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::channel_v1::CloudChannelServiceClient(
google::cloud::channel_v1::MakeCloudChannelServiceConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document provides a list of available versions for the Cloud Channel C++ 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 use Application Default Credentials for authentication with Google Cloud Services unless an override is configured.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication can be overridden by providing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, allowing the explicit loading of a service account key file, as demonstrated in the example.\u003c/p\u003e\n"],["\u003cp\u003eExamples for overriding authentication credentials are provided for \u003ccode\u003echannel_v1::CloudChannelServiceClient\u003c/code\u003e and \u003ccode\u003echannel_v1::CloudChannelReportsServiceClient\u003c/code\u003e classes, using version 2.18.0.\u003c/p\u003e\n"],["\u003cp\u003eThe document refers users to further information on factory functions to create \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, and to a guide with best practices for managing service account keys.\u003c/p\u003e\n"]]],[],null,[]]
