Codex CLI

Codex reads MCP servers from ~/.codex/config.toml, and its own codex mcp command writes that file for you.

Before you start

You need a Reduck account, and a paired browser if you want scripts to run on your own Chrome. Both are in the quick start.

Install the Codex version Reduck is tested against:

npm i -g @openai/[email protected]

Pin that version. Later releases have broken the connection to Reduck.

Add the server

codex mcp add reduck --url https://mcp.reduck.ai

Confirm it is connected

Run /mcp in a session. Reduck is listed, and the first call opens a browser to sign in to your Reduck account.

Settings worth changing

Codex asks for approval before each tool call, which interrupts a script mid-run. To let Reduck run unattended, set the approval mode for the server in ~/.codex/config.toml:

[mcp_servers.reduck]
url = "https://mcp.reduck.ai"
default_tools_approval_mode = "auto"

This applies to Reduck alone; every other server keeps asking.

To lift approvals for one session instead, start Codex with codex --full-auto (sandbox workspace-write, approval on-failure). That choice lasts only as long as the session.

If it does not appear

The account is on the free tier. Codex Pro is required for MCP servers.
Codex is a version other than 0.141.0. Reinstall the pinned version above.
Sign-in never finished. The browser tab that opens on the first call has to be completed before any tool works.

Try it

Ask for something on a real site, and let the agent pick the script:

Reduck finds a script for the site, runs it, and hands back the result. The script catalogue lists everything it can already do.