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::binaryauthorization_v1::
BinauthzManagementServiceV1Client(
google::cloud::binaryauthorization_v1::
MakeBinauthzManagementServiceV1Connection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 release candidate version is 2.37.0-rc, and the content details version 2.28.0.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically use Application Default Credentials for Google Cloud Service authentication, but this can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eTo override the default credentials, you can use \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated with an example of loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples for overriding credentials with other \u003ccode\u003e*Client\u003c/code\u003e classes are provided for \u003ccode\u003eBinauthzManagementServiceV1Client\u003c/code\u003e, \u003ccode\u003eSystemPolicyV1Client\u003c/code\u003e, and \u003ccode\u003eValidationHelperV1Client\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eFor best practices regarding service account keys, refer to the linked guide, and the Authentication Components link offers further details on \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e object creation.\u003c/p\u003e\n"]]],[],null,[]]