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::translate_v3::TranslationServiceClient(
google::cloud::translate_v3::MakeTranslationServiceConnection(options));
}
[[["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 2025-03-21 UTC."],[[["This document provides a reference for overriding default authentication credentials when using Google Cloud client libraries, specifically within the context of the C++ Translation API."],["The latest version documented is 2.37.0-rc, with a comprehensive list of previous versions ranging down to 2.11.0, all of which are accessible via provided links."],["Client libraries typically rely on Application Default Credentials for authentication, but users can override this by employing the UnifiedCredentialsOption."],["An example is provided that demonstrates how to explicitly load authentication credentials from a service account key file using `google::cloud::UnifiedCredentialsOption`."],["Additional information on creating `google::cloud::Credentials` objects can be found in the Authentication Components section, and for best practices, users should reference the service account key guide."]]],[]]
