Firebase Docs Reference firebase. auth. UserMetadata Interface representing a user's metadata. Index Properties creationTime lastSignInTime Properties Optional creationTime creationTime: string Optional lastSignInTime lastSignInTime: string 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 March 22, 2019.