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::developerconnect_v1::DeveloperConnectClient(
google::cloud::developerconnect_v1::MakeDeveloperConnectConnection(
options));
}
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 details how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services.\u003c/p\u003e\n"],["\u003cp\u003eThe default authentication method utilizes Application Default Credentials, but alternative methods can be implemented using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eA service account key file can be explicitly loaded to override the default credentials, as demonstrated in the provided code example.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eAuthentication Components\u003c/code\u003e section offers further guidance on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects and other factory functions.\u003c/p\u003e\n"],["\u003cp\u003eRefer to the \u003ccode\u003eBest practices for managing service account keys\u003c/code\u003e guide for more comprehensive details on managing service account keys effectively.\u003c/p\u003e\n"]]],[],null,[]]
