rulecheck

rulecheck is a skill for Claude Code, Codex from coleam00/Archon. It costs 46 tokens per session (454 once invoked), scanned A, original, MIT.

An automated checker for project rules written in AGENTS.md files. It scans a codebase, fixes selected violations in a separate worktree, validates the changes, and reports the result.

In plain words
What is it for?
Use it to check adherence to repository instructions, apply high-impact fixes, run validation, and create a pull request.
Why use it?
It reduces the manual effort of finding rule violations and keeps automated fixes separate from your working files.

Skill for Claude CodeCodex

About the project

Archon is a workflow engine for AI coding agents that turns development processes into YAML-defined sequences with phases, validation gates, and artifacts. Developers use it to run repeatable processes such as planning, implementation, testing, code review, and pull-request creation across projects. The catalogue entries provide commands, agents, skills, hooks, instructions, and settings for working with Archon.

coleam00/Archon · 23,366 stars · on GitHub

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/coleam00/archon/rulecheck
Any agent
npx skills add coleam00/Archon --skill rulecheck
Clone the repo
git clone --depth 1 https://github.com/coleam00/Archon

Made for: Claude Code, Codex.

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.

agentmods badge for rulecheck

README.md
[![agentmods](https://agentmods.dev/badge/skills/coleam00/archon/rulecheck.svg)](https://agentmods.dev/skills/coleam00/archon/rulecheck)
Your own site
<a href="https://agentmods.dev/skills/coleam00/archon/rulecheck"><img src="https://agentmods.dev/badge/skills/coleam00/archon/rulecheck.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 454 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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.

ModelPer sessionOnce invoked
Fable 5 $0.00046 $0.00454
Opus 5 $0.00023 $0.00227
Sonnet 5 $0.00009 $0.00091
Haiku 4.5 $0.00005 $0.00045

Measured yesterday against content hash fa080ff12b82, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rulecheck 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 yesterday.

The scan reads SKILL.md. This mod also ships 2 executable files (hooks/block-dangerous.sh, hooks/slack-notify.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.claude/skills/rulecheck/SKILL.md · 38 lines

What it actually says

Rulecheck

Launch the rulecheck-agent to autonomously scan and fix AGENTS.md rule violations.

Your Job (Main Agent)

You are the orchestrator. Your ONLY job is to launch the rulecheck-agent and report its results when it completes. You do NOT do the scanning or fixing yourself.

  1. Launch the rulecheck-agent with the focus area (if any): $ARGUMENTS
  2. Wait for it to complete — do NOT poll, tail, or check on it. You will be notified automatically when it finishes.
  3. Report ONLY what the agent told you — relay its final message verbatim or summarize it. Do NOT search for PRs, read files, or fabricate results. If the agent hit its context limit, say so. If it didn't produce a PR URL in its output, don't go looking for one.

Rules for You

  • Do NOT scan the codebase yourself — that's the agent's job
  • Do NOT grep, read source files, or run linters — the agent handles all of that
  • Do NOT edit any files — you are the orchestrator, not the fixer
  • Do NOT try to resume or check on the agent while it's running — just wait
  • Do NOT do the agent's work if it fails or hits context limits — report the failure to the user and stop. NEVER pick up where the agent left off. You are not in a worktree and would be editing main directly.
  • Do NOT update project memory — the agent maintains its own memory at .claude/agent-memory/rulecheck-agent/. Do not duplicate run results into your project memory.
  • Trust the agent. It runs in an isolated worktree and will create a PR when done.
Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

  1. yesterday First seen · 38 lines · 46 tokens per session scan A fa080ff12b82

Subscribe to this mod's changes

rulecheck is a skill published in the GitHub repository coleam00/Archon (23,366 stars, last pushed yesterday), licensed MIT. It adds 46 tokens to every session and 454 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.