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::servicemanagement_v1::ServiceManagerClient(
google::cloud::servicemanagement_v1::MakeServiceManagerConnection(
options));
}
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides documentation for various versions of the service management API, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe content demonstrates how to override default authentication credentials using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, especially for cases where Application Default Credentials are not suitable.\u003c/p\u003e\n"],["\u003cp\u003eThe example code shows how to explicitly load authentication details from a service account key file, which can be useful in numerous situations, but users are advised to check best practices for key management.\u003c/p\u003e\n"],["\u003cp\u003eUsers can consult the "Authentication Components" section for more information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
