OpenAI OAuth v2's new Sign in with ChatGPT button lets users securely link their free or paid ChatGPT account that your app can use as an OpenAI API. It uses a reverse-engineered version of Codex's OAuth flow under-the-hood, and authenticates directly between your browser and OpenAI's servers with the credentials passed locally through a Sign in with ChatGPT browser extension.

And, just like OpenAI OAuth v1, you can always run `npx openai-oauth@latest` to instantly get a free local OpenAI API with your Codex account.

OpenAI OAuth v2 is open source under Apache-2.0 on GitHub: https://github.com/EvanZhouDev/openai-oauth

Let me know if you have any feedback or find any bugs!