I want to create a browser extension that reproduce the Stack Overflow navbar (inbox and achievements): [![Stack Overflow navbar][1]][1] I need for that to authenticate the current user using the [authentication API](https://api.stackexchange.com/docs/authentication). For this step, I need to provide a `redirect_uri` parameter that *must be under an app's registered domain*. It is used to redirected the user when he/she logged in. My issue is that browser extensions don't have a URL (it's just like a local web application). So how can I log a user in a browser extension using the API? [1]: https://i.sstatic.net/mPVlg.png