> ## Documentation Index
> Fetch the complete documentation index at: https://docs.yellow.pro/llms.txt
> Use this file to discover all available pages before exploring further.

# Install Codex CLI

> Set up OpenAI's Codex CLI on your machine before wiring in the Yellow.pro MCP server.

<Warning>
  Before installing an AI CLI, make sure you've completed Yellow\.pro's account setup first — connecting your wallet, creating a sub-account, and completing verification. See **[Agent Onboarding](/mcp/getting-started)** for the full walkthrough. The steps below assume your Yellow\.pro account is already set up and you're ready to pair an AI agent to it.
</Warning>

If `codex --version` already works in your terminal, skip ahead to [Installation](/mcp/installation) and use `yellow-pro setup codex`. Otherwise, follow the steps below first.

<Steps>
  <Step title="Install">
    Install Codex CLI globally via npm:

    ```bash theme={null} theme={null}
    npm install -g @openai/codex
    ```

    Alternative install methods:

    ```bash theme={null} theme={null}
    # macOS (Homebrew)
    brew install --cask codex
    ```

    ```bash theme={null} theme={null}
    # Windows
    winget install OpenAI.Codex
    ```
  </Step>

  <Step title="Verify">
    Open a **new** terminal window (a window that was already open won't see an updated `PATH`), then run:

    ```bash theme={null} theme={null}
    codex --version
    ```

    <Warning>
      If you see `command not found: codex`, npm's global bin directory likely isn't on your `PATH`. Check where npm installs global packages with `npm config get prefix`, then add `<that path>/bin` to your `PATH` (e.g. in `~/.zshrc`) and open a fresh terminal window.
    </Warning>
  </Step>

  <Step title="Log in">
    Run:

    ```bash theme={null} theme={null}
    codex login
    ```

    This opens a browser-based sign-in flow using your ChatGPT account. Check that it worked with:

    ```bash theme={null} theme={null}
    codex login status
    ```

    <Info>
      For headless machines without a browser, use `codex login --device-auth` instead. To authenticate with an API key rather than a ChatGPT account, use `codex login --with-api-key` or set the `CODEX_API_KEY` environment variable.
    </Info>
  </Step>
</Steps>

Next: continue to [Installation](/mcp/installation) and run `yellow-pro setup codex` to register the Yellow\.pro MCP server with Codex CLI.