Amazon Cognito
Developer Guide

Amazon Cognito User Pools API Reference

With Amazon Cognito user pools, you can enable your web and mobile app users to sign up and sign in. You can change passwords for authenticated users and initiate forgotten password flows for unauthenticated users. For more information, see User Pool Authentication Flow and Using Tokens with User Pools.

For a complete user pool API reference see Amazon Cognito User Pools API Reference.