Codex on your Mac

Mention @Codex in a thread and the turn runs on your own Mac - your installed Codex CLI, in a folder you choose, on your own ChatGPT plan.

Updated September 22, 20265 min read

@Codex is the twin of @Claude Code for OpenAI's Codex CLI. Mention it in a thread and Naumu hands that turn to the Naumu desktop app on your own Mac, which runs the codex you already have installed, inside a folder you choose. What it thinks, the commands it runs, the files it edits and its answer all stream back into the thread like any other agent reply.

Everything that is true of @Claude Code is true here: it is personal (your machine, your folder, your account, only your own messages), it has your access to the space over MCP, it keeps a session per thread, and you can keep typing while it works. This page covers only what is different.

This is not the same as connecting Codex to Naumu over MCP. There, Codex runs in your terminal and reaches into Naumu for context. Here, the conversation is in Naumu and the run happens on your Mac.

What you need

A Mac running the Naumu desktop app, the same build that carries Codex. If the composer says Update the Naumu desktop app to use Codex, get the latest one at naumu.ai/download.
Codex installed and signed in on that Mac. Install it with brew install codex or npm install -g @openai/codex@latest, then run codex login once. Naumu only checks that a login exists; it never handles your OpenAI account. Runs spend your ChatGPT plan's Codex usage, not your Naumu credits.
A seat in the space. Guests and public visitors don't get it.

Find it in your space

There is nothing to switch on. The first time someone with a seat opens a space, a Codex member is added next to Claude Code. From then on you can @-mention it like anyone else, and it appears in the agents list in Settings.

Both agents share the space's folder on your Mac: pick it once for either of them and the other uses it too.

Two agents, one thread

Tagging @Codex makes it the thread's default replier on this device, the same way tagging @Claude Code does. Tagging the other one, or @Naumu, hands the thread over. Each agent keeps its own session in the thread, so switching back later continues where that agent left off.

A message you post while your own Codex run is working joins that run, once the turn is under way. A message that tags the other agent asks for a fresh turn instead, and your Mac runs one turn per thread at a time, so it comes back as Your Mac is already running a turn in this thread, so Codex couldn't start. Try again when it finishes. Nothing is queued: send it again once the run is done.

Model, effort and access

The gear's Codex block reads the model list from the Codex on your Mac, so it shows exactly what your ChatGPT plan offers:

Model - Default (whatever your Codex config says) or any model your account lists.
Effort - Default or one of the reasoning efforts the chosen model supports.
Access - how far it may go on your machine:
- Read - a read-only sandbox: it can look around and run commands that don't write.
- Edit - edits files and runs commands inside the folder, no network. This is the default.
- Full - no sandbox.

Full lets Codex run anything on your Mac unattended, so it is honoured only for a message you typed in the desktop app on that same Mac. A message sent from a browser tab or your phone runs at Edit instead.

Your space is reachable at every access level: Read limits what Codex may do to your files, not what it may do in Naumu, exactly as with @Claude Code.

The context ring

The ring on the reply chip shows how full the thread's Codex session is, against the context window of the model in use. Compact runs Codex's own compaction on the session, on the Mac that holds it.

When something goes wrong

Errors come back as plain messages in the thread: Codex isn't signed in on your Mac (run codex login), Codex on your Mac is too old for Naumu (update it with brew upgrade codex or npm install -g @openai/codex@latest - unlike Claude Code, Codex does not update itself), Your Mac is already running a turn in this thread, so Codex couldn't start. A ChatGPT usage limit shows up as the run's error, with Codex's own wording.

Claude Code on your Mac - the same feature with Claude Code; everything not covered here works the same way.
Codex - the other direction: Codex in your terminal, reaching into Naumu.
Agents - the Naumu-hosted agents every space can have.