agents-md-kit AGENTS.md

A toolkit for creating and checking AGENTS.md and SKILL.md files, which are instruction files that define how coding agents behave and what they can do. It includes tools for parsing, validating, linting, and reporting on those files.

In plain words
What is it for?
It helps scaffold instruction files, validate their structure, lint their content, and produce reports in several formats.
Why use it?
It catches missing, invalid, or inconsistent agent instructions before they cause problems. It also gives teams a consistent way to maintain these files in a pnpm monorepo, a repository containing multiple related packages.

Instructions file for CodexOpenCode

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 instructions/reaatech/agents-md-kit/agents-md
Clone the repo
git clone --depth 1 https://github.com/reaatech/agents-md-kit

Made for: Codex, OpenCode.

Per session 4,162 This file is loaded in full into every session.
When invoked 4,162 The same file — it is already loaded in full.
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 $0.04162 $0.04162
Opus 5 $0.02081 $0.02081
Sonnet 5 $0.00832 $0.00832
Haiku 4.5 $0.00416 $0.00416

Measured yesterday against content hash 6f6b7f97bb5f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agents-md-kit AGENTS.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 yesterday.

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.

AGENTS.md · 532 lines

How it starts

The opening of the file, as written. The whole thing — 532 lines — stays where its author put it; the contents beside it link to each section on GitHub.

agents-md-kit — Agent Development Guide

What this is

This document defines how to use agents-md-kit to create, validate, and maintain AGENTS.md and SKILL.md files — the "durable agent instruction artifacts" that define how AI agents behave, what skills they possess, and how they integrate into multi-agent systems.

Target audience: Engineers building AI agents who need to create standardized agent instruction files that follow community best practices and can be validated for correctness, completeness, and quality.


Architecture Overview

agents-md-kit is a pnpm monorepo of 9 independently versioned packages published under the @reaatech/agents-markdown-* scope, plus examples and end-to-end tests.

┌─────────────┐    ┌─────────────┐    ┌─────────────┐    ┌─────────────┐
│   Parser    │    │  Validator  │    │   Linter    │    │  Reporter   │
│  (remark)   │───▶│   (zod)     │───▶│  (rules)    │───▶│ (4 formats) │
└─────────────┘    └─────────────┘    └─────────────┘    └─────────────┘
       │                                                       │
       ▼                                                       ▼
┌─────────────┐                                        ┌─────────────┐
│    Core     │                                        │  Scaffold   │
│  (types +   │                                        │ (handlebars)│
│   schemas)  │                                        └─────────────┘
└─────────────┘                                               │
       │                                               ┌──────┴──────┐
       ▼                                               ▼             ▼
┌─────────────────────────────────────────────────────────────────────┐
│                        CLI          │        MCP Server             │
│                    (commander)       │    (@modelcontextprotocol)    │
└─────────────────────────────────────────────────────────────────────┘
                               │
                               ▼
┌─────────────────────────────────────────────────────────────────────┐
│                      Observability (pino + OTel)                     │
└─────────────────────────────────────────────────────────────────────┘

Read the full file on GitHub · 532 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.

  1. yesterday First seen · 532 lines · 4,162 tokens per session scan A 6f6b7f97bb5f

Subscribe to this mod's changes

agents-md-kit AGENTS.md is an instructions file published in the GitHub repository reaatech/agents-md-kit (2 stars, last pushed 8d ago), licensed MIT. It adds 4,162 tokens to every session, about $0.0208 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 2026-08-31.