feat: Zulip v3 resilience contract + restore playbook

- zulip-resilience-v3.prose.md: Production resilience rewrite contract covering circuit breaker, retry with jitter, queue lifecycle management, supervisor watchdog, and PM2 hardening. Research-backed from Zulip event system docs. - abiba-zulip-restore.prose.md: Quick-restore playbook for recovery scenarios.
2026-07-13 21:29:35 +00:00
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+---
+kind: function
+name: abiba-zulip-restore
+description: >
+  Restores Zulip connectivity for Abiba (pi agent). Verifies the v2 router-worker
+  extension code, starts a PM2 process as the Zulip gateway with correct env vars,
+  validates health endpoint, and confirms DM delivery. Run this whenever Abiba
+  stops responding on Zulip or after system restart.
+agent: abiba
+version: 1.0.0
+status: active
+runtime_contract: 2
+---
+
+# Abiba Zulip Restore — Resume pi Zulip Communication
+
+Single-shot function that restores full Zulip connectivity for the Abiba pi agent.
+Covers extension code validation, PM2 process management, health endpoint
+verification, and DM loopback testing.
+
+## Live-State Fields
+
+| Field | Value | Trust |
+|-------|-------|-------|
+| Agent name | abiba | ✅ |
+| Bot email | abiba-bot@chat.sysloggh.net | ✅ |
+| Zulip server | https://chat.sysloggh.net | ✅ |
+| Extension path | /root/.pi/agent/extensions/zulip/index.js | ✅ |
+| Config path | /root/.pi/agent/extensions/zulip/config.yaml | ✅ |
+| Health port | 9200 | ✅ |
+| @all-bots user ID | 20 | ✅ (config, verified by API at runtime) |
+| PM2 process name | abiba-zulip | ✅ |
+| Provider | syslog-harness (http://192.168.68.116/v1) | ✅ |
+| Default model | deepseek-v4-pro | ✅ (settings.json) |
+
+## Architecture
+
+The pi Zulip extension uses a **router-worker architecture** (v2):
+
+- **Router** (PM2 `abiba-zulip`, `ZULIP_ROLE=router`): Polls Zulip for events,
+  maintains a per-sender pool of pi RPC worker processes. Each sender gets
+  their own `pi --mode rpc --session-dir` process with persistent sessions.
+  Handles streaming edits back to Zulip.
+- **Worker** (child `pi --mode rpc`): Runs the agent with per-sender persistent
+  sessions. No Zulip logic in the worker — the router handles all Zulip I/O.
+
+The extension loads in ALL pi sessions (via `settings.json` extensions array)
+but is a **NO-OP** unless `ZULIP_ROLE=router` is set. Only the PM2 router process
+carries the env var.
+
+## Maintains
+
+- extension_valid: bool — Extension code imports without errors
+- pm2_running: bool — PM2 process `abiba-zulip` is online
+- health_responding: bool — GET :9200/health returns "ok"
+- zulip_connected: bool — Queue registered, bot identity resolved
+- loopback_delivered: bool — Test DM sent and received
+- model_valid: bool — Configured models match LiteLLM authorized models
+
+### Postconditions
+
+- PM2 process `abiba-zulip` online and stable (uptime > 30s)
+- Health endpoint returns `{ status: "ok", connected: true }`
+- Worker pool creates sessions on demand
+- Echo prevention active (BOT_EMAILS includes all known bots)
+- PM2 saved for auto-restart on boot
+
+## Requires
+
+- Node.js with `yaml` module available
+- PM2 installed globally
+- Zulip API key in `config.yaml`
+- `pi` CLI available on PATH
+- Zulip server accessible at https://chat.sysloggh.net
+- LiteLLM provider accessible at http://192.168.68.116/v1
+
+## Execution
+
+### Step 1: Validate Extension Code
+
+```bash
+node -e "import('file:///root/.pi/agent/extensions/zulip/index.js').then(() => console.log('OK')).catch(e => {console.error('FAIL:', e.message); process.exit(1)})"
+```
+
+Expected: `OK`. If FAIL → check for missing dependencies, syntax errors.
+
+### Step 2: Validate Model IDs
+
+Compare configured models against LiteLLM authorized models:
+
+```bash
+API_KEY=$(grep -oP 'apiKey:\s*\K.*' /root/.pi/agent/models.json | head -1)
+curl -s -H "Authorization: Bearer $API_KEY" http://192.168.68.116/v1/models | \
+  python3 -c "import json,sys; d=json.load(sys.stdin); [print(m['id']) for m in d.get('data',[])]" 2>/dev/null
+```
+
+Check: Every model ID in `models.json` must appear in the authorized list.
+If not → fix `models.json` to only include authorized models (prefer `syslog-auto`).
+
+### Step 3: Verify Config Integrity
+
+```bash
+python3 -c "
+import yaml, sys
+with open('/root/.pi/agent/extensions/zulip/config.yaml') as f:
+    cfg = yaml.safe_load(f)
+required = ['zulip.site', 'zulip.email', 'zulip.api_key', 'agent.name']
+for k in required:
+    keys = k.split('.')
+    v = cfg
+    for kk in keys:
+        v = v.get(kk)
+        if v is None:
+            print(f'MISSING: {k}')
+            sys.exit(1)
+print('Config valid')
+print(f'  site={cfg[\"zulip\"][\"site\"]}')
+print(f'  email={cfg[\"zulip\"][\"email\"]}')
+print(f'  agent={cfg[\"agent\"][\"name\"]}')
+print(f'  health_port={cfg.get(\"health_port\", 9200)}')
+"
+```
+
+Expected: Config valid with all fields non-empty.
+
+### Step 4: Remove Stale Systemd Service
+
+The old `abiba-zulip.service` points to `/opt/abiba-zulip/dist/index.js` (compiled
+TypeScript, not the v2 extension). It's disabled and stale. Remove it:
+
+```bash
+systemctl stop abiba-zulip 2>/dev/null || true
+systemctl disable abiba-zulip 2>/dev/null || true
+rm -f /etc/systemd/system/abiba-zulip.service
+systemctl daemon-reload
+```
+
+### Step 5: Start PM2 Process
+
+**Critical:** The extension MUST run via `pi --mode rpc`, NOT `node index.js` directly.
+The extension exports a function that requires pi's session lifecycle. Running
+`node index.js` loads the module but never calls the export, so nothing happens.
+`pi --mode rpc` loads all extensions (including Zulip) and fires `session_start`.
+
+```bash
+# Stop existing if any
+pm2 delete abiba-zulip 2>/dev/null || true
+
+# Start pi in RPC mode with ZULIP_ROLE=router env
+ZULIP_ROLE=router pm2 start "$(which pi)" \
+  --name abiba-zulip \
+  --interpreter none \
+  -- --mode rpc --no-session
+```
+
+Wait 10 seconds for pi to load all extensions, fire session_start, and the Zulip
+router to register its event queue.
+
+### Step 6: Validate PM2 Process
+
+```bash
+pm2 show abiba-zulip --no-color
+```
+
+Check: `status=online`, `restarts=0`, `uptime > 5s`.
+
+### Step 7: Check Logs for Connection
+
+```bash
+sleep 3
+tail -20 /root/.pm2/logs/abiba-zulip-out.log
+```
+
+Look for:
+- `[zulip-ext] Connecting to https://chat.sysloggh.net as abiba-bot@chat.sysloggh.net…`
+- `[zulip-ext] Bot user_id=N, all-bots user_id=N`
+- `[zulip-ext] Connected, queue=N`
+- `[zulip-ext] Echo prevention: N bot emails`
+- `[zulip-ext] Health endpoint on :9200`
+
+If error → check API key, network to chat.sysloggh.net.
+
+### Step 8: Health Endpoint
+
+```bash
+curl -s http://localhost:9200/health | python3 -m json.tool
+```
+
+Check:
+- `status: "ok"` (not "down")
+- `zulip.connected: true`
+- `zulip.queue_id` is non-null string
+- `zulip.bot_user_id` is positive integer
+
+### Step 9: DM Loopback Test
+
+```bash
+curl -s http://localhost:9200/health | python3 -c "
+import json,sys
+d = json.load(sys.stdin)
+if d.get('zulip',{}).get('connected'):
+    print(f'✅ Zulip connected. Queue: {d[\"zulip\"][\"queue_id\"]}')
+    print(f'   Bot user_id: {d[\"zulip\"][\"bot_user_id\"]}')
+    print(f'   Messages processed: {d[\"zulip\"][\"messages_processed\"]}')
+else:
+    print('❌ Zulip NOT connected')
+    sys.exit(1)
+"
+```
+
+### Step 10: Save PM2 for Auto-Start
+
+```bash
+pm2 save
+pm2 startup systemd -u root --hp /root 2>/dev/null || true
+```
+
+### Step 11: Report
+
+Compile results:
+
+| Check | Pass? |
+|-------|-------|
+| Extension code imports | extension_valid |
+| Model IDs authorized | model_valid |
+| Config integrity | config_valid |
+| PM2 process online | pm2_running |
+| Health endpoint | health_responding |
+| Zulip connected | zulip_connected |
+
+All pass → ✅ **Abiba Zulip restored.** Relay success to user.
+
+Partial failure → see recovery matrix below.
+
+## Recovery Matrix
+
+| Failure | Recovery |
+|---------|----------|
+| Extension import fails | Check `node_modules/zulip-js` exists; run `npm install` in extension dir |
+| Model ID mismatch | Fix `models.json` to use `syslog-auto` as default model; remove invalid IDs |
+| Config missing | Restore from backup or recreate from scratch |
+| PM2 won't start | Check `node` version (>=18); check port 9200 not in use |
+| Health "down" | Check logs for connection errors; verify Zulip API key; check network |
+| "address already in use" | Kill old process: `fuser -k 9200/tcp` |
+| Queue registration fails | Check Zulip API key validity; verify bot is active in Zulip admin |
+| Rate limit (429) | Extension has built-in retry-after handling — wait, don't restart |
+
+## Known Failure Modes
+
+| Symptom | Root Cause | Recovery |
+|---------|-----------|----------|
+| Extension loads but no events | `ZULIP_ROLE` not set | Ensure PM2 env has `ZULIP_ROLE=router` |
+| Worker stays "busy" forever | Model ID not authorized by LiteLLM | Fix models.json (lesson #11) |
+| Placeholder sent but no response | editMessage API fails silently | Extension has fallback (sends new msg); check Zulip API |
+| Queue expires rapidly | Poll interval too aggressive | v2 uses 3s poll with long-poll — should be fine |
+| Bot doesn't respond to @mentions | Not subscribed to stream | Bot auto-subscribes via API |
+| Stale error in health | `last_error` not cleared | v2 clears on successful poll (lesson #4) |
+
+## Appendix: Root Cause & Fix Summary (2026-07-13)
+
+**Problem:** Zulip extension was offline — no PM2 process running.
+
+**Root cause:** The PM2 command ran `node index.js` directly (which loads the
+extension module but never calls the exported function). The extension requires
+pi's session lifecycle — pi loads extensions, fires `session_start`, and the
+Zulip extension hooks into that event.
+
+**Fix:** Run `pi --mode rpc` (not `node index.js`). The `--mode rpc` flag keeps
+pi alive listening for RPC commands on stdin while the Zulip extension's router
+runs in the background via the `session_start` hook.
+
+```bash
+ZULIP_ROLE=router pm2 start "$(which pi)" --name abiba-zulip \
+  --interpreter none -- --mode rpc --no-session
+```
+
+**Additional fixes applied:**
+- Fixed `models.json`: replaced `qwen3.6-35B-A3B` (not authorized by LiteLLM)
+  with `syslog-auto` + `ornith-1.0-35b` (prevents silent worker failure per
+  Lesson #11)
+- Removed stale systemd unit `abiba-zulip.service` (pointed to old TS code)
+- PM2 saved for auto-restart on boot
+
+## Appendix: PM2 Ecosystem Config (Optional)
+
+If preferred over manual `pm2 start`, create `/root/ecosystem.config.js` entry:
+
+```js
+module.exports = {
+  apps: [{
+    name: 'abiba-zulip',
+    script: '/bin/pi',
+    interpreter: 'none',
+    args: '--mode rpc --no-session',
+    cwd: '/root',
+    env: {
+      ZULIP_ROLE: 'router',
+    },
+    log_file: '/root/.pm2/logs/abiba-zulip-out.log',
+    error_file: '/root/.pm2/logs/abiba-zulip-error.log',
+    max_restarts: 20,
+    restart_delay: 5000,
+  }]
+};
+```
+
+---
+
+**Last verified good state**: 2026-07-13 — Extension v2 running via `pi --mode rpc`, health endpoint :9200 returning `{status:"ok",connected:true}`, queue a669f21e.
@@ -0,0 +1,411 @@
+---
+kind: responsibility
+name: zulip-resilience-v3
+description: >
+  Rewrite the pi Zulip gateway with production-grade resilience patterns drawn from
+  Zulip's own event system docs (queue lifecycle, heartbeat monitoring, BAD_EVENT_QUEUE_ID
+  handling, idle_queue_timeout) and battle-tested Node.js resilience patterns
+  (circuit breaker, exponential backoff with jitter, bulkhead isolation, supervisor watchdog).
+replaces: zulip-self-heal (retired)
+agent: abiba
+triggers:
+  - "/zulip self-heal v3"
+  - "zulip stopped responding"
+  - "PM2 abiba-zulip crashed"
+---
+
+# Zulip Gateway v3 — Production Resilience
+
+## Architecture Overview
+
+The current v2 gateway (`/root/.pi/agent/extensions/zulip/index.js`) has three structural
+weaknesses that cause repeated deaths:
+
+1. **No crash recovery** — uncaught errors kill the Node process, PM2 exhausts max_restarts
+2. **No circuit breaker** — 502/fetch-failed errors escalate to process death with no fallback
+3. **No queue lifecycle management** — doesn't use Zulip's documented heartbeat protocol or
+   idle_queue_timeout, so BAD_EVENT_QUEUE_ID errors cascade into crashes
+
+The v3 rewrite addresses all three, following patterns from:
+
+- [Zulip Events System docs](https://zulip.readthedocs.io/en/11.6/subsystems/events-system.html) —
+  queue registration, heartbeat, BAD_EVENT_QUEUE_ID recovery, call_on_each_event loop
+- [Zulip API: Get Events](https://zulip.com/api/get-events) — long-poll timeout, dont_block, event ack
+- [Circuit Breaker & Retry Patterns in Node.js 2026](https://1xapi.com/blog/resilient-api-circuit-breaker-bulkhead-retry-nodejs-2026) —
+  Opossum-based circuit breaker with fallback, retry with jitter, bulkhead isolation
+
+---
+
+## Maintains
+
+- `zulip-gateway`: { status: "healthy" | "degraded" | "down" }
+- `circuit-breaker`: { state: "CLOSED" | "OPEN" | "HALF_OPEN", failures, successes }
+- `queue-lifecycle`: { queue_id, last_event_id, idle_timeout, heartbeat_age }
+- `workers`: { count, busy, idle, stuck }
+- `supervisor`: { pid, last_check, health_failures }
+
+---
+
+## Detection Rules
+
+### Rule 1: Queue Expired (BAD_EVENT_QUEUE_ID)
+- **Detect**: Events API returns error with BAD_EVENT_QUEUE_ID in body
+- **Fix**: Call `POST /register` to create new queue, update queue_id and last_event_id
+- **Debounce**: If 3 re-registrations fail within 60s, escalate (server may be down)
+- **Ref**: Zulip docs: "Your software will need to handle that error condition by re-initializing itself"
+
+### Rule 2: Network Degradation (502/ECONNREFUSED/fetch failed)
+- **Detect**: Events API returns 502 or network error
+- **Circuit breaker**: Track failure rate over 10s rolling window
+  - CLOSED → OPEN: 50% failure rate with ≥5 requests
+  - OPEN → HALF_OPEN: After 30s reset timeout
+  - HALF_OPEN → CLOSED: Probe succeeds
+  - HALF_OPEN → OPEN: Probe fails
+- **While OPEN**: Log errors, skip events, notify user via DM: "⚠️ Zulip connection degraded — will retry in 30s"
+
+### Rule 3: Long-Poll Timeout (natural)
+- **Detect**: Events API response takes > `event_queue_longpoll_timeout_seconds`
+- **Not an error**: Server sends heartbeat events when no real events. Simply re-poll.
+
+### Rule 4: Worker Busy Timeout (>5 min)
+- **Detect**: Worker `busySince` exceeds 5 minutes
+- **Fix**: SIGKILL worker, send error DM, clean up pending replies
+
+### Rule 5: Process Crash (uncaught)
+- **Detect**: `uncaughtException` / `unhandledRejection` fires
+- **Fix**: Log → clear poll timer → attempt reconnect with backoff → if reconnect fails 3x, exit(1) and let PM2 restart
+
+### Rule 6: Supervisor Detects Router Stall
+- **Detect**: External supervisor (`zulip-watchdog`) polls `/health` every 30s. If 3 consecutive failures:
+- **Fix**: `pm2 restart abiba-zulip` gracefully (SIGTERM, drain workers, restart)
+
+---
+
+## Implementation Plan
+
+### Phase 1: Rewrite Router Core (circuit-breaker + queue lifecycle)
+
+Replace the poll loop in index.js with a resilience-first event loop:
+
+```js
+// Queue lifecycle (Zulip docs pattern)
+async function createOrRefreshQueue() {
+  // POST /register with event_types=["message"]
+  // Store: queueId, lastEventId, eventQueueLongpollTimeoutSeconds
+  // NEW: pass idle_queue_timeout parameter (Zulip 12.0+)
+}
+
+// Circuit breaker (Opossum pattern, implemented inline to avoid dependency)
+class ZulipCircuitBreaker {
+  constructor({ failureThreshold=0.5, resetTimeout=30000, volumeThreshold=5, windowMs=10000 }) {
+    this.state = "CLOSED"; // CLOSED | OPEN | HALF_OPEN
+    this.failures = 0;
+    this.successes = 0;
+    this.totalRequests = 0;
+    this.lastFailureTime = null;
+    this.openedAt = null;
+    this.failureThreshold = failureThreshold;
+    this.resetTimeout = resetTimeout;
+    this.volumeThreshold = volumeThreshold;
+    this.windowMs = windowMs;
+  }
+
+  async fire(fn) {
+    if (this.state === "OPEN") {
+      if (Date.now() - this.openedAt > this.resetTimeout) {
+        this.state = "HALF_OPEN";
+      } else {
+        throw new CircuitOpenError("Circuit is OPEN");
+      }
+    }
+    try {
+      const result = await fn();
+      this.onSuccess();
+      return result;
+    } catch (err) {
+      this.onFailure();
+      throw err;
+    }
+  }
+
+  onSuccess() {
+    this.successes++;
+    this.totalRequests++;
+    if (this.state === "HALF_OPEN") {
+      this.state = "CLOSED";
+      this.failures = 0;
+    }
+    // Reset counters periodically
+    if (this.totalRequests > this.volumeThreshold * 2) {
+      this.failures = Math.floor(this.failures / 2);
+      this.successes = Math.floor(this.successes / 2);
+      this.totalRequests = Math.floor(this.totalRequests / 2);
+    }
+  }
+
+  onFailure() {
+    this.failures++;
+    this.totalRequests++;
+    this.lastFailureTime = Date.now();
+    if (this.totalRequests >= this.volumeThreshold &&
+        this.failures / this.totalRequests >= this.failureThreshold) {
+      if (this.state !== "OPEN") {
+        this.state = "OPEN";
+        this.openedAt = Date.now();
+        console.error(`[zulip-ext] CIRCUIT BREAKER OPEN — ${this.failures}/${this.totalRequests} failures`);
+      }
+    }
+  }
+}
+
+// Retry with exponential backoff + jitter (from resilience patterns)
+async function withRetry(fn, { maxAttempts=3, baseDelay=200, maxDelay=10000, shouldRetry=()=>true }={}) {
+  let lastError;
+  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
+    try {
+      return await fn();
+    } catch (err) {
+      lastError = err;
+      if (attempt === maxAttempts || !shouldRetry(err)) throw err;
+      const delay = Math.min(baseDelay * Math.pow(2, attempt - 1), maxDelay);
+      const jitter = delay * (0.5 + Math.random() * 0.5); // 50-100% of delay
+      console.warn(`[zulip-ext] Retry ${attempt}/${maxAttempts} after ${Math.round(jitter)}ms: ${err.message.slice(0,80)}`);
+      await new Promise(r => setTimeout(r, jitter));
+    }
+  }
+  throw lastError;
+}
+
+// Resilience-first event loop (Zulip call_on_each_event pattern)
+async function resilientPollLoop() {
+  while (connected) {
+    try {
+      const events = await circuitBreaker.fire(() =>
+        withRetry(() => zulipQueue.poll(), {
+          maxAttempts: 2,
+          baseDelay: 1000,
+          shouldRetry: (err) => {
+            const msg = err.message || "";
+            return msg.includes("fetch failed") || msg.includes("ECONN") || msg.includes("network");
+          }
+        })
+      );
+
+      lastError = null;
+      retryCount = 0;
+
+      for (const ev of events) {
+        await processEvent(ev);
+      }
+
+      heartbeat();
+    } catch (err) {
+      const msg = err instanceof Error ? err.message : String(err);
+
+      if (msg.includes("BAD_EVENT_QUEUE_ID") || msg.includes("deregistered")) {
+        // Queue expired — re-register (Zulip docs pattern)
+        console.log(`[zulip-ext] Queue expired, re-registering… (${msg.slice(0,80)})`);
+        try {
+          zulipQueue = await createZulipQueue();
+          console.log(`[zulip-ext] Re-registered, new queue=${zulipQueue.queueId}`);
+        } catch (reRegErr) {
+          console.error(`[zulip-ext] Re-registration failed: ${reRegErr.message}`);
+          connected = false;
+          retryCount++;
+          const backoff = Math.min(5000 * Math.pow(2, retryCount), 300000);
+          console.log(`[zulip-ext] Full reconnect in ${Math.round(backoff/1000)}s`);
+          await new Promise(r => setTimeout(r, backoff));
+          await startPolling();
+          return;
+        }
+      } else if (err.name === "CircuitOpenError") {
+        // Circuit is open — skip this cycle, wait for HALF_OPEN
+        lastError = "circuit_open";
+        await new Promise(r => setTimeout(r, POLL_INTERVAL_MS));
+      } else {
+        lastError = msg;
+        retryCount++;
+        const backoff = Math.min(POLL_INTERVAL_MS * Math.pow(1.5, Math.min(retryCount, 8)), 60000);
+        console.error(`[zulip-ext] Poll error (retry ${retryCount}, backoff ${backoff}ms): ${msg}`);
+        await new Promise(r => setTimeout(r, backoff));
+      }
+    }
+  }
+}
+```
+
+### Phase 2: PM2 Hardening
+
+Create `/root/.pm2/ecosystem.config.cjs`:
+
+```js
+module.exports = {
+  apps: [
+    {
+      name: "abiba-zulip",
+      script: "/bin/pi",
+      args: "--mode rpc --session-id zulip-service",
+      env: {
+        ZULIP_ROLE: "router",
+        ZULIP_SITE: "https://chat.sysloggh.net",
+        ZULIP_EMAIL: "abiba-bot@chat.sysloggh.net",
+        ZULIP_API_KEY: process.env.ZULIP_API_KEY,
+        AGENT_NAME: "abiba",
+        AGENT_OWNER_EMAIL: "jerome@sysloggh.com",
+      },
+      max_restarts: 100,            // Up from default 10 — crash loops won't exhaust
+      min_uptime: "10s",            // Must survive 10s to count as "alive"
+      max_memory_restart: "500M",   // OOM protection
+      restart_delay: 5000,          // 5s between restarts
+      kill_timeout: 15000,          // 15s SIGTERM grace before SIGKILL
+      listen_timeout: 30000,        // 30s to bind health port
+      log_date_format: "YYYY-MM-DD HH:mm:ss Z",
+      error_file: "/root/.pm2/logs/abiba-zulip-error.log",
+      out_file: "/root/.pm2/logs/abiba-zulip-out.log",
+      merge_logs: true,
+      autorestart: true,
+      watch: false,
+      instances: 1,
+      exec_mode: "fork",
+    },
+    {
+      name: "zulip-watchdog",
+      script: "/root/.pi/agent/extensions/zulip/watchdog.js",
+      max_restarts: 10,
+      min_uptime: "3s",
+      restart_delay: 3000,
+      autorestart: true,
+    },
+  ],
+};
+```
+
+### Phase 3: Supervisor Watchdog
+
+Create `/root/.pi/agent/extensions/zulip/watchdog.js`:
+
+```js
+// External supervisor — monitors router health and restarts if stalled.
+// This is the pattern Hermes uses: an external process that can recover
+// the gateway even if the gateway process itself is hung (not just crashed).
+
+const HEALTH_URL = "http://127.0.0.1:9200/health";
+const CHECK_INTERVAL_MS = 30_000;
+const MAX_FAILURES = 3;
+
+let failures = 0;
+
+async function check() {
+  try {
+    const res = await fetch(HEALTH_URL, { signal: AbortSignal.timeout(5000) });
+    if (res.ok) {
+      const data = await res.json();
+      if (data.status === "ok" && data.zulip?.connected) {
+        if (failures > 0) {
+          console.log(`[watchdog] Router recovered after ${failures} failures`);
+        }
+        failures = 0;
+        return;
+      }
+    }
+    failures++;
+    console.warn(`[watchdog] Health check ${failures}/${MAX_FAILURES}: status not ok`);
+  } catch (err) {
+    failures++;
+    console.warn(`[watchdog] Health check ${failures}/${MAX_FAILURES}: ${err.message}`);
+  }
+
+  if (failures >= MAX_FAILURES) {
+    console.error(`[watchdog] ${MAX_FAILURES} consecutive failures — restarting abiba-zulip`);
+    const { execSync } = require("child_process");
+    try {
+      execSync("pm2 restart abiba-zulip", { timeout: 30000 });
+      console.log("[watchdog] Restart command sent");
+    } catch (e) {
+      console.error(`[watchdog] Restart failed: ${e.message}`);
+    }
+    failures = 0;
+    // Wait for restart to complete before checking again
+    await new Promise(r => setTimeout(r, 15000));
+  }
+}
+
+console.log("[watchdog] Zulip gateway supervisor started");
+setInterval(check, CHECK_INTERVAL_MS);
+check(); // Immediate first check
+```
+
+### Phase 4: Health Endpoint Enhancement
+
+Add circuit breaker stats to the existing health endpoint:
+
+```js
+// In /health response, add:
+"circuit_breaker": {
+  "state": circuitBreaker.state,
+  "failures": circuitBreaker.failures,
+  "successes": circuitBreaker.successes,
+  "total_requests": circuitBreaker.totalRequests,
+  "failure_rate": circuitBreaker.totalRequests > 0
+    ? (circuitBreaker.failures / circuitBreaker.totalRequests).toFixed(2)
+    : "0.00"
+}
+```
+
+---
+
+## Test Plan
+
+### Test 1: Queue Re-registration
+1. Manually delete the Zulip event queue via API
+2. Next poll should detect BAD_EVENT_QUEUE_ID
+3. Router should auto re-register within 1 poll cycle
+4. Verify: `/health` shows new queue_id, connected=true
+
+### Test 2: Circuit Breaker Trip
+1. Block Zulip server with iptables: `iptables -A OUTPUT -d 192.168.68.19 -j DROP`
+2. Router should detect failures, trip circuit after 5 failures
+3. `/health` should show circuit_breaker.state = "OPEN"
+4. Remove iptables rule
+5. Circuit should transition to HALF_OPEN → CLOSED within 60s
+6. Verify: messages processed after recovery
+
+### Test 3: Supervisor Recovery
+1. Kill the router process: `kill -STOP $(pm2 pid abiba-zulip)` (freeze, don't kill)
+2. Watchdog should detect 3 failed health checks in 90s
+3. Watchdog should execute `pm2 restart abiba-zulip`
+4. Verify: router back online, connected=true
+
+### Test 4: Worker Busy Timeout
+1. Send a message that triggers a long-running operation
+2. If worker stays busy >5 minutes, should receive SIGKILL
+3. User should receive error DM: "Response timed out"
+
+### Test 5: End-to-End Message
+1. Send DM "What time is it?" from Jerome
+2. Should receive response within 30s
+3. `/health` should show messages_processed incremented
+
+---
+
+## Rollback Plan
+
+If v3 causes issues:
+1. `pm2 delete abiba-zulip; pm2 delete zulip-watchdog`
+2. Restore v2 from git: `cd /root/.pi/agent/extensions/zulip && git checkout index.js`
+3. `pm2 resurrect` to reload previous process list
+4. Verify: `/health` returns ok
+
+Backup v2 before starting: `cp index.js index.js.v2-backup-$(date +%Y%m%d-%H%M%S)`
+
+---
+
+## Success Metrics
+
+| Metric | Current (v2) | Target (v3) |
+|--------|-------------|-------------|
+| Uptime between manual interventions | 1-3 days | 30+ days |
+| Crash recovery | Manual (PM2 resurrect) | Automatic (circuit breaker + supervisor) |
+| Queue expiry handling | Crash | Auto re-register |
+| Busy worker deadlock | Router death | Worker SIGKILL + error DM |
+| PM2 restart exhaustion | Yes (max_restarts=10) | No (max_restarts=100 + watchdog) |