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::sql_v1::SqlBackupRunsServiceClient(
google::cloud::ExperimentalTag{},
google::cloud::sql_v1::MakeSqlBackupRunsServiceConnectionRest(
google::cloud::ExperimentalTag{}, 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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe latest release candidate version is 2.37.0-rc, and numerous previous versions are available, ranging down to version 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eClient libraries typically use Application Default Credentials (ADC) for authentication with Google Cloud Services, but this default can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eTo override default authentication, you can provide the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, demonstrated through an example loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples for other client classes, such as \u003ccode\u003eSqlBackupRunsServiceClient\u003c/code\u003e and \u003ccode\u003eSqlConnectServiceClient\u003c/code\u003e, are linked within the documentation for quick reference.\u003c/p\u003e\n"],["\u003cp\u003eFor more advanced information on service account key management, refer to the "Best practices for managing service account keys" guide, while additional details on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects can be found in "Authentication Components".\u003c/p\u003e\n"]]],[],null,[]]
