Install AI Game Developer: MCP for Unity, Unreal and Godot in Codex
What you need first
- Codex, installed.
- Nothing else: the server runs on its publisher's machines and Codex connects to it.
Steps
- Run this in a terminal. It writes the server into
~/.codex/config.toml, which the Codex CLI, its IDE extension and the ChatGPT desktop app share.
codex mcp add unity-mcp --url https://ai-game.dev/mcp- Start Codex again and type
/mcp: the server is listed.
Check it worked
Ask Codex: List the tools of unity-mcp.
If it does not start
- 401 Unauthorized
- The endpoint wants a sign-in or a key. Sign in when Codex asks.