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::sql_v1::MakeSqlBackupRunsServiceConnectionRest(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides documentation for overriding default authentication credentials when using Google Cloud SQL client libraries in C++.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version for which documentation is available is \u003ccode\u003e2.37.0-rc\u003c/code\u003e, but documentation is available from \u003ccode\u003e2.11.0\u003c/code\u003e onward.\u003c/p\u003e\n"],["\u003cp\u003eOverriding default credentials is achieved using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, allowing you to explicitly provide credentials like a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided on how to override authentication for several \u003ccode\u003e*Client\u003c/code\u003e classes including \u003ccode\u003eSqlBackupRunsServiceClient\u003c/code\u003e, \u003ccode\u003eSqlConnectServiceClient\u003c/code\u003e, \u003ccode\u003eSqlDatabasesServiceClient\u003c/code\u003e, \u003ccode\u003eSqlFlagsServiceClient\u003c/code\u003e, \u003ccode\u003eSqlInstancesServiceClient\u003c/code\u003e, \u003ccode\u003eSqlOperationsServiceClient\u003c/code\u003e, \u003ccode\u003eSqlSslCertsServiceClient\u003c/code\u003e, \u003ccode\u003eSqlTiersServiceClient\u003c/code\u003e, and \u003ccode\u003eSqlUsersServiceClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eFor more details on managing credentials, see the "Best practices for managing service account keys" guide, or for more information on creating credentials, see "Authentication Components".\u003c/p\u003e\n"]]],[],null,[]]
