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::language_v1::LanguageServiceClient(
google::cloud::language_v1::MakeLanguageServiceConnection(options));
}
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-14 UTC."],[[["This page provides documentation for various versions of the C++ client library, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc."],["The primary content focuses on how to override the default authentication credentials used by the client libraries when interacting with Google Cloud Services."],["The example code demonstrates how to use `UnifiedCredentialsOption` to explicitly load a service account key file for authentication, instead of using the default Application Default Credentials."],["Users can find more details on creating `google::cloud::Credentials` objects in the \"Authentication Components\" section, which is also linked on the page."],["It is recommended that users review the provided guide for \"Best practices for managing service account keys\" to be compliant and secure when working with the credentials."]]],[]]