Install mcptest-py in Codex

What you need first

• Codex, installed.
• uv, which gives the uvx command the server starts with.

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 mcptest -- uvx mcptest-py

2. Start Codex again and type /mcp: the server is listed.

Check it worked

Ask Codex: List the tools of mcptest.

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.