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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document provides information on how to override the default Application Default Credentials (ADC) used by client libraries for authentication with Google Cloud Services.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default credentials by providing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, which can be used to load a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe example demonstrates how to load a service account key file using \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e, with links to similar examples for \u003ccode\u003eworkflows_executions_v1::ExecutionsClient\u003c/code\u003e and \u003ccode\u003eworkflows_v1::WorkflowsClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe document links to other helpful information, such as the best practices for managing service account keys and authentication components for creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"],["\u003cp\u003eThe page provides access to the documentation of various versions of the C++ Workflows API, including the most recent release candidate (2.37.0-rc), version 2.36.0, and then down to 2.11.0.\u003c/p\u003e\n"]]],[],null,[]]
