canary-watch

Use it when:: You've just deployed, merged a risky PR or upgraded dependencies and want to confirm the live site didn't regress.
It does:: Checks eight things, from HTTP status and new console errors to LCP, CLS and INP, key page elements, API response times, static assets and SSE heartbeats.
You get:: A canary report: each check against its baseline, sorted into critical, warning and info by set thresholds.
Runs:: One pass by default, every N minutes for M hours in sustained mode, or as a staging-versus-production comparison.
Alerts:: A desktop notification, an optional Slack or Discord webhook and a line in ~/.claude/canary-watch.log.
Needs:: A browser tool the agent can drive for the console and performance checks; the skill names none.

TL;DR

A post-deploy watch for a live URL. It defines what to look at: HTTP status, new console errors, failed network calls and 5xx responses, LCP, CLS and INP against a baseline, whether key elements like the h1, nav, footer and call to action are still there, critical API endpoints within their SLA, JS, CSS, image and font requests with the expected content types, and event-stream (SSE) endpoints that connect and receive a first event or heartbeat. Thresholds sort findings: a non-200 status, more than five new console errors, LCP over 4 seconds, a 5xx API or a broken asset are critical; slower responses, layout shift, new console warnings and changed content types are warnings. Modes are a single quick check, a sustained watch at an interval for a set duration, and a diff of staging against production. Critical findings trigger a desktop notification, an optional Slack or Discord webhook and a log entry. It suggests pairing it with browser-qa before deploys, a hook after git push, or a CI step after deploy.

Summarizes the skill at d2ef268.

npx skills add https://github.com/affaan-m/ecc --skill canary-watch

skills.sh page Source on GitHub All skills from affaan-m/ecc

Total Downloads: 5,400 on skills.sh, Nov 9, 2026
Repo stars: 299,776 affaan-m/ecc
First seen: May 19, 2026 on skills.sh

Weekly Downloads

444

+73% over the 8 weeks to Nov 9

Weekly values

Week to	Installs
Sep 21	257
Sep 28	157
Oct 5	137
Oct 12	233
Oct 19	410
Oct 26	403
Nov 2	468
Nov 9	444

Category	category:debugging category:cloud category:software-engineering Find root causes, review code and test what you built. Deploy, provision, observe and debug cloud apps. Everything for building software: planning, coding, debugging, design, frameworks, cloud, agents and skills.
Type	type:workflow A multi-step process the agent follows: interview, debug, run a TDD loop, review.
Effect	effect:local Its own steps create or change files, git state or local tools.
Needs	needs:browser Drives a real Chromium or Chrome browser.
Publisher	by:community Everyone else. Unverified vendor claims default to community.
Topics	deployment observability performance verification

SKILL.md

From affaan-m/ecc at d2ef268. Checked daily, last changed Nov 6, 2026.

Frontmatter

name: canary-watch
description: Use this skill to monitor and verify a deployed URL after releases — checks HTTP endpoints, SSE streams, static assets, console errors, and performance regressions after deploys, merges, or dependency upgrades. Smoke / canary / post-deploy verification.
metadata:
  origin: ECC

Canary Watch — Post-Deploy Monitoring

When to Use

After deploying to production or staging
After merging a risky PR
When you want to verify a fix actually fixed it
Continuous monitoring during a launch window
After dependency upgrades

How It Works

Monitors a deployed URL for regressions. Runs in a loop until stopped or until the watch window expires.

What It Watches

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?

Watch Modes

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

Alert Thresholds

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?)

Notifications

When a critical threshold is crossed:

Desktop notification (macOS/Linux)
Optional: Slack/Discord webhook
Log to ~/.claude/canary-watch.log

Output

## 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.

Integration

Pair with:

/browser-qa for pre-deploy verification
Hooks: add as a PostToolUse hook on git push to auto-check after deploys
CI: run in GitHub Actions after deploy step