canary

Monitors deployed web apps for console errors, performance regressions, and page failures using browser automation.

Updated Mar 26, 2026
One-click install
npx skills add https://github.com/LGJ-Jonathan/Jonathan_Global_Claude_Skills --skill canary-lgj-jonathan
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: canary
Source: https://github.com/LGJ-Jonathan/Jonathan_Global_Claude_Skills/tree/main/gstack/canary
Command: npx skills add https://github.com/LGJ-Jonathan/Jonathan_Global_Claude_Skills --skill canary-lgj-jonathan

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Deploys that pass CI can still break in production due to missing environment variables, stale CDN caches, or slow migrations. This Skill watches your live app in the critical first minutes after a deploy, catching regressions before users report them. ## Core Features & Use Cases - Baseline Capture: Take screenshots, console error counts, and load times before deploying, then compare post-deploy state against them. - Continuous Monitoring Loop: Check pages every 60 seconds for a configurable duration (1-30 minutes), alerting only on changes that persist across consecutive checks. - Severity-Based Alerts: Classify issues as CRITICAL (page load failure), HIGH (new console errors), MEDIUM (2x performance regression), or LOW (broken links), each with screenshot evidence. - Use Case: After shipping a new release, run the canary against your production URL for 10 minutes. It auto-discovers your main navigation pages, watches them, and produces a health report with a HEALTHY, DEGRADED, or BROKEN verdict. ## Quick Start Ask the assistant to run /canary against your production URL to monitor the deploy for 10 minutes and report any console errors or performance regressions.

Frequently Asked Questions about canary

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I monitor my website after a deployment?

Run /canary with your production URL to start a 10-minute monitoring loop. It checks pages every 60 seconds for new console errors, load failures, and performance regressions, then produces a health report with a HEALTHY, DEGRADED, or BROKEN verdict.

How do I capture a baseline before deploying?

Run /canary with your URL and the --baseline flag before deploying. It records screenshots, console error counts, and page load times for each page into a baseline.json manifest, which later monitoring runs compare against.

Can I customize which pages and how long the canary monitors?

Yes. Use --pages to specify exact paths like /,/dashboard,/settings, and --duration to set monitoring from 1 to 30 minutes. Without --pages, it auto-discovers the top navigation links and asks you to confirm.

Why does the canary not alert on a single console error?

It alerts on changes relative to the baseline, not absolute counts, and only on patterns persisting across two or more consecutive checks. This filters out transient network blips and pre-existing errors that were present before the deploy.

What counts as a performance regression in canary monitoring?

A page load time exceeding 2x the baseline is flagged as a MEDIUM severity regression. A 1.5x increase is treated as normal variance, since thresholds are relative to your own baseline rather than fixed industry numbers.