Skip to content

Codex

Codex is OpenAI’s coding agent for inspecting, editing, and checking project files. Start with a local copy or choose a cloud workspace when you need the work to run elsewhere.

Read official information

Where will Codex work on your project?

For local work, open the project folder in the ChatGPT desktop app, the Codex CLI, or a supported editor extension. Local work runs edits and commands on your computer. Codex can still send task context to its online model service. A cloud task uses a separate remote workspace. Review changed files and check results before applying them.

The usual local sign-in paths are ChatGPT and a supported API key. Managed workspaces may offer other options. For Codex Cloud, sign in to ChatGPT and choose an environment you can access. If the task needs a repository, choose one you have permission to share. When the default cloud environment is available, you can start without a repository.

What can Codex do before it asks you?

Check the selected project folder and the permission settings before you start. OpenAI documents local settings that can allow edits and commands inside the project without a prompt for every action. Your selected mode and workspace policy govern what needs approval.

Ask for a small change you can check. Read any permission request before approving it. For work that repeats, keep the project’s build and test instructions in an AGENTS.md file and check whether Codex picked them up.

Can you verify one local Codex edit?

Save the sample in a new local Git repository with no remote, credentials, or existing project files. Keep it separate from your app and live services, and limit write permissions to the sample folder. If you can’t verify the folder and its permissions, mark the expected edit on paper.

const pickupMessage = "Pickup starts at noon"

console.log(pickupMessage)
  1. Set a small target
    Save the sample as pickup.js and record its starting version in Git. Open only this sample folder in your local Codex client.
  2. Ask for one edit
    Ask Codex to change the pickup time from noon to 1 pm in pickup.js. Keep the task local and use only the existing file. The exercise needs no additional packages or service connections.
  3. Check the file and the result
    Use your Git client to confirm that only the pickup message in pickup.js changed from noon to 1 pm. If you see any other edits or files, stop at inspection. If the change matches and Node.js is already installed, run node pickup.js in the sample folder and check that it prints Pickup starts at 1 pm. With no Node.js, check the exact message in the file.

Which account pays for a Codex task?

A ChatGPT sign-in uses the allowance and any extra-credit options of your eligible plan or workspace. A supported local API-key sign-in instead bills usage to the associated OpenAI Platform account at API rates.

For applicable credit-based plans, the Standard-speed table quotes credits per million tokens, with separate rates for input, cached input, and output. A token is a small piece of text. Check the rates and access for your plan, model and speed. Cloud and workspace features can be limited or unavailable with an API key.