Unless otherwise configured, the client libraries useApplication Default Credentialsto 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 theUnifiedCredentialsOptionThe 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*Clientclasses:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThe latest version available is 2.37.0-rc, with numerous other versions, starting at 2.36.0 and going all the way to 2.11.0, available for browsing.\u003c/p\u003e\n"],["\u003cp\u003eThis page details how to override the default authentication credentials, which typically use Application Default Credentials, by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe example code demonstrates explicitly loading a service account key file to override the default authentication settings, using the \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e function.\u003c/p\u003e\n"],["\u003cp\u003eExamples for other \u003ccode\u003e*Client\u003c/code\u003e classes are provided, including \u003ccode\u003eSqlBackupRunsServiceClient\u003c/code\u003e, \u003ccode\u003eSqlConnectServiceClient\u003c/code\u003e, and \u003ccode\u003eSqlDatabasesServiceClient\u003c/code\u003e among others, all within the \u003ccode\u003esql_v1\u003c/code\u003e namespace.\u003c/p\u003e\n"],["\u003cp\u003eFor best practices on handling service accounts, refer to the provided "Best practices for managing service account keys" guide.\u003c/p\u003e\n"]]],[],null,["Version 2.21.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/sql/latest/sql-override-authentication)\n- [2.41.0](/cpp/docs/reference/sql/2.41.0/sql-override-authentication)\n- [2.40.0](/cpp/docs/reference/sql/2.40.0/sql-override-authentication)\n- [2.39.0](/cpp/docs/reference/sql/2.39.0/sql-override-authentication)\n- [2.38.0](/cpp/docs/reference/sql/2.38.0/sql-override-authentication)\n- [2.37.0](/cpp/docs/reference/sql/2.37.0/sql-override-authentication)\n- [2.36.0](/cpp/docs/reference/sql/2.36.0/sql-override-authentication)\n- [2.35.0](/cpp/docs/reference/sql/2.35.0/sql-override-authentication)\n- [2.34.0](/cpp/docs/reference/sql/2.34.0/sql-override-authentication)\n- [2.33.0](/cpp/docs/reference/sql/2.33.0/sql-override-authentication)\n- [2.32.0](/cpp/docs/reference/sql/2.32.0/sql-override-authentication)\n- [2.31.0](/cpp/docs/reference/sql/2.31.0/sql-override-authentication)\n- [2.30.0](/cpp/docs/reference/sql/2.30.0/sql-override-authentication)\n- [2.29.0](/cpp/docs/reference/sql/2.29.0/sql-override-authentication)\n- [2.28.0](/cpp/docs/reference/sql/2.28.0/sql-override-authentication)\n- [2.27.0](/cpp/docs/reference/sql/2.27.0/sql-override-authentication)\n- [2.26.0](/cpp/docs/reference/sql/2.26.0/sql-override-authentication)\n- [2.25.1](/cpp/docs/reference/sql/2.25.1/sql-override-authentication)\n- [2.24.0](/cpp/docs/reference/sql/2.24.0/sql-override-authentication)\n- [2.23.0](/cpp/docs/reference/sql/2.23.0/sql-override-authentication)\n- [2.22.1](/cpp/docs/reference/sql/2.22.1/sql-override-authentication)\n- [2.21.0](/cpp/docs/reference/sql/2.21.0/sql-override-authentication)\n- [2.20.0](/cpp/docs/reference/sql/2.20.0/sql-override-authentication)\n- [2.19.0](/cpp/docs/reference/sql/2.19.0/sql-override-authentication)\n- [2.18.0](/cpp/docs/reference/sql/2.18.0/sql-override-authentication)\n- [2.17.0](/cpp/docs/reference/sql/2.17.0/sql-override-authentication)\n- [2.16.0](/cpp/docs/reference/sql/2.16.0/sql-override-authentication)\n- [2.15.1](/cpp/docs/reference/sql/2.15.1/sql-override-authentication)\n- [2.14.0](/cpp/docs/reference/sql/2.14.0/sql-override-authentication)\n- [2.13.0](/cpp/docs/reference/sql/2.13.0/sql-override-authentication)\n- [2.12.0](/cpp/docs/reference/sql/2.12.0/sql-override-authentication)\n- [2.11.0](/cpp/docs/reference/sql/2.11.0/sql-override-authentication) \n\nHow to Override the Authentication Credentials\n==============================================\n\nUnless otherwise configured, the client libraries use [Application Default Credentials](https://cloud.google.com/docs/authentication#adc) 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](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1UnifiedCredentialsOption.html) The following example shows how to explicitly load a service account key file: \n\n [](std::string const& keyfile) {\n auto is = std::ifstream(keyfile);\n is.exceptions(std::ios::badbit); // Minimal error handling in examples\n auto contents = std::string(std::istreambuf_iterator\u003cchar\u003e(is.rdbuf()), {});\n auto options =\n google::cloud::Options{}.set\u003cgoogle::cloud::UnifiedCredentialsOption\u003e(\n google::cloud::MakeServiceAccountCredentials(contents));\n return google::cloud::sql_v1::SqlBackupRunsServiceClient(\n google::cloud::sql_v1::MakeSqlBackupRunsServiceConnectionRest(options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`sql_v1::SqlBackupRunsServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlBackupRunsServiceClient-service-account-snippet)\n- [`sql_v1::SqlConnectServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlConnectServiceClient-service-account-snippet)\n- [`sql_v1::SqlDatabasesServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlDatabasesServiceClient-service-account-snippet)\n- [`sql_v1::SqlFlagsServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlFlagsServiceClient-service-account-snippet)\n- [`sql_v1::SqlInstancesServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlInstancesServiceClient-service-account-snippet)\n- [`sql_v1::SqlOperationsServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlOperationsServiceClient-service-account-snippet)\n- [`sql_v1::SqlSslCertsServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlSslCertsServiceClient-service-account-snippet)\n- [`sql_v1::SqlTiersServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlTiersServiceClient-service-account-snippet)\n- [`sql_v1::SqlUsersServiceClient`](/cpp/docs/reference/sql/2.21.0/sql_v1_1_1SqlUsersServiceClient-service-account-snippet)\n\nKeep in mind that we chose this as an example because it is relatively easy to understand. Consult the [Best practices for managing service account keys](https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys) guide for more details.\n\n###### See Also\n\n[Authentication Components](https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html) - for more information on the factory functions to create [`google::cloud::Credentials`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1Credentials.html) objects."]]