Install Evals in Amp

What you need first

• Amp, installed.
• Node.js, which gives the npx command the server starts with.

Steps

1. Open ~/.codex/config.toml, or create it. The Codex CLI, its IDE extension and the ChatGPT desktop app share this file.
2. Add this table at the end of the file.

{
  "amp.mcpServers": {
    "evals-mcp-server": {
      "command": "npx",
      "args": ["-y", "@cyanheads/[email protected]"]
    }
  }
}

3. Save the file and restart Amp.

Check it worked

Ask Amp: List the tools of evals-mcp-server.

If it does not start

spawn npx ENOENT

Node.js is not on the PATH that Amp sees. Install it, or write the full path of npx in the config.

Nothing changes after a restart

The file is not valid JSON any more. Look for a missing comma where the block was added.