Use the Codex CLI

The Codex CLI is OpenAI's coding agent for the terminal. Xandria can run the Agent on it, using your own Codex sign-in and plan. Tested on Windows, macOS and Linux.

1. Install and sign in to Codex

1. Install the Codex CLI by following OpenAI's instructions.
2. Open a terminal, run codex and sign in when it asks.
3. Check it works: ask it something, then quit.

Xandria never sees your Codex password; it uses the sign-in Codex saved.

2. Choose Codex in Xandria

Xandria already lists Codex under Configured Providers, set to run the codex command.

1. Open Settings → AI.
2. Under Model Defaults, open the Chat list and choose Codex.
3. Find Codex in Configured Providers and choose Test. Xandria runs Codex and reports whether it answered.

If Codex isn't on your PATH, enter the full path to the codex program in Binary Path in its card. To pick a model, choose it in Model; left empty, Codex uses its own default.

Open Agent from the rail and ask a question. See Ask your library.

If you removed Codex, add it again: under Model Defaults, open Chat, choose Add Provider, set Model Kind to Agent Harness and Served By to Codex CLI, then choose Add Provider.

What Codex can touch

Codex works on your library through Xandria's own tools, with the same approvals as any Agent: changes to Notes, Canvas and Collections wait for you to approve them. See Let AI edit Notes and Canvas.

Sandbox in the provider's card controls what Codex may do on your computer outside Xandria. It starts at Read Only; leave it there unless you know you need more.

Your questions and the passages the Agent reads go to OpenAI under your Codex account and its terms. See What stays private.

If the test fails

• Codex isn't found: set Binary Path to the full path of codex. In a terminal, which codex (macOS, Linux) or where codex (Windows) shows it.
• Codex isn't signed in: run codex in a terminal and sign in again.
• It times out: check Codex works in a terminal, then test again.

Next: Use the OpenCode CLI