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::eventarc_publishing_v1::PublisherClient(
google::cloud::eventarc_publishing_v1::MakePublisherConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 provides documentation for various versions of the Eventarc C++ client library, with version 2.37.0-rc being the latest release candidate.\u003c/p\u003e\n"],["\u003cp\u003eThe content demonstrates how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples of overriding credentials are provided for \u003ccode\u003eeventarc_publishing_v1::PublisherClient\u003c/code\u003e and \u003ccode\u003eeventarc_v1::EventarcClient\u003c/code\u003e classes.\u003c/p\u003e\n"],["\u003cp\u003eThe page emphasizes that while the provided service account key file example is simple, users should consult the best practices guide for managing service account keys for production environments.\u003c/p\u003e\n"],["\u003cp\u003eThe page includes links to resources on Authentication Components for more information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
