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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 a version history for the C++ Key Management Service (KMS) client library, detailing versions from 2.10.1 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe document explains how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe content demonstrates explicitly loading a service account key file as an example of overriding authentication credentials, showing a code snippet to do so.\u003c/p\u003e\n"],["\u003cp\u003eLinks are provided to code examples for different client classes, including \u003ccode\u003eKeyDashboardServiceClient\u003c/code\u003e, \u003ccode\u003eKeyTrackingServiceClient\u003c/code\u003e, \u003ccode\u003eEkmServiceClient\u003c/code\u003e, and \u003ccode\u003eKeyManagementServiceClient\u003c/code\u003e, all under version 2.15.1.\u003c/p\u003e\n"],["\u003cp\u003eFor best practices on handling service accounts, the user is directed to the "Best practices for managing service account keys" guide and to the "Authentication Components" for more details.\u003c/p\u003e\n"]]],[],null,[]]
