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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe latest release candidate version available is 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThis document provides a list of available versions, ranging from the latest release candidate down to version 2.11.0 for the service management documentation.\u003c/p\u003e\n"],["\u003cp\u003eThe default authentication method for client libraries is Application Default Credentials, however it is possible to override this.\u003c/p\u003e\n"],["\u003cp\u003eUsers can override default authentication by utilizing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, with an example provided demonstrating the explicit loading of a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eFor further information on authentication credentials creation, refer to the Authentication Components section.\u003c/p\u003e\n"]]],[],null,[]]
