What is check-ai CLAUDE.md?

Repository-specific instructions for check-ai, a Node.js command-line tool that checks whether a code repository is ready for AI-assisted development. They describe its checks, commands, and tests.

Use them when developing, testing, linting, formatting, or running the check-ai command locally.

They give a coding agent the project context and the exact ways to test and inspect changes.

How f/check-ai configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to f/check-ai. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/f/check-ai/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/f/check-ai

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/f/check-ai/claude-md/github.svg)](https://agentmods.dev/instructions/f/check-ai/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/f/check-ai/claude-md"><img src="https://agentmods.dev/badge/instructions/f/check-ai/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/f/check-ai/claude-md"><img src="https://agentmods.dev/badge/instructions/f/check-ai/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,396 This file is loaded in full into every session.

When invoked 1,396 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 97% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.01396	$0.01396
Opus 5.5	$0.00558	$0.00558
Sonnet 5.5	$0.00279	$0.00279
Haiku 4.5	$0.00140	$0.00140

Measured 2mo ago against content hash aacfb9c767b9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

check-ai CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

97% identical to check-ai AGENTS.md — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

CLAUDE.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

check-ai is a zero-dependency CLI tool that audits repositories for AI-readiness. It runs 66 checks across 8 sections (Repo Hygiene, Grounding Docs, Testing, Agent Configs, AI Context, Prompts & Skills, MCP, AI Deps) and produces a 0-10 score with letter grades.

The tool is designed to be run via npx check-ai and works entirely offline using Node.js built-ins.

Commands

Development

# Run tests (Node.js native test runner)
npm test

# Run linting
npm run lint
npm run lint:fix

# Format code
npm run format
npm run format:check

# Run the CLI locally
node bin/cli.mjs
node bin/cli.mjs /path/to/repo
node bin/cli.mjs --json
node bin/cli.mjs --verbose
node bin/cli.mjs badge

Testing

The test suite uses Node.js native test runner (node:test). Tests are in tests/*.test.mjs:

audits.test.mjs - Tests for individual audit modules
cli.test.mjs - CLI argument parsing and integration tests
scanner.test.mjs - Scanner logic and deep scan tests
scorer.test.mjs - Scoring and grading logic tests

Test fixtures are dynamically created in tests/.fixtures/ during test runs.

Architecture

Core Components

bin/cli.mjs - Entry point. Handles argument parsing, determines interactive vs static output mode, coordinates scan → score → report flow. Exits with code 1 if score < 3 (for CI integration).

src/scanner.mjs - The scanning engine:

Dynamically loads all audit modules from src/audits/*.mjs
Performs a single-pass deep tree walk (up to 6 levels) to collect files matching deep-scan patterns
Evaluates each check: file/dir existence, deep-scan matches, or custom handlers
Returns raw findings array with found, matches, detail for each check

src/scorer.mjs - Converts findings into scores:

Sums weight values from passed checks
Normalizes to 0-10 scale
Assigns letter grade (A+, A, B, C, D, F) based on score thresholds
Groups findings by section in a fixed order

Read the full file on GitHub · 133 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 133 lines · 1,396 tokens per session scan A aacfb9c767b9

Subscribe to this mod's changes

check-ai CLAUDE.md is an instructions file published in the GitHub repository f/check-ai (66 stars, last pushed 7mo ago), licensed MIT. It adds 1,396 tokens to every session, about $0.0056 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 97% identical to check-ai AGENTS.md, differing in 2 lines, and is treated as a copy.

agents ai-readiness

check-ai CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
check-ai CLAUDE.mdf/check-ai	Instructions file	66	7mo ago	MIT	A	1,396	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

check-ai: Instructions file for Claude Code