Install Factcheck in Codex

What you need first

• Codex, installed.
• Docker, which gives the docker command the server starts with.
• Your own value for YOUR_OPENAI_API_KEY.

Steps

1. 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 mcp-factcheck --env OPENAI_API_KEY=YOUR_OPENAI_API_KEY -- docker run -i --rm -e OPENAI_API_KEY ghcr.io/carlisia/mcp-factcheck:v1.0.0

2. Replace YOUR_OPENAI_API_KEY with your own value.
3. Start Codex again and type /mcp: the server is listed.

Check it worked

Ask Codex: List the tools of mcp-factcheck.

If it does not start

Cannot connect to the Docker daemon

Docker is not running. Start it, then restart Codex.

The server starts, but its tools fail

A YOUR_… placeholder is still in the config, or its value is wrong.