# How to run Codex in a desktop app on Mac and Windows with your ChatGPT sign-in

> HB Code is a desktop app for Mac and Windows that runs Codex with your ChatGPT sign-in. It's separate from OpenAI's own ChatGPT desktop app.

OpenAI has its own desktop app for Codex, the ChatGPT desktop app. HB Code is a separate app by another company, helpful bits GmbH, and it runs Codex on your computer with your ChatGPT sign-in.

HB Code is a desktop app for Mac and Windows. It runs Claude Code and Codex on your own computer with your own Claude and ChatGPT plans.

## Steps

1. Install HB Code. The Mac download is on this site and needs Apple silicon and macOS 12 or later. The Windows app is in the Microsoft Store and needs an x64 PC with Windows 10 version 1809 or later.
2. Start the app. On the screen Connect your ChatGPT account, press Sign in with ChatGPT. Finish the sign-in in your browser. You need a ChatGPT account with Codex access.
3. Press Add project in the sidebar. Choose a project folder. Press New session on the project. Choose Codex under Agent. Press Start Codex session.
4. To continue a saved Codex thread of that folder, select it in the same dialog. Read the preview. Then press Continue conversation.
5. Choose the model and the reasoning effort with the model control in the composer. The list comes from Codex for your account. The speed is Standard or Fast.
6. Open Settings › Agents. Select Codex. The Subscriptions card lists each ChatGPT account with its limit windows. Press Add subscription to sign in to one more account.

## Notes

- HB Code ships its own build of the Codex app-server inside the app, made from OpenAI's open-source Codex with HB Code's own changes. It doesn't use a codex that you installed. An app update brings a new build.
- The sign-in is with ChatGPT only. The app has no API-key sign-in for Codex, and HB Code doesn't read the credential that Codex keeps.
- HB Code saves its Codex sessions in a Codex profile folder inside its own application data, not in ~/.codex.
- The access levels have the Codex names: Read only, Full auto, Full access, and Never ask.

## Details in the handbook

- [Profiles and sign-in](https://www.hbcode.ai/docs/codex-app-server.md#accounts): The Codex app-server integration
- [Usage limits](https://www.hbcode.ai/docs/codex-app-server.md#usage-limits): The Codex app-server integration
- [You choose the agent when you create the session](https://www.hbcode.ai/docs/agents.md#agent-choice): How Codex and Claude share one chat layer
- [Sign-ins and optional keys](https://www.hbcode.ai/docs/setup.md#accounts): Setup: sign-ins, regions, and remote access

## Guides

- [How to check usage limits and use more than one account](https://www.hbcode.ai/claude-code-usage-limits.md)
- [How to check what Claude Code or Codex did](https://www.hbcode.ai/claude-code-ui.md)
- [How to run several Claude Code and Codex sessions](https://www.hbcode.ai/claude-code-sessions.md)
- [How to use Claude Code or Codex on your phone](https://www.hbcode.ai/claude-code-mobile.md)
- [How to see what the subagents of Claude Code do](https://www.hbcode.ai/claude-code-subagents.md)
- [How to try Claude Code and Codex on the same task](https://www.hbcode.ai/claude-code-vs-codex.md)
- [Download HB Code](https://www.hbcode.ai/downloads)