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::billing_budgets_v1::BudgetServiceClient(
google::cloud::billing_budgets_v1::MakeBudgetServiceConnection(
options));
}
Follow these links to find examples for other *Client classes:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-14 UTC."],[[["This page provides documentation for various versions of the Google Cloud C++ client library, ranging from version 2.11.0 to 2.37.0-rc, including links to specific version documentation."],["The content explains how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud services by using the `UnifiedCredentialsOption`."],["A service account key file can be explicitly loaded to override default credentials, as demonstrated in the provided code example that uses `google::cloud::MakeServiceAccountCredentials`."],["Examples for overriding credentials are provided for `billing_budgets_v1::BudgetServiceClient`, `billing_v1::CloudBillingClient`, and `billing_v1::CloudCatalogClient`."],["For further information about creating `google::cloud::Credentials` objects, refer to the Authentication Components documentation."]]],[]]