Install mcp-server-sigma in Codex

What you need first

• Codex, installed.
• uv, which gives the uvx command the server starts with.
• Your own values for YOUR_SIGMA_CLIENT_ID,YOUR_SIGMA_CLIENT_SECRET,YOUR_SIGMA_API_BASE_URL.

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 sigma --env SIGMA_CLIENT_ID=YOUR_SIGMA_CLIENT_ID --env SIGMA_CLIENT_SECRET=YOUR_SIGMA_CLIENT_SECRET --env SIGMA_API_BASE_URL=YOUR_SIGMA_API_BASE_URL -- uvx mcp-server-sigma==2.1.1

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

Check it worked

Ask Codex: List the tools of sigma.

If it does not start

spawn uvx ENOENT

uv is not on the PATH that Codex sees. Install it, or write the full path of uvx in the config.

The server starts, but its tools fail

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