Codex is OpenAI's terminal coding agent. It reads and writes files, runs commands, and iterates under version control, with sandbox modes (read-only, workspace-write, full-access) and multi-provider support. In August 2026 OpenAI shipped a native Codex app for Linux; it runs on Omarchy and is available from the Omarchy Package Repository (OPR) for immediate install in Quattro.
What Codex CLI is
Codex CLI is OpenAI’s lightweight coding agent that runs locally in your terminal. It is part of a larger Codex family that also includes IDE extensions, a desktop app, and a cloud web agent.
Key features
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Local terminal agent - runs on your machine, not in the cloud.
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ChatGPT plan integration - sign in with an existing ChatGPT Plus/Pro plan.
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OpenAI API key support - bring your own API key for programmatic use.
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Simple and focused - minimal UI, fast to start.
Install
curl -fsSL https://chatgpt.com/codex/install.sh | sh
Or via npm:
npm install -g @openai/codex
Use case
Codex CLI is best for developers who already pay for ChatGPT and want a quick, official OpenAI terminal agent. It is less configurable than open-source alternatives but requires no setup beyond authentication.
License
Apache 2.0.
Honest caveat
Codex CLI is tied to OpenAI’s models and billing. If you want local models or fine-grained control, look at Aider, Cline, or OpenCode instead.