agents-md

agents-md is a skill for Claude Code from MountainUnicorn/add. It costs 32 tokens per session (2,440 once invoked), scanned A, original, MIT.

A project skill that creates an AGENTS.md file from the project’s .add/ settings. AGENTS.md is a shared instruction file that different coding agents can read when starting work.

In plain words
What is it for?
Use it to create, check, preview, merge, or import project instructions for coding agents.
Why use it?
It keeps instructions consistent when a team uses several coding-agent tools. It can also detect when the generated file no longer matches its source settings.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions Claude Code; mentions AGENTS.md; mentions Codex.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python3 scripts/generate-agents-md.py # --write (default).

Good fit Use it to create, check, preview, merge, or import project instructions for coding agents.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/MountainUnicorn/add
agentmods
npx agentmods add skills/mountainunicorn/add/agents-md

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.

agentmods badge for agents-md

README.md
[![agentmods](https://agentmods.dev/badge/skills/mountainunicorn/add/agents-md/github.svg)](https://agentmods.dev/skills/mountainunicorn/add/agents-md)
Your own site
<a href="https://agentmods.dev/skills/mountainunicorn/add/agents-md"><img src="https://agentmods.dev/badge/skills/mountainunicorn/add/agents-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.

agentmods 80×15 button for agents-md

Your own site · 80×15
<a href="https://agentmods.dev/skills/mountainunicorn/add/agents-md"><img src="https://agentmods.dev/badge/skills/mountainunicorn/add/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,440 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00032 $0.02440
Opus 5.5 $0.00013 $0.00976
Sonnet 5.5 $0.00006 $0.00488
Haiku 4.5 $0.00003 $0.00244

Measured 2mo ago against content hash e21b81c20e65, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

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 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.

core/skills/agents-md/SKILL.md · 231 lines

How it starts

The opening of the file, as written. The whole thing — 231 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ADD AGENTS.md Skill v{{VERSION}}

Generate a portable AGENTS.md at project root from the project's .add/ state. AGENTS.md is the cross-tool open standard for project-level agent instructions — any agent (Claude Code, Cursor, Codex CLI, Windsurf, Amp, Devin, Copilot) will read it on session start. Publishing one lets mixed-toolchain teams respect the same invariants without installing ADD.

This skill is the only way to regenerate AGENTS.md. A PostToolUse hook marks the file stale when source inputs change — the human triggers the actual regeneration.

Invocation

/add:agents-md               # default: --write
/add:agents-md --check       # drift detection, CI-friendly (exit 1 on drift)
/add:agents-md --merge       # prepend ADD block to an existing hand-curated AGENTS.md
/add:agents-md --import      # one-time absorption (same as --merge; explicit intent)
/add:agents-md --dry-run     # preview without writing (combines with any mode)

Pre-Flight Checks

  1. Read .add/config.json

    • Load project.name, project.description
    • Load maturity.level (poc | alpha | beta | ga)
    • Load architecture.languages — determines whether the TDD Discipline section applies
    • Load environments.*.autoPromote — determines the autonomy ceiling summary
  2. Read docs/prd.md if present

    • The H1 + first paragraph become the project identity section
    • If absent, fall back to project.description from config
  3. Read .add/handoff.md if present

    • Extract the currently-active spec reference (first specs/*.md match in the file)
    • If absent, pick the most recently mutated specs/*.md by mtime
  4. Check .add/agents-md.stale

    • If present, announce the stale state and the source files that changed since the last regen
    • This marker is removed automatically after a successful --write
  5. Detect existing AGENTS.md

    • No file → default --write creates it fresh
    • File with ADD marker block → --write replaces managed content, preserves user-authored content outside the markers
    • File without ADD marker → --write aborts with guidance to use --merge or --import
    • Frontmatter (YAML / TOML / +++) at top is preserved verbatim

Read the full file on GitHub · 231 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. 2mo ago First seen · 231 lines · 32 tokens per session scan A e21b81c20e65

Subscribe to this mod's changes

agents-md is a skill published in the GitHub repository MountainUnicorn/add (11 stars, last pushed 13d ago), licensed MIT. It adds 32 tokens to every session and 2,440 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-30.

Related

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