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::dataplex_v1::CatalogServiceClient(
google::cloud::dataplex_v1::MakeCatalogServiceConnection(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 from 2.36.0 down to 2.11.0 also documented.\u003c/p\u003e\n"],["\u003cp\u003eClient libraries generally authenticate using Application Default Credentials, but this can be overridden when needed.\u003c/p\u003e\n"],["\u003cp\u003eOverriding the default credentials involves providing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as illustrated using a service account key file in the provided example.\u003c/p\u003e\n"],["\u003cp\u003eService account key override examples are available for several \u003ccode\u003e*Client\u003c/code\u003e classes, including \u003ccode\u003eCatalogServiceClient\u003c/code\u003e, \u003ccode\u003eContentServiceClient\u003c/code\u003e, and \u003ccode\u003eDataTaxonomyServiceClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eFor more comprehensive details on service account key management, refer to the "Best practices for managing service account keys" guide, while additional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects can be found in Authentication Components.\u003c/p\u003e\n"]]],[],null,["Version 2.26.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/dataplex/latest/dataplex-override-authentication)\n- [2.41.0](/cpp/docs/reference/dataplex/2.41.0/dataplex-override-authentication)\n- [2.40.0](/cpp/docs/reference/dataplex/2.40.0/dataplex-override-authentication)\n- [2.39.0](/cpp/docs/reference/dataplex/2.39.0/dataplex-override-authentication)\n- [2.38.0](/cpp/docs/reference/dataplex/2.38.0/dataplex-override-authentication)\n- [2.37.0](/cpp/docs/reference/dataplex/2.37.0/dataplex-override-authentication)\n- [2.36.0](/cpp/docs/reference/dataplex/2.36.0/dataplex-override-authentication)\n- [2.35.0](/cpp/docs/reference/dataplex/2.35.0/dataplex-override-authentication)\n- [2.34.0](/cpp/docs/reference/dataplex/2.34.0/dataplex-override-authentication)\n- [2.33.0](/cpp/docs/reference/dataplex/2.33.0/dataplex-override-authentication)\n- [2.32.0](/cpp/docs/reference/dataplex/2.32.0/dataplex-override-authentication)\n- [2.31.0](/cpp/docs/reference/dataplex/2.31.0/dataplex-override-authentication)\n- [2.30.0](/cpp/docs/reference/dataplex/2.30.0/dataplex-override-authentication)\n- [2.29.0](/cpp/docs/reference/dataplex/2.29.0/dataplex-override-authentication)\n- [2.28.0](/cpp/docs/reference/dataplex/2.28.0/dataplex-override-authentication)\n- [2.27.0](/cpp/docs/reference/dataplex/2.27.0/dataplex-override-authentication)\n- [2.26.0](/cpp/docs/reference/dataplex/2.26.0/dataplex-override-authentication)\n- [2.25.1](/cpp/docs/reference/dataplex/2.25.1/dataplex-override-authentication)\n- [2.24.0](/cpp/docs/reference/dataplex/2.24.0/dataplex-override-authentication)\n- [2.23.0](/cpp/docs/reference/dataplex/2.23.0/dataplex-override-authentication)\n- [2.22.1](/cpp/docs/reference/dataplex/2.22.1/dataplex-override-authentication)\n- [2.21.0](/cpp/docs/reference/dataplex/2.21.0/dataplex-override-authentication)\n- [2.20.0](/cpp/docs/reference/dataplex/2.20.0/dataplex-override-authentication)\n- [2.19.0](/cpp/docs/reference/dataplex/2.19.0/dataplex-override-authentication)\n- [2.18.0](/cpp/docs/reference/dataplex/2.18.0/dataplex-override-authentication)\n- [2.17.0](/cpp/docs/reference/dataplex/2.17.0/dataplex-override-authentication)\n- [2.16.0](/cpp/docs/reference/dataplex/2.16.0/dataplex-override-authentication)\n- [2.15.1](/cpp/docs/reference/dataplex/2.15.1/dataplex-override-authentication)\n- [2.14.0](/cpp/docs/reference/dataplex/2.14.0/dataplex-override-authentication)\n- [2.13.0](/cpp/docs/reference/dataplex/2.13.0/dataplex-override-authentication)\n- [2.12.0](/cpp/docs/reference/dataplex/2.12.0/dataplex-override-authentication)\n- [2.11.0](/cpp/docs/reference/dataplex/2.11.0/dataplex-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::dataplex_v1::CatalogServiceClient(\n google::cloud::dataplex_v1::MakeCatalogServiceConnection(options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`dataplex_v1::CatalogServiceClient`](/cpp/docs/reference/dataplex/2.26.0/dataplex_v1_1_1CatalogServiceClient-service-account-snippet)\n- [`dataplex_v1::ContentServiceClient`](/cpp/docs/reference/dataplex/2.26.0/dataplex_v1_1_1ContentServiceClient-service-account-snippet)\n- [`dataplex_v1::DataScanServiceClient`](/cpp/docs/reference/dataplex/2.26.0/dataplex_v1_1_1DataScanServiceClient-service-account-snippet)\n- [`dataplex_v1::DataTaxonomyServiceClient`](/cpp/docs/reference/dataplex/2.26.0/dataplex_v1_1_1DataTaxonomyServiceClient-service-account-snippet)\n- [`dataplex_v1::DataplexServiceClient`](/cpp/docs/reference/dataplex/2.26.0/dataplex_v1_1_1DataplexServiceClient-service-account-snippet)\n- [`dataplex_v1::MetadataServiceClient`](/cpp/docs/reference/dataplex/2.26.0/dataplex_v1_1_1MetadataServiceClient-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."]]