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::shell_v1::CloudShellServiceClient(
google::cloud::shell_v1::MakeCloudShellServiceConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-22 UTC."],[[["\u003cp\u003eThe webpage provides documentation for various versions of a C++ library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc, with each version having specific details on shell override authentication.\u003c/p\u003e\n"],["\u003cp\u003eThe library by default uses Application Default Credentials for authentication with Google Cloud Services, but it allows overriding this default using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eA service account key file can be explicitly loaded to override default credentials, demonstrated through a code example that loads a service account key file and creates a \u003ccode\u003eCloudShellServiceClient\u003c/code\u003e with custom authentication options.\u003c/p\u003e\n"],["\u003cp\u003eUsers are advised to refer to the "Best practices for managing service account keys" guide for more detailed information on securely managing service account credentials.\u003c/p\u003e\n"],["\u003cp\u003eAdditional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects can be found in the "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,[]]
