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::redis_cluster_v1::CloudRedisClusterClient(
google::cloud::redis_cluster_v1::MakeCloudRedisClusterConnection(
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\u003eThis document provides information on how to override the default authentication credentials used by client libraries to connect to Google Cloud Services.\u003c/p\u003e\n"],["\u003cp\u003eThe default authentication method is the Application Default Credentials, but the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e allows overriding these defaults.\u003c/p\u003e\n"],["\u003cp\u003eAn example is provided for loading a service account key file to authenticate, which uses \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe document references other client classes, specifically \u003ccode\u003eredis_cluster_v1::CloudRedisClusterClient\u003c/code\u003e and \u003ccode\u003eredis_v1::CloudRedisClient\u003c/code\u003e, with links to further examples.\u003c/p\u003e\n"],["\u003cp\u003eA link to the "Best practices for managing service account keys" guide is provided for more detailed information, as well as a link to "Authentication Components".\u003c/p\u003e\n"]]],[],null,["Version 2.22.1keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/redis/latest/redis-override-authentication)\n- [2.41.0](/cpp/docs/reference/redis/2.41.0/redis-override-authentication)\n- [2.40.0](/cpp/docs/reference/redis/2.40.0/redis-override-authentication)\n- [2.39.0](/cpp/docs/reference/redis/2.39.0/redis-override-authentication)\n- [2.38.0](/cpp/docs/reference/redis/2.38.0/redis-override-authentication)\n- [2.37.0](/cpp/docs/reference/redis/2.37.0/redis-override-authentication)\n- [2.36.0](/cpp/docs/reference/redis/2.36.0/redis-override-authentication)\n- [2.35.0](/cpp/docs/reference/redis/2.35.0/redis-override-authentication)\n- [2.34.0](/cpp/docs/reference/redis/2.34.0/redis-override-authentication)\n- [2.33.0](/cpp/docs/reference/redis/2.33.0/redis-override-authentication)\n- [2.32.0](/cpp/docs/reference/redis/2.32.0/redis-override-authentication)\n- [2.31.0](/cpp/docs/reference/redis/2.31.0/redis-override-authentication)\n- [2.30.0](/cpp/docs/reference/redis/2.30.0/redis-override-authentication)\n- [2.29.0](/cpp/docs/reference/redis/2.29.0/redis-override-authentication)\n- [2.28.0](/cpp/docs/reference/redis/2.28.0/redis-override-authentication)\n- [2.27.0](/cpp/docs/reference/redis/2.27.0/redis-override-authentication)\n- [2.26.0](/cpp/docs/reference/redis/2.26.0/redis-override-authentication)\n- [2.25.1](/cpp/docs/reference/redis/2.25.1/redis-override-authentication)\n- [2.24.0](/cpp/docs/reference/redis/2.24.0/redis-override-authentication)\n- [2.23.0](/cpp/docs/reference/redis/2.23.0/redis-override-authentication)\n- [2.22.1](/cpp/docs/reference/redis/2.22.1/redis-override-authentication)\n- [2.21.0](/cpp/docs/reference/redis/2.21.0/redis-override-authentication)\n- [2.20.0](/cpp/docs/reference/redis/2.20.0/redis-override-authentication)\n- [2.19.0](/cpp/docs/reference/redis/2.19.0/redis-override-authentication)\n- [2.18.0](/cpp/docs/reference/redis/2.18.0/redis-override-authentication)\n- [2.17.0](/cpp/docs/reference/redis/2.17.0/redis-override-authentication)\n- [2.16.0](/cpp/docs/reference/redis/2.16.0/redis-override-authentication)\n- [2.15.1](/cpp/docs/reference/redis/2.15.1/redis-override-authentication)\n- [2.14.0](/cpp/docs/reference/redis/2.14.0/redis-override-authentication)\n- [2.13.0](/cpp/docs/reference/redis/2.13.0/redis-override-authentication)\n- [2.12.0](/cpp/docs/reference/redis/2.12.0/redis-override-authentication)\n- [2.11.0](/cpp/docs/reference/redis/2.11.0/redis-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::redis_cluster_v1::CloudRedisClusterClient(\n google::cloud::redis_cluster_v1::MakeCloudRedisClusterConnection(\n options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`redis_cluster_v1::CloudRedisClusterClient`](/cpp/docs/reference/redis/2.22.1/redis_cluster_v1_1_1CloudRedisClusterClient-service-account-snippet)\n- [`redis_v1::CloudRedisClient`](/cpp/docs/reference/redis/2.22.1/redis_v1_1_1CloudRedisClient-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."]]