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::developerconnect_v1::DeveloperConnectClient(
google::cloud::developerconnect_v1::MakeDeveloperConnectConnection(
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 2025-08-01 UTC."],[[["This document details how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services."],["The default authentication method utilizes Application Default Credentials, but this can be superseded by providing a `UnifiedCredentialsOption`."],["A service account key file can be explicitly loaded to override the default credentials, as demonstrated in the example code provided."],["The provided example uses `google::cloud::MakeServiceAccountCredentials` for clarity, but it's crucial to refer to Google's best practices for managing service account keys for production environments."],["For further information on creating `google::cloud::Credentials` objects, refer to the Authentication Components documentation."]]],[]]
