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::documentai_v1::DocumentProcessorServiceClient(
google::cloud::documentai_v1::MakeDocumentProcessorServiceConnection(
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 2025-05-07 UTC."],[[["This page provides documentation for various versions of the Document AI C++ client library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc."],["The content explains how to override the default authentication credentials used by the client libraries to interact with Google Cloud Services."],["Overriding the default credentials can be accomplished by using the `UnifiedCredentialsOption` and providing a service account key file for authentication."],["The example demonstrates how to explicitly load a service account key file and set the relevant credentials options for the Document Processor Service Client."],["For more details on managing service account keys and creating `Credentials` objects, users can refer to the best practices guide and the Authentication Components documentation, respectively."]]],[]]
