From ecc
Monitors deployed URLs after releases: checks HTTP status, console errors, static assets, SSE streams, and performance regressions. Use after deploys, risky merges, or dependency upgrades.
How this skill is triggered — by the user, by Claude, or both
Slash command
/ecc:canary-watchThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
- After deploying to production or staging
Monitors a deployed URL for regressions. Runs in a loop until stopped or until the watch window expires.
1. HTTP Status — is the page returning 200?
2. Console Errors — new errors that weren't there before?
3. Network Failures — failed API calls, 5xx responses?
4. Performance — LCP/CLS/INP regression vs baseline?
5. Content — did key elements disappear? (h1, nav, footer, CTA)
6. API Health — are critical endpoints responding within SLA?
7. Static Assets — are JS, CSS, image, and font requests returning 2xx/3xx with expected content types?
8. SSE Streams — do event-stream endpoints connect and receive an initial event or heartbeat?
Quick check (default): single pass, report results
/canary-watch https://myapp.com
Sustained watch: check every N minutes for M hours
/canary-watch https://myapp.com --interval 5m --duration 2h
Diff mode: compare staging vs production
/canary-watch --compare https://staging.myapp.com https://myapp.com
critical: # immediate alert
- HTTP status != 200
- Console error count > 5 (new errors only)
- LCP > 4s
- API endpoint returns 5xx
- Static asset returns 4xx/5xx
- SSE endpoint cannot connect or drops before first heartbeat
warning: # flag in report
- LCP increased > 500ms from baseline
- CLS > 0.1
- New console warnings
- Response time > 2x baseline
- Static asset content type changed unexpectedly
- SSE heartbeat latency > 2x baseline
info: # log only
- Minor performance variance
- New network requests (third-party scripts added?)
When a critical threshold is crossed:
~/.claude/canary-watch.log## Canary Report — myapp.com — 2026-03-23 03:15 PST
### Status: HEALTHY ✓
| Check | Result | Baseline | Delta |
|-------|--------|----------|-------|
| HTTP | 200 ✓ | 200 | — |
| Console errors | 0 ✓ | 0 | — |
| LCP | 1.8s ✓ | 1.6s | +200ms |
| CLS | 0.01 ✓ | 0.01 | — |
| API /health | 145ms ✓ | 120ms | +25ms |
| Static assets | 42/42 ✓ | 42/42 | — |
| SSE /events | connected ✓ | connected | +80ms heartbeat |
### No regressions detected. Deploy is clean.
Pair with:
/browser-qa for pre-deploy verificationgit push to auto-check after deploysnpx claudepluginhub affaan-m/ecc --plugin eccMonitors deployed URLs post-release for HTTP status, SSE streams, static assets, console errors, and performance regressions. Use for smoke tests, canary checks, and deployment validation after deploys, risky merges, or dependency upgrades.
Verifies production site health post-deploy via canary monitoring: checks HTTP status, response time, and error patterns, compares against baseline to detect regressions, and guides rollback decisions.
Runs post-deploy health checks on web apps: HTTP status, response times, error detection, performance patterns, smoke test report. Auto-triggers after deploy/launch.