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::secretmanager_v1::SecretManagerServiceClient(
google::cloud::secretmanager_v1::MakeSecretManagerServiceConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 webpage provides documentation for overriding default authentication credentials when using Google Cloud Secret Manager C++ client libraries.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate for the Secret Manager client library is version 2.37.0-rc, while version 2.30.0 is selected as the version currently being viewed.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default credentials by providing a \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as shown in the example demonstrating how to load a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically use Application Default Credentials, but this can be overridden when necessary.\u003c/p\u003e\n"],["\u003cp\u003eThe page references external resources to aid in understanding, including the best practices for managing service account keys, and authentication components.\u003c/p\u003e\n"]]],[],null,[]]
