Unless otherwise configured, the client libraries useApplication Default Credentialsto authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing theUnifiedCredentialsOptionThe following example shows how to explicitly load a service account key file:
[](std::string const& keyfile) {
auto is = std::ifstream(keyfile);
is.exceptions(std::ios::badbit); // Minimal error handling in examples
auto contents = std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
auto options =
google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
google::cloud::MakeServiceAccountCredentials(contents));
return google::cloud::video_livestream_v1::LivestreamServiceClient(
google::cloud::video_livestream_v1::MakeLivestreamServiceConnection(
options));
}
Follow these links to find examples for other*Clientclasses:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThe latest version available is 2.37.0-rc, with multiple previous versions available dating back to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries primarily use Application Default Credentials for Google Cloud service authentication, but this can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication can be overridden by providing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated with loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided for \u003ccode\u003evideo_livestream_v1::LivestreamServiceClient\u003c/code\u003e, \u003ccode\u003evideo_stitcher_v1::VideoStitcherServiceClient\u003c/code\u003e, and \u003ccode\u003evideo_transcoder_v1::TranscoderServiceClient\u003c/code\u003e to show overriding authentication.\u003c/p\u003e\n"],["\u003cp\u003eFor best practices and security, users should refer to the "Best practices for managing service account keys" guide and the "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,["Version 2.34.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/video/latest/video-override-authentication)\n- [2.41.0](/cpp/docs/reference/video/2.41.0/video-override-authentication)\n- [2.40.0](/cpp/docs/reference/video/2.40.0/video-override-authentication)\n- [2.39.0](/cpp/docs/reference/video/2.39.0/video-override-authentication)\n- [2.38.0](/cpp/docs/reference/video/2.38.0/video-override-authentication)\n- [2.37.0](/cpp/docs/reference/video/2.37.0/video-override-authentication)\n- [2.36.0](/cpp/docs/reference/video/2.36.0/video-override-authentication)\n- [2.35.0](/cpp/docs/reference/video/2.35.0/video-override-authentication)\n- [2.34.0](/cpp/docs/reference/video/2.34.0/video-override-authentication)\n- [2.33.0](/cpp/docs/reference/video/2.33.0/video-override-authentication)\n- [2.32.0](/cpp/docs/reference/video/2.32.0/video-override-authentication)\n- [2.31.0](/cpp/docs/reference/video/2.31.0/video-override-authentication)\n- [2.30.0](/cpp/docs/reference/video/2.30.0/video-override-authentication)\n- [2.29.0](/cpp/docs/reference/video/2.29.0/video-override-authentication)\n- [2.28.0](/cpp/docs/reference/video/2.28.0/video-override-authentication)\n- [2.27.0](/cpp/docs/reference/video/2.27.0/video-override-authentication)\n- [2.26.0](/cpp/docs/reference/video/2.26.0/video-override-authentication)\n- [2.25.1](/cpp/docs/reference/video/2.25.1/video-override-authentication)\n- [2.24.0](/cpp/docs/reference/video/2.24.0/video-override-authentication)\n- [2.23.0](/cpp/docs/reference/video/2.23.0/video-override-authentication)\n- [2.22.1](/cpp/docs/reference/video/2.22.1/video-override-authentication)\n- [2.21.0](/cpp/docs/reference/video/2.21.0/video-override-authentication)\n- [2.20.0](/cpp/docs/reference/video/2.20.0/video-override-authentication)\n- [2.19.0](/cpp/docs/reference/video/2.19.0/video-override-authentication)\n- [2.18.0](/cpp/docs/reference/video/2.18.0/video-override-authentication)\n- [2.17.0](/cpp/docs/reference/video/2.17.0/video-override-authentication)\n- [2.16.0](/cpp/docs/reference/video/2.16.0/video-override-authentication)\n- [2.15.1](/cpp/docs/reference/video/2.15.1/video-override-authentication)\n- [2.14.0](/cpp/docs/reference/video/2.14.0/video-override-authentication)\n- [2.13.0](/cpp/docs/reference/video/2.13.0/video-override-authentication)\n- [2.12.0](/cpp/docs/reference/video/2.12.0/video-override-authentication)\n- [2.11.0](/cpp/docs/reference/video/2.11.0/video-override-authentication) \n\nHow to Override the Authentication Credentials\n==============================================\n\nUnless otherwise configured, the client libraries use [Application Default Credentials](https://cloud.google.com/docs/authentication#adc) to authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing the [UnifiedCredentialsOption](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1UnifiedCredentialsOption.html) The following example shows how to explicitly load a service account key file: \n\n [](std::string const& keyfile) {\n auto is = std::ifstream(keyfile);\n is.exceptions(std::ios::badbit); // Minimal error handling in examples\n auto contents = std::string(std::istreambuf_iterator\u003cchar\u003e(is.rdbuf()), {});\n auto options =\n google::cloud::Options{}.set\u003cgoogle::cloud::UnifiedCredentialsOption\u003e(\n google::cloud::MakeServiceAccountCredentials(contents));\n return google::cloud::video_livestream_v1::LivestreamServiceClient(\n google::cloud::video_livestream_v1::MakeLivestreamServiceConnection(\n options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`video_livestream_v1::LivestreamServiceClient`](/cpp/docs/reference/video/2.34.0/video_livestream_v1_1_1LivestreamServiceClient-service-account-snippet)\n- [`video_stitcher_v1::VideoStitcherServiceClient`](/cpp/docs/reference/video/2.34.0/video_stitcher_v1_1_1VideoStitcherServiceClient-service-account-snippet)\n- [`video_transcoder_v1::TranscoderServiceClient`](/cpp/docs/reference/video/2.34.0/video_transcoder_v1_1_1TranscoderServiceClient-service-account-snippet)\n\nKeep in mind that we chose this as an example because it is relatively easy to understand. Consult the [Best practices for managing service account keys](https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys) guide for more details.\n\n###### See Also\n\n[Authentication Components](https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html) - for more information on the factory functions to create [`google::cloud::Credentials`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1Credentials.html) objects."]]