adaptation related to meta-core api changes

packages/meta-fuse-core/src/index.ts

@@ -11,6 +11,7 @@ import 'dotenv/config';
 import { Logger } from 'tslog';
 import { KVManager } from './kv/KVManager.js';
 import { RedisClient, StreamMessage } from './kv/RedisClient.js';
+import { SSEEventClient, type SSEEvent } from './kv/SSEEventClient.js';
 import { VirtualFileSystem } from './vfs/VirtualFileSystem.js';
 import { StreamingStateBuilder } from './vfs/StreamingStateBuilder.js';
 import { APIServer } from './api/APIServer.js';
@@ -76,13 +77,16 @@ async function main(): Promise<void> {
     let vfs: VirtualFileSystem | null = null;
     let stateBuilder: StreamingStateBuilder | null = null;
     let apiServer: APIServer | null = null;
+    let sseClient: SSEEventClient | null = null;
 
     // Graceful shutdown
     const shutdown = async (signal: string): Promise<void> => {
         logger.info(`Received ${signal}, shutting down...`);
 
         try {
-            // Stop stream consumer first
+            // Stop SSE consumer first
+            if (sseClient) await sseClient.stop();
+            // Stop legacy stream consumer if it ever ran
             if (redisClient) {
                 redisClient.stopStreamConsumer();
             }
@@ -155,35 +159,52 @@ async function main(): Promise<void> {
             // This enables vfs.refresh() to replay the event stream
             vfs.setStreamingStateBuilder(stateBuilder);
 
-            // Bootstrap: Replay meta:events stream from position 0
-            // This rebuilds state from all historical events
-            logger.info(`Replaying ${EVENTS_STREAM} stream from position 0 (streaming bootstrap)...`);
-            const bootstrapStart = Date.now();
-
-            const lastId = await redisClient.replayStream(
-                EVENTS_STREAM,
-                '0',
-                async (message: StreamMessage) => {
+            // Bootstrap + live stream via SSE on /api/events/meta.
+            //
+            // We persist the cursor; on a clean restart we resume from where
+            // we left off. On a `gap` event (cursor trimmed out of retention)
+            // we fall back to replaying from the oldest available entry,
+            // which is good enough to rebuild VFS state because every property
+            // change has been republished into the stream by meta-core.
+            const apiUrl = leaderInfo?.apiUrl;
+            if (!apiUrl) {
+                throw new Error('meta-core apiUrl not available from leader info; cannot start SSE consumer');
+            }
+            logger.info(`Starting SSE consumer for /api/events/meta (apiUrl=${apiUrl})...`);
+            sseClient = new SSEEventClient({
+                url: `${apiUrl.replace(/\/+$/, '')}/api/events/meta`,
+                // Deliberately NOT persisting the cursor. meta-fuse holds
+                // VFS state purely in memory, so each restart needs to
+                // rebuild from a full event replay. Setting cursorPath to
+                // null + initialCursor to "0-0" forces the gap-handling
+                // path which resumes from the oldest available stream
+                // entry — i.e. effectively a full bootstrap.
+                cursorPath: null,
+                logTag: '[meta-fuse SSE]',
+                initialCursor: '0-0',
+                onEvent: async (e: SSEEvent) => {
+                    // Translate SSE event back into the StreamMessage shape
+                    // StreamingStateBuilder expects.
+                    const message: StreamMessage = {
+                        id: e.id,
+                        type: e.event as any,
+                        key: e.data?.key,
+                        path: e.data?.path,
+                        size: e.data?.size,
+                        midhash256: e.data?.midhash256,
+                        oldPath: e.data?.oldPath,
+                        watcherId: e.data?.watcherId,
+                        timestamp: e.data?.timestamp ?? e.data?.ts,
+                    } as StreamMessage;
                     await handleStreamingEvent(message, stateBuilder!);
                 },
-                100 // Batch size
-            );
-
-            const bootstrapTime = Date.now() - bootstrapStart;
-            const stats = vfs.getStats();
-            logger.info(`Streaming bootstrap complete: ${stats.fileCount} files in ${bootstrapTime}ms`);
-
-            // Start live stream consumer from where replay left off
-            logger.info(`Starting live stream consumer from ${lastId}...`);
-            redisClient.startSimpleStreamConsumer(
-                EVENTS_STREAM,
-                lastId,
-                async (message: StreamMessage) => {
-                    await handleStreamingEvent(message, stateBuilder!);
+                onGap: (payload) => {
+                    logger.warn(`SSE cursor ${payload.requested} trimmed; resuming from ${payload.resumeFrom}`);
                 },
-                5000 // 5 second block timeout
-            ).catch(error => {
-                logger.error('Stream consumer error:', error);
+            });
+            // Fire-and-forget; start() returns when stop() fires.
+            sseClient.start().catch((error) => {
+                logger.error('SSE consumer terminated:', error);
             });
 
             // Initialize API server (with kvManager for service discovery)

packages/meta-fuse-core/src/kv/KVManager.ts

@@ -113,7 +113,7 @@ export class KVManager {
         try {
             const leaderInfo = await this.leaderClient.waitForLeader(30000);
             logger.info(`Connecting to Redis at ${leaderInfo.redisUrl}...`);
-            await this.connectToRedis(leaderInfo.redisUrl);
+            await this.connectToRedis(leaderInfo.redisUrl, leaderInfo.apiUrl);
         } catch (error: any) {
             logger.error(`Failed to connect to leader: ${error.message}`);
             throw error;
@@ -141,7 +141,7 @@ export class KVManager {
         try {
             const leaderInfo = await this.leaderClient.waitForLeader(30000);
             logger.info(`Reconnecting to Redis at ${leaderInfo.redisUrl}...`);
-            await this.connectToRedis(leaderInfo.redisUrl);
+            await this.connectToRedis(leaderInfo.redisUrl, leaderInfo.apiUrl);
         } catch (error: any) {
             logger.error(`Failed to reconnect: ${error.message}`);
         }
@@ -178,20 +178,28 @@ export class KVManager {
     /**
      * Connect to Redis
      */
-    private async connectToRedis(url: string): Promise<void> {
+    private async connectToRedis(url: string, apiUrl?: string): Promise<void> {
         try {
             // Disconnect existing client if any
             await this.disconnectRedis();
 
-            // Create new client
+            // Create new client. When apiUrl is supplied, reads route
+            // through meta-core HTTP (api-mediated-access PR C).
+            // When url is also empty, the client is HTTP-only and never
+            // opens a Redis socket (post-PR D state).
             this.redisClient = new RedisClient({
-                url,
+                url,  // may be '' in PR D world
                 prefix: this.config.redisPrefix,
-                filesVolume: this.config.filesPath
+                filesVolume: this.config.filesPath,
+                metaCoreApiUrl: apiUrl,
             });
 
             await this.redisClient.connect();
-            logger.info('Connected to Redis');
+            if (url) {
+                logger.info('Connected to Redis');
+            } else {
+                logger.info('Storage client ready (HTTP-only mode, no Redis)');
+            }
 
             // Notify ready
             this.notifyReady();

packages/meta-fuse-core/src/kv/MetaCoreApiClient.ts

@@ -0,0 +1,121 @@
+/**
+ * MetaCoreApiClient — HTTP read client against meta-core for meta-fuse.
+ *
+ * meta-fuse needs to read file metadata (property GETs, full-record fetch,
+ * hashId enumeration) as it builds the VFS. After the api-mediated-access
+ * lockdown lands these go through meta-core's /meta/{hash} family instead
+ * of direct Redis reads.
+ *
+ * Only the methods meta-fuse actually calls are implemented. See
+ * meta-core docs/api-mediated-access.md for the full surface.
+ */
+
+export interface MetaCoreApiClientConfig {
+    apiUrl: string;
+    timeoutMs?: number;
+}
+
+export class MetaCoreApiClient {
+    private apiUrl: string;
+    private timeoutMs: number;
+
+    constructor(config: MetaCoreApiClientConfig) {
+        this.apiUrl = config.apiUrl.replace(/\/+$/, '');
+        this.timeoutMs = config.timeoutMs ?? 30000;
+    }
+
+    /**
+     * GET /meta/{hash}/{prop}. Returns the raw string value or null on 404.
+     * meta-core sends text/plain for property reads.
+     */
+    async getProperty(hashId: string, property: string): Promise<string | null> {
+        const path = `/meta/${encodeURIComponent(hashId)}/${this.encodePropertyPath(property)}`;
+        const url = `${this.apiUrl}${path}`;
+        const response = await fetch(url, {
+            method: 'GET',
+            signal: AbortSignal.timeout(this.timeoutMs),
+            headers: { Accept: 'text/plain' },
+        });
+        if (response.status === 404) return null;
+        if (!response.ok) {
+            throw new Error(`[MetaCoreApiClient] GET ${path} → ${response.status} ${response.statusText}`);
+        }
+        const text = await response.text();
+        return text === '' ? null : text;
+    }
+
+    /**
+     * GET /meta/{hash}. Returns the flat property map or null on 404.
+     */
+    async getMetadataFlat(hashId: string): Promise<Record<string, string> | null> {
+        const path = `/meta/${encodeURIComponent(hashId)}`;
+        const body = await this.fetchJsonAllowing404('GET', path);
+        if (body === null) return null;
+        const flat = (body as any)?.metadata;
+        if (!flat || typeof flat !== 'object') return null;
+        return flat as Record<string, string>;
+    }
+
+    /**
+     * GET /meta. Enumerates every known hashId.
+     */
+    async getAllHashIds(): Promise<string[]> {
+        const body = await this.fetchJson('GET', '/meta');
+        const ids = (body as any)?.hashIds;
+        return Array.isArray(ids) ? ids : [];
+    }
+
+    /**
+     * GET /health on meta-core. Used as the connectivity probe.
+     */
+    async health(): Promise<boolean> {
+        try {
+            const response = await fetch(`${this.apiUrl}/health`, {
+                method: 'GET',
+                signal: AbortSignal.timeout(Math.min(this.timeoutMs, 5000)),
+                headers: { Accept: 'application/json' },
+            });
+            return response.ok;
+        } catch {
+            return false;
+        }
+    }
+
+    private encodePropertyPath(property: string): string {
+        return property
+            .split('/')
+            .map(segment => encodeURIComponent(segment))
+            .join('/');
+    }
+
+    private async fetchJson(method: string, path: string): Promise<unknown> {
+        const url = `${this.apiUrl}${path}`;
+        const response = await fetch(url, {
+            method,
+            signal: AbortSignal.timeout(this.timeoutMs),
+            headers: { Accept: 'application/json' },
+        });
+        if (!response.ok) {
+            throw new Error(`[MetaCoreApiClient] ${method} ${path} → ${response.status} ${response.statusText}`);
+        }
+        const text = await response.text();
+        if (!text) return null;
+        try { return JSON.parse(text); } catch { return text; }
+    }
+
+    private async fetchJsonAllowing404(method: string, path: string): Promise<unknown> {
+        const url = `${this.apiUrl}${path}`;
+        const response = await fetch(url, {
+            method,
+            signal: AbortSignal.timeout(this.timeoutMs),
+            headers: { Accept: 'application/json' },
+        });
+        if (response.status === 404) return null;
+        if (!response.ok) {
+            throw new Error(`[MetaCoreApiClient] ${method} ${path} → ${response.status} ${response.statusText}`);
+        }
+        const text = await response.text();
+        if (!text) return null;
+        try { return JSON.parse(text); } catch { return text; }
+    }
+}

packages/meta-fuse-core/src/kv/RedisClient.ts

@@ -12,6 +12,7 @@ import { Redis } from 'ioredis';
 import { Logger } from 'tslog';
 import * as os from 'os';
 import type { IKVClient, KeyValuePair } from './IKVClient.js';
+import { MetaCoreApiClient } from './MetaCoreApiClient.js';
 
 const logger = new Logger({ name: 'RedisClient' });
 
@@ -104,15 +105,27 @@ export interface RedisClientConfig {
     prefix?: string;
     filesVolume?: string;
     reconnectInterval?: number;
+
+    /**
+     * meta-core HTTP API base URL. When set, read methods (getProperty,
+     * getProperties, getMetadataFlat, getAllHashIds, health) route through
+     * the /meta/{hash} HTTP family instead of touching Redis directly.
+     *
+     * This is the meta-fuse half of the api-mediated-access lockdown (see
+     * meta-core docs/api-mediated-access.md). Reads stay on Redis when
+     * left unset so tests / one-off scripts still work.
+     */
+    metaCoreApiUrl?: string;
 }
 
 export class RedisClient implements Partial<IKVClient> {
     private client: Redis | null = null;
     private subscriber: Redis | null = null;
-    private config: Required<RedisClientConfig>;
+    private config: Required<Omit<RedisClientConfig, 'metaCoreApiUrl'>> & Pick<RedisClientConfig, 'metaCoreApiUrl'>;
     private isConnected = false;
     private reconnectTimer: NodeJS.Timeout | null = null;
     private subscriptions: Map<string, (message: string) => void> = new Map();
+    private apiClient: MetaCoreApiClient | null = null;
 
     // Stream consumer state
     private streamConsumerRunning = false;
@@ -125,20 +138,33 @@ export class RedisClient implements Partial<IKVClient> {
             prefix: config.prefix ?? process.env.REDIS_PREFIX ?? '',
             filesVolume: config.filesVolume ?? process.env.FILES_VOLUME ?? '/files',
             reconnectInterval: config.reconnectInterval ?? 5000,
+            metaCoreApiUrl: config.metaCoreApiUrl,
         };
 
+        if (this.config.metaCoreApiUrl) {
+            this.apiClient = new MetaCoreApiClient({ apiUrl: this.config.metaCoreApiUrl });
+            logger.info(`Reads routed through meta-core API at ${this.config.metaCoreApiUrl}`);
+        }
+
         // Unique consumer name for this instance
         this.consumerName = `${os.hostname()}-${process.pid}`;
     }
 
     /**
-     * Connect to Redis
+     * Connect to Redis. In HTTP-only mode (no URL + apiClient set) this is
+     * a no-op — reads route through MetaCoreApiClient and stream
+     * consumption is owned by SSEEventClient at the index.ts layer.
      */
     async connect(): Promise<void> {
         if (this.client && this.isConnected) {
             return;
         }
 
+        if (this.apiClient && !this.config.url) {
+            logger.info('HTTP-only mode — no direct Redis connection');
+            return;
+        }
+
         try {
             this.client = new Redis(this.config.url, {
                 retryStrategy: (times: number) => {
@@ -236,9 +262,18 @@ export class RedisClient implements Partial<IKVClient> {
     }
 
     /**
-     * Check if connected
+     * Check if the metadata backend is reachable.
+     *
+     * In HTTP-only mode (api-mediated-access PR D) there's no Redis socket;
+     * reachability is signalled by having an apiClient configured. The
+     * health badge is keyed off this; reporting `false` there would make
+     * the UI permanently show "Disconnected" even though the service is
+     * working fine over HTTP.
      */
     get connected(): boolean {
+        if (this.apiClient && !this.config.url) {
+            return true;
+        }
         return this.isConnected;
     }
 
@@ -255,6 +290,15 @@ export class RedisClient implements Partial<IKVClient> {
      * @returns The property value or null if not found
      */
     async getProperty(hashId: string, property: string): Promise<string | null> {
+        if (this.apiClient) {
+            try {
+                return await this.apiClient.getProperty(hashId, property);
+            } catch (error: any) {
+                logger.error(`HTTP getProperty failed for ${hashId}/${property}:`, error.message);
+                return null;
+            }
+        }
+
         if (!this.client || !this.isConnected) {
             return null;
         }

packages/meta-fuse-core/src/kv/SSEEventClient.ts

@@ -0,0 +1,229 @@
+/**
+ * SSEEventClient — HTTP Server-Sent Events client for meta-core event streams.
+ *
+ * Replaces direct Redis Streams consumption. See the same-named module in
+ * meta-sort for the design rationale (meta-core docs/api-mediated-access.md).
+ */
+import { promises as fs } from 'fs';
+import { dirname } from 'path';
+
+export interface SSEEvent {
+    id: string;
+    event: string;
+    data: any;
+}
+
+export interface SSEClientOptions {
+    url: string;
+    cursorPath: string | null;
+    onEvent: (e: SSEEvent) => Promise<void> | void;
+    onGap?: (payload: { requested: string; resumeFrom: string; reason: string }) => Promise<void> | void;
+    logTag?: string;
+    reconnectBaseMs?: number;
+    reconnectMaxMs?: number;
+    flushIntervalMs?: number;
+    /** When set, sent as Last-Event-ID on the *first* connect (e.g. to
+     *  force replay from a specific point). After the first event the
+     *  persisted cursor takes over. */
+    initialCursor?: string;
+}
+
+export class SSEEventClient {
+    private readonly opts: Required<Omit<SSEClientOptions, 'onGap' | 'initialCursor'>> & Pick<SSEClientOptions, 'onGap' | 'initialCursor'>;
+    private cursor: string = '';
+    private cursorDirty = false;
+    private abort: AbortController | null = null;
+    private flushTimer: NodeJS.Timeout | null = null;
+    private stopped = false;
+    private backoff = 0;
+    private firstConnect = true;
+
+    constructor(options: SSEClientOptions) {
+        this.opts = {
+            url: options.url,
+            cursorPath: options.cursorPath,
+            onEvent: options.onEvent,
+            onGap: options.onGap,
+            logTag: options.logTag ?? '[SSE]',
+            reconnectBaseMs: options.reconnectBaseMs ?? 500,
+            reconnectMaxMs: options.reconnectMaxMs ?? 30_000,
+            flushIntervalMs: options.flushIntervalMs ?? 2000,
+            initialCursor: options.initialCursor,
+        };
+        this.backoff = this.opts.reconnectBaseMs;
+    }
+
+    async start(): Promise<void> {
+        await this.loadCursor();
+        if (!this.cursor && this.opts.initialCursor) {
+            this.cursor = this.opts.initialCursor;
+        }
+        this.startFlushTimer();
+        await this.runLoop();
+    }
+
+    async stop(): Promise<void> {
+        this.stopped = true;
+        if (this.abort) {
+            this.abort.abort();
+            this.abort = null;
+        }
+        if (this.flushTimer) {
+            clearInterval(this.flushTimer);
+            this.flushTimer = null;
+        }
+        await this.flushCursor();
+    }
+
+    getCursor(): string {
+        return this.cursor;
+    }
+
+    private async loadCursor(): Promise<void> {
+        if (!this.opts.cursorPath) return;
+        try {
+            const data = await fs.readFile(this.opts.cursorPath, 'utf-8');
+            const trimmed = data.trim();
+            if (trimmed) {
+                this.cursor = trimmed;
+                console.log(`${this.opts.logTag} Resuming from cursor ${this.cursor}`);
+            }
+        } catch (err: any) {
+            if (err.code !== 'ENOENT') {
+                console.warn(`${this.opts.logTag} Could not read cursor file ${this.opts.cursorPath}: ${err.message}`);
+            }
+        }
+    }
+
+    private startFlushTimer(): void {
+        this.flushTimer = setInterval(() => {
+            if (this.cursorDirty) {
+                this.flushCursor().catch(err =>
+                    console.warn(`${this.opts.logTag} Cursor flush failed: ${err.message}`)
+                );
+            }
+        }, this.opts.flushIntervalMs);
+    }
+
+    private async flushCursor(): Promise<void> {
+        if (!this.opts.cursorPath || !this.cursorDirty) return;
+        this.cursorDirty = false;
+        try {
+            await fs.mkdir(dirname(this.opts.cursorPath), { recursive: true });
+            await fs.writeFile(this.opts.cursorPath, this.cursor, 'utf-8');
+        } catch (err: any) {
+            this.cursorDirty = true;
+            throw err;
+        }
+    }
+
+    private async runLoop(): Promise<void> {
+        while (!this.stopped) {
+            try {
+                await this.connect();
+                this.backoff = this.opts.reconnectBaseMs;
+            } catch (err: any) {
+                if (this.stopped) return;
+                console.warn(`${this.opts.logTag} Stream error, reconnecting in ${this.backoff}ms: ${err?.message ?? err}`);
+                await this.sleep(this.backoff);
+                this.backoff = Math.min(this.backoff * 2, this.opts.reconnectMaxMs);
+            }
+        }
+    }
+
+    private async connect(): Promise<void> {
+        this.abort = new AbortController();
+        const headers: Record<string, string> = {
+            Accept: 'text/event-stream',
+            'Cache-Control': 'no-cache',
+        };
+        if (this.cursor) {
+            headers['Last-Event-ID'] = this.cursor;
+        }
+        this.firstConnect = false;
+
+        const response = await fetch(this.opts.url, {
+            method: 'GET',
+            headers,
+            signal: this.abort.signal,
+        });
+        if (!response.ok) throw new Error(`HTTP ${response.status} ${response.statusText}`);
+        if (!response.body) throw new Error('Response has no body');
+
+        const reader = response.body.getReader();
+        const decoder = new TextDecoder('utf-8');
+        let buffer = '';
+
+        try {
+            while (!this.stopped) {
+                const { value, done } = await reader.read();
+                if (done) return;
+                buffer += decoder.decode(value, { stream: true });
+                let idx: number;
+                while ((idx = buffer.indexOf('\n\n')) !== -1) {
+                    const rawChunk = buffer.slice(0, idx);
+                    buffer = buffer.slice(idx + 2);
+                    await this.handleChunk(rawChunk);
+                }
+            }
+        } finally {
+            try { reader.releaseLock(); } catch { /* nothing useful */ }
+        }
+    }
+
+    private async handleChunk(chunk: string): Promise<void> {
+        let id = '';
+        let event = '';
+        const dataLines: string[] = [];
+        for (const rawLine of chunk.split('\n')) {
+            if (!rawLine || rawLine.startsWith(':')) continue;
+            const colon = rawLine.indexOf(':');
+            if (colon === -1) continue;
+            const field = rawLine.slice(0, colon);
+            let value = rawLine.slice(colon + 1);
+            if (value.startsWith(' ')) value = value.slice(1);
+            switch (field) {
+                case 'id': id = value; break;
+                case 'event': event = value; break;
+                case 'data': dataLines.push(value); break;
+            }
+        }
+        if (dataLines.length === 0) return;
+
+        let data: any;
+        try {
+            data = JSON.parse(dataLines.join('\n'));
+        } catch (err: any) {
+            console.warn(`${this.opts.logTag} Skipping unparseable event ${id || '(no id)'}: ${err.message}`);
+            return;
+        }
+
+        const ev: SSEEvent = { id, event: event || 'message', data };
+        if (ev.event === 'gap') {
+            if (this.opts.onGap) {
+                await this.opts.onGap(ev.data);
+            } else {
+                console.warn(`${this.opts.logTag} Gap event (cursor ${ev.data?.requested} trimmed): resumed from ${ev.data?.resumeFrom}`);
+            }
+            if (typeof ev.data?.resumeFrom === 'string' && ev.data.resumeFrom) {
+                this.cursor = ev.data.resumeFrom;
+                this.cursorDirty = true;
+            }
+            return;
+        }
+
+        try {
+            await this.opts.onEvent(ev);
+        } catch (err: any) {
+            console.error(`${this.opts.logTag} onEvent handler failed for ${ev.id}: ${err?.stack ?? err}`);
+        }
+        if (ev.id) {
+            this.cursor = ev.id;
+            this.cursorDirty = true;
+        }
+    }
+
+    private sleep(ms: number): Promise<void> {
+        return new Promise(resolve => setTimeout(resolve, ms));
+    }
+}