It uses GitHub's own APIs for syncing the storage with your repository, so there is no proxying, only direct access to GitHub.
When you sign in, a token is obtained on your behalf by the Penmark GitHub app, the redirect goes through and passes your own token to your browser, and then this allows the browser code of Penmark to use it to store & sync to GitHub directly
When you sign in, a token is obtained on your behalf by the Penmark GitHub app, the redirect goes through and passes your own token to your browser, and then this allows the browser code of Penmark to use it to store & sync to GitHub directly