lawbook

Lawbook checks a directory against the rules in its lawbook.yaml: regular expressions that files must or must not match, paths that must or must not exist, and standards written in prose that a model judges file by file or as a set. A failing rule names the file and the reason, and the exit code says whether the check passed.

npm install --global lawbook
lawbook init      # writes a starter lawbook.yaml
lawbook check     # exit 0 pass, 1 a rule failed, 2 could not run
lawbook test      # judges each standard rule's example files

version: 1
rules:
  - id: no-console
    files: ["src/**/*.ts"]
    forbid: 'console\.(log|debug)\('
  - id: has-readme
    exists: README.md
  - id: errors-are-actionable
    files: ["src/**/*.ts"]
    standard: Every error message says what went wrong and what to do next.

standard rules run the installed Claude Code CLI by default, so a Claude subscription pays; provider: codex or provider: kiro runs the Codex or Kiro CLI instead. check --no-llm skips them. The docs describe the configuration format, LLM rules, providers, the commands, and the exit codes. The clean-code example, also at examples/clean-code.lawbook.yaml, is a drop-in config built from ten software engineering books.

Agent skill

skills/lawbook/SKILL.md teaches a coding agent such as Claude Code to run lawbook, read its findings, and write or tune a lawbook.yaml. Copy the skills/lawbook directory into .claude/skills/ in a project, or into ~/.claude/skills/ for every project, and the agent picks it up.

Install

Lawbook needs Node.js 22.12 or newer.

npm install --global lawbook

Or from a clone:

pnpm install
pnpm run build
npm install --global .

Development

The project uses Node.js 24 and pnpm. Before submitting a change, run:

pnpm run lint
pnpm run typecheck
pnpm test
pnpm pack --dry-run

CI also runs poly-crap with a threshold of 5 and fails the build when a function is over it. CLAUDE.md describes the layout and the rules the code follows.

The docs site lives in docs/. Run pnpm --dir docs install once, then pnpm --dir docs run dev to serve it locally.

See CONTRIBUTING.md for contribution guidance, SECURITY.md for vulnerability reporting, and RELEASING.md for maintainer release steps.

License

MIT