Amazon Cognito
Developer Guide

Adding User Pool Sign-in Through a Third Party

Your users can sign in through social identity providers like Facebook or Amazon, and through SAML identity providers. Whether they sign in directly or through a third party, all users have a user profile with customizable user attributes in the user pool directory.

Amazon Cognito User Pools provides a common set of tokens for all authenticated users from all IdPs, so backend systems can standardize on one set of tokens.