Codex & Gemini CLI — Code with AI
Codex: OpenAI's coding agent
Codex runs in your terminal (Codex CLI), inside editors like VS Code and Cursor, as a desktop app, and in the cloud at chatgpt.com/codex, where it works in a sandbox and comes back with a diff or pull request. Sign in with your ChatGPT account (Plus and up) or an API key.
$ npm install -g @openai/codex# or: brew install --cask codex$ codex✻ Sign in with ChatGPT to continue…
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Codex: OpenAI's coding agent
Codex runs in your terminal (Codex CLI), inside editors like VS Code and Cursor, as a desktop app, and in the cloud at chatgpt.com/codex, where it works in a sandbox and comes back with a diff or pull request. Sign in with your ChatGPT account (Plus and up) or an API key.
Codex essentials
- /init — creates an AGENTS.md with instructions for your repo (the open standard many agents read).
- /permissions — choose what Codex may do without asking (edit files, run commands) and review the sandbox.
- /model — pick the model and reasoning effort.
- /review — have it review your changes and find issues before you commit.
- codex exec "…" — run it non-interactively in scripts and pipelines. codex resume — reopen a past session.
Gemini CLI: the free on-ramp
Google's open-source Gemini CLI brings Gemini into your terminal. Sign in with a personal Google account for a generous free tier — the easiest zero-cost way to try a terminal coding agent. It supports a GEMINI.md context file, Google Search grounding, and MCP.
Part of 💻 Code with AI in the free AI Bootcamp.