Install 402MCP.org — HTTP 402 & Agent Payment Registry in Amp

What you need first

• Amp, installed.
• Nothing else: the server runs on its publisher's machines and Amp connects to it.

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": {
    "registry": {
      "url": "https://402mcp.org/api/v1/mcp"
    }
  }
}

3. Save the file and restart Amp.

Check it worked

Ask Amp: List the tools of registry.

If it does not start

401 Unauthorized

The endpoint wants a sign-in or a key. Sign in when Amp asks.

Nothing changes after a restart

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