How to install Codex CLI on macOS, Linux, and Windows

Codex is OpenAI’s coding agent for the terminal. Once it’s installed, you type codex, and it reads your code, edits files, and runs commands, turning natural-language requests into real changes. This article breaks the setup into four steps: check the system requirements, pick an install method, run the installer, and sign in. Every step has a command you can copy and run as-is.

Check the system requirements first

Codex CLI does not demand much from your machine, but a quick look at the official list saves you from discovering an incompatibility halfway through. It supports macOS, the common Linux distributions, and Windows 11 running through WSL2.

Four install methods, pick one

OpenAI ships four install paths that cover different habits. Any of them works day to day; the differences are the command and the environment dependencies.

If none of these appeal to you, grab the archive for your platform from the GitHub Releases page, extract it, rename the binary to codex, and put it on your PATH.

Step 1, install with the official script on macOS or Linux

Run this one line in your terminal. The script downloads the latest release for your platform and finishes the setup.

curl -fsSL https://chatgpt.com/codex/install.sh | sh

Open a new terminal window afterward so the updated PATH takes effect.

Step 2, Windows users install with PowerShell

Open PowerShell and run this line:

powershell -ExecutionPolicy ByPass -c "irm https://chatgpt.com/codex/install.ps1 | iex"

If you do most of your development inside WSL2, you can also run the Linux script from Step 1 in the WSL2 terminal. Both paths work.

Step 3, prefer a package manager, use npm or Homebrew

When Node.js is already on the machine, npm is the most convenient route:

npm install -g @openai/codex

macOS users can go through Homebrew instead:

brew install --cask codex

Step 4, sign in to your ChatGPT account

Once installed, type codex in the terminal. The first run walks you through the login flow. Pick Sign in with ChatGPT, approve the request in the browser, and you are back in the terminal, ready to go. Plus, Pro, Business, Edu, and Enterprise plans all include Codex usage.

If you would rather not use a ChatGPT account, the API key route works too; the setup steps are on the Codex authentication page in OpenAI’s documentation. If the subscription step is what blocks you, we wrote a guide on subscribing to ChatGPT and Claude Code without a credit card.

Verify the install and run a first task

Confirm the version prints correctly:

codex --version

Then start Codex in your project directory and give it a simple first task, like explaining the codebase:

codex exec "explain this codebase to me"

A normal response means the install and login both work. From there you can hand Codex real jobs; the piece on cutting landing page build time to 30 minutes with Codex and Claude Code shows that workflow in practice.

The full flow at a glance

The whole setup compresses to four steps. If you get stuck on any of them, jump back to the matching section for the exact command.