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::cloudquotas_v1::CloudQuotasClient(
google::cloud::cloudquotas_v1::MakeCloudQuotasConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides documentation for various versions of the Cloud Quotas C++ client library, ranging from version 2.20.0 up to the latest release candidate, 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe primary focus of the content is on how to override the default authentication credentials used by the client libraries, which typically rely on Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eTo override default credentials, users can leverage the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e by supplying service account key file contents.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code example demonstrates loading a service account key file to create a \u003ccode\u003eCloudQuotasClient\u003c/code\u003e with custom credentials.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation also points to additional resources for managing service account keys, and further information on the \u003ccode\u003eCredentials\u003c/code\u003e factory functions.\u003c/p\u003e\n"]]],[],null,[]]
