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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 Services, specifically for Content Warehouse clients.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release is version 2.37.0-rc, and the page includes a list of previous versions from 2.36.0 down to 2.12.0, all related to the Content Warehouse service.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication is typically managed through Application Default Credentials, but specific cases may require you to use \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e to provide custom credentials, such as a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided to show how to load a service account key file, and there are links to examples for other client classes including \u003ccode\u003eDocumentServiceClient\u003c/code\u003e, \u003ccode\u003eDocumentLinkServiceClient\u003c/code\u003e, \u003ccode\u003eDocumentSchemaServiceClient\u003c/code\u003e, \u003ccode\u003eRuleSetServiceClient\u003c/code\u003e, and \u003ccode\u003eSynonymSetServiceClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eUsers are directed to the "Best practices for managing service account keys" guide and the "Authentication Components" documentation for further details on secure credential management and creating \u003ccode\u003eCredentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
