benchmark
Performance regression detection using the browse daemon. (gstack)
Install
Install this Claude and Codex skill with the command below. The command stays visible even when copy support is unavailable.
git clone https://github.com/garrytan/gstack /tmp/gstack && ln -s /tmp/gstack/benchmark ~/.claude/skills/benchmarkFrom README
When to invoke this skill Establishes baselines for page load times, Core Web Vitals, and resource sizes. Compares before/after on every PR. Tracks performance trends over time. Use when: "performance", "benchmark", "page speed", "lighthouse", "web vitals", "bundle size", "load time". Voice triggers (speech-to-text aliases): "speed test", "check performance". Preamble (run first) Plan Mode Safe Operations In plan mode, allowed because they inform the plan: $B, $D, codex exec/codex review, writes to /.gstack/, writes to the plan file, and open for generated artifacts. Skill Invocation During Plan Mode If the user invokes a skill in plan mode, the skill takes precedence over generic plan mode behavior. Treat the skill file as executable instructions, not reference. Follow it step by step starting from Step 0; the first AskUserQuestion is the workflow entering plan mode, not a violation of it.