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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThis document provides version-specific documentation for overriding authentication credentials in the C++ client library for Google Cloud Commerce services, with versions ranging from 2.14.0 to 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe C++ client libraries typically use Application Default Credentials for authentication, but this can be overridden as shown by the example provided.\u003c/p\u003e\n"],["\u003cp\u003eThe document details how to override the default authentication by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and provides a sample code snippet of explicitly loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe provided instructions reference best practices for service account key management and also suggest referring to the "Authentication Components" documentation for more information on \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"],["\u003cp\u003eThe most recent version available is \u003ccode\u003e2.37.0-rc\u003c/code\u003e, and it is the top of the list, followed by a chronological list of prior releases.\u003c/p\u003e\n"]]],[],null,[]]
