Verified reference

Which AI agent files work with Cursor, Claude Code, and Codex?

Use AGENTS.md for shared project instructions, CLAUDE.md for Claude Code, Cursor project rules for Cursor, Agent Skills for reusable tasks, and MCP setup for tool connections.

Last checked: 31 August 2026.

Quick comparison

Which file works where?

File or setup	What it does	Cursor	Claude Code	Codex	Can a team share it?
AGENTS.md	Project instructions written as a normal text file.	Supported for simple project-wide instructions.	Use CLAUDE.md instead for Claude Code.	Supported. Instructions can apply to a folder and its subfolders.	Yes. Keep it in Git with the project.
CLAUDE.md	Instructions that Claude Code reads in every work session.	Not the main Cursor rules format.	Supported. Best for facts and rules that should always be available.	Use AGENTS.md instead for Codex.	Yes. Keep the project file in Git.
Cursor project rules	Cursor-only instructions that can apply to certain files or tasks.	Supported in the .cursor/rules folder.	Not a Claude Code format.	Not a Codex format.	Yes. Keep the .cursor/rules folder in Git.
Agent Skill	A reusable task, guide, or set of steps stored with a SKILL.md file.	AIPM can install Cursor-ready skill files. Check how your Cursor version loads them.	Supported. Claude can choose a skill or you can start it with a slash command.	Supported. Codex can choose a skill or use one named by the user.	Yes. AIPM can package and install the same skill in several projects.
MCP setup	Settings that connect an AI tool to another tool or source of information.	Supported through Cursor MCP settings.	Supported through Claude Code MCP settings.	Support depends on the Codex product and current setup.	Share safe settings and instructions. Never share passwords or private tokens.

AI tools change quickly. Use the source links below to check a detail before making a large team change.

Simple choice

Use AGENTS.md when several coding agents need the same basic project instructions.

Use CLAUDE.md for instructions that only Claude Code needs.

Use Cursor project rules when Cursor needs rules for certain files or tasks.

Use a skill when you want the AI to repeat a useful task.

Use MCP when the AI needs to connect to another tool or source of information.

How AIPM helps

AIPM does not replace these files. It helps a team package, install, and update reusable AI instructions. Start with the install guide or read how to share instructions across projects.