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::kms_inventory_v1::KeyDashboardServiceClient(
google::cloud::kms_inventory_v1::MakeKeyDashboardServiceConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThis document provides guidance on overriding default authentication credentials when interacting with Google Cloud Services, which by default utilizes Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default authentication by supplying the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, including the use of a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe provided example demonstrates how to explicitly load a service account key file to override the default credentials.\u003c/p\u003e\n"],["\u003cp\u003eThis content also lists the different versions of the library, where the latest release candidate is 2.37.0-rc, and also provides examples for various client classes like \u003ccode\u003eKeyDashboardServiceClient\u003c/code\u003e, \u003ccode\u003eKeyTrackingServiceClient\u003c/code\u003e, \u003ccode\u003eAutokeyAdminClient\u003c/code\u003e, \u003ccode\u003eAutokeyClient\u003c/code\u003e, \u003ccode\u003eEkmServiceClient\u003c/code\u003e, and \u003ccode\u003eKeyManagementServiceClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation covers additional information on authentication with the provided link to the \u003ca href=\"https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html\"\u003eAuthentication Components\u003c/a\u003e section and managing service accounts, with a link to \u003ca href=\"https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys\"\u003eBest practices for managing service account keys\u003c/a\u003e.\u003c/p\u003e\n"]]],[],null,[]]
