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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 reference for overriding default authentication credentials when using Google Cloud C++ client libraries, specifically in the context of AutoML.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version available is 2.37.0-rc, but a range of prior versions, from 2.36.0 down to 2.11.0, are also documented and accessible.\u003c/p\u003e\n"],["\u003cp\u003eUsers can override default credentials by leveraging the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, illustrated via an example of how to load a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided for \u003ccode\u003eautoml_v1::AutoMlClient\u003c/code\u003e and \u003ccode\u003eautoml_v1::PredictionServiceClient\u003c/code\u003e classes, demonstrating the application of credential overrides.\u003c/p\u003e\n"],["\u003cp\u003eIt's suggested that users follow the best practices for managing service account keys for security and efficiency, with links provided.\u003c/p\u003e\n"]]],[],null,[]]
