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::notebooks_v1::ManagedNotebookServiceClient(
google::cloud::notebooks_v1::MakeManagedNotebookServiceConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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, with version-specific information available from 2.11.0 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically use Application Default Credentials, but you can override this by providing the UnifiedCredentialsOption, as demonstrated with loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided for \u003ccode\u003enotebooks_v1::ManagedNotebookServiceClient\u003c/code\u003e, \u003ccode\u003enotebooks_v1::NotebookServiceClient\u003c/code\u003e, and \u003ccode\u003enotebooks_v2::NotebookServiceClient\u003c/code\u003e, showing how to override authentication in each of these classes.\u003c/p\u003e\n"],["\u003cp\u003eIt is recommended to review the best practices for managing service account keys guide, as well as the Authentication Components documentation, for further information on credential creation and security.\u003c/p\u003e\n"],["\u003cp\u003eThe page details how to override the default authentication, allowing users to load service accounts explicitly.\u003c/p\u003e\n"]]],[],null,[]]
