Using Codex in VS Code, Cursor and Other IDEs

Who this is for and what you will get

If you write code in VS Code, Cursor or Windsurf and want Codex working right beside it, this guide is for you. You will learn how to install the extension, open the Codex sidebar, start a chat with editor context, review the changes Codex makes and roll them back when needed.^[1]

What the extension does

The Codex IDE extension keeps Codex next to your code. You bring open files and selections into the prompt, review edits in place, and hand longer work off without leaving the editor.^[1] Codex starts from the code you are already looking at, so the first message can stay short. You also spend less time restating the problem in the chat.^[1]

Where it installs

VS Code and compatible editors use the Codex extension. The docs name Visual Studio Code, Cursor, Windsurf and Visual Studio Code Insiders as editors. The VS Code listing is on the Visual Studio Marketplace under the item openai.chatgpt.^[1] Xcode and the JetBrains IDEs provide their own integrations instead.^[1] The docs link Xcode's setup instructions for its coding assistant and the JetBrains help page for the Codex agent.^[1] For VS Code, Cursor and Windsurf, the install links open the extension directly in each editor.^[1]

How to open Codex

In VS Code, Cursor or Windsurf, select the Codex icon. If the icon is not visible, open the Command Palette and run Codex: Open Codex Sidebar.^[1] In Xcode, open the coding assistant, start a new chat and choose Codex as the agent.^[1] In a JetBrains IDE, open AI Chat and select Codex.^[1]

Your first chat

Open a project and ask Codex to explain the codebase, make a focused change or help you debug an issue.^[1] Three typical first requests are an explanation of the code, a focused change, or help with a bug.^[1] In the composer you can reference open files, selected code and recent chats, and Codex works with that material.^[1] Create Git checkpoints before and after each task, so you can revert the changes if the result is not what you wanted.^[1] The docs also link to a guide of best practices for working with Codex.^[1]

Reviewing changes

Codex shows a concise summary together with the changed lines, without an extra navigation pane. You can inspect the affected files, keep only the edits you want, and ask for a follow-up from the same view. While you decide which changes to keep, the code and the rationale stay visible together.^[1]

When the IDE extension fits

The docs describe four good fits. The first is focused edits, where the relevant files and Codex sit in one view. The second is learning unfamiliar code by asking about the files and symbols that are already open. The third is reviewing changes in place next to the code. The fourth is delegating a larger task.^[1]

Bigger tasks

Keep quick, hands-on iteration local. For a task that needs more time or room, connect Codex web and delegate it from the IDE. The chat stays available, so you can come back later and review the result.^[1]

Whether a task stays local depends on how much time and room it needs.^[1]

Next steps

The docs have separate pages on prompting with editor context, on IDE commands and on configuring the extension.^[1]