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::workstations_v1::WorkstationsClient(
google::cloud::workstations_v1::MakeWorkstationsConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document provides versioned documentation for overriding authentication in C++ using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e for Google Cloud Workstations.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release is version 2.37.0-rc, with multiple preceding versions available down to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eThe default authentication method uses Application Default Credentials, but can be overridden by loading a service account key file as demonstrated in the example.\u003c/p\u003e\n"],["\u003cp\u003eUsers can reference the \u003ccode\u003eAuthentication Components\u003c/code\u003e documentation for further details on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"],["\u003cp\u003eThe best practices guide for managing service account keys should be consulted for security and best practices.\u003c/p\u003e\n"]]],[],null,[]]
