I’ve been doing this for a while now with many projects. Essentially we have three ways to login: Google, Facebook and E-mail. In all cases it delegates autho

I’ve been doing this for a while now with many projects. Essentially we have three ways to login: Google, Facebook and E-mail. In all cases it delegates authority to an external place that you’ve setup before. For the social networks we use the e-mail as the key. For e-mail we decided to just send a code instead of using a url. Since the pattern of checking your e-mail on your device while working on your desktop is quite common.