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ChatGPT and Codex guides
How to download, sign in to and use ChatGPT and Codex themselves. First check how you pay, then follow the matching route.
This section covers downloading, signing in to and using ChatGPT and Codex themselves. If you only want to put your 2api key into Codex, Claude Code and other tools, go straight to Set up every agent with magpie.
Where Codex is now
Section titled “Where Codex is now”Since July 2026, the Codex desktop app has been part of the ChatGPT desktop app. You can now use Codex from these places:
| Entry point | Who it’s for | Notes |
|---|---|---|
| Codex in the ChatGPT desktop app | You want a graphical interface | Open the ChatGPT desktop app and choose Codex from the dropdown menu in the top-left corner. Available for macOS, Windows and Linux |
| Codex CLI | You’re used to the terminal | Run codex in your project directory |
| IDE extension | You write code in VS Code or Cursor | The official extension’s ID is openai.chatgpt |
| Codex cloud | You hand tasks off to run in the cloud | You must sign in with a ChatGPT account |
That’s why the download page says ChatGPT, not Codex. This is normal. If you installed the Codex desktop app before, it becomes the ChatGPT desktop app after an update. Open it, then switch to Codex.
Two ways to pay
Section titled “Two ways to pay”When you sign in to Codex, you can choose between signing in with ChatGPT and using an API key. The two don’t take money from the same place:
| With a ChatGPT subscription | With a 2api key | |
|---|---|---|
| Who it’s for | You topped up Plus or Pro at cz.2api.dev | You have balance or a plan on 2api |
| Billing | Uses the usage included in your plan. When it runs out, you wait for it to reset (Plus has a 5-hour limit) | Charged by tokens from your 2api balance. For prices, see the group multipliers |
| Sign-in | Sign in with your ChatGPT account | Sign in with an API key. We recommend one-click setup with magpie |
| Features | All of them, including cloud tasks and the mobile app | Everything for coding locally works. Features that depend on a ChatGPT account, such as cloud tasks, don’t |
To use both, let magpie handle it: Codex stays signed in with ChatGPT, and one toggle in magpie switches between 2api and your subscription. No config files to edit.
If you use a ChatGPT subscription, note this: Free and Go can only use Codex (GPT-6 Luna) in the desktop app. Only Plus and Pro can use it in the CLI, the IDE extension, on the web and on iOS.
Where to start
Section titled “Where to start”First check that the plan is active. Then download ChatGPT and sign in to Codex with your ChatGPT account.
I use my 2api balanceInstall Codex first, then set up your 2api key in one click with magpie.
All pages
Section titled “All pages”- ChatGPT: Download and sign in, Plus and Pro, Common features
- Codex: Install, Sign in, Get started, Windows tips
- Having problems: Codex install and sign-in, ChatGPT
This section follows OpenAI’s official documentation, checked in October 2026. OpenAI updates often, so button names and menu locations may differ slightly. Go by what you see on screen.