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::workflows_executions_v1::ExecutionsClient(
google::cloud::workflows_executions_v1::MakeExecutionsConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page details how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services, which is necessary in certain cases.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version covered in the documentation is 2.37.0-rc, while the current version that is being documented is 2.22.1 and there is a list of versions from 2.11.0 up to 2.37.0-rc, which has a corresponding link for how to override authentication for each version.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default authentication by providing a \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, and an example is given on how to load a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThere are examples for how to do this with both \u003ccode\u003eworkflows_executions_v1::ExecutionsClient\u003c/code\u003e and \u003ccode\u003eworkflows_v1::WorkflowsClient\u003c/code\u003e classes, linked on this page.\u003c/p\u003e\n"],["\u003cp\u003eThe page references best practices for managing service account keys and provides a link to the "Authentication Components" documentation for further information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
