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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 release candidate version is 2.37.0-rc, with version 2.15.1 being the lowest documented version.\u003c/p\u003e\n"],["\u003cp\u003eBy default, the client libraries use Application Default Credentials for authenticating with Google Cloud Services, but this can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eYou can override default authentication by using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, such as loading a service account key file, as demonstrated in the provided example.\u003c/p\u003e\n"],["\u003cp\u003eThe example demonstrates loading service account credentials via a key file, but users are encouraged to review best practices for managing service account keys for production environments.\u003c/p\u003e\n"],["\u003cp\u003eRefer to the Authentication Components section for additional information on how to create \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
