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::pubsublite::AdminServiceClient(
google::cloud::pubsublite::MakeAdminServiceConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 webpage provides documentation for various versions of the C++ Pub/Sub Lite client library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically use Application Default Credentials for Google Cloud authentication, but users can override this with the UnifiedCredentialsOption.\u003c/p\u003e\n"],["\u003cp\u003eUsers can override authentication by loading a service account key file, as demonstrated in the provided C++ code example that utilizes the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation provides examples for \u003ccode\u003eAdminServiceClient\u003c/code\u003e and \u003ccode\u003eTopicStatsServiceClient\u003c/code\u003e classes on how to override authentication, and it directs users to the best practices for managing service account keys for further guidance.\u003c/p\u003e\n"],["\u003cp\u003eAdditional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects is available in the Authentication Components section.\u003c/p\u003e\n"]]],[],null,[]]
