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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 numerous other versions from 2.36.0 down to 2.14.0 also documented.\u003c/p\u003e\n"],["\u003cp\u003eClient libraries default to using Application Default Credentials for Google Cloud Services authentication, but this can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eTo override the default authentication, users can provide a \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated by explicitly loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eUsers can find more information on factory functions for creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects in the Authentication Components documentation.\u003c/p\u003e\n"],["\u003cp\u003eConsult the best practices for managing service account keys guide to understand how to manage service account keys.\u003c/p\u003e\n"]]],[],null,[]]
