diff --git a/.github/workflows/cpp-packaging.yml b/.github/workflows/cpp-packaging.yml
index f77cdd13cc..a4278b74d1 100644
--- a/.github/workflows/cpp-packaging.yml
+++ b/.github/workflows/cpp-packaging.yml
@@ -351,7 +351,7 @@ jobs:
       # Run the build in the host OS default shell since Windows can't handle long path names in bash.
       - name: Build desktop SDK
         run: |
-          python scripts/gha/build_desktop.py --arch "${{ matrix.architecture }}" --config "${{ matrix.build_type }}" --msvc_runtime_library "${{ matrix.msvc_runtime }}" --linux_abi "${{ matrix.linux_abi }}" --build_dir out-sdk ${VERBOSE_FLAG} ${{ matrix.additional_build_flags }}
+          python scripts/gha/build_desktop.py --arch "${{ matrix.architecture }}" --config "${{ matrix.build_type }}" --msvc_runtime_library "${{ matrix.msvc_runtime }}" --linux_abi "${{ matrix.linux_abi }}" --build_dir out-sdk ${VERBOSE_FLAG} ${{ matrix.additional_build_flags }} --gha_build
 
       - name: Archive SDK
         shell: bash
diff --git a/.github/workflows/desktop.yml b/.github/workflows/desktop.yml
index 103ab7066a..5ff5df0911 100644
--- a/.github/workflows/desktop.yml
+++ b/.github/workflows/desktop.yml
@@ -151,7 +151,7 @@ jobs:
       - name: Build SDK
         shell: bash
         run: |
-          python scripts/gha/build_desktop.py --build_tests --arch "${{ matrix.architecture }}" --config "${{ matrix.build_type }}" --msvc_runtime_library "${{ matrix.msvc_runtime }}"
+          python scripts/gha/build_desktop.py --build_tests --arch "${{ matrix.architecture }}" --config "${{ matrix.build_type }}" --msvc_runtime_library "${{ matrix.msvc_runtime }}" --gha_build
 
       - name: Stats for ccache (mac and linux)
         if: startsWith(matrix.os, 'ubuntu') || startsWith(matrix.os, 'macos')
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7795d9a946..a33df70e74 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -66,11 +66,15 @@ option(FIREBASE_FORCE_FAKE_SECURE_STORAGE
 option(FIREBASE_CPP_BUILD_PACKAGE
        "Bundle the Firebase C++ libraries into a zip file." OFF)
 option(FIREBASE_CPP_USE_PRIOR_GRADLE_BUILD
-        "When building with Gradle, use the previously built libraries." OFF)
+       "When building with Gradle, use the previously built libraries." OFF)
 option(FIREBASE_USE_BORINGSSL
-        "Build against BoringSSL instead of using your system's OpenSSL." OFF)
+       "Build against BoringSSL instead of using your system's OpenSSL." OFF)
 option(FIREBASE_USE_LINUX_CXX11_ABI
-        "Build Linux SDK using the C++11 ABI instead of the legacy ABI." OFF)
+       "Build Linux SDK using the C++11 ABI instead of the legacy ABI." OFF)
+
+# This should only be enabled by the GitHub Action build script.
+option(FIREBASE_GITHUB_ACTION_BUILD
+       "Indicates that this build was created from a GitHub Action" OFF)
 
 set(FIREBASE_ANDROID_STL "" CACHE STRING "STL implementation to use.")
 if (NOT FIREBASE_ANDROID_STL STREQUAL "")
@@ -139,6 +143,12 @@ if(DESKTOP AND NOT MSVC AND NOT APPLE)
   endif()
 endif()
 
+if(FIREBASE_GITHUB_ACTION_BUILD)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DFIREBASE_GITHUB_ACTION_BUILD=1")
+else()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DFIREBASE_GITHUB_ACTION_BUILD=0")
+endif()
+
 # Set directories needed by the Firebase subprojects
 # Directory to store generated files.
 set(FIREBASE_GEN_FILE_DIR ${CMAKE_BINARY_DIR}/generated)
diff --git a/app/src/app_common.cc b/app/src/app_common.cc
index 99425b7e54..a931b23db3 100644
--- a/app/src/app_common.cc
+++ b/app/src/app_common.cc
@@ -164,6 +164,12 @@ const char* kCpuArchitecture = "x86";
 #else
 #error Unknown operating system.
 #endif  // Operating system
+
+#if FIREBASE_GITHUB_ACTION_BUILD
+const char* kBuildSource = "github_action_built";
+#else
+const char* kBuildSource = "custom_built";
+#endif
 // clang-format=on
 
 const char* kApiClientHeader = "x-firebase-client";
@@ -303,6 +309,8 @@ App* AddApp(App* app, std::map<std::string, InitResult>* results) {
                          kCpuArchitecture);
     App::RegisterLibrary(FIREBASE_CPP_USER_AGENT_PREFIX "-stl",
                          kCppRuntimeOrStl);
+    App::RegisterLibrary(FIREBASE_CPP_USER_AGENT_PREFIX "-buildsrc",
+                         kBuildSource);
   }
   callback::Initialize();
   AppCallback::NotifyAllAppCreated(app, results);
diff --git a/app/src/app_common.h b/app/src/app_common.h
index 2f585acab2..1769da3674 100644
--- a/app/src/app_common.h
+++ b/app/src/app_common.h
@@ -45,6 +45,7 @@ namespace app_common {
 extern const char* kOperatingSystem;
 extern const char* kCppRuntimeOrStl;
 extern const char* kCpuArchitecture;
+extern const char* kBuildSource;
 
 // Extended API client header for Google user agent strings.
 extern const char* kApiClientHeader;
diff --git a/scripts/gha/build_desktop.py b/scripts/gha/build_desktop.py
index 186abe3ac4..3542a27713 100644
--- a/scripts/gha/build_desktop.py
+++ b/scripts/gha/build_desktop.py
@@ -150,7 +150,7 @@ def install_cpp_dependencies_with_vcpkg(arch, msvc_runtime_library, cleanup=True
 
 def cmake_configure(build_dir, arch, msvc_runtime_library='static', linux_abi='legacy',
                     build_tests=True, config=None, target_format=None,
-                    use_openssl=False, disable_vcpkg=False, verbose=False):
+                    use_openssl=False, disable_vcpkg=False, gha_build=False, verbose=False):
   """ CMake configure.
 
   If you are seeing problems when running this multiple times,
@@ -168,6 +168,8 @@ def cmake_configure(build_dir, arch, msvc_runtime_library='static', linux_abi='l
    use_openssl (bool) : Use prebuilt OpenSSL library instead of using boringssl
                         downloaded and built during the cmake configure step.
    disable_vcpkg (bool): If True, skip vcpkg and just use CMake for deps.
+   gha_build (bool): If True, this build will be marked as having been built
+                     from GitHub, which is useful for metrics tracking.
    verbose (bool): If True, enable verbose mode in the CMake file.
   """
   cmd = ['cmake', '-S', '.', '-B', build_dir]
@@ -216,6 +218,10 @@ def cmake_configure(build_dir, arch, msvc_runtime_library='static', linux_abi='l
   if not use_openssl:
     cmd.append('-DFIREBASE_USE_BORINGSSL=ON')
 
+  # When building from GitHub Actions, this should always be set.
+  if gha_build:
+    cmd.append('-DFIREBASE_GITHUB_ACTION_BUILD=ON')
+
   # Print out every command while building.
   if verbose:
     cmd.append('-DCMAKE_VERBOSE_MAKEFILE=1')
@@ -248,7 +254,7 @@ def main():
   # CMake configure
   cmake_configure(args.build_dir, args.arch, args.msvc_runtime_library, args.linux_abi,
                   args.build_tests, args.config, args.target_format,
-                  args.use_openssl, args.disable_vcpkg, args.verbose)
+                  args.use_openssl, args.disable_vcpkg, args.gha_build, args.verbose)
 
   # CMake build
   # cmake --build build -j 8
@@ -278,6 +284,7 @@ def parse_cmdline_args():
   parser.add_argument('--target', nargs='+', help='A list of CMake build targets (eg: firebase_app firebase_auth)')
   parser.add_argument('--target_format', default=None, help='(Mac only) whether to output frameworks (default) or libraries.')
   parser.add_argument('--use_openssl', action='store_true', default=None, help='Use openssl for build instead of boringssl')
+  parser.add_argument('--gha_build', action='store_true', default=None, help='Set to true when building on GitHub, for metric tracking purposes')
   args = parser.parse_args()
   return args