ChatGPT Codex CLI

Connect ChatGPT Codex CLI to NeoStack AI.

Codex is OpenAI’s coding agent. It works with any ChatGPT account, including the free tier, so it’s a low-friction way to get started with NeoStack AI.

You need the NeoStack AI plugin version 3.1.8 or newer in your project.

Setup

Step 1 — install Codex (skip if you already have it)

npm install -g @openai/codex

Run codex once and sign in with your ChatGPT account. The desktop app from developers.openai.com/codex/app works too, and shares the same config.

Step 2 — download the NeoStack bridge

Grab the file for your machine and put it somewhere permanent (for example your user folder):

On macOS and Linux, make it executable once: chmod +x ~/neostack-bridge-macos-arm64

Step 3 — register it with Codex

codex mcp add unreal -- /path/to/the/bridge/you/downloaded

That’s the whole setup. There are no ports or tokens to configure. The bridge finds your running editor by itself, even after editor restarts.

Step 4 — try it

Open your project in Unreal, then ask Codex:

Use the unreal tool to print “hello from codex”.

If the message shows up in the editor’s Output Log, you’re done.

How it finds the editor

The bridge prefers the project of the folder you’re running Codex in. Outside a project folder, it connects to the single running editor, or asks you to choose when several are open (ask Codex to “list unreal projects” and “select” one).

If something doesn’t connect, ask Codex to “run unreal_status”. It reports what the bridge found and what’s wrong.

Use Codex inside the editor (ACP)

If you’d rather not set up the bridge, you can run Codex entirely from the editor’s chat panel via ACP.

1. Install Codex CLI (Step 1 above).
2. Authenticate by running codex once in a terminal.
3. Open Agent Chat in Unreal (Tools → Agent Chat).
4. Select Codex CLI from the agent dropdown.

Plugin settings

Which ChatGPT plan?

See Choosing an Agent for the full breakdown.

Troubleshooting