anton-abyzov/agents-md-author

agents-md-author

Generate cross-vendor project instruction files: AGENTS.md for Codex (and most other tools), CLAUDE.md for Claude Code, or both kept in sync. Load references/agents-md-spec.md if you need the cross-vendor convention details.

When to activate

• User asks to "write AGENTS.md", "create CLAUDE.md", or "set up project instructions for AI"
• User wants the same project doc to work in Codex, Claude Code, Cursor, or any tool that follows the AGENTS.md convention
• User mentions onboarding a new AI tool to an existing repo and wants conventions captured

Procedure

1. Detect project context (always do this first)

Read the project root and determine:

• Project name — from package.json name, pyproject.toml [project].name, go.mod module, Cargo.toml [package].name, or fallback to repo dir name
• Language & runtime — package.json (Node + lockfile flavor), requirements.txt / pyproject.toml (Python), go.mod (Go), Cargo.toml (Rust), pom.xml / build.gradle (JVM), *.csproj (.NET)
• Common scripts — Node scripts.{dev,build,test,lint,typecheck}; Python tox.ini / Makefile; Go/Rust task tools
• Test framework — vitest, jest, pytest, go test, cargo test, etc.
• Repo conventions — existing .editorconfig, .prettierrc, eslint.config.*, pre-commit-config.yaml

If the user provided context (e.g., "this is a Next.js + Prisma app"), use it; otherwise infer from files. Don't ask questions you can answer from disk.

2. Decide the target file(s)

| User wants | Write | |---|---| | Codex / OpenAI tools only | AGENTS.md | | Claude Code only | CLAUDE.md | | Both, kept in sync | AGENTS.md + CLAUDE.md (identical content), or AGENTS.md plus a one-line CLAUDE.md that says "See AGENTS.md" | | Single source (recommended) | AGENTS.md + CLAUDE.md symlink → AGENTS.md |

Default to "both, identical content" unless the user specifies — it's the lowest-risk option and works everywhere.

3. Compose content

Use this canonical structure (load references/agents-md-spec.md if you need the field-by-field rationale or cross-vendor details):

# <Project name>

<one-sentence description>

## Tech stack

- <language + version>
- <framework + version>
- <database / runtime / deployment>

## Dev commands

- Install: `<command>`
- Dev server: `<command>`
- Build: `<command>`
- Test: `<command>` (unit) / `<command>` (e2e)
- Lint / typecheck: `<command>`

## Code conventions

- <indent + line length>
- <import style>
- <naming conventions>
- <test colocation>
- <commit style>

## Architecture notes

<2-5 bullets on layout — where routes live, where business logic lives, what's shared>

## Out of scope for AI agents

<deliberate "don't touch" list — generated files, secrets, migrations, etc.>

Keep it under ~150 lines. AI agents skim — verbose docs are skipped or ignored.

4. Write files

• Use canonical line endings for the OS (LF on macOS/Linux)
• Don't add a trailing summary or "generated by" footer — the file is now the user's
• If a file already exists, read it first, propose a diff, and ask the user before overwriting

5. Verify

• Print the relative paths written
• If both AGENTS.md and CLAUDE.md were written, confirm they're byte-identical (or show the symlink)
• Suggest the user commit the files

References

• references/agents-md-spec.md — full cross-vendor convention summary (Anthropic, OpenAI, Cursor, etc.) — load on demand for spec details, vendor matrix, and the AGENTS.md ≠ SKILL.md distinction
• Anthropic Agent Skills spec: https://github.com/anthropics/skills
• OpenAI Codex AGENTS.md guide: https://developers.openai.com/codex/guides/agents-md
• agents.md cross-vendor standard: https://agents.md