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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThis document details how to override the default authentication credentials for Google Cloud services, which typically use Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate version is 2.37.0-rc, with the most recent stable version being 2.36.0, and there are several versions available that are listed.\u003c/p\u003e\n"],["\u003cp\u003eOverriding the default credentials can be accomplished by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and providing a service account key file, as shown in the provided example code.\u003c/p\u003e\n"],["\u003cp\u003eExamples for \u003ccode\u003ecloudbuild_v1::CloudBuildClient\u003c/code\u003e and \u003ccode\u003ecloudbuild_v2::RepositoryManagerClient\u003c/code\u003e are provided, demonstrating how to apply service account credentials to them.\u003c/p\u003e\n"],["\u003cp\u003eThe provided documentation links to the \u003ccode\u003eAuthentication Components\u003c/code\u003e page for more information on creating \u003ca href=\"https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1Credentials.html\"\u003e\u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e\u003c/a\u003e and it is recommended to check out the best practices for managing service account keys.\u003c/p\u003e\n"]]],[],null,[]]
