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::commerce_consumer_procurement_v1::
ConsumerProcurementServiceClient(
google::cloud::commerce_consumer_procurement_v1::
MakeConsumerProcurementServiceConnection(options));
}
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 the provided list detailing versions down to 2.14.0 for the C++ commerce override authentication documentation.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries primarily utilize Application Default Credentials for Google Cloud Services authentication, but this can be overridden when necessary.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default authentication by employing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated through the example of loading a service account key file, which is explained in the document.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code snippet shows an example of loading a service account key file to override the default credentials using \u003ccode\u003egoogle::cloud::MakeServiceAccountCredentials\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eFor in depth information regarding the best way to manage your service account keys, and more information on \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e you can refer to the provided links.\u003c/p\u003e\n"]]],[],null,[]]
