Codex CLI runs natively on Windows: install it from PowerShell, sign in with your ChatGPT plan, and it works inside OpenAI’s own Windows sandbox, with no WSL needed. Codee3 is a free Windows IDE that runs that same Codex beside your code, so each Codex session sits next to your files, terminal and project.
Native Windows or WSL?
Native. OpenAI’s Windows guide says to use Codex’s native Windows sandbox by default: it enforces Codex’s file and network permissions on every command it runs. It lists three: mxc, recommended on compatible devices, with elevated and unelevated as older fallbacks. WSL is for when your work needs Linux tools, or already lives in WSL. Windows 11 is OpenAI’s recommended baseline; a recent, fully updated Windows 10 can work but is less reliable.
Windows support from learn.chatgpt.com/docs/windows/windows-sandbox, checked 2026-10-21.What you get in Codee3
Codex itself doesn’t change. Codee3 starts your own copy, on your own account, under OpenAI’s terms. What Codee3 adds is the window around it: an editor, a terminal and your project, with every agent’s chat beside them.
Free, for as long as you like
- A code editor, terminal, search and extensions
- Codex sessions beside your code: start as many as you like
- Claude Code and Gemini CLI in the same window, if you use them too
- Needs you: when Codex asks before running a command, the question usually shows in one rail
- Agents read the project brain, a written record of what you decided
- Each new agent in its own git worktree; land its work in one step, and undo it
- Up to 2 projects open at a time
Founder, US$149 a year, adds
- An orchestrator: say what you want in plain words, and it plans the jobs
- Helpers working in parallel, each in its own git worktree
- Guards: a change that breaks a recorded decision is stopped
- Unlimited projects
1. Install Codex CLI
OpenAI’s README gives a PowerShell installer for Windows; npm install -g @openai/codex works too. Codee3 uses Git for every project, so install Git for Windows as well.
Install commands from github.com/openai/codex, checked 2026-10-21.2. Sign in, inside Codex
Run codex once and choose Sign in with ChatGPT. OpenAI’s README recommends it for Plus, Pro, Business, Edu and Enterprise plans; an API key also works, with more setup. The sign-in stays between you and OpenAI. Codee3 never sees a key or a password, and never resells AI.
Plans and sign-in from github.com/openai/codex, checked 2026-10-21.3. Open your folder in Codee3
Open Codee3, choose your project’s folder, then press New agent and choose Codex. It opens beside your files, and every agent you start is listed there, each with its own stop. For now, read Codex’s replies on its Screen tab: they don’t show in its chat yet (known limits, below).
Which Codex GUI: OpenAI’s app or Codee3?
OpenAI’s ChatGPT desktop app also runs Codex natively on Windows, with a Windows sandbox. If Codex is the only agent you use, it may be all you need. Codee3 suits you if you also use Claude Code or Gemini CLI, want a full code editor around your agents, or want one written record of decisions that every agent reads. Side by side: Codee3 vs the Codex app.
The app’s Windows support from learn.chatgpt.com/docs/windows/windows-sandbox, checked 2026-10-21.Known limits today
- On Windows, the first command in each new Codex session takes a second or two while its sandbox prepares the folder. The very first time Codex runs on a computer, it may take a few minutes to set up its sandbox before your first command starts.
Each release and what it fixed is on the changelog. Using Claude too? See the Claude Code GUI for Windows. Moving over from Cursor? See what changes if you switch.