Agent harnesses
Codex
Lightweight coding agent that runs in your terminal or as a native Linux app
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.
GitHub stars
128,904
daily snapshots
2026-09-01 to 2026-10-13
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
- Local terminal agent - runs on your machine, not in the cloud.
- ChatGPT plan integration - sign in with an existing ChatGPT Plus/Pro plan.
- OpenAI API key support - bring your own API key for programmatic use.
- 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.
At a glance
Who's behind it
OpenAI
- GitHub stars
-
https://github.com/openai/codex
128,904 stars - updated 2026-10-13
- License
- Apache-2.0
- Platforms
- cli, linux
- Install
npm install -g @openai/codex # or install via OPR on Omarchy/Quattro- Model support
- OpenAI models (ChatGPT plan or API key), plus OpenRouter, Gemini, Ollama