Cursor rules, CLAUDE.md, AGENTS.md & .windsurfrules — config files that make AI coders smarter

📐 What this is

The dotfiles of the AI era: CLAUDE.md, .cursor/rules, AGENTS.md, .windsurfrules, .github/copilot-instructions.md — the project-level config that makes AI coding tools actually understand your codebase.

The difference between a useless AI suggestion and a great one is usually this file.

📁 The collection

By tool

| File | Tool | Loaded | |—|—|—| | CLAUDE.md | Claude Code | Automatically, repo root | | .cursor/rules/*.mdc | Cursor | Glob-matched or always | | AGENTS.md | OpenAI Codex, others | Emerging standard | | .windsurfrules | Windsurf | Project root | | .github/copilot-instructions.md | Copilot | Workspace | | .continue/config | Continue | IDE config | | .aider.conf.yml | Aider | CLI config |

By stack — ready-made templates

| Template | Best lines inside | |—|—| | python-fastapi.md | pydantic v2 syntax, async patterns, no print() — use logging | | typescript-nextjs.md | app router conventions, server components default, zod validation | | rust-cli.md | clap v4, anyhow vs thiserror split | | go-service.md | standard layout, no global state | | react-vite.md | hooks rules, tanstack-query for fetching |

✍️ What a great rules file contains

# Project: Acme API

## Stack
FastAPI + SQLAlchemy async + Postgres. Tests: pytest-asyncio.

## Conventions
- All endpoints return Pydantic schemas, never dicts
- DB access only through `db/repositories/`
- No `print()` — `structlog` only
- Commits: conventional format (`feat:`, `fix:`)

## Commands
- Test: `pytest -xvs`
- Lint: `ruff check --fix`
- Run dev: `uvicorn app:app --reload`

## Never do
- Don't add deps without asking
- Don't modify migrations by hand — alembic generates them
- Don't commit `.env`

🧠 Rules that measurably help (community-tested)

  1. Commands section — the AI stops guessing how to run tests
  2. “Never do” list — negative constraints prevent the worst diffs
  3. One-file-per-domain in .cursor/rules with globs: frontend/*.mdc → **/*.tsx
  4. Link, don’t paste — reference real files: @src/db/base.py as the ORM example
  5. Keep under 150 lines — longer rules get ignored/truncated

Maintained by aixisstudio.