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::contentwarehouse_v1::DocumentServiceClient(
google::cloud::contentwarehouse_v1::MakeDocumentServiceConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 overriding default authentication credentials when using Google Cloud client libraries, specifically for the Content Warehouse API.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically use Application Default Credentials for authentication, but users can override this by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe most recent version of the library is 2.37.0-rc, but the page also lists versions going as far back as 2.12.0.\u003c/p\u003e\n"],["\u003cp\u003eThe example provided shows how to load a service account key file to explicitly set credentials for a \u003ccode\u003eDocumentServiceClient\u003c/code\u003e while also providing examples for other \u003ccode\u003e*Client\u003c/code\u003e classes.\u003c/p\u003e\n"],["\u003cp\u003eFor more information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, users can consult the "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,[]]
