> For the complete documentation index, see [llms.txt](https://docs.adnuntius.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.adnuntius.com/other-useful-information/mcp-server/openai-codex.md).

# OpenAI Codex

Follow the 3 steps below to get setup with OpenAI Codex

#### 1. Install the Codex Command Line Interface (CLI)

This is recommended even if you want to use the desktop app, because the app MCP has a number of bugs<sup>1</sup> which make it unreliable to manage MCP servers in. The latest steps for installing the CLI can be found at:

{% embed url="<https://developers.openai.com/codex/quickstart?setup=cli>" %}

1. omits the RFC 8707 resource= parameter so tokens get the wrong audience (#13891), sends a malformed /token exchange that fails with "Required argument is missing" (#5045), silently does nothing when DCR isn't supported and prints "No authorization support detected" in the CLI (#11585), can't reach its own localhost:1455 callback in Windows+WSL or other multi-namespace setups (#12263), and even when login succeeds the Desktop app still reports auth\_status: "unsupported" and never imports the server's tools into threads (#20009)

#### 2. Add the Adnuntius MCP Server and Authorize it

In a terminal, run

`codex mcp add adnuntius --url https://api.adnuntius.com/api/mcp`

This will open a browser window for you to complete the authentication by pressing the Authorize button. If you are not already signed in to the Adnuntius platform you will be asked to do so first.

#### 3. Use codex to ask questions about Adnuntius

Type `codex`to start the CLI and start asking questions.

#### 4. (Optional) Use the desktop app

This can be installed from here:

{% embed url="<https://developers.openai.com/codex/quickstart?setup=app>" %}

If you completed steps 1 and 2 above, you should be able to ask questions about Adnuntius in the app. If you didn't you can try and add the integration in the app using the following steps:

* Go to the `MCP Server` page in settings, and select `+Add Server`
* Select `Streamable HTTP` and enter [`https://api.adnuntius.com/api/mcp`](https://api.adnuntius.com/api/mcp) as the URL. You can name the server anything you like.
* Back on the MCP servers page, an Authorize button should appear after about 10 seconds (otherwise click on the gear icon). This Authorize button will open your browser to complete the login flow.