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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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, and the documentation page covers versions from 2.14.0 up to this latest candidate.\u003c/p\u003e\n"],["\u003cp\u003eBy default, client libraries authenticate with Google Cloud Services using Application Default Credentials, but this can be overridden for specific use cases.\u003c/p\u003e\n"],["\u003cp\u003eTo override default authentication, you can use the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, such as by loading a service account key file, using the \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e function.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code example demonstrates loading a service account key file and creating a \u003ccode\u003eConsumerProcurementServiceClient\u003c/code\u003e with the specified credentials, showcasing how to override the default authentication.\u003c/p\u003e\n"],["\u003cp\u003eYou can refer to the Authentication Components section for a deeper dive into the factory functions used to create \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
