Social Authentication Patterns — Beyond 'Sign In With Google'

Social authentication is the most user-friendly way to handle login. No passwords to remember, no email verification delays, no "forgot password" flows. Users click one button, authorize with a provider they already trust, and they're in. It's so smooth that most new applications default to it.

Your AI agent can set up Google or GitHub login in minutes. That part's easy. The hard part — the part that AI agents routinely get wrong — is everything that happens after the first login. What happens when a user signs up with Google and later tries to log in with GitHub using the same email? What happens when they want to link both accounts? What happens when Apple hides their real email?

These are the edge cases that determine whether your auth system is solid or a source of endless support