Unless otherwise configured, the client libraries use Application Default Credentials 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 The 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::cloudbuild_v1::CloudBuildClient(
google::cloud::cloudbuild_v1::MakeCloudBuildConnection(options));
}
Follow these links to find examples for other *Client classes:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThe latest version available is 2.37.0-rc, with a range of previous versions from 2.36.0 down to 2.11.0 also accessible.\u003c/p\u003e\n"],["\u003cp\u003eBy default, client libraries utilize Application Default Credentials for authentication with Google Cloud Services, but this can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default authentication by supplying the UnifiedCredentialsOption, and a service account key file can be loaded directly for this purpose, using the provided code example.\u003c/p\u003e\n"],["\u003cp\u003eExamples are available for both \u003ccode\u003ecloudbuild_v1::CloudBuildClient\u003c/code\u003e and \u003ccode\u003ecloudbuild_v2::RepositoryManagerClient\u003c/code\u003e for overriding authentication.\u003c/p\u003e\n"],["\u003cp\u003eFor in depth information regarding creating the credentials object itself, see the Authentication Components document.\u003c/p\u003e\n"]]],[],null,[]]