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));
}
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"]],[["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 details how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services using the `UnifiedCredentialsOption`."],["You can explicitly load a service account key file to override the default credentials, as demonstrated in the provided code example."],["The provided links offer examples for `language_v1::LanguageServiceClient` and `language_v2::LanguageServiceClient` classes on how to implement service account credentials."],["Version history is available, ranging from version 2.11.0 to the latest release candidate version, 2.37.0-rc, with each link providing version-specific documentation."],["The page links to more resources, including the [Best practices for managing service account keys](https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys) and the [Authentication Components](https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html) documentation."]]],[]]