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::osconfig_agentendpoint_v1::AgentEndpointServiceClient(
google::cloud::osconfig_agentendpoint_v1::
MakeAgentEndpointServiceConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-07-26 UTC."],[[["The latest release candidate version is 2.37.0-rc, while 2.27.0 is the current displayed version."],["This documentation provides a reference for multiple versions of the osconfig service, ranging from version 2.11.0 to 2.37.0-rc, each with its specific documentation link."],["Client libraries use Application Default Credentials for authentication with Google Cloud Services unless a different method is specified, such as through UnifiedCredentialsOption."],["You can override default authentication credentials by providing the UnifiedCredentialsOption, for example, by explicitly loading a service account key file."],["Examples of how to override authentication are available for AgentEndpointServiceClient, OsConfigServiceClient, and OsConfigZonalServiceClient, although its important to follow the best practice guidelines for managing service account keys."]]],[]]
