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::automl_v1::AutoMlClient(
google::cloud::automl_v1::MakeAutoMlConnection(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"]],[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 a list of available versions for the AutoML C++ client library, ranging from version 2.11.0 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 for Google Cloud services when using the client libraries.\u003c/p\u003e\n"],["\u003cp\u003eUsers can override authentication by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and providing a service account key file, as demonstrated in the provided code example.\u003c/p\u003e\n"],["\u003cp\u003eExamples are given for \u003ccode\u003eAutoMlClient\u003c/code\u003e and \u003ccode\u003ePredictionServiceClient\u003c/code\u003e to understand how to override authentication credentials.\u003c/p\u003e\n"],["\u003cp\u003eThe document directs users to consult the "Best practices for managing service account keys" guide for additional details and also links to information on Authentication Components.\u003c/p\u003e\n"]]],[],null,[]]