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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 details how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version of the documentation provided is 2.37.0-rc, and it includes a list of other versions dating back to 2.11.0, all linking to documentation on overriding authentication.\u003c/p\u003e\n"],["\u003cp\u003eOverriding the default credentials can be accomplished by loading a service account key file using the provided example code snippet and the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation includes links to code examples for multiple \u003ccode\u003e*Client\u003c/code\u003e classes, such as \u003ccode\u003eSqlBackupRunsServiceClient\u003c/code\u003e, \u003ccode\u003eSqlConnectServiceClient\u003c/code\u003e, and \u003ccode\u003eSqlUsersServiceClient\u003c/code\u003e, all at version 2.19.0.\u003c/p\u003e\n"],["\u003cp\u003eFor best practices in managing service account keys and additional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, external resources are provided.\u003c/p\u003e\n"]]],[],null,[]]
