Firebase Docs Reference FirebaseFunctions Framework Reference Constants The following constants are available globally. FunctionsErrorDomain Undocumented Declaration Swift let FunctionsErrorDomain: String FunctionsErrorDetailsKey Undocumented Declaration Swift let FunctionsErrorDetailsKey: 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 June 20, 2018.