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::dataplex_v1::CatalogServiceClient(
google::cloud::dataplex_v1::MakeCatalogServiceConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\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,[]]
