Introduction

Lawbook checks code standards with repeatable rules and LLM decisions.

Lawbook checks a directory against the rules in its lawbook.yaml. Most rules are repeatable: the same files always give the same result, and a failing rule names the file and line that broke it. A standard rule states a standard in prose and lets a model judge each file against it. Lawbook ships as an npm package and needs Node.js 22.12 or newer.

npm install --global lawbook
lawbook init
lawbook check

Getting started walks through the first run.
Configuration describes the rule kinds and the config file.
LLM rules explains standard rules and how to write one.
Clean-code example is a drop-in lawbook.yaml built from ten software engineering books.
Providers configures the Claude Code, Codex, or Kiro CLI, so a subscription pays for standard rules.
Suppressions turns a rule off for a line or a file with a comment.
Baseline records today’s findings so only new ones fail.
Commands lists every command and flag.
Exit codes says what 0, 1, and 2 mean.

Build from source

With Node.js 22.12 or newer and pnpm, from a clone of the repository:

pnpm install
pnpm run build
npm install --global .

Then check the install:

lawbook --version