Setup is where most people get stuck — so here's every step, with video. Pick your tool below, then follow one path start to finish: install the free editor, add your agent inside it, and sign in with an account you already have.
This is the window everything runs inside. Go to code.visualstudio.com, click the big Download button for your computer (Mac or Windows), and run the installer like any other app. It's free.
Open it like any other app — from your Applications folder on Mac or the Start menu on Windows. Once it opens, it'll look like this:
In the thin bar down the left side of VS Code, click the Extensions icon (four little squares). This is the add-ons store built into the editor.
Shortcut: Cmd+Shift+X on Mac, Ctrl+Shift+X on Windows.
In the search box at the top, type Claude Code. Pick the one published by Anthropic, then click Install. In the search box at the top, type Codex. Pick the official one published by OpenAI (it may be listed under the OpenAI / ChatGPT name), then click Install.
By default the panel can come and go. Let's keep it in view: click the Secondary Side Bar button in the top-right of VS Code, then right-click the bar that opens and choose Claude Code. Now it lives on the right for good. By default the panel can come and go. Let's keep it in view: click the Secondary Side Bar button in the top-right of VS Code, then right-click the bar that opens and choose Codex. Now it lives on the right for good.
Hit the orange Sign in button in the panel — it'll take you to Claude to log in and authorize the app. No card, no API key — your paid Claude plan already includes it. The first time you open it, it asks you to sign in. Click Sign in and finish in your browser using your ChatGPT account. No card, no extra setup — your paid ChatGPT plan already includes it.
You're already signed in, so the panel's ready. Type something simple like "hello, are you working?" — if it answers back, you're all set. Open the Codex panel from its icon, then type something simple like "hello, are you working?" If it answers, you're set.