Firebase Docs Reference Namespace: auth functions.auth namespace static Namespace for Firebase Authentication functions. Interfaces UserBuilder UserInfo UserMetadata UserRecord Method user static user() returns functions.auth.UserBuilder Registers a Cloud Function to handle user authentication events. Returns non-null functions.auth.UserBuilder UserBuilder interface. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated April 5, 2018.