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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 multiple prior versions, such as 2.36.0, 2.35.0, and so on, all the way down to 2.11.0, each with specific documentation pages.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries use Application Default Credentials to authenticate with Google Cloud Services unless configured otherwise, and overriding is possible.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication can be overridden by providing a \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated by loading a service account key file in the example code snippet.\u003c/p\u003e\n"],["\u003cp\u003eExamples for overriding authentication are provided for \u003ccode\u003ecloudbuild_v1::CloudBuildClient\u003c/code\u003e and \u003ccode\u003ecloudbuild_v2::RepositoryManagerClient\u003c/code\u003e classes, both accessible via links.\u003c/p\u003e\n"],["\u003cp\u003eFor details about creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, refer to the Authentication Components page.\u003c/p\u003e\n"]]],[],null,[]]
