This directory contains a Package.swift file that allows us to fetch the Firebase iOS SDK and Google User Messaging Platform via Swift Package Manager (SwiftPM). The Package.swift here must declare all Swift packages used by the Firebase C++ SDK. The packages are resolved automatically during the CMake configure step, and the header files and xcframeworks within them are referenced by the Objective-C++ and C++ code in this SDK (see setup_spm_headers in CMakeLists.txt for details).

The swift_headers subdirectory contains copies of the most recent Swift bridging headers (*-Swift.h) for the Firebase iOS libraries that are written in Swift, enabling them to be called from this SDK's Objective-C++ code. These headers are updated via this repository's update-dependencies.yml GitHub Actions workflow.