# Codex CLI

Add the Reduck MCP server to the Codex command line, pin the Codex release Reduck is tested against, and let scripts run without an approval prompt.

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

> [!WARNING]
> **Codex Pro is required.** MCP servers are not available to free Codex accounts.

## 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](https://docs.reduck.ai/#quick-start).

Install the Codex version Reduck is tested against:

```bash
npm i -g @openai/codex@0.141.0
```

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

## Add the server

```bash
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`:

```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:

> Use Reduck to get me the weather in Paris for the next two weeks.

Reduck finds a script for the site, runs it, and hands back the result. The
[script catalogue](https://reduck.ai/explore/scripts) lists everything it can already do.