
 		t.Errorf("post-clear GetByCID(bafkorphan) = %q (err %v), want \"\"", got, err)
 	}
-		})
-	}
 }
 
 // TestClearAllMetadata_LeavesForeignKeysAlone guards the sweep's blast radius:
-// it must key off buildCIDIndexKey (namespace-aware), not a hardcoded "cid:",
-// so a clear on a prefixed client cannot reach another namespace's index.
+// keys outside the metadata namespaces (magnet cache, coverage markers, a key
+// that merely CONTAINS "cid:") must survive a metadata wipe.
 func TestClearAllMetadata_LeavesForeignKeysAlone(t *testing.T) {
-	c, s := newTestClient(t, "mm:")
+	c := newTestClient(t)
 
 	uuid, err := c.Mint("watch/a.mkv", 100, 1000)
 	if err != nil {
@@ -114,25 +125,28 @@ func TestClearAllMetadata_LeavesForeignKeysAlone(t *testing.T) {
 	if err := c.AddAlias(uuid, "bafkmine"); err != nil {
 		t.Fatalf("add alias: %v", err)
 	}
-
-	// Another namespace's reverse-index entry, plus an unrelated key.
-	if err := s.Set("other:cid:bafktheirs", "01THEIRROOT"); err != nil {
-		t.Fatalf("seed foreign cid: %v", err)
+	for k, v := range map[string]string{"other:cid:bafktheirs": "01THEIRROOT", "btmagnet:abc": "magnet:?xt=urn:btih:abc", "unrelated": "keep-me"} {
+		if err := c.SetRawValue(k, v); err != nil {
+			t.Fatalf("seed %s: %v", k, err)
 		}
-	if err := s.Set("unrelated", "keep-me"); err != nil {
-		t.Fatalf("seed unrelated: %v", err)
 	}
 
 	if _, err := c.ClearAllMetadata(); err != nil {
 		t.Fatalf("ClearAllMetadata: %v", err)
 	}
 
-	for _, k := range []string{"other:cid:bafktheirs", "unrelated"} {
-		if !s.Exists(k) {
-			t.Errorf("clear deleted foreign key %q — the cid sweep is not namespace-aware", k)
+	for _, k := range []string{"other:cid:bafktheirs", "btmagnet:abc", "unrelated"} {
+		if _, _, ok, _ := c.GetKeyInfo(k); !ok {
+			t.Errorf("clear deleted foreign key %q", k)
 		}
 	}
-	if s.Exists(c.buildCIDIndexKey("bafkmine")) {
+	if _, _, ok, _ := c.GetKeyInfo(CIDIndexPrefix + "bafkmine"); ok {
 		t.Errorf("own reverse-index entry survived the clear")
 	}
 }
+
+// withClient runs fn against a fresh client.
+func withClient(t *testing.T, fn func(t *testing.T, c *Client)) {
+	t.Helper()
+	fn(t, newTestClient(t))
+}

internal/storage/dual_root_migration.go

@@ -1,41 +0,0 @@
-package storage
-
-import (
-	"context"
-	"fmt"
-)
-
-// MigrateDualRoots was a one-shot repair for the "dual-root" pattern in the
-// legacy storage model: /meta/{hash} write handlers that didn't resolve
-// CID → UUID first created a parallel midhash-rooted entry alongside the
-// watcher's UUID root.
-//
-// That pattern is now structurally impossible:
-//   - writes resolve via ResolveRoot before landing (see handlers), and
-//   - CIDs are stored as a bare-CID key-set (cids/<cid>) keyed off opaque
-//     UUID roots, with the reverse index cid:<cid> → uuid as the single
-//     resolution path.
-//
-// The legacy on-disk shape this migration targeted (midhash-rooted entries,
-// <algo>:<value> tokens, named midhash256 fields) no longer exists, and the
-// cut-over wipes Redis, so there is nothing to migrate. The function is kept
-// as a no-op so the admin endpoint and its wrappers continue to compile and
-// respond.
-func (c *Client) MigrateDualRoots(ctx context.Context) (int, error) {
-	if c.client == nil {
-		return 0, fmt.Errorf("not connected")
-	}
-	return 0, nil
-}
-
-// MigrateDualRootsWithTimeout is a convenience wrapper used by the API
-// handler and the startup hook.
-func (c *Client) MigrateDualRootsWithTimeout() (int, error) {
-	return c.MigrateDualRoots(context.Background())
-}
-
-// MigrateDualRootsReport returns a human-readable summary. With the dual-root
-// pattern retired (see MigrateDualRoots), this always reports nothing to do.
-func (c *Client) MigrateDualRootsReport(ctx context.Context) (string, int, error) {
-	return "dual-root migration is obsolete under the bare-CID key-set model; nothing to do", 0, nil
-}

internal/storage/schema_version.go

@@ -1,83 +1,70 @@
 package storage
 
 import (
-	"context"
 	"fmt"
 	"strconv"
-	"time"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
-// SchemaVersion is the Redis-layout version this build of meta-core expects.
+// SchemaVersion is the key-layout version this build of meta-core expects.
 // Distinct from the snapshot manifest version (which is on-disk format);
-// this number describes the in-memory Redis schema — primarily, "are roots
-// UUIDs or content-hash tokens, and do reverse-index keys cid:* exist?"
+// this number describes the record layout — primarily, "are roots UUIDs or
+// content-hash tokens, and do reverse-index keys cid:* exist?"
 //
-// Bump only when a Redis-layout change can't be detected from the data
-// itself or healed by the auto-alias hooks. Each bump is a flag day in
-// alpha: operators wipe and restart.
+// The Redis → SQLite move did not change the record layout (file:<rid>/<field>,
+// cid:<cid>), so it did not bump this: the one-time migration copied records
+// verbatim.
+//
+// Bump only when a layout change can't be detected from the data itself or
+// healed by the write path. Each bump is a flag day in alpha: operators wipe
+// and restart.
 const SchemaVersion = 2
 
-// SchemaVersionKey is the sentinel under which we record SchemaVersion in
-// Redis. Checked on every meta-core boot.
+// SchemaVersionKey is the sentinel under which we record SchemaVersion.
+// Checked on every meta-core boot.
 const SchemaVersionKey = "meta-core:schema-version"
 
-// EnsureSchemaVersion verifies the Redis store matches the expected schema
-// version. Called once at startup, before any other reads/writes.
+// EnsureSchemaVersion verifies the store matches the expected schema version.
+// Called once at startup, before any other reads/writes.
 //
 // Behavior:
 //   - sentinel present and matches expected → OK
-//   - sentinel missing AND file:__index__ empty → fresh store, stamp sentinel
-//   - sentinel missing AND file:__index__ non-empty → legacy data, refuse
+//   - sentinel missing AND no roots → fresh store, stamp sentinel
+//   - sentinel missing AND roots exist → legacy data, refuse
 //   - sentinel present but mismatched → refuse, point operator at clean:all
 //
 // Refusal is hard-fail; the caller is expected to log.Fatalf and exit.
 // The error message names the wipe remediation because in alpha there
 // is no automated migration — operators bring up a clean store.
 func (c *Client) EnsureSchemaVersion(expected int) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	if c.client == nil {
-		return fmt.Errorf("not connected")
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	key := c.buildKey(SchemaVersionKey)
-	have, err := c.client.Get(ctx, key).Result()
-	if err != nil && err != redis.Nil {
+	return c.update(func(tx *kv.Tx) error {
+		ctx := tx.Context()
+		have, ok, err := tx.Get(ctx, SchemaVersionKey)
+		if err != nil {
 			return fmt.Errorf("get schema version: %w", err)
 		}
-
-	if err == redis.Nil {
-		// Sentinel absent. Fresh store iff there's no file:__index__ membership.
-		n, sErr := c.client.SCard(ctx, c.buildIndexKey()).Result()
-		if sErr != nil && sErr != redis.Nil {
-			return fmt.Errorf("scard file:__index__: %w", sErr)
+		if !ok {
+			n, err := tx.Count(ctx, rootsNS)
+			if err != nil {
+				return fmt.Errorf("count roots: %w", err)
 			}
 			if n > 0 {
 				return fmt.Errorf(
-				"redis has %d indexed roots but no %q sentinel — this is alpha "+
-					"data from before the UUID-rooted schema landed. Run "+
-					"`pnpm run clean:all` (or `docker exec metacore-app redis-cli FLUSHDB`) "+
-					"to wipe and restart, or downgrade meta-core to a compatible build",
+					"the store has %d indexed roots but no %q sentinel — this is alpha "+
+						"data from before the UUID-rooted schema landed. Delete the "+
+						"database file to wipe and restart, or downgrade meta-core to a compatible build",
 					n, SchemaVersionKey)
 			}
-		if err := c.client.Set(ctx, key, strconv.Itoa(expected), 0).Err(); err != nil {
-			return fmt.Errorf("set schema version: %w", err)
+			return tx.Put(SchemaVersionKey, strconv.Itoa(expected))
 		}
-		return nil
-	}
-
 		if have == strconv.Itoa(expected) {
 			return nil
 		}
 		return fmt.Errorf(
-		"redis schema version is %q, this build of meta-core expects %d. "+
-			"Run `pnpm run clean:all` to wipe and restart, or use a meta-core "+
+			"store schema version is %q, this build of meta-core expects %d. "+
+				"Delete the database file to wipe and restart, or use a meta-core "+
 				"build that matches the existing data",
 			have, expected)
+	})
 }

internal/storage/search.go

@@ -0,0 +1,565 @@
+package storage
+
+// Search over the KV store.
+//
+// The Redis era answered POST /api/metadata/search from an in-memory copy of
+// every record (the API's searchIndex), because Redis could not filter
+// server-side. That copy cost ~30 KB of RAM per record (5.1 GB at 169k records
+// on watch.nsl.sh) and was the reason meta-core kept getting OOM-killed. It is
+// gone: search now runs against two derived structures inside the database.
+//
+//   - kv_field_v — an expression index over (lowercased field name parsed out
+//     of the key, lowercased value, value), covering only record keys. It answers "which
+//     records have field F with a value like V" for ANY field, including ones
+//     invented tomorrow: the data stays schema-free, the index is over the key
+//     itself.
+//   - fts — an FTS5 trigram table holding one row per record: the record's
+//     haystack (buildHaystack) plus its rid. Trigrams make every substring of
+//     3+ characters indexable, which is the matching rule search always had.
+//
+// SQL produces a SUPERSET of candidates; the caller verifies each hydrated
+// record with the exact Go matchers (api.recordMatchesFilters et al.), so the
+// semantics are bit-identical to the in-memory matcher and nothing depends on
+// SQLite's ASCII-only lower() agreeing with Go's Unicode folding.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/metazla/meta-core/internal/kv"
+)
+
+// The field expression and the partial-index predicate MUST appear verbatim
+// (as literals, never bound parameters) in every query meant to use kv_field_v —
+// SQLite only matches a partial index whose WHERE clause it can see implied by
+// the query text. TestSearchFilterUsesFieldIndex pins this.
+const (
+	fieldExpr  = `lower(substr(k, instr(k,'/')+1))`
+	recordPred = `k >= 'file:' AND k < 'file;' AND instr(k,'/') > 0`
+	ridExpr    = `substr(k, 6, instr(k,'/')-6)`
+)
+
+// searchSchema is the derived DDL applied when the database is opened.
+//
+// kv_field_v carries the raw value as a third column so the filters' substring
+// test (instr(lower(v), …)) is answered from the index alone. Without it,
+// SQLite fetched the table row for every entry of the field: 1.48 s vs 13 ms
+// for tmdbid (110k entries) on watch.nsl.sh. It replaced kv_field (field,
+// lower(v)), which is dropped here; the rebuild costs ~80 s once.
+const searchSchema = `
+DROP INDEX IF EXISTS kv_field;
+CREATE INDEX IF NOT EXISTS kv_field_v ON kv(` + fieldExpr + `, lower(v), v) WHERE ` + recordPred + `;
+CREATE VIRTUAL TABLE IF NOT EXISTS fts USING fts5(rid UNINDEXED, hay, tokenize='trigram');
+`
+
+// searchIndexFields are the metadata fields folded into a record's search
+// haystack — must stay in sync with the fields the search handler documents.
+var searchIndexFields = []string{"title", "fileName", "originaltitle", "showtitle", "filePath"}
+
+// affectsHaystack reports whether writing field can change the haystack.
+func affectsHaystack(field string) bool {
+	if strings.HasPrefix(field, "titles/") {
+		return true
+	}
+	for _, f := range searchIndexFields {
+		if field == f {
+			return true
+		}
+	}
+	return false
+}
+
+// Haystack folds a record's searchable text fields into one lowercased blob —
+// what free-text tokens must each be a substring of.
+//
+// Beyond the flat fields it folds in every `titles/<lang3>/<name>` member's
+// name (METADATA_KEYS.md §3): the name lives in the key and the value is the
+// sentinel "true", so a search for an alternative title (`3 percent`) finds the
+// record whose `title` is `3%`.
+func Haystack(fields map[string]string) string {
+	var sb strings.Builder
+	for _, f := range searchIndexFields {
+		if v, ok := fields[f]; ok && v != "" {
+			sb.WriteString(strings.ToLower(v))
+			sb.WriteByte('\n')
+		}
+	}
+	for _, name := range titleMemberNames(fields) {
+		sb.WriteString(strings.ToLower(name))
+		sb.WriteByte('\n')
+	}
+	return sb.String()
+}
+
+// titleMemberNames returns the names of a record's `titles/<lang3>/<name>`
+// key-set members, with the `∕` (U+2215) a writer substitutes for `/` mapped
+// back. Sorted so the haystack is deterministic.
+func titleMemberNames(fields map[string]string) []string {
+	var names []string
+	for k, v := range fields {
+		rest, ok := strings.CutPrefix(k, "titles/")
+		if !ok || v == "" || v == "false" {
+			continue
+		}
+		_, name, ok := strings.Cut(rest, "/")
+		if !ok || name == "" {
+			continue
+		}
+		names = append(names, strings.ReplaceAll(name, "∕", "/"))
+	}
+	sort.Strings(names)
+	return names
+}
+
+// ftsHay is what the FTS row indexes: the haystack plus the rid, so the
+// "query is a substring of the hashID" rule also has an indexed candidate path.
+// Verification checks the two separately (a rid token plus a title token must
+// not match together).
+func ftsHay(hashID string, fields map[string]string) string {
+	return Haystack(fields) + strings.ToLower(hashID) + "\n"
+}
+
+// refreshSearchTx rewrites a record's FTS row from its current fields, or
+// drops it when the record is gone.
+func refreshSearchTx(tx *kv.Tx, hashID string) error {
+	fields, err := readRecord(tx.Context(), tx, hashID)
+	if err != nil {
+		return err
+	}
+	if len(fields) == 0 {
+		return deleteSearchRowTx(tx, hashID)
+	}
+	return upsertSearchRowTx(tx, hashID, ftsHay(hashID, fields))
+}
+
+// ensureSearchRowTx creates the record's FTS row if it has none (a record
+// whose writes never touched a haystack field still needs one for the rid
+// rule).
+func ensureSearchRowTx(tx *kv.Tx, hashID string) error {
+	_, ok, err := tx.Get(tx.Context(), ftsNS+hashID)
+	if err != nil || ok {
+		return err
+	}
+	return refreshSearchTx(tx, hashID)
+}
+
+func upsertSearchRowTx(tx *kv.Tx, hashID, hay string) error {
+	rowidStr, ok, err := tx.Get(tx.Context(), ftsNS+hashID)
+	if err != nil {
+		return err
+	}
+	if ok {
+		if _, err := tx.Exec(`UPDATE fts SET hay = ? WHERE rowid = ?`, hay, rowidStr); err != nil {
+			return fmt.Errorf("fts update %s: %w", hashID, err)
+		}
+		return nil
+	}
+	res, err := tx.Exec(`INSERT INTO fts(rid, hay) VALUES(?, ?)`, hashID, hay)
+	if err != nil {
+		return fmt.Errorf("fts insert %s: %w", hashID, err)
+	}
+	rowid, err := res.LastInsertId()
+	if err != nil {
+		return err
+	}
+	return tx.Put(ftsNS+hashID, strconv.FormatInt(rowid, 10))
+}
+
+func deleteSearchRowTx(tx *kv.Tx, hashID string) error {
+	rowidStr, ok, err := tx.Get(tx.Context(), ftsNS+hashID)
+	if err != nil || !ok {
+		return err
+	}
+	if _, err := tx.Exec(`DELETE FROM fts WHERE rowid = ?`, rowidStr); err != nil {
+		return fmt.Errorf("fts delete %s: %w", hashID, err)
+	}
+	_, err = tx.Delete(ftsNS + hashID)
+	return err
+}
+
+// SearchFilter is one structured filter: AND across filters, OR across Values.
+type SearchFilter struct {
+	Property string
+	Values   []string
+}
+
+// SearchHit is one verified result.
+type SearchHit struct {
+	HashID string
+	Fields map[string]string
+}
+
+// Search returns up to limit records, in hashID order, that satisfy match.
+//
+// query and filters only NARROW the candidates (SQL, superset semantics);
+// match is the authoritative test, run on each hydrated record. Pass the same
+// query/filters match evaluates, or results will be missing.
+func (c *Client) Search(query string, filters []SearchFilter, limit int, match func(hashID string, fields map[string]string) bool) ([]SearchHit, error) {
+	s, err := c.kv()
+	if err != nil {
+		return nil, err
+	}
+	if limit <= 0 {
+		limit = 100
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+
+	driver, probes, err := c.planCandidates(ctx, s, query, filters)
+	if err != nil {
+		return nil, err
+	}
+	page := max(limit*2, 500)
+	hits := make([]SearchHit, 0, limit)
+	after := ""
+	for len(hits) < limit {
+		ids, err := queryIDs(ctx, s, driver.sql, driver.args, after, page)
+		if err != nil {
+			return nil, err
+		}
+		survivors := ids
+		if len(probes) > 0 && len(ids) > 0 {
+			if survivors, err = probeIDs(ctx, s, ids, probes); err != nil {
+				return nil, err
+			}
+		}
+		for _, id := range survivors {
+			fields, err := readRecord(ctx, s, id)
+			if err != nil {
+				return nil, err
+			}
+			if fields == nil || !match(id, fields) {
+				continue
+			}
+			hits = append(hits, SearchHit{HashID: id, Fields: fields})
+			if len(hits) >= limit {
+				break
+			}
+		}
+		if len(ids) < page {
+			break
+		}
+		after = ids[len(ids)-1]
+	}
+	return hits, nil
+}
+
+// queryIDs returns one page of the driver's candidates, in rid order.
+func queryIDs(ctx context.Context, s *kv.Store, candSQL string, args []any, after string, limit int) ([]string, error) {
+	q := `SELECT DISTINCT rid FROM (` + candSQL + `) WHERE rid > ? ORDER BY rid LIMIT ?`
+	rows, err := s.DB().QueryContext(ctx, q, append(append([]any{}, args...), after, limit)...)
+	if err != nil {
+		return nil, fmt.Errorf("search candidates: %w", err)
+	}
+	defer rows.Close()
+	var out []string
+	for rows.Next() {
+		var id string
+		if err := rows.Scan(&id); err != nil {
+			return nil, err
+		}
+		out = append(out, id)
+	}
+	return out, rows.Err()
+}
+
+// probeSQL applies the non-driving filters to one page of candidate rids
+// (passed as a JSON array) — each an EXISTS over the candidate's own key range.
+func probeSQL(probes []candidatePart) (string, []any) {
+	where := make([]string, len(probes))
+	var args []any
+	for i, p := range probes {
+		where[i] = p.exists
+		args = append(args, p.existsArgs...)
+	}
+	return `WITH c(rid) AS (SELECT value FROM json_each(?)) SELECT rid FROM c WHERE ` + strings.Join(where, " AND "), args
+}
+
+// probeIDs keeps the ids (in their order) that pass every probe.
+func probeIDs(ctx context.Context, s *kv.Store, ids []string, probes []candidatePart) ([]string, error) {
+	q, args := probeSQL(probes)
+	list, err := json.Marshal(ids)
+	if err != nil {
+		return nil, err
+	}
+	rows, err := s.DB().QueryContext(ctx, q, append([]any{string(list)}, args...)...)
+	if err != nil {
+		return nil, fmt.Errorf("search probes: %w", err)
+	}
+	defer rows.Close()
+	pass := make(map[string]bool, len(ids))
+	for rows.Next() {
+		var id string
+		if err := rows.Scan(&id); err != nil {
+			return nil, err
+		}
+		pass[id] = true
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	out := ids[:0:0]
+	for _, id := range ids {
+		if pass[id] {
+			out = append(out, id)
+		}
+	}
+	return out, nil
+}
+
+// candidatePart is one narrowing condition: free text, or one filter.
+type candidatePart struct {
+	sql  string // SELECT … AS rid
+	args []any
+	// exists is the same filter as a predicate on candidate row c.rid (empty
+	// for free text, which has no per-record probe: the FTS rid column is not
+	// indexed).
+	exists     string
+	existsArgs []any
+}
+
+// estimateCap bounds the count used to pick the driving part: it only has to
+// tell a 50-row part from a 100k-row one.
+const estimateCap = 1000
+
+// planCandidates picks how to narrow a search: one DRIVING part (the most
+// selective, by a capped count) that lists candidate rids in order, plus PROBES
+// — every other filter, checked as an EXISTS over each candidate's own key
+// range (a primary-key range read of ~40 rows).
+//
+// Search pages the driver in Go and probes one page at a time, so a broad
+// query stops as soon as `limit` records verify. Two earlier shapes were
+// measured on watch.nsl.sh and rejected: INTERSECTing fully materialised sets
+// (`naruto` + `fileType:video` built all ~120k video rows on every page, 5.7 s)
+// and probing inside the driver query (SQLite evaluates the probe on every
+// driver row before ORDER BY … LIMIT can stop: `1080p` + `fileType:video`,
+// both ~100k, 10 s). Free text that does not drive is dropped from SQL
+// entirely — the verifier still applies it, and dropping a condition only
+// widens the superset.
+func (c *Client) planCandidates(ctx context.Context, s *kv.Store, query string, filters []SearchFilter) (candidatePart, []candidatePart, error) {
+	var parts []candidatePart
+	if p, ok := textCandidates(query); ok {
+		parts = append(parts, p)
+	}
+	for _, f := range filters {
+		if p, ok := filterCandidates(f); ok {
+			parts = append(parts, p)
+		}
+	}
+	if len(parts) == 0 {
+		return candidatePart{sql: `SELECT substr(k, ` + strconv.Itoa(len(rootsNS)+1) + `) AS rid FROM kv WHERE k >= '` + rootsNS + `' AND k < '` + kv.PrefixEnd(rootsNS) + `'`}, nil, nil
+	}
+
+	driver := 0
+	if len(parts) > 1 {
+		best := int64(-1)
+		for i, p := range parts {
+			var n int64
+			q := `SELECT count(*) FROM (SELECT rid FROM (` + p.sql + `) LIMIT ` + strconv.Itoa(estimateCap) + `)`
+			if err := s.DB().QueryRowContext(ctx, q, p.args...).Scan(&n); err != nil {
+				return candidatePart{}, nil, fmt.Errorf("estimate candidates: %w", err)
+			}
+			if best < 0 || n < best {
+				best, driver = n, i
+			}
+		}
+	}
+	var probes []candidatePart
+	for i, p := range parts {
+		if i != driver && p.exists != "" {
+			probes = append(probes, p)
+		}
+	}
+	return parts[driver], probes, nil
+}
+
+// candidateSQL is planCandidates without the store: text plus filters, the
+// first part driving. Used by tests that inspect the plan.
+func candidateSQL(query string, filters []SearchFilter) (string, []any) {
+	var parts []candidatePart
+	if p, ok := textCandidates(query); ok {
+		parts = append(parts, p)
+	}
+	for _, f := range filters {
+		if p, ok := filterCandidates(f); ok {
+			parts = append(parts, p)
+		}
+	}
+	if len(parts) == 0 {
+		return "", nil
+	}
+	return parts[0].sql, parts[0].args
+}
+
+// textCandidates narrows by free text: every whitespace token must be a
+// substring of the FTS hay (haystack + rid). Tokens of 3+ runes go through the
+// trigram index; shorter ones (trigrams cannot index them) are a LIKE on the
+// same rows.
+func textCandidates(query string) (candidatePart, bool) {
+	tokens := strings.Fields(strings.ToLower(query))
+	if len(tokens) == 0 {
+		return candidatePart{}, false
+	}
+	var match []string
+	var likes []string
+	var likeArgs []any
+	for _, t := range tokens {
+		if utf8.RuneCountInString(t) >= 3 {
+			match = append(match, `"`+strings.ReplaceAll(t, `"`, `""`)+`"`)
+		} else {
+			likes = append(likes, `hay LIKE ? ESCAPE '\'`)
+			likeArgs = append(likeArgs, "%"+escapeLike(t)+"%")
+		}
+	}
+	var where []string
+	var args []any
+	if len(match) > 0 {
+		where = append(where, `fts MATCH ?`)
+		args = append(args, strings.Join(match, " "))
+	}
+	where = append(where, likes...)
+	args = append(args, likeArgs...)
+	return candidatePart{sql: `SELECT rid FROM fts WHERE ` + strings.Join(where, " AND "), args: args}, true
+}
+
+func escapeLike(s string) string {
+	r := strings.NewReplacer(`\`, `\\`, `%`, `\%`, `_`, `\_`)
+	return r.Replace(s)
+}
+
+// filterCandidates narrows by one filter — the UNION, over its values, of the
+// two storage shapes recordMatchesFilter probes:
+//
+//   - key-set member `<prop>/<value>` (any case): the lowercased field equals
+//     lower(prop/value); for a non-ASCII value, any member of prop (SQLite's
+//     lower() only folds ASCII, Go's folds Unicode, so an exact lowercase
+//     comparison could miss);
+//   - flat field `<prop>` whose lowercased value contains the lowercased value
+//     — covers exact and contains alike, and comma-split csv-set values.
+//
+// ok=false means "this filter cannot narrow" (blank, or a non-ASCII property
+// name): it constrains nothing in SQL and is left to the verifier.
+func filterCandidates(f SearchFilter) (candidatePart, bool) {
+	var values []string
+	for _, v := range f.Values {
+		if v = strings.TrimSpace(v); v != "" {
+			values = append(values, v)
+		}
+	}
+	if f.Property == "" || len(values) == 0 || !isASCII(f.Property) {
+		return candidatePart{}, false
+	}
+	prop := asciiLower(f.Property)
+	var conds []string
+	var args []any
+	memberRange := false
+	for _, v := range values {
+		if isASCII(v) {
+			lv := asciiLower(v)
+			conds = append(conds, fieldExpr+` = ?`)
+			args = append(args, prop+"/"+lv)
+			conds = append(conds, fieldExpr+` = ? AND instr(lower(v), ?) > 0`)
+			args = append(args, prop, lv)
+		} else {
+			memberRange = true
+			conds = append(conds, fieldExpr+` = ?`)
+			args = append(args, prop)
+		}
+	}
+	if memberRange {
+		conds = append(conds, fieldExpr+` >= ? AND `+fieldExpr+` < ?`)
+		args = append(args, prop+"/", kv.PrefixEnd(prop+"/"))
+	}
+
+	// As a driver: one indexed SELECT per condition, joined with UNION ALL (an
+	// OR inside one SELECT would defeat the partial index; plain UNION would
+	// dedupe by materialising every row first — 1.8 s vs 0.25 s for a capped
+	// count over fileType:video on watch.nsl.sh). queryIDs applies DISTINCT.
+	base := `SELECT ` + ridExpr + ` AS rid FROM kv WHERE ` + recordPred + ` AND `
+	selects := make([]string, len(conds))
+	for i, cond := range conds {
+		selects[i] = base + cond
+	}
+	// As a probe: the same conditions over one candidate's key range.
+	exists := `EXISTS (SELECT 1 FROM kv WHERE k >= 'file:' || c.rid || '/' AND k < 'file:' || c.rid || '0' AND ((` +
+		strings.Join(conds, ") OR (") + `)))`
+	return candidatePart{
+		sql: strings.Join(selects, " UNION ALL "), args: args,
+		exists: exists, existsArgs: args,
+	}, true
+}
+
+func isASCII(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] >= utf8.RuneSelf {
+			return false
+		}
+	}
+	return true
+}
+
+// asciiLower lowercases A–Z only, exactly like SQLite's lower().
+func asciiLower(s string) string {
+	b := []byte(s)
+	for i, c := range b {
+		if 'A' <= c && c <= 'Z' {
+			b[i] = c + ('a' - 'A')
+		}
+	}
+	return string(b)
+}
+
+func envInt(name string, def int) int {
+	if v, err := strconv.Atoi(os.Getenv(name)); err == nil && v > 0 {
+		return v
+	}
+	return def
+}
+
+// RebuildSearchIfEmpty rebuilds every record's FTS row when the FTS table is
+// empty but records exist — a store restored from a snapshot, a copy made
+// outside meta-core (the 2026-10 Redis export), or an FTS table dropped to
+// change its tokenizer. The rows are derived, so this is a repair, not a
+// migration. Runs in bounded batches so writes keep flowing; until it
+// finishes, free-text search under-matches (filters are unaffected).
+func (c *Client) RebuildSearchIfEmpty() (int, error) {
+	s, err := c.kv()
+	if err != nil {
+		return 0, err
+	}
+	ctx, cancel := opCtx()
+	var rows int64
+	err = s.DB().QueryRowContext(ctx, `SELECT count(*) FROM fts`).Scan(&rows)
+	cancel()
+	if err != nil {
+		return 0, fmt.Errorf("count fts rows: %w", err)
+	}
+	if rows > 0 {
+		return 0, nil
+	}
+	ids, err := c.GetAllHashIDs()
+	if err != nil {
+		return 0, err
+	}
+	const batch = 500
+	for start := 0; start < len(ids); start += batch {
+		chunk := ids[start:min(start+batch, len(ids))]
+		if err := c.update(func(tx *kv.Tx) error {
+			for _, id := range chunk {
+				if err := refreshSearchTx(tx, id); err != nil {
+					return err
+				}
+			}
+			return nil
+		}); err != nil {
+			return start, fmt.Errorf("rebuild search rows: %w", err)
+		}
+	}
+	return len(ids), nil
+}

internal/storage/search_test.go

@@ -0,0 +1,327 @@
+package storage
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/metazla/meta-core/internal/kv"
+)
+
+// These tests pin the one property storage.Search must have: its SQL
+// candidates are a SUPERSET of the records the exact matcher accepts. A
+// candidate miss is a silently dropped search result, so each case below is a
+// shape where SQLite and Go disagree about text (case folding, csv values,
+// FTS syntax, trigram length) and the candidate query has to cover for it.
+//
+// The matcher here mirrors api.recordMatchesFilter closely enough to exercise
+// every candidate path; the API tests own the matcher itself.
+
+func seed(t *testing.T, c *Client, records map[string]map[string]string) {
+	t.Helper()
+	for id, fields := range records {
+		if err := c.SetMetadataFlat(id, fields); err != nil {
+			t.Fatalf("seed %s: %v", id, err)
+		}
+	}
+}
+
+// matchFilter is a faithful copy of api.recordMatchesFilter's semantics.
+func matchFilter(fields map[string]string, prop string, exact bool, values ...string) bool {
+	for _, v := range values {
+		if fields[prop+"/"+v] != "" && fields[prop+"/"+v] != "false" {
+			return true
+		}
+	}
+	prefix := strings.ToLower(prop) + "/"
+	for k, val := range fields {
+		if len(k) > len(prefix) && strings.EqualFold(k[:len(prefix)], prefix) {
+			for _, v := range values {
+				if strings.EqualFold(k[len(prefix):], v) && val != "" && val != "false" {
+					return true
+				}
+			}
+		}
+	}
+	fv, ok := fields[prop]
+	if !ok {
+		return false
+	}
+	for _, piece := range strings.Split(fv, ",") {
+		piece = strings.TrimSpace(piece)
+		for _, v := range values {
+			if exact && strings.EqualFold(piece, v) {
+				return true
+			}
+			if !exact && strings.Contains(strings.ToLower(piece), strings.ToLower(v)) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func search(t *testing.T, c *Client, query string, filters []SearchFilter, match func(string, map[string]string) bool) []string {
+	t.Helper()
+	hits, err := c.Search(query, filters, 100, match)
+	if err != nil {
+		t.Fatalf("search: %v", err)
+	}
+	ids := make([]string, 0, len(hits))
+	for _, h := range hits {
+		ids = append(ids, h.HashID)
+	}
+	return ids
+}
+
+func textMatch(query string) func(string, map[string]string) bool {
+	tokens := strings.Fields(strings.ToLower(query))
+	return func(id string, fields map[string]string) bool {
+		hay := Haystack(fields)
+		for _, tok := range tokens {
+			if !strings.Contains(hay, tok) {
+				return strings.Contains(strings.ToLower(id), strings.ToLower(query))
+			}
+		}
+		return true
+	}
+}
+
+func filterMatch(prop string, exact bool, values ...string) func(string, map[string]string) bool {
+	return func(_ string, fields map[string]string) bool { return matchFilter(fields, prop, exact, values...) }
+}
+
+func equalIDs(t *testing.T, got []string, want ...string) {
+	t.Helper()
+	sort.Strings(want)
+	if strings.Join(got, ",") != strings.Join(want, ",") {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestSearchFilterCandidates(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{
+		"R1": {"title": "One", "genres/Action": "true", "videoType": "tv, anime", "fileType": "video"},
+		"R2": {"title": "Two", "genres/Comedy": "true", "videoType": "movie", "fileType": "VIDEO"},
+		"R3": {"title": "Three", "Genres/Drama": "true", "fileType": "audio", "tmdbid": "21405"},
+		"R4": {"title": "Four", "genres/Ärger": "true", "tmdbid": "1405", "genres/Action": "false"},
+	})
+
+	cases := []struct {
+		name   string
+		prop   string
+		exact  bool
+		values []string
+		want   []string
+	}{
+		{"key-set member, query lowercased", "genres", false, []string{"action"}, []string{"R1"}},
+		{"key-set member under a capitalised property", "genres", false, []string{"drama"}, []string{"R3"}},
+		{"key-set member, non-ASCII value", "genres", false, []string{"ärger"}, []string{"R4"}},
+		{"csv value, exact", "videoType", true, []string{"anime"}, []string{"R1"}},
+		{"flat value, case differs", "fileType", true, []string{"video"}, []string{"R1", "R2"}},
+		{"exact rejects a superstring", "tmdbid", true, []string{"1405"}, []string{"R4"}},
+		{"contains admits a superstring", "tmdbid", false, []string{"1405"}, []string{"R3", "R4"}},
+		{"OR across values", "genres", false, []string{"action", "comedy"}, []string{"R1", "R2"}},
+		{"falsey member is not membership", "genres", false, []string{"action"}, []string{"R1"}},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := search(t, c, "", []SearchFilter{{Property: tc.prop, Values: tc.values}}, filterMatch(tc.prop, tc.exact, tc.values...))
+			equalIDs(t, got, tc.want...)
+		})
+	}
+}
+
+func TestSearchFiltersAreAndedAcrossEntries(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{
+		"R1": {"genres/Action": "true", "fileType": "video"},
+		"R2": {"genres/Action": "true", "fileType": "audio"},
+	})
+	match := func(_ string, f map[string]string) bool {
+		return matchFilter(f, "genres", false, "action") && matchFilter(f, "fileType", true, "video")
+	}
+	got := search(t, c, "", []SearchFilter{{Property: "genres", Values: []string{"action"}}, {Property: "fileType", Values: []string{"video"}}}, match)
+	equalIDs(t, got, "R1")
+}
+
+func TestSearchFreeTextCandidates(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{
+		"01KAAA": {"title": "Naruto Shippuden", "fileName": "naruto.s01e02.mkv"},
+		"01KBBB": {"title": "Dune: Part Two"},
+		"01KCCC": {"title": "進撃の巨人"},
+		"01KDDD": {"title": "3%", "titles/eng/3 percent": "true"},
+		"01KEEE": {"title": "AND -x a:b * \"quoted\""},
+		"01KFFF": {"title": "Unrelated"},
+	})
+	cases := []struct {
+		query string
+		want  []string
+	}{
+		{"naruto", []string{"01KAAA"}},
+		{"NARUTO s01e02", []string{"01KAAA"}},
+		{"dune:", []string{"01KBBB"}},
+		{"巨人", []string{"01KCCC"}},        // 2 runes: below trigram length
+		{"3 percent", []string{"01KDDD"}}, // AKA via titles/ key-set
+		{"3%", []string{"01KDDD"}},        // LIKE metacharacter in a short token
+		{"AND", []string{"01KEEE"}},       // FTS operator as a literal
+		{"-x", []string{"01KEEE"}},
+		{"a:b", []string{"01KEEE"}},
+		{"*", []string{"01KEEE"}},
+		{`"quoted"`, []string{"01KEEE"}},
+		{"01kbb", []string{"01KBBB"}}, // whole query is a hashID substring
+	}
+	for _, tc := range cases {
+		t.Run(tc.query, func(t *testing.T) {
+			got := search(t, c, tc.query, nil, textMatch(tc.query))
+			equalIDs(t, got, tc.want...)
+		})
+	}
+}
+
+// A rid token and a title token must not match together: the rid is in the
+// FTS row only as a candidate path for the "whole query is a hashID substring"
+// rule, and verification checks the two separately.
+func TestSearchRidAndTitleTokensDoNotCombine(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{"01KZZZ": {"title": "Naruto"}})
+	if got := search(t, c, "01kzz naruto", nil, textMatch("01kzz naruto")); len(got) != 0 {
+		t.Fatalf("rid + title token matched: %v", got)
+	}
+}
+
+func TestSearchFollowsWritesAndDeletes(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{"R1": {"title": "Before"}})
+	if err := c.SetProperty("R1", "title", "After"); err != nil {
+		t.Fatal(err)
+	}
+	equalIDs(t, search(t, c, "after", nil, textMatch("after")), "R1")
+	equalIDs(t, search(t, c, "before", nil, textMatch("before")))
+	if _, err := c.DeleteMetadata("R1"); err != nil {
+		t.Fatal(err)
+	}
+	equalIDs(t, search(t, c, "after", nil, textMatch("after")))
+	equalIDs(t, search(t, c, "", nil, func(string, map[string]string) bool { return true }))
+}
+
+func TestSearchPagesPastRejectedCandidates(t *testing.T) {
+	c := newTestClient(t)
+	records := map[string]map[string]string{}
+	for i := 0; i < 450; i++ {
+		id := "R" + string(rune('A'+i/26%26)) + string(rune('A'+i%26)) + strings.Repeat("0", 3)
+		records[id+string(rune('a'+i/676))] = map[string]string{"fileType": "video"}
+	}
+	records["RZZZZ"] = map[string]string{"fileType": "video", "keep": "yes"}
+	seed(t, c, records)
+	got := search(t, c, "", []SearchFilter{{Property: "fileType", Values: []string{"video"}}},
+		func(_ string, f map[string]string) bool { return f["keep"] == "yes" })
+	equalIDs(t, got, "RZZZZ")
+}
+
+// The filter candidates only scale if SQLite actually uses the partial
+// expression index — which it does only when the query repeats the index's
+// expression and WHERE clause as literals.
+func TestSearchFilterUsesFieldIndex(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{"R1": {"fileType": "video"}})
+	q, args := candidateSQL("", []SearchFilter{{Property: "fileType", Values: []string{"video"}}})
+	rows, err := c.Store().DB().QueryContext(context.Background(), "EXPLAIN QUERY PLAN "+q, args...)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+	var plan []string
+	for rows.Next() {
+		var id, parent, notused int
+		var detail string
+		if err := rows.Scan(&id, &parent, &notused, &detail); err != nil {
+			t.Fatal(err)
+		}
+		plan = append(plan, detail)
+	}
+	joined := strings.Join(plan, " | ")
+	if !strings.Contains(joined, "COVERING INDEX kv_field_v") || strings.Contains(joined, "SCAN kv") {
+		t.Fatalf("filter candidates do not use kv_field_v: %s", joined)
+	}
+}
+
+func TestCIDRootedRecordsParseAtTheFirstSlash(t *testing.T) {
+	if h, f, ok := splitRecordKey("file:bafkreiabc/titles/eng/x"); !ok || h != "bafkreiabc" || f != "titles/eng/x" {
+		t.Fatalf("got %q %q %v", h, f, ok)
+	}
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{"bafkreiabcdefghijklmnop": {"fileType": "video"}})
+	got := search(t, c, "", []SearchFilter{{Property: "fileType", Values: []string{"video"}}}, filterMatch("fileType", true, "video"))
+	equalIDs(t, got, "bafkreiabcdefghijklmnop")
+}
+
+func TestRebuildSearchIfEmptyRestoresFreeText(t *testing.T) {
+	c := newTestClient(t)
+	seed(t, c, map[string]map[string]string{"R1": {"title": "Naruto"}, "R2": {"title": "Dune"}})
+	if err := c.update(func(tx *kv.Tx) error {
+		if _, err := tx.Exec(`DELETE FROM fts`); err != nil {
+			return err
+		}
+		_, err := tx.DeletePrefix(ftsNS, 0)
+		return err
+	}); err != nil {
+		t.Fatal(err)
+	}
+	equalIDs(t, search(t, c, "naruto", nil, textMatch("naruto")))
+	n, err := c.RebuildSearchIfEmpty()
+	if err != nil || n != 2 {
+		t.Fatalf("rebuilt %d (err %v), want 2", n, err)
+	}
+	equalIDs(t, search(t, c, "naruto", nil, textMatch("naruto")), "R1")
+	if n, _ := c.RebuildSearchIfEmpty(); n != 0 {
+		t.Fatalf("second rebuild ran again (%d)", n)
+	}
+}
+
+// Text plus a broad filter: the selective part drives and the filter becomes a
+// per-candidate probe over the record's own key range — never a full
+// materialisation of the filter's result set.
+func TestSearchCombinedPlanProbesByPrimaryKey(t *testing.T) {
+	c := newTestClient(t)
+	recs := map[string]map[string]string{"R0000": {"title": "Naruto", "fileType": "video"}}
+	for i := 1; i < 300; i++ {
+		recs[fmt.Sprintf("R%04d", i)] = map[string]string{"title": "Other", "fileType": "video"}
+	}
+	seed(t, c, recs)
+	filters := []SearchFilter{{Property: "fileType", Values: []string{"video"}}}
+	driver, probes, err := c.planCandidates(context.Background(), c.Store(), "naruto", filters)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(driver.sql, "SELECT rid FROM fts") || len(probes) != 1 {
+		t.Fatalf("free text should drive with the filter as a probe, got driver %q, %d probes", driver.sql, len(probes))
+	}
+	q, pargs := probeSQL(probes)
+	args := append([]any{`["R0000"]`}, pargs...)
+	rows, err := c.Store().DB().QueryContext(context.Background(), "EXPLAIN QUERY PLAN "+q, args...)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+	var plan []string
+	for rows.Next() {
+		var id, parent, notused int
+		var detail string
+		if err := rows.Scan(&id, &parent, &notused, &detail); err != nil {
+			t.Fatal(err)
+		}
+		plan = append(plan, detail)
+	}
+	joined := strings.Join(plan, " | ")
+	if !strings.Contains(joined, "PRIMARY KEY") || strings.Contains(joined, "SCAN kv") {
+		t.Fatalf("filter probe is not a primary-key range read: %s", joined)
+	}
+	equalIDs(t, search(t, c, "naruto", filters, func(id string, f map[string]string) bool {
+		return textMatch("naruto")(id, f) && matchFilter(f, "fileType", false, "video")
+	}), "R0000")
+}

internal/storage/stats.go

@@ -0,0 +1,45 @@
+package storage
+
+import (
+	"time"
+)
+
+// CountRoots returns the number of metadata roots in the root index — one
+// range count over idx:roots/, never the list itself.
+func (c *Client) CountRoots() (int64, error) {
+	s, err := c.kv()
+	if err != nil {
+		return 0, err
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+	return s.Count(ctx, rootsNS)
+}
+
+// keyCountTTL bounds how stale CountKeys may be. Counting every row is a full
+// table scan (~a second at millions of keys), and the only reader is a polled
+// dashboard tile — it needs a number, not a fresh one every few seconds.
+const keyCountTTL = 60 * time.Second
+
+// CountKeys returns the number of rows in the database — every key, not just
+// records. It is the denominator for "how much of the store is records": the
+// flat per-field keys (file:{root}/{field}) dominate, which is expected.
+func (c *Client) CountKeys() (int64, error) {
+	c.keysMu.Lock()
+	defer c.keysMu.Unlock()
+	if !c.keysAt.IsZero() && time.Since(c.keysAt) < keyCountTTL {
+		return c.keysCount, nil
+	}
+	s, err := c.kv()
+	if err != nil {
+		return 0, err
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+	n, err := s.CountAll(ctx)
+	if err != nil {
+		return 0, err
+	}
+	c.keysCount, c.keysAt = n, time.Now()
+	return n, nil
+}

internal/storage/udl.go

@@ -12,25 +12,31 @@ package storage
 // strictly exceeds the stored one (a per-cell high-water-mark, replacing the
 // op-log merge that used to live in meta-watch's store.rs).
 //
-// Redis model (all under the literal "udl:" prefix, mirroring the "file:" one):
+// Key model (all under the literal "udl:" prefix, mirroring the "file:" one):
 //
-//	udl:rec:<uid>/<cid>/<key>       HASH { record, version, ts, value? }
-//	udl:idx:user:<uid>:key:<key>    SET of <cid>   -> active_for_user_key (My List, Continue Watching)
-//	udl:idx:user:<uid>:cid:<cid>    SET of <key>   -> list_for_user_cid
-//	udl:idx:cid:<cid>:key:<key>     SET of <uid>   -> aggregate
-//	udl:idx:cid:<cid>:users         SET of <uid>   -> uids_for_cid
+//	udl:rec:<uid>/<cid>/<key>       JSON { record, version, ts, value? }
+//	udl:idx:user:<uid>:key:<key>    set of <cid>   -> active_for_user_key (My List, Continue Watching)
+//	udl:idx:user:<uid>:cid:<cid>    set of <key>   -> list_for_user_cid
+//	udl:idx:user:<uid>:cids         set of <cid>   -> whole-profile export (recovery)
+//	udl:idx:cid:<cid>:key:<key>     set of <uid>   -> aggregate
+//	udl:idx:cid:<cid>:users         set of <uid>   -> uids_for_cid
 //
-// The `value` hash field is the plaintext JSON scalar for PUBLIC keys only
+// A "set" is a key-set: one key `<set>\x1f<member>` = "" per member, read as
+// the key range under `<set>\x1f`. The separator is a control character
+// because UDL keys are not validated — with `/` the members of
+// `…:key:a/b` would show up as members of `…:key:a`.
+//
+// The `value` field is the plaintext JSON scalar for PUBLIC keys only
 // (like/rating), used for aggregation; it is absent for private-tier keys
 // (whose real value rides encrypted inside `record`) and for tombstones.
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
-	"strconv"
-	"time"
+	"sort"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
 // UDLCell is a decoded (uid, cid, key) record cell.
@@ -66,151 +72,208 @@ func udlIdxUserCid(uid, cid string) string { return fmt.Sprintf("udl:idx:user:%s
 func udlIdxCidKey(cid, key string) string  { return fmt.Sprintf("udl:idx:cid:%s:key:%s", cid, key) }
 func udlIdxCidUsers(cid string) string     { return fmt.Sprintf("udl:idx:cid:%s:users", cid) }
 
-// udlUpsertScript performs the version-gated upsert + index maintenance
-// atomically. Accepts (returns 1) only when the incoming version strictly
-// exceeds the stored one; otherwise returns 0 (stale).
+// udlIdxUserCids is the set of every cid a uid has ANY record for — the one
+// index that makes "export this whole profile" a set read instead of a
+// keyspace scan.
 //
-//	KEYS: 1=cell 2=idx:user:key 3=idx:user:cid 4=idx:cid:key 5=idx:cid:users
-//	ARGV: 1=version 2=ts 3=record 4=value 5=hasValue("1"/"0")
-//	      6=cid 7=key 8=uid 9=tombstone("1"/"0")
-//
-// A tombstone still writes the cell — that is the CRDT state, and dropping it
-// would let an older write resurrect the value — but it SREMs the cid from the
-// user+key index. That index is what `active_for_user_key` returns, so leaving
-// deleted cids in it means every My List / Continue Watching read carries every
-// title ever un-liked or finished, forever. The other three indexes are left
-// alone: they answer "who has an opinion about this cid", where a tombstone is
-// still an answer.
-var udlUpsertScript = redis.NewScript(`
-local stored = redis.call('HGET', KEYS[1], 'version')
-if stored and tonumber(stored) >= tonumber(ARGV[1]) then
-  return 0
-end
-redis.call('HSET', KEYS[1], 'version', ARGV[1], 'ts', ARGV[2], 'record', ARGV[3])
-if ARGV[5] == '1' then
-  redis.call('HSET', KEYS[1], 'value', ARGV[4])
-else
-  redis.call('HDEL', KEYS[1], 'value')
-end
-if ARGV[9] == '1' then
-  redis.call('SREM', KEYS[2], ARGV[6])
-else
-  redis.call('SADD', KEYS[2], ARGV[6])
-end
-redis.call('SADD', KEYS[3], ARGV[7])
-redis.call('SADD', KEYS[4], ARGV[8])
-redis.call('SADD', KEYS[5], ARGV[8])
-return 1
-`)
+// The other four indexes each answer a question with one coordinate already
+// known (a key, a cid). Cross-instance recovery knows neither: it has a uid and
+// nothing else. Without this set the only ways to enumerate a profile are to
+// iterate the hardcoded key list — which silently misses any key added later —
+// or to SCAN `udl:rec:<uid>/*`, which is the full-keyspace-read pathology that
+// already made `/api/udl/users/stats` admin-only.
+func udlIdxUserCids(uid string) string { return fmt.Sprintf("udl:idx:user:%s:cids", uid) }
+
+// udlSetSep separates a set key from a member (see the key model above).
+const udlSetSep = "\x1f"
+
+// udlCellJSON is a cell's stored form. Value is a pointer so an absent value
+// (private-tier key, tombstone) stays distinguishable from an empty one.
+type udlCellJSON struct {
+	Record  string  `json:"record"`
+	Version int64   `json:"version"`
+	Ts      int64   `json:"ts"`
+	Value   *string `json:"value,omitempty"`
+}
+
+func decodeUDLCell(raw string) (UDLCell, error) {
+	var j udlCellJSON
+	if err := json.Unmarshal([]byte(raw), &j); err != nil {
+		return UDLCell{}, err
+	}
+	cell := UDLCell{Record: j.Record, Version: j.Version, Ts: j.Ts}
+	if j.Value != nil {
+		cell.Value, cell.HasValue = *j.Value, true
+	}
+	return cell, nil
+}
+
+// udlMembers lists a key-set's members, sorted.
+func udlMembers(ctx context.Context, r kv.Reader, set string) ([]string, error) {
+	prefix := set + udlSetSep
+	rows, err := r.Range(ctx, prefix, "", 0)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]string, 0, len(rows))
+	for _, row := range rows {
+		out = append(out, row.K[len(prefix):])
+	}
+	return out, nil
+}
+
+func udlAdd(tx *kv.Tx, set, member string) error {
+	_, err := tx.PutIfAbsent(set+udlSetSep+member, "")
+	return err
+}
+
+func udlRem(tx *kv.Tx, set, member string) error {
+	_, err := tx.Delete(set + udlSetSep + member)
+	return err
+}
+
+// readUDLCell reads one cell. exists is false when it was never written.
+func readUDLCell(ctx context.Context, r kv.Reader, recKey string) (UDLCell, bool, error) {
+	raw, ok, err := r.Get(ctx, recKey)
+	if err != nil || !ok {
+		return UDLCell{}, false, err
+	}
+	cell, err := decodeUDLCell(raw)
+	if err != nil {
+		return UDLCell{}, false, fmt.Errorf("decode %s: %w", recKey, err)
+	}
+	return cell, true, nil
+}
+
+// readUDLCells reads many cells in one multi-key read; absent cells are
+// omitted from the map.
+func readUDLCells(ctx context.Context, r kv.Reader, recKeys []string) (map[string]UDLCell, error) {
+	raws, err := r.MGet(ctx, recKeys)
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[string]UDLCell, len(raws))
+	for k, raw := range raws {
+		cell, err := decodeUDLCell(raw)
+		if err != nil {
+			return nil, fmt.Errorf("decode %s: %w", k, err)
+		}
+		out[k] = cell
+	}
+	return out, nil
+}
 
 // UDLUpsertIfNewer stores a record cell iff version strictly exceeds the stored
-// one. publicValue/hasValue carry the plaintext JSON scalar for public keys
-// (used by aggregation); pass hasValue=false for private-tier keys and
-// tombstones. Set tombstone=true when the record deletes the cell, which also
-// prunes the cid from the user+key index. Returns accepted=false when the write
-// is stale.
+// one, and maintains the indexes — one transaction, so the gate and the write
+// cannot interleave with a concurrent upsert of the same cell.
+// publicValue/hasValue carry the plaintext JSON scalar for public keys (used by
+// aggregation); pass hasValue=false for private-tier keys and tombstones. Set
+// tombstone=true when the record deletes the cell.
+//
+// A tombstone still writes the cell — that is the CRDT state, and dropping it
+// would let an older write resurrect the value — but it removes the cid from
+// the user+key index. That index is what `active_for_user_key` returns, so
+// leaving deleted cids in it means every My List / Continue Watching read
+// carries every title ever un-liked or finished, forever. The other four
+// indexes are left alone: they answer "who has an opinion about this cid",
+// where a tombstone is still an answer.
+//
+// ⚠ `idx:user:cids` in particular must NEVER be pruned on a tombstone, even
+// though it looks symmetric with the user+key index. It is the export index: a
+// cid dropped from it is a cid whose tombstone never travels, and a tombstone
+// that does not travel is exactly how an un-liked title comes back from the
+// dead on the other box — the peer still holds the older `like` at a lower
+// version, and with no tombstone to beat it, nothing ever supersedes it.
+//
+// Returns accepted=false when the write is stale.
 func (c *Client) UDLUpsertIfNewer(uid, cid, key string, version, ts int64, record, publicValue string, hasValue, tombstone bool) (bool, error) {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	if c.client == nil {
-		return false, fmt.Errorf("not connected")
+	accepted := false
+	err := c.update(func(tx *kv.Tx) error {
+		recKey := udlRecKey(uid, cid, key)
+		stored, ok, err := readUDLCell(tx.Context(), tx, recKey)
+		if err != nil {
+			return err
 		}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	keys := []string{
-		c.buildKey(udlRecKey(uid, cid, key)),
-		c.buildKey(udlIdxUserKey(uid, key)),
-		c.buildKey(udlIdxUserCid(uid, cid)),
-		c.buildKey(udlIdxCidKey(cid, key)),
-		c.buildKey(udlIdxCidUsers(cid)),
+		if ok && stored.Version >= version {
+			return nil
 		}
-	hv := "0"
+		cell := udlCellJSON{Record: record, Version: version, Ts: ts}
 		if hasValue {
-		hv = "1"
+			v := publicValue
+			cell.Value = &v
+		}
+		body, err := json.Marshal(cell)
+		if err != nil {
+			return err
+		}
+		if err := tx.Put(recKey, string(body)); err != nil {
+			return err
 		}
-	tomb := "0"
 		if tombstone {
-		tomb = "1"
+			err = udlRem(tx, udlIdxUserKey(uid, key), cid)
+		} else {
+			err = udlAdd(tx, udlIdxUserKey(uid, key), cid)
 		}
-	res, err := udlUpsertScript.Run(ctx, c.client, keys, version, ts, record, publicValue, hv, cid, key, uid, tomb).Result()
+		if err != nil {
+			return err
+		}
+		for _, add := range [][2]string{
+			{udlIdxUserCid(uid, cid), key},
+			{udlIdxCidKey(cid, key), uid},
+			{udlIdxCidUsers(cid), uid},
+			{udlIdxUserCids(uid), cid},
+		} {
+			if err := udlAdd(tx, add[0], add[1]); err != nil {
+				return err
+			}
+		}
+		accepted = true
+		return nil
+	})
 	if err != nil {
 		return false, fmt.Errorf("udl upsert failed: %w", err)
 	}
-	n, _ := res.(int64)
-	return n == 1, nil
+	return accepted, nil
 }
 
 // UDLGetCell returns the record cell for (uid, cid, key). exists is false when
 // no record has ever been written for the cell.
 func (c *Client) UDLGetCell(uid, cid, key string) (UDLCell, bool, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return UDLCell{}, false, fmt.Errorf("not connected")
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	return c.udlReadCell(ctx, udlRecKey(uid, cid, key))
-}
-
-// udlReadCell HMGETs a cell hash. Caller holds the lock. exists is false when
-// the version field is absent (i.e. the hash does not exist).
-func (c *Client) udlReadCell(ctx context.Context, recKey string) (UDLCell, bool, error) {
-	vals, err := c.client.HMGet(ctx, c.buildKey(recKey), "record", "version", "ts", "value").Result()
+	s, err := c.kv()
 	if err != nil {
-		return UDLCell{}, false, fmt.Errorf("hmget failed: %w", err)
+		return UDLCell{}, false, err
 	}
-	// vals: [record, version, ts, value] — nil for absent fields.
-	if len(vals) < 4 || vals[1] == nil {
-		return UDLCell{}, false, nil
-	}
-	cell := UDLCell{}
-	if s, ok := vals[0].(string); ok {
-		cell.Record = s
-	}
-	if s, ok := vals[1].(string); ok {
-		cell.Version, _ = strconv.ParseInt(s, 10, 64)
-	}
-	if s, ok := vals[2].(string); ok {
-		cell.Ts, _ = strconv.ParseInt(s, 10, 64)
-	}
-	if s, ok := vals[3].(string); ok {
-		cell.Value = s
-		cell.HasValue = true
-	}
-	return cell, true, nil
+	ctx, cancel := opCtx()
+	defer cancel()
+	return readUDLCell(ctx, s, udlRecKey(uid, cid, key))
 }
 
 // UDLListUserKey returns every cell for (uid, key) across all cids — the
 // projection behind active_for_user_key (My List, Continue Watching). Includes
 // tombstones; the caller decodes each record and filters.
 func (c *Client) UDLListUserKey(uid, key string) ([]UDLUserKeyEntry, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return nil, fmt.Errorf("not connected")
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	defer cancel()
-
-	cids, err := c.client.SMembers(ctx, c.buildKey(udlIdxUserKey(uid, key))).Result()
-	if err != nil {
-		return nil, fmt.Errorf("smembers failed: %w", err)
-	}
-	out := make([]UDLUserKeyEntry, 0, len(cids))
-	for _, cid := range cids {
-		cell, ok, err := c.udlReadCell(ctx, udlRecKey(uid, cid, key))
+	s, err := c.kv()
 	if err != nil {
 		return nil, err
 	}
+	ctx, cancel := opCtx()
+	defer cancel()
+
+	cids, err := udlMembers(ctx, s, udlIdxUserKey(uid, key))
+	if err != nil {
+		return nil, err
+	}
+	recKeys := make([]string, len(cids))
+	for i, cid := range cids {
+		recKeys[i] = udlRecKey(uid, cid, key)
+	}
+	cells, err := readUDLCells(ctx, s, recKeys)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]UDLUserKeyEntry, 0, len(cids))
+	for i, cid := range cids {
+		cell, ok := cells[recKeys[i]]
 		if !ok {
 			continue
 		}
@@ -222,26 +285,28 @@ func (c *Client) UDLListUserKey(uid, key string) ([]UDLUserKeyEntry, error) {
 // UDLListUserCid returns every cell for (uid, cid) across all keys — the
 // projection behind list_for_user_cid.
 func (c *Client) UDLListUserCid(uid, cid string) ([]UDLUserCidEntry, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return nil, fmt.Errorf("not connected")
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	defer cancel()
-
-	keys, err := c.client.SMembers(ctx, c.buildKey(udlIdxUserCid(uid, cid))).Result()
-	if err != nil {
-		return nil, fmt.Errorf("smembers failed: %w", err)
-	}
-	out := make([]UDLUserCidEntry, 0, len(keys))
-	for _, key := range keys {
-		cell, ok, err := c.udlReadCell(ctx, udlRecKey(uid, cid, key))
+	s, err := c.kv()
 	if err != nil {
 		return nil, err
 	}
+	ctx, cancel := opCtx()
+	defer cancel()
+
+	keys, err := udlMembers(ctx, s, udlIdxUserCid(uid, cid))
+	if err != nil {
+		return nil, err
+	}
+	recKeys := make([]string, len(keys))
+	for i, key := range keys {
+		recKeys[i] = udlRecKey(uid, cid, key)
+	}
+	cells, err := readUDLCells(ctx, s, recKeys)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]UDLUserCidEntry, 0, len(keys))
+	for i, key := range keys {
+		cell, ok := cells[recKeys[i]]
 		if !ok {
 			continue
 		}
@@ -250,53 +315,128 @@ func (c *Client) UDLListUserCid(uid, cid string) ([]UDLUserCidEntry, error) {
 	return out, nil
 }
 
-// UDLCidUsers returns every uid that has any record for cid — uids_for_cid.
-func (c *Client) UDLCidUsers(cid string) ([]string, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return nil, fmt.Errorf("not connected")
+// UDLUserAllEntry is one row of a whole-profile export.
+type UDLUserAllEntry struct {
+	Cid     string `json:"cid"`
+	Key     string `json:"key"`
+	Record  string `json:"record"`
+	Version int64  `json:"version"`
+	Ts      int64  `json:"ts"`
 }
 
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+// UDLAllForUser returns every cell a uid owns, for cross-instance recovery.
+//
+// Ordered by cid, starting strictly after `afterCid`. A cid's keys are never
+// split across a page: the page ends on a cid boundary once `limit` rows have
+// been emitted, and `nextCid` is the last cid included — pass it back as
+// `afterCid` to continue. `nextCid` is empty when the export is complete.
+//
+// Tombstones are included. They are the CRDT state that stops a deleted value
+// resurrecting on the box that receives this export, so omitting them would
+// make recovery actively wrong rather than merely incomplete.
+func (c *Client) UDLAllForUser(uid, afterCid string, limit int) ([]UDLUserAllEntry, string, error) {
+	s, err := c.kv()
+	if err != nil {
+		return nil, "", err
+	}
+	if limit <= 0 {
+		limit = 1000
+	}
+	ctx, cancel := opCtx()
 	defer cancel()
 
-	uids, err := c.client.SMembers(ctx, c.buildKey(udlIdxCidUsers(cid))).Result()
+	cids, err := udlMembers(ctx, s, udlIdxUserCids(uid))
 	if err != nil {
-		return nil, fmt.Errorf("smembers failed: %w", err)
+		return nil, "", err
 	}
-	return uids, nil
+	sort.Strings(cids)
+
+	out := make([]UDLUserAllEntry, 0, limit)
+	nextCid := ""
+	for _, cid := range cids {
+		if afterCid != "" && cid <= afterCid {
+			continue
+		}
+		if len(out) >= limit {
+			nextCid = out[len(out)-1].Cid
+			break
+		}
+		keys, err := udlMembers(ctx, s, udlIdxUserCid(uid, cid))
+		if err != nil {
+			return nil, "", err
+		}
+		for _, key := range keys {
+			cell, ok, err := readUDLCell(ctx, s, udlRecKey(uid, cid, key))
+			if err != nil {
+				return nil, "", err
+			}
+			if !ok {
+				continue
+			}
+			out = append(out, UDLUserAllEntry{
+				Cid: cid, Key: key, Record: cell.Record, Version: cell.Version, Ts: cell.Ts,
+			})
+		}
+	}
+	return out, nextCid, nil
+}
+
+// UDLCountUserCids is the number of distinct cids a uid holds records for.
+//
+// One index range count, which is what makes it usable as a per-push quota
+// check on the gateway mirror — a quota that cost a keyspace walk would be a
+// denial-of-service in its own right. Counts cids rather than cells because
+// that is what the index holds; a profile is bounded by the titles it has
+// touched, not by how many keys it has per title.
+func (c *Client) UDLCountUserCids(uid string) (int64, error) {
+	s, err := c.kv()
+	if err != nil {
+		return 0, err
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+	return s.Count(ctx, udlIdxUserCids(uid)+udlSetSep)
+}
+
+// UDLCidUsers returns every uid that has any record for cid — uids_for_cid.
+func (c *Client) UDLCidUsers(cid string) ([]string, error) {
+	s, err := c.kv()
+	if err != nil {
+		return nil, err
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+	return udlMembers(ctx, s, udlIdxCidUsers(cid))
 }
 
 // UDLPublicValues returns the live plaintext public JSON scalar values for
 // (cid, key) across all uids — the input to aggregation. Cells without a value
-// field (private-tier or tombstoned) are skipped.
+// (private-tier or tombstoned) are skipped.
 func (c *Client) UDLPublicValues(cid, key string) ([]string, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.client == nil {
-		return nil, fmt.Errorf("not connected")
+	s, err := c.kv()
+	if err != nil {
+		return nil, err
 	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	ctx, cancel := opCtx()
 	defer cancel()
 
-	uids, err := c.client.SMembers(ctx, c.buildKey(udlIdxCidKey(cid, key))).Result()
+	uids, err := udlMembers(ctx, s, udlIdxCidKey(cid, key))
 	if err != nil {
-		return nil, fmt.Errorf("smembers failed: %w", err)
+		return nil, err
+	}
+	recKeys := make([]string, len(uids))
+	for i, uid := range uids {
+		recKeys[i] = udlRecKey(uid, cid, key)
+	}
+	cells, err := readUDLCells(ctx, s, recKeys)
+	if err != nil {
+		return nil, err
 	}
 	out := make([]string, 0, len(uids))
-	for _, uid := range uids {
-		v, err := c.client.HGet(ctx, c.buildKey(udlRecKey(uid, cid, key)), "value").Result()
-		if err == redis.Nil {
-			continue // private-tier or tombstoned
+	for _, k := range recKeys {
+		if cell, ok := cells[k]; ok && cell.HasValue {
+			out = append(out, cell.Value)
 		}
-		if err != nil {
-			return nil, fmt.Errorf("hget failed: %w", err)
-		}
-		out = append(out, v)
 	}
 	return out, nil
 }

internal/storage/udl_admin.go

@@ -0,0 +1,179 @@
+package storage
+
+// Account-scoped UDL administration: what a uid holds, and removing all of it.
+//
+// Both operations enumerate the same thing — every `udl:rec:<uid>/<cid>/<key>`
+// cell. Keys are ordered, so one account's cells are the key range under
+// `udl:rec:<uid>/`, and every account's are the range under `udl:rec:`.
+// UDLAllUserStats stays a bulk call (one walk buckets every account) because
+// the accounts page needs a number for each.
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/metazla/meta-core/internal/kv"
+)
+
+// UDLUserStats counts what one account holds. Records is the number of cells,
+// including tombstones — a retracted rating is still a row this account owns
+// and still something a purge has to remove.
+type UDLUserStats struct {
+	Records int `json:"records"`
+	Cids    int `json:"cids"`
+	Keys    int `json:"keys"`
+}
+
+// safeUIDForPattern rejects anything that would reach across the key
+// structure (a `/` would let a uid prefix-match another account's range). meta-core's uids are alphanumeric
+// (identity.validUID), so this only ever fires on a hostile or malformed one —
+// but it fires here, in the layer that builds the pattern, rather than relying
+// on every caller having validated first.
+func safeUIDForPattern(uid string) error {
+	if uid == "" {
+		return fmt.Errorf("empty uid")
+	}
+	if strings.ContainsAny(uid, "*?[]\\/:") {
+		return fmt.Errorf("uid contains characters that are not valid in a uid: %q", uid)
+	}
+	return nil
+}
+
+// splitUDLRecSuffix splits the "<uid>/<cid>/<key>" tail of a udl:rec key.
+//
+// SplitN with a limit of 3 so a key containing a slash survives intact. cids
+// never contain one; keys are a controlled vocabulary today, but a namespaced
+// one arriving later must not silently truncate here — a truncated key would
+// make the purge SREM the wrong index member and leave the real one behind.
+func splitUDLRecSuffix(suffix string) (uid, cid, key string, ok bool) {
+	parts := strings.SplitN(suffix, "/", 3)
+	if len(parts) != 3 || parts[0] == "" || parts[1] == "" || parts[2] == "" {
+		return "", "", "", false
+	}
+	return parts[0], parts[1], parts[2], true
+}
+
+// UDLUserCells returns every (cid, key) pair this account holds a cell for,
+// keyed by the "cid/key" tail with the cid as value (the purge needs them
+// grouped).
+func (c *Client) UDLUserCells(uid string) (map[string]string, error) {
+	if err := safeUIDForPattern(uid); err != nil {
+		return nil, err
+	}
+	s, err := c.kv()
+	if err != nil {
+		return nil, err
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+
+	out := make(map[string]string)
+	err = s.ScanPrefix(ctx, "udl:rec:"+uid+"/", readerPage, func(rows []kv.KV) error {
+		for _, row := range rows {
+			gotUID, cid, key, ok := splitUDLRecSuffix(strings.TrimPrefix(row.K, "udl:rec:"))
+			if !ok || gotUID != uid {
+				continue
+			}
+			out[cid+"/"+key] = cid
+		}
+		return nil
+	})
+	return out, err
+}
+
+// UDLAllUserStats counts every account's cells in one walk.
+//
+// Returns only accounts that actually hold records; a uid absent from the map
+// holds none. Callers render a zero for those rather than treating it as an
+// error — an account created a minute ago legitimately has nothing.
+func (c *Client) UDLAllUserStats() (map[string]UDLUserStats, error) {
+	s, err := c.kv()
+	if err != nil {
+		return nil, err
+	}
+	ctx, cancel := opCtx()
+	defer cancel()
+
+	type acc struct {
+		cells int
+		cids  map[string]struct{}
+		keys  map[string]struct{}
+	}
+	byUID := make(map[string]*acc)
+	err = s.ScanPrefix(ctx, "udl:rec:", readerPage, func(rows []kv.KV) error {
+		for _, row := range rows {
+			uid, cid, key, ok := splitUDLRecSuffix(strings.TrimPrefix(row.K, "udl:rec:"))
+			if !ok {
+				continue
+			}
+			a := byUID[uid]
+			if a == nil {
+				a = &acc{cids: make(map[string]struct{}), keys: make(map[string]struct{})}
+				byUID[uid] = a
+			}
+			a.cells++
+			a.cids[cid] = struct{}{}
+			a.keys[key] = struct{}{}
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[string]UDLUserStats, len(byUID))
+	for uid, a := range byUID {
+		out[uid] = UDLUserStats{Records: a.cells, Cids: len(a.cids), Keys: len(a.keys)}
+	}
+	return out, nil
+}
+
+// UDLPurgeUser removes every trace of one account from the User Data Layer:
+// its cells, its three user-scoped indexes, and its membership in the shared
+// cid-scoped indexes. Returns what was removed.
+//
+// The shared indexes are the part that is easy to miss and expensive to leave.
+// `udl:idx:cid:<cid>:key:<key>` and `udl:idx:cid:<cid>:users` are keyed by cid,
+// not by uid, so a purge that only deleted `udl:rec:<uid>/*` would leave this
+// uid listed as an opinion-holder on every title it ever touched.
+//
+// Idempotent: purging an account with nothing stored is a no-op returning
+// zeroes, so a retry is safe.
+func (c *Client) UDLPurgeUser(uid string) (UDLUserStats, error) {
+	cells, err := c.UDLUserCells(uid)
+	if err != nil {
+		return UDLUserStats{}, err
+	}
+
+	stats := UDLUserStats{Records: len(cells)}
+	distinctCids := make(map[string]struct{})
+	distinctKeys := make(map[string]struct{})
+	err = c.update(func(tx *kv.Tx) error {
+		for cidKey, cid := range cells {
+			key := strings.TrimPrefix(cidKey, cid+"/")
+			distinctCids[cid] = struct{}{}
+			distinctKeys[key] = struct{}{}
+			if _, err := tx.Delete(udlRecKey(uid, cid, key)); err != nil {
+				return err
+			}
+			if err := udlRem(tx, udlIdxCidKey(cid, key), uid); err != nil {
+				return err
+			}
+		}
+		for cid := range distinctCids {
+			if err := udlRem(tx, udlIdxCidUsers(cid), uid); err != nil {
+				return err
+			}
+		}
+		// The three user-scoped indexes (`:key:*`, `:cid:*`, `:cids`) are one
+		// key range, dropped whole — which also catches index entries whose
+		// cell is already gone (the state a half-finished purge leaves).
+		_, err := tx.DeletePrefix("udl:idx:user:"+uid+":", 0)
+		return err
+	})
+	if err != nil {
+		return UDLUserStats{}, fmt.Errorf("purge: %w", err)
+	}
+	stats.Cids = len(distinctCids)
+	stats.Keys = len(distinctKeys)
+	return stats, nil
+}

internal/storage/udl_admin_test.go

@@ -0,0 +1,233 @@
+package storage
+
+import (
+	"testing"
+)
+
+// seedCell writes one live UDL cell the way a real client would.
+func seedCell(t *testing.T, c *Client, uid, cid, key string) {
+	t.Helper()
+	if ok, err := c.UDLUpsertIfNewer(uid, cid, key, 1, 100, "rec", "", false, false); err != nil || !ok {
+		t.Fatalf("seed %s/%s/%s: ok=%v err=%v", uid, cid, key, ok, err)
+	}
+}
+
+// The purge has to reach the cid-scoped indexes, not just the user's own rows.
+//
+// This is the failure that motivated the whole endpoint: deleting an account
+// while leaving `udl:idx:cid:<cid>:users` intact means every aggregate read on
+// every title that account ever touched keeps naming a uid nobody can resolve,
+// forever — and the rows are unreachable through any API, so nothing will ever
+// clean them up.
+func TestUDLPurgeUser_RemovesCellsAndBothIndexFamilies(t *testing.T) {
+	c := newTestClient(t)
+
+	seedCell(t, c, "zAlice", "cidOne", "like")
+	seedCell(t, c, "zAlice", "cidOne", "rating")
+	seedCell(t, c, "zAlice", "cidTwo", "seek")
+
+	stats, err := c.UDLPurgeUser("zAlice")
+	if err != nil {
+		t.Fatalf("purge: %v", err)
+	}
+	if stats.Records != 3 || stats.Cids != 2 || stats.Keys != 3 {
+		t.Fatalf("stats = %+v, want 3 records / 2 cids / 3 keys", stats)
+	}
+
+	// Cells gone.
+	if _, ok, err := c.UDLGetCell("zAlice", "cidOne", "like"); err != nil || ok {
+		t.Fatalf("cell survived the purge: ok=%v err=%v", ok, err)
+	}
+	// User-scoped indexes gone.
+	if entries, err := c.UDLListUserKey("zAlice", "like"); err != nil || len(entries) != 0 {
+		t.Fatalf("user+key index survived: %d entries, err=%v", len(entries), err)
+	}
+	if entries, err := c.UDLListUserCid("zAlice", "cidOne"); err != nil || len(entries) != 0 {
+		t.Fatalf("user+cid index survived: %d entries, err=%v", len(entries), err)
+	}
+	// Cid-scoped index gone — the one that is easy to miss.
+	for _, cid := range []string{"cidOne", "cidTwo"} {
+		uids, err := c.UDLCidUsers(cid)
+		if err != nil {
+			t.Fatalf("cid users %s: %v", cid, err)
+		}
+		for _, u := range uids {
+			if u == "zAlice" {
+				t.Fatalf("%s still lists the deleted account in uids_for_cid", cid)
+			}
+		}
+	}
+}
+
+// Purging one account must not touch another's rows, including on a cid they
+// both have an opinion about — where the two share an index set and a careless
+// DEL of the whole key would take the survivor's membership with it.
+func TestUDLPurgeUser_LeavesOtherAccountsIntact(t *testing.T) {
+	c := newTestClient(t)
+
+	seedCell(t, c, "zAlice", "shared", "rating")
+	seedCell(t, c, "zBob", "shared", "rating")
+
+	if _, err := c.UDLPurgeUser("zAlice"); err != nil {
+		t.Fatalf("purge: %v", err)
+	}
+
+	if _, ok, err := c.UDLGetCell("zBob", "shared", "rating"); err != nil || !ok {
+		t.Fatalf("bob's cell must survive alice's purge: ok=%v err=%v", ok, err)
+	}
+	uids, err := c.UDLCidUsers("shared")
+	if err != nil {
+		t.Fatalf("cid users: %v", err)
+	}
+	if len(uids) != 1 || uids[0] != "zBob" {
+		t.Fatalf("uids_for_cid = %v, want exactly [zBob]", uids)
+	}
+	entries, err := c.UDLListUserKey("zBob", "rating")
+	if err != nil || len(entries) != 1 {
+		t.Fatalf("bob's user+key index must survive: %d entries, err=%v", len(entries), err)
+	}
+}
+
+// A uid that is a prefix of another must not drag its neighbour's rows out.
+// The key layout separates them with '/' and ':', so this passes only as long
+// as the scan patterns keep those separators.
+func TestUDLPurgeUser_DoesNotMatchUIDsByPrefix(t *testing.T) {
+	c := newTestClient(t)
+
+	seedCell(t, c, "zAlice", "cidOne", "like")
+	seedCell(t, c, "zAliceExtra", "cidOne", "like")
+
+	stats, err := c.UDLPurgeUser("zAlice")
+	if err != nil {
+		t.Fatalf("purge: %v", err)
+	}
+	if stats.Records != 1 {
+		t.Fatalf("purged %d records, want exactly alice's 1", stats.Records)
+	}
+	if _, ok, err := c.UDLGetCell("zAliceExtra", "cidOne", "like"); err != nil || !ok {
+		t.Fatalf("zAliceExtra's cell must survive: ok=%v err=%v", ok, err)
+	}
+}
+
+// Tombstoned cells still belong to the account. They are absent from the
+// user+key index by design (see udl.go), so a purge that enumerated *that*
+// index instead of the cells would leave every retracted rating behind — the
+// rows most likely to have accumulated over an account's life.
+func TestUDLPurgeUser_RemovesTombstonedCellsToo(t *testing.T) {
+	c := newTestClient(t)
+
+	seedCell(t, c, "zAlice", "cidOne", "like")
+	if ok, err := c.UDLUpsertIfNewer("zAlice", "cidOne", "like", 2, 200, "rec-tomb", "", false, true); err != nil || !ok {
+		t.Fatalf("tombstone: ok=%v err=%v", ok, err)
+	}
+	// Precondition: the tombstone left the cell but dropped it from the index.
+	if entries, _ := c.UDLListUserKey("zAlice", "like"); len(entries) != 0 {
+		t.Fatalf("precondition: tombstone should be out of the user+key index")
+	}
+
+	stats, err := c.UDLPurgeUser("zAlice")
+	if err != nil {
+		t.Fatalf("purge: %v", err)
+	}
+	if stats.Records != 1 {
+		t.Fatalf("purged %d records, want the 1 tombstoned cell", stats.Records)
+	}
+	if _, ok, _ := c.UDLGetCell("zAlice", "cidOne", "like"); ok {
+		t.Fatal("tombstoned cell survived the purge")
+	}
+}
+
+// Retry-safe: the delete handler purges before removing the key, so a caller
+// that retries after a partial failure runs this a second time.
+func TestUDLPurgeUser_IsIdempotent(t *testing.T) {
+	c := newTestClient(t)
+	seedCell(t, c, "zAlice", "cidOne", "like")
+
+	if _, err := c.UDLPurgeUser("zAlice"); err != nil {
+		t.Fatalf("first purge: %v", err)
+	}
+	stats, err := c.UDLPurgeUser("zAlice")
+	if err != nil {
+		t.Fatalf("second purge must be a no-op, got: %v", err)
+	}
+	if stats.Records != 0 || stats.Cids != 0 {
+		t.Fatalf("second purge = %+v, want zeroes", stats)
+	}
+}
+
+func TestUDLPurgeUser_RefusesGlobInjection(t *testing.T) {
+	c := newTestClient(t)
+	seedCell(t, c, "zAlice", "cidOne", "like")
+
+	// "*" would otherwise match every account in the keyspace — a wildcard
+	// purge dressed up as a uid.
+	for _, uid := range []string{"*", "z*", "", "z:Alice", "z/Alice"} {
+		if _, err := c.UDLPurgeUser(uid); err == nil {
+			t.Errorf("uid %q must be refused before it reaches a SCAN pattern", uid)
+		}
+	}
+	if _, ok, _ := c.UDLGetCell("zAlice", "cidOne", "like"); !ok {
+		t.Fatal("a refused purge must not have deleted anything")
+	}
+}
+
+func TestUDLAllUserStats_CountsEachAccountSeparately(t *testing.T) {
+	c := newTestClient(t)
+
+	seedCell(t, c, "zAlice", "cidOne", "like")
+	seedCell(t, c, "zAlice", "cidOne", "rating")
+	seedCell(t, c, "zAlice", "cidTwo", "like")
+	seedCell(t, c, "zBob", "cidOne", "seek")
+
+	stats, err := c.UDLAllUserStats()
+	if err != nil {
+		t.Fatalf("stats: %v", err)
+	}
+	if got := stats["zAlice"]; got.Records != 3 || got.Cids != 2 || got.Keys != 2 {
+		t.Fatalf("alice = %+v, want 3 records / 2 cids / 2 keys", got)
+	}
+	if got := stats["zBob"]; got.Records != 1 || got.Cids != 1 || got.Keys != 1 {
+		t.Fatalf("bob = %+v, want 1/1/1", got)
+	}
+	// An account with nothing stored is simply absent — the caller renders 0.
+	if _, present := stats["zNobody"]; present {
+		t.Fatal("an account with no records must not appear in the map")
+	}
+}
+
+// The stats and the purge must agree: the number shown in the delete
+// confirmation is the number of rows the delete then removes.
+func TestUDLAllUserStats_AgreesWithWhatPurgeRemoves(t *testing.T) {
+	c := newTestClient(t)
+
+	seedCell(t, c, "zAlice", "cidOne", "like")
+	seedCell(t, c, "zAlice", "cidTwo", "rating")
+	seedCell(t, c, "zAlice", "cidTwo", "seek")
+
+	before, err := c.UDLAllUserStats()
+	if err != nil {
+		t.Fatalf("stats: %v", err)
+	}
+	purged, err := c.UDLPurgeUser("zAlice")
+	if err != nil {
+		t.Fatalf("purge: %v", err)
+	}
+	if before["zAlice"] != purged {
+		t.Fatalf("stats said %+v but purge removed %+v", before["zAlice"], purged)
+	}
+}
+
+func TestSplitUDLRecSuffix_KeepsSlashesInTheKey(t *testing.T) {
+	// A namespaced key arriving later must not be truncated: the purge SREMs
+	// `udl:idx:cid:<cid>:key:<key>`, so a half-read key removes the wrong
+	// member and leaves the real one behind.
+	uid, cid, key, ok := splitUDLRecSuffix("zAlice/cidOne/ns/sub:key")
+	if !ok || uid != "zAlice" || cid != "cidOne" || key != "ns/sub:key" {
+		t.Fatalf("got (%q,%q,%q,%v)", uid, cid, key, ok)
+	}
+	for _, bad := range []string{"", "zAlice", "zAlice/cidOne", "zAlice//key", "/cid/key"} {
+		if _, _, _, ok := splitUDLRecSuffix(bad); ok {
+			t.Errorf("%q should not parse", bad)
+		}
+	}
+}

internal/storage/udl_export_test.go

@@ -0,0 +1,160 @@
+package storage
+
+import (
+	"testing"
+)
+
+// The whole-profile export is what cross-instance recovery reads: a box that
+// has just imported a secret key knows the uid and nothing else — not which
+// cids the profile touched, not which keys. Every one of these tests is about
+// that one caller.
+
+func TestUDLAllForUser_ReturnsEveryCellAcrossCidsAndKeys(t *testing.T) {
+	c := newTestClient(t)
+
+	const uid = "zAlice"
+	writes := []struct{ cid, key, rec string }{
+		{"bagcsaaaaone", "like", "rec-one-like"},
+		{"bagcsaaaaone", "seek", "rec-one-seek"},
+		{"bagcsaaaatwo", "rating", "rec-two-rating"},
+		{"bagcsaaaatwo", "profile:name", "rec-two-name"},
+		{"bagcsaaathree", "watched", "rec-three-watched"},
+	}
+	for _, w := range writes {
+		if ok, err := c.UDLUpsertIfNewer(uid, w.cid, w.key, 1, 100, w.rec, "", false, false); err != nil || !ok {
+			t.Fatalf("upsert %s/%s: ok=%v err=%v", w.cid, w.key, ok, err)
+		}
+	}
+
+	entries, next, err := c.UDLAllForUser(uid, "", 0)
+	if err != nil {
+		t.Fatalf("export: %v", err)
+	}
+	if next != "" {
+		t.Fatalf("export of 5 rows should be complete, got nextCid=%q", next)
+	}
+	if len(entries) != len(writes) {
+		t.Fatalf("want %d rows, got %d: %+v", len(writes), len(entries), entries)
+	}
+	seen := map[string]string{}
+	for _, e := range entries {
+		seen[e.Cid+"/"+e.Key] = e.Record
+	}
+	for _, w := range writes {
+		if got := seen[w.cid+"/"+w.key]; got != w.rec {
+			t.Errorf("%s/%s: want record %q, got %q", w.cid, w.key, w.rec, got)
+		}
+	}
+}
+
+// The failure this guards is silent and total: a uid whose cids were never
+// indexed exports as empty, and recovery reports success having restored
+// nothing.
+func TestUDLAllForUser_IsEmptyForAnUnknownUid(t *testing.T) {
+	c := newTestClient(t)
+
+	if ok, err := c.UDLUpsertIfNewer("zAlice", "bagcsaaaaone", "like", 1, 100, "rec", "", false, false); err != nil || !ok {
+		t.Fatalf("upsert: ok=%v err=%v", ok, err)
+	}
+	entries, _, err := c.UDLAllForUser("zBob", "", 0)
+	if err != nil {
+		t.Fatalf("export: %v", err)
+	}
+	if len(entries) != 0 {
+		t.Fatalf("Bob owns nothing; got %+v", entries)
+	}
+}
+
+// ⚠ The tombstone rule, and the reason the cids index is never pruned.
+//
+// A tombstone must EXPORT. It is the only thing that can beat the older live
+// value the other box still holds at a lower version — drop it from the export
+// and an un-liked title comes back from the dead on every peer that already
+// saw the `like`. This is the one place the cids index deliberately diverges
+// from the user+key index, which does prune.
+func TestUDLAllForUser_ExportsTombstones(t *testing.T) {
+	c := newTestClient(t)
+
+	const (
+		uid = "zAlice"
+		cid = "bagcsaaaaone"
+		key = "like"
+	)
+	if ok, err := c.UDLUpsertIfNewer(uid, cid, key, 1, 100, "rec-liked", "", false, false); err != nil || !ok {
+		t.Fatalf("live upsert: ok=%v err=%v", ok, err)
+	}
+	if ok, err := c.UDLUpsertIfNewer(uid, cid, key, 2, 200, "rec-unliked", "", false, true); err != nil || !ok {
+		t.Fatalf("tombstone upsert: ok=%v err=%v", ok, err)
+	}
+
+	// The user+key index prunes it — that is what keeps My List short.
+	live, err := c.UDLListUserKey(uid, key)
+	if err != nil {
+		t.Fatalf("active_for_user_key: %v", err)
+	}
+	if len(live) != 0 {
+		t.Fatalf("tombstoned cid should leave the user+key index, got %+v", live)
+	}
+
+	// The export must still carry it, at the tombstone's version.
+	entries, _, err := c.UDLAllForUser(uid, "", 0)
+	if err != nil {
+		t.Fatalf("export: %v", err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("tombstone must export, got %+v", entries)
+	}
+	if entries[0].Record != "rec-unliked" || entries[0].Version != 2 {
+		t.Fatalf("export must carry the tombstone, not the superseded value: %+v", entries[0])
+	}
+}
+
+func TestUDLAllForUser_PagesOnACidBoundaryAndResumes(t *testing.T) {
+	c := newTestClient(t)
+
+	const uid = "zAlice"
+	cids := []string{"bagcsaaaaa1", "bagcsaaaaa2", "bagcsaaaaa3"}
+	for _, cid := range cids {
+		for _, key := range []string{"like", "seek"} {
+			if ok, err := c.UDLUpsertIfNewer(uid, cid, key, 1, 100, "rec-"+cid+"-"+key, "", false, false); err != nil || !ok {
+				t.Fatalf("upsert: ok=%v err=%v", ok, err)
+			}
+		}
+	}
+
+	// A cid's keys are never split across a page, so a limit of 1 still yields
+	// both of the first cid's rows.
+	page1, next1, err := c.UDLAllForUser(uid, "", 1)
+	if err != nil {
+		t.Fatalf("page 1: %v", err)
+	}
+	if len(page1) != 2 || page1[0].Cid != cids[0] {
+		t.Fatalf("page 1 should hold both rows of %s, got %+v", cids[0], page1)
+	}
+	if next1 != cids[0] {
+		t.Fatalf("cursor should name the last cid emitted, want %q got %q", cids[0], next1)
+	}
+
+	// Walking the cursor must visit every row exactly once.
+	all := append([]UDLUserAllEntry{}, page1...)
+	cursor := next1
+	for cursor != "" {
+		page, next, err := c.UDLAllForUser(uid, cursor, 1)
+		if err != nil {
+			t.Fatalf("page after %q: %v", cursor, err)
+		}
+		all = append(all, page...)
+		cursor = next
+	}
+	if len(all) != 6 {
+		t.Fatalf("want 6 rows across all pages, got %d: %+v", len(all), all)
+	}
+	seen := map[string]bool{}
+	for _, e := range all {
+		k := e.Cid + "/" + e.Key
+		if seen[k] {
+			t.Fatalf("%s emitted twice across pages", k)
+		}
+		seen[k] = true
+	}
+}

internal/storage/udl_test.go

@@ -15,7 +15,7 @@ import (
 // forever. The reader filters them out again, so the cost is invisible until
 // the account is old.
 func TestUDLUpsert_TombstonePrunesUserKeyIndexButKeepsCell(t *testing.T) {
-	c, _ := newTestClient(t, "")
+	c := newTestClient(t)
 
 	const (
 		uid = "zAlice"

internal/storage/uuid.go

@@ -8,7 +8,7 @@ import (
 // layout). Used as the root key for file metadata entries.
 //
 // Why this format over canonical 8-4-4-4-12 hex:
-//   - 26 chars vs 36 — shorter Redis keys, less prefix space waste
+//   - 26 chars vs 36 — shorter keys, less prefix space waste
 //   - Time-sortable prefix — KEYS file:01JKR* returns entries minted in a
 //     given time window, restoring some of the debug-ability lost vs the
 //     previous midhash256:abc rooting

internal/storage/write_bench_test.go

@@ -0,0 +1,59 @@
+package storage
+
+import (
+	"fmt"
+	"path/filepath"
+	"sync"
+	"sync/atomic"
+	"testing"
+)
+
+// BenchmarkConcurrentRecordWrites is the ingest shape the single-writer model
+// has to absorb: many goroutines (feeder flushes, gateway persists, plugin
+// callbacks) each writing a ~40-field record. SQLite serialises them; this
+// measures what that costs. Reported as records/s.
+func BenchmarkConcurrentRecordWrites(b *testing.B) {
+	c := NewClient()
+	if err := c.Connect(filepath.Join(b.TempDir(), "bench.db")); err != nil {
+		b.Fatal(err)
+	}
+	defer c.Close()
+
+	record := func(i int64) map[string]string {
+		m := map[string]string{
+			"title":                               fmt.Sprintf("Some Show S01E%02d", i%40),
+			"fileName":                            fmt.Sprintf("some.show.s01e%02d.1080p.mkv", i%40),
+			"filePath":                            fmt.Sprintf("/files/watch/some.show.%d.mkv", i),
+			"fileType":                            "video",
+			"tmdbid":                              fmt.Sprintf("%d", 1000+i%500),
+			fmt.Sprintf("cids/bafkbench%020d", i): "true",
+		}
+		for f := 0; len(m) < 40; f++ {
+			m[fmt.Sprintf("categories/%d", f)] = "true"
+		}
+		return m
+	}
+
+	const writers = 16
+	var next int64
+	b.ResetTimer()
+	var wg sync.WaitGroup
+	for w := 0; w < writers; w++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				i := atomic.AddInt64(&next, 1)
+				if i > int64(b.N) {
+					return
+				}
+				if err := c.SetMetadataFlat(fmt.Sprintf("01BENCH%019d", i), record(i)); err != nil {
+					b.Error(err)
+					return
+				}
+			}
+		}()
+	}
+	wg.Wait()
+	b.ReportMetric(float64(b.N)/b.Elapsed().Seconds(), "records/s")
+}

internal/watcher/dispatcher.go

@@ -11,7 +11,7 @@ import (
 )
 
 const (
-	// EventsStream is the Redis Stream name for file events
+	// EventsStream is the stream name for file events
 	EventsStream = "file:events"
 
 	// EventsStreamMaxLen is the approximate cap on stream length. Bounded
@@ -20,7 +20,7 @@ const (
 	EventsStreamMaxLen = 100_000
 )
 
-// Dispatcher sends file events to Redis Stream
+// Dispatcher sends file events to the file:events stream
 type Dispatcher struct {
 	mu            sync.RWMutex
 	storageClient *storage.Client
@@ -31,27 +31,37 @@ func NewDispatcher() *Dispatcher {
 	return &Dispatcher{}
 }
 
-// SetStorageClient sets the storage client for Redis Stream publishing
+// SetStorageClient sets the storage client for file:events publishing
 func (d *Dispatcher) SetStorageClient(client *storage.Client) {
 	d.mu.Lock()
 	defer d.mu.Unlock()
 	d.storageClient = client
-	log.Println("[Dispatcher] Storage client set for Redis Stream publishing")
+	log.Println("[Dispatcher] Storage client set for file:events publishing")
 }
 
-// Dispatch sends an event to Redis Stream
+// Dispatch sends an event to the file:events stream
 func (d *Dispatcher) Dispatch(event FileEvent) {
 	go d.dispatchToStream(event)
 }
 
-// dispatchToStream publishes event to Redis Stream for service consumption
+// dispatchToStream publishes event to the file:events stream for service consumption
 func (d *Dispatcher) dispatchToStream(event FileEvent) {
 	d.mu.RLock()
 	client := d.storageClient
 	d.mu.RUnlock()
 
+	if err := PublishEvent(client, event); err != nil {
+		log.Printf("[Dispatcher] Failed to publish to stream: %v", err)
+	}
+}
+
+// PublishEvent appends one file event to the file:events stream. Exported so a
+// caller with no Dispatcher (POST /api/files/register on a box whose watcher is
+// off) emits exactly the entry the watcher would — meta-share's ipfs_seed
+// consumes this stream to chunk, seed and provide new files.
+func PublishEvent(client *storage.Client, event FileEvent) error {
 	if client == nil || !client.IsConnected() {
-		return
+		return fmt.Errorf("storage client not connected")
 	}
 
 	// Build stream fields
@@ -79,9 +89,7 @@ func (d *Dispatcher) dispatchToStream(event FileEvent) {
 	// `EmitReset → ClearStream` path is still the only way the stream gets
 	// truncated to zero (signalled to consumers via the `reset` event).
 	_, err := client.XAdd(EventsStream, EventsStreamMaxLen, fields)
-	if err != nil {
-		log.Printf("[Dispatcher] Failed to publish to stream: %v", err)
-	}
+	return err
 }
 
 // EmitReset clears the stream and emits a reset event
@@ -117,7 +125,7 @@ func (d *Dispatcher) EmitReset(watcherID string) error {
 	return nil
 }
 
-// GetRecentEvents reads recent events from the Redis stream, newest first.
+// GetRecentEvents reads recent events from the stream, newest first.
 // If sinceMS > 0, only events strictly newer than that timestamp are returned.
 // limit caps the number of returned events (defaults to 100 when <= 0).
 func (d *Dispatcher) GetRecentEvents(sinceMS int64, limit int) ([]FileEvent, error) {
@@ -152,7 +160,7 @@ func (d *Dispatcher) GetRecentEvents(sinceMS int64, limit int) ([]FileEvent, err
 	return events, nil
 }
 
-// parseStreamEntry converts a Redis stream entry back into a FileEvent.
+// parseStreamEntry converts a stream entry back into a FileEvent.
 // All fields are stored as strings by XADD, so numerics need parsing.
 func parseStreamEntry(entry storage.StreamEntry) FileEvent {
 	event := FileEvent{}
@@ -184,7 +192,7 @@ func parseStreamEntry(entry storage.StreamEntry) FileEvent {
 	}
 
 	// Fall back to the stream ID's millisecond prefix if the timestamp
-	// field is missing or unparseable — every Redis stream ID starts with ms.
+	// field is missing or unparseable — every stream ID starts with ms.
 	if event.Timestamp == 0 && entry.ID != "" {
 		if dash := strings.IndexByte(entry.ID, '-'); dash > 0 {
 			if n, err := strconv.ParseInt(entry.ID[:dash], 10, 64); err == nil {

internal/watcher/handlers.go

@@ -25,7 +25,7 @@ func NewHandlers(watcher *Watcher, dispatcher *Dispatcher) *Handlers {
 
 // RegisterRoutes registers all watcher-related routes
 func (h *Handlers) RegisterRoutes(r *mux.Router) {
-	// Event polling (for services that don't use Redis Streams)
+	// Event polling (for services that don't consume the SSE stream)
 	r.HandleFunc("/api/events/poll", h.handlePoll).Methods("GET")
 
 	// Deprecated scan endpoints - redirect to /api/watchers
@@ -61,7 +61,7 @@ func (h *Handlers) handlePoll(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	// Read events from the Redis `file:events` stream rather than the
+	// Read events from the `file:events` stream rather than the
 	// in-memory buffer. The buffer is fed by the unused debouncer path,
 	// so it is always empty in practice — the stream is the source of truth.
 	events, err := h.dispatcher.GetRecentEvents(sinceMS, limit)

internal/watcher/watcher.go

@@ -4,7 +4,6 @@ import (
 	"log"
 	"os"
 	"path/filepath"
-	"strconv"
 	"strings"
 	"sync"
 
@@ -12,7 +11,6 @@ import (
 	"github.com/metazla/meta-core/internal/storage"
 )
 
-
 // Watcher provides file scanning and event dispatching
 type Watcher struct {
 	config        *config.Config
@@ -27,8 +25,8 @@ type Watcher struct {
 }
 
 // SetStorageClient lets the watcher persist the (path, size, mtime, midhash)
-// tuple to Redis whenever it computes a midhash. Without this, only the
-// in-memory state registry knows about the file — Redis would only learn
+// tuple to the store whenever it computes a midhash. Without this, only the
+// in-memory state registry knows about the file — the store would only learn
 // about it via downstream consumers of the event stream.
 func (w *Watcher) SetStorageClient(s *storage.Client) {
 	w.storage = s
@@ -36,7 +34,7 @@ func (w *Watcher) SetStorageClient(s *storage.Client) {
 
 // writeFileTuple persists path/size/mtime/midhash for a freshly-hashed file.
 // Caller already has all four values from its existing os.Stat / FileInfo —
-// no extra IO is performed here beyond the Redis writes themselves.
+// no extra IO is performed here beyond the store writes themselves.
 //
 // Flow:
 //   - Look up the midhash CID in the reverse index (cid:<midhash> → uuid)
@@ -47,49 +45,15 @@ func (w *Watcher) SetStorageClient(s *storage.Client) {
 //     record the new path in the duplicates set and refresh size/mtime
 //
 // This is also the inverse-index that lets a fresh meta-core boot skip
-// re-mid-hashing files whose (path, size, mtime) match what's in Redis,
+// re-mid-hashing files whose (path, size, mtime) match what's stored,
 // via HydrateStateFromStorage below.
 func (w *Watcher) writeFileTuple(absPath string, size, mtimeNano int64, midhash string) {
 	if w.storage == nil || midhash == "" {
 		return
 	}
 
-	uuid, err := w.storage.GetByCID(midhash)
-	if err != nil {
-		log.Printf("[Watcher] GetByCID(%s): %v", midhash, err)
-		return
-	}
-
-	if uuid == "" {
-		// New content. Mint sets filePath/sizeByte/mtimeNano; SetProperty
-		// then writes the midhash as a cids/<cid> key-set member — and the
-		// cid_resolution.go hook registers the reverse-index alias for us.
-		uuid, err = w.storage.Mint(absPath, size, mtimeNano)
-		if err != nil {
-			log.Printf("[Watcher] Mint(%s): %v", absPath, err)
-			return
-		}
-		if err := w.storage.SetProperty(uuid, storage.CIDsKeyPrefix+midhash, "true"); err != nil {
-			log.Printf("[Watcher] SetProperty cids/%s for %s: %v", midhash, uuid, err)
-		}
-		return
-	}
-
-	// Known content. If this is a new physical path for the same content,
-	// record it as a duplicate. Otherwise refresh size/mtime — same content,
-	// same path, but the file may have been rewritten with a fresh mtime.
-	existing, _ := w.storage.GetProperty(uuid, "filePath")
-	if existing != absPath {
-		if _, err := w.storage.AddDuplicatePath(uuid, absPath); err != nil {
-			log.Printf("[Watcher] AddDuplicatePath %s @ %s: %v", uuid, absPath, err)
-		}
-		return
-	}
-	if _, err := w.storage.MergeMetadataFlat(uuid, map[string]string{
-		"sizeByte":  strconv.FormatInt(size, 10),
-		"mtimeNano": strconv.FormatInt(mtimeNano, 10),
-	}); err != nil {
-		log.Printf("[Watcher] refresh tuple for %s: %v", uuid, err)
+	if _, _, err := w.storage.RegisterFileTuple(absPath, size, mtimeNano, midhash); err != nil {
+		log.Printf("[Watcher] register %s: %v", absPath, err)
 	}
 }
 
@@ -305,7 +269,7 @@ func (w *Watcher) ScanDirectoryDiff(root string, watcherID string) DiffScanResul
 }
 
 // WatcherRoot pairs a watcher's id with the absolute path it watches. The
-// hydrator uses Root to decide which Redis-tracked file belongs to which
+// hydrator uses Root to decide which stored file belongs to which
 // in-memory WatcherState.
 type WatcherRoot struct {
 	ID   string
@@ -313,7 +277,7 @@ type WatcherRoot struct {
 }
 
 // HydrateStateFromStorage repopulates the per-watcher in-memory state from
-// the (filePath, sizeByte, mtimeNano) tuples in Redis. After this runs, the
+// the (filePath, sizeByte, mtimeNano) tuples in the store. After this runs, the
 // next scan tick will see existing files as "known" and skip
 // ComputeMidHash256 for any whose size+mtime match — turning a cold-start
 // rescan from minutes to seconds on a populated library.
@@ -451,4 +415,3 @@ func (w *Watcher) GetRecentEvents(sinceMS int64, limit int) []FileEvent {
 func (w *Watcher) GetFilesPath() string {
 	return w.filesPath
 }
-

internal/watchers/poller.go

@@ -74,7 +74,7 @@ func (p *Poller) Start() error {
 	// consumer state without buying anything. The historical reason for
 	// wiping — "in-memory state is empty, all files re-emit as add" —
 	// stopped being true when HydrateStateFromStorage landed: state is
-	// hydrated from Redis before this runs, so a startup EmitReset would
+	// hydrated from the store before this runs, so a startup EmitReset would
 	// tell consumers to throw out their world without sending the
 	// re-emission they need to rebuild it.
 	//
@@ -308,7 +308,7 @@ func (p *Poller) TriggerScanAll() (int, error) {
 }
 
 // TriggerReset performs a full reset for a watcher:
-// 1. Clears the Redis stream and emits a reset event
+// 1. Clears the file:events stream and emits a reset event
 // 2. Clears the watcher's state
 // 3. Performs a full scan (all files are "new")
 func (p *Poller) TriggerReset(watcherID string) (int, error) {

test/config_test.go

@@ -30,8 +30,8 @@ func TestConfigDefaults(t *testing.T) {
 		t.Errorf("Expected HTTPPort 9000, got %d", cfg.HTTPPort)
 	}
 
-	if cfg.RedisPort != 6379 {
-		t.Errorf("Expected RedisPort 6379, got %d", cfg.RedisPort)
+	if cfg.DBPath() != cfg.MetaCorePath+"/db/meta-core.db" {
+		t.Errorf("Expected DBPath under MetaCorePath, got %q", cfg.DBPath())
 	}
 }
 
@@ -41,7 +41,7 @@ func TestConfigFromEnv(t *testing.T) {
 	os.Setenv("FILES_PATH", "/custom/files")
 	os.Setenv("SERVICE_NAME", "test-service")
 	os.Setenv("META_CORE_HTTP_PORT", "8080")
-	os.Setenv("REDIS_PORT", "6380")
+	os.Setenv("META_CORE_DB_PATH", "/custom/db.sqlite")
 	defer os.Clearenv()
 
 	cfg := config.Load()
@@ -62,8 +62,8 @@ func TestConfigFromEnv(t *testing.T) {
 		t.Errorf("Expected HTTPPort 8080, got %d", cfg.HTTPPort)
 	}
 
-	if cfg.RedisPort != 6380 {
-		t.Errorf("Expected RedisPort 6380, got %d", cfg.RedisPort)
+	if cfg.DBPath() != "/custom/db.sqlite" {
+		t.Errorf("Expected DBPath '/custom/db.sqlite', got %q", cfg.DBPath())
 	}
 }
 
@@ -77,15 +77,8 @@ func TestConfigPaths(t *testing.T) {
 		t.Errorf("Unexpected LockFilePath: %s", cfg.LockFilePath())
 	}
 
-	if cfg.InfoFilePath() != "/test/locks/kv-leader.info" {
-		t.Errorf("Unexpected InfoFilePath: %s", cfg.InfoFilePath())
+	if cfg.DBPath() != "/test/db/meta-core.db" {
+		t.Errorf("Unexpected DBPath: %s", cfg.DBPath())
 	}
 
-	if cfg.RedisDataDir() != "/test/db/redis" {
-		t.Errorf("Unexpected RedisDataDir: %s", cfg.RedisDataDir())
-	}
-
-	if cfg.ServicesDir() != "/test/services" {
-		t.Errorf("Unexpected ServicesDir: %s", cfg.ServicesDir())
-	}
 }

test/election_test.go

@@ -1,144 +0,0 @@
-package test
-
-import (
-	"encoding/json"
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/metazla/meta-core/internal/leader"
-)
-
-func TestLeaderLockInfoJSON(t *testing.T) {
-	info := &leader.LeaderLockInfo{
-		Host:      "test-host",
-		API:       "redis://10.0.0.1:6379",
-		HTTP:      "http://10.0.0.1:8180",
-		BaseURL:   "http://localhost:8180",
-		Timestamp: 1704067200000,
-		PID:       12345,
-	}
-
-	// Marshal to JSON
-	data, err := json.MarshalIndent(info, "", "  ")
-	if err != nil {
-		t.Fatalf("Failed to marshal: %v", err)
-	}
-
-	// Verify JSON structure matches TypeScript format
-	var parsed map[string]interface{}
-	if err := json.Unmarshal(data, &parsed); err != nil {
-		t.Fatalf("Failed to unmarshal: %v", err)
-	}
-
-	if parsed["host"] != "test-host" {
-		t.Errorf("Expected host 'test-host', got '%v'", parsed["host"])
-	}
-
-	if parsed["api"] != "redis://10.0.0.1:6379" {
-		t.Errorf("Expected api 'redis://10.0.0.1:6379', got '%v'", parsed["api"])
-	}
-
-	if parsed["http"] != "http://10.0.0.1:8180" {
-		t.Errorf("Expected http 'http://10.0.0.1:8180', got '%v'", parsed["http"])
-	}
-
-	if parsed["baseUrl"] != "http://localhost:8180" {
-		t.Errorf("Expected baseUrl 'http://localhost:8180', got '%v'", parsed["baseUrl"])
-	}
-
-	// Timestamp should be a number
-	if _, ok := parsed["timestamp"].(float64); !ok {
-		t.Errorf("Expected timestamp to be a number, got %T", parsed["timestamp"])
-	}
-
-	// PID should be a number
-	if _, ok := parsed["pid"].(float64); !ok {
-		t.Errorf("Expected pid to be a number, got %T", parsed["pid"])
-	}
-}
-
-func TestLeaderLockInfoJSONOmitEmpty(t *testing.T) {
-	info := &leader.LeaderLockInfo{
-		Host:      "test-host",
-		API:       "redis://10.0.0.1:6379",
-		HTTP:      "http://10.0.0.1:8180",
-		BaseURL:   "", // Empty - should be omitted
-		Timestamp: 1704067200000,
-		PID:       12345,
-	}
-
-	data, err := json.Marshal(info)
-	if err != nil {
-		t.Fatalf("Failed to marshal: %v", err)
-	}
-
-	// baseUrl should not be present when empty
-	var parsed map[string]interface{}
-	if err := json.Unmarshal(data, &parsed); err != nil {
-		t.Fatalf("Failed to unmarshal: %v", err)
-	}
-
-	if _, exists := parsed["baseUrl"]; exists {
-		t.Error("Expected baseUrl to be omitted when empty")
-	}
-}
-
-func TestLeaderInfoFileFormat(t *testing.T) {
-	// Create a temp directory
-	tmpDir, err := os.MkdirTemp("", "meta-core-test")
-	if err != nil {
-		t.Fatalf("Failed to create temp dir: %v", err)
-	}
-	defer os.RemoveAll(tmpDir)
-
-	info := &leader.LeaderLockInfo{
-		Host:      "test-host",
-		API:       "redis://10.0.0.1:6379",
-		HTTP:      "http://10.0.0.1:8180",
-		Timestamp: 1704067200000,
-		PID:       12345,
-	}
-
-	// Write to file
-	infoPath := filepath.Join(tmpDir, "kv-leader.info")
-	data, err := json.MarshalIndent(info, "", "  ")
-	if err != nil {
-		t.Fatalf("Failed to marshal: %v", err)
-	}
-
-	if err := os.WriteFile(infoPath, data, 0644); err != nil {
-		t.Fatalf("Failed to write file: %v", err)
-	}
-
-	// Read and parse
-	readData, err := os.ReadFile(infoPath)
-	if err != nil {
-		t.Fatalf("Failed to read file: %v", err)
-	}
-
-	var parsed leader.LeaderLockInfo
-	if err := json.Unmarshal(readData, &parsed); err != nil {
-		t.Fatalf("Failed to unmarshal: %v", err)
-	}
-
-	if parsed.Host != info.Host {
-		t.Errorf("Host mismatch: expected '%s', got '%s'", info.Host, parsed.Host)
-	}
-
-	if parsed.API != info.API {
-		t.Errorf("API mismatch: expected '%s', got '%s'", info.API, parsed.API)
-	}
-
-	if parsed.HTTP != info.HTTP {
-		t.Errorf("HTTP mismatch: expected '%s', got '%s'", info.HTTP, parsed.HTTP)
-	}
-
-	if parsed.Timestamp != info.Timestamp {
-		t.Errorf("Timestamp mismatch: expected %d, got %d", info.Timestamp, parsed.Timestamp)
-	}
-
-	if parsed.PID != info.PID {
-		t.Errorf("PID mismatch: expected %d, got %d", info.PID, parsed.PID)
-	}
-}