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::speech_v1::AdaptationClient(
google::cloud::speech_v1::MakeAdaptationConnection(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 2025-03-21 UTC."],[[["This page details how to override default authentication credentials for Google Cloud Services, which typically rely on Application Default Credentials."],["The latest release for the C++ library is version 2.37.0-rc, while the current documentation version is 2.17.0, and it lists many previous versions."],["You can override the default credentials by providing a `UnifiedCredentialsOption`, demonstrated here by loading a service account key file."],["The provided code example illustrates how to explicitly load a service account key file and apply it to a client, such as `AdaptationClient`."],["There are links provided to examples for other client classes such as `speech_v1::SpeechClient`, and `speech_v2::SpeechClient`, as well as to further documentation on authentication."]]],[]]
