Install Pi-hole MCP Server in Codex

What you need first

• Codex, installed.
• Docker, which gives the docker command the server starts with.
• Your own values for YOUR_PIHOLE_URL,YOUR_PIHOLE_PASSWORD.

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 pihole-mcp --env PIHOLE_URL=YOUR_PIHOLE_URL --env PIHOLE_PASSWORD=YOUR_PIHOLE_PASSWORD -- docker run -i --rm -e PIHOLE_URL -e PIHOLE_PASSWORD ghcr.io/hexamatic/pihole-mcp:0.9.0

2. Replace YOUR_PIHOLE_URL,YOUR_PIHOLE_PASSWORD with your own values.
3. Start Codex again and type /mcp: the server is listed.

Check it worked

Ask Codex: List the tools of pihole-mcp.

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.