diff --git a/zulip-mention-reliability.prose.md b/zulip-mention-reliability.prose.md
new file mode 100644
index 0000000..b7c8513
--- /dev/null
+++ b/zulip-mention-reliability.prose.md
@@ -0,0 +1,72 @@
+---
+kind: responsibility
+name: zulip-mention-reliability
+description: >
+  Monitors whether Abiba Bot is correctly detecting and responding to
+  @mentions in Zulip stream topics. Tests periodically, diagnoses
+  failures, and attempts fixes. Same self-improving pattern as
+  litellm-self-heal.
+---
+
+## Maintains
+
+- mention_response_rate: number — % of @mentions that get a response (target: >95%)
+- last_test_result: "pass" | "fail" | "degraded"
+- known_failure_modes: array — History of what went wrong and how it was fixed
+- queue_health: "healthy" | "expired" | "reconnecting"
+
+## Success Criteria
+
+- test_mention_gets_response == true — Send @Abiba Bot test, confirm response within 30s
+- stream_subscription_active == true — Bot is subscribed to #agent-hub and #general chat
+- queue_active == true — PM2's event queue is registered and polling
+- no_echo_loop == true — Bot doesn't respond to its own messages
+- dm_always_works == true — DMs still respond even if streams are broken
+
+## Known Failure Modes (from History)
+
+| Failure | Root Cause | Fix |
+|---|---|---|
+| No stream events | Bot had 0 stream subscriptions | Subscribe via API |
+| No @mention detection | botUserId was null (register endpoint doesn't return it) | Fetch from /api/v1/users/me |
+| No stream events | zulip-js library sends multipart/form-data instead of form-urlencoded | Use URLSearchParams directly |
+| Double responses | Both TUI and PM2 loaded the extension | ZULIP_EXTENSION_ACTIVE guard |
+
+## Remediation Rules
+
+### Rule 1: Queue Expired
+- Detect: Poll returns BAD_EVENT_QUEUE_ID
+- Fix: `pm2 restart abiba-zulip`
+- Verify: Check logs for "Connected, queue:"
+
+### Rule 2: Subscription Missing
+- Detect: `GET /api/v1/users/me/subscriptions` returns 0 for #agent-hub
+- Fix: Subscribe via `POST /api/v1/users/me/subscriptions`
+- Verify: Re-check subscriptions
+
+### Rule 3: Extension Crashed
+- Detect: PM2 status shows "errored" for abiba-zulip
+- Fix: `pm2 restart abiba-zulip`
+- Escalate: If restarts >5 in last hour, alert user
+
+### Rule 4: No Response to Test Mention
+- Detect: Send test @mention, wait 30s, check if response appeared
+- Fix: Run diagnostics (check queue, check code, check logs)
+- Log: Record failure mode as new entry in Known Failure Modes
+
+## Continuity
+
+- **On user report**: User says "you didn't respond" → run diagnostic
+- **On test failure**: Test mention fails → run remediation
+- **Retrospective**: Every 6 hours — send a test @mention to self-verify
+- **On PM2 restart**: Always run a self-test after restart
+
+## Execution
+
+1. **Self-test**: Send `@**Abiba Bot** _selftest_` in #agent-hub, wait for response
+2. **If no response in 30s**: Run diagnostics
+3. **Diagnose**: Check queue, subscriptions, PM2 status, logs
+4. **Fix**: Apply matching remediation rule
+5. **Retest**: Try again
+6. **Log**: Record success or new failure mode
+7. **Report**: DM user only if escalation needed