Groundrule

Your engineering standards, taught to every coding agent and checked on every PR.

Write a standard once, as a small YAML file in git. Groundrule:

• teaches your coding agents. It generates AGENTS.md, CLAUDE.md, Cursor rules, and Copilot instructions containing only the standards that apply, without touching what you wrote by hand. An MCP server and hooks let Claude Code, Codex, Cursor and Copilot follow action policies before each tool call and check their own changes before they finish.
• checks the code. It runs locally and in CI against your changes or the whole repository, with deterministic checks (files, patterns, dependencies, imports, layout, metrics, change sets), Semgrep, and optional AI checks on the Groundrule platform.
• tells you why. Every finding names the standard, shows the evidence, says how to fix it, and labels whether it came from a deterministic check or AI.

Everything in this repository works offline and without an account. The Groundrule platform adds a shared rulebook, staged rollout, hosted checks and a compliance report on top of it.

Status: 0.x. Groundrule checks its own repositories with it. The document format is groundrule.dev/v1alpha1 and may still change before 1.0; changes are announced in Discussions.

See it in 60 seconds

Quick start

Thirty seconds, no account, nothing leaves your machine:

npx @groundrule/cli init      # detects your stack, picks packs, writes .groundrule/config.yaml
npx @groundrule/cli sync      # writes AGENTS.md / CLAUDE.md / Cursor / Copilot instructions
npx @groundrule/cli check     # checks your uncommitted changes

 groundrule check · 11 standards · 2 files changed

 ✕ TS-003  No eval or new Function
   BLOCKER · deterministic (regex)
   src/app.ts:3
     eval or new Function in application code
     3: return eval(input);
   → Parse the input instead: JSON.parse, a schema, or a lookup table of allowed operations.
   → groundrule explain TS-003

 Failed  ✓ 7 passed  ✕ 1 failed  ◇ 2 guidance  · 0.1s

A standard

apiVersion: groundrule.dev/v1alpha1
kind: Standard
metadata:
  id: DEP-008
  title: Use the platform HTTP client
  type: forbidden-tech
  owner: team:platform
spec:
  severity: warning
  requirement: Backend services must use @acme/http-client for outbound HTTP calls.
  examples:
    forbidden: ["import axios from 'axios'"]
  checks:
    - evaluator: dependencies
      forbid: [axios, got, node-fetch]
      allowInstead: ["@acme/http-client"]

More in examples/foundation.

Commands

... View full README on GitHub