lighthouse-skill
AGENTS.md4 starsChanged 5 months agoMITView on GitHub
Guidance for AI coding agents working in this repository. A single Agent Skill that teaches an agent to run Google Lighthouse — CLI, performance budgets, CI, and the programmatic API — to measure and verify web quality.
Where files are headingNew AGENTS.md files have more rules about keeping secrets out of the code, and fewer about code style.
Of the AGENTS.md files we read, the 31,774 first seen in the last six months, against the older ones: the kind of rule that gained most share, and the kind that lost most. About files like this in general, not this one, and an estimate, since a kind is a pattern in the words.
In this repositoryOne other file it gives its agents.
- lighthouseSkill
The file
We split this AGENTS.md into the rules it gives an agent
3 rules. About 0 are common, 1 is distinctive, and 2 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈1
Distinctive · estimate
This author's own choices. Worth a look.
2
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Distinctive: line 35
Code examples: use ❌ bad / ✅ good where it clarifies, and prefer copy-pasteable commands.
- Very specific: line 36
Scripts: follow: #!/bin/bash + set -euo pipefail.
- Very specific: line 41
Keep the lab-vs-field distinction prominent — Lighthouse is a lab tool.
≈ “Common” is an estimate: at least 1 in 5 of the 40,246 AGENTS.md files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
AGENTS.md
Guidance for AI coding agents working in this repository.
Project overview
A single Agent Skill that teaches an agent to run Google Lighthouse — CLI, performance budgets, CI, and the programmatic API — to measure and verify web quality.
Structure
lighthouse-skill/
├── README.md
├── LICENSE
├── .claude-plugin/ # Claude Code plugin + marketplace manifests
├── .antigravity-plugin/ # Antigravity plugin manifest (agy plugin install)
├── .cursor-plugin/ # Cursor plugin manifest
├── codex/, .agents/plugins/ # Codex plugin + marketplace (codex/skills → ../skills)
├── gemini-extension.json # Gemini CLI extension manifest
└── skills/
└── lighthouse/
├── SKILL.md # main instructions (keep under 500 lines)
├── scripts/
│ └── run-lighthouse.sh
└── references/
├── CLI-FLAGS.md
├── CI.md
└── PROGRAMMATIC-API.mdConventions
- SKILL.md stays under 500 lines; push deep/look-up material into
references/. - Descriptions include trigger phrases so the skill activates on the right prompts.
- Code examples use ❌ bad / ✅ good where it clarifies, and prefer copy-pasteable commands.
- Scripts follow:
#!/bin/bash+set -euo pipefail; human logs to stderr, machine-readable JSON to stdout; cleanup trap for temp files; document dependencies (jq, Node/npx).
Accuracy notes
- Lighthouse evolves. Audit IDs and metric weights shift between major versions (see the v13 Insight Audits note in SKILL.md). When editing, prefer linking to upstream docs over hardcoding numbers that drift.
- Keep the lab-vs-field distinction prominent — Lighthouse is a lab tool; INP and real-user data come from the field (CrUX /
web-vitals).
Testing changes
- Validate the YAML frontmatter in
SKILL.md. shellcheck skills/lighthouse/scripts/run-lighthouse.sh.- Smoke-test the script against a real URL:
skills/lighthouse/scripts/run-lighthouse.sh https://example.com 1. - Confirm all referenced files exist and links resolve.
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.

