Cloud Document AI API C++ Client Library

An idiomatic C++ client library for the Cloud Document AI API, a service that uses machine learning on a scalable cloud-based platform to help your organization efficiently scan, analyze, and understand documents.

While this library is GA, please note Google Cloud C++ client libraries do not follow Semantic Versioning.


The following shows the code that you'll run in the google/cloud/documentai/quickstart/ directory, which should give you a taste of the Cloud Document AI API C++ client library API.

#include "google/cloud/documentai/v1/document_processor_client.h"
#include <fstream>
#include <iostream>

int main(int argc, char* argv[]) try {
  if (argc != 5) {
    std::cerr << "Usage: " << argv[0]
              << " project-id location-id processor-id filename (PDF only)\n";
    return 1;
  std::string const location = argv[2];
  if (location != "us" && location != "eu") {
    std::cerr << "location-id must be either 'us' or 'eu'\n";
    return 1;

  namespace documentai = ::google::cloud::documentai_v1;
  auto client = documentai::DocumentProcessorServiceClient(

  auto const resource = std::string{"projects/"} + argv[1] + "/locations/" +
                        location + "/processors/" + argv[3];

  google::cloud::documentai::v1::ProcessRequest req;
  auto& doc = *req.mutable_raw_document();
  std::ifstream is(argv[4]);
  doc.set_content(std::string{std::istreambuf_iterator<char>(is), {}});

  auto resp = client.ProcessDocument(std::move(req));
  if (!resp) throw std::move(resp).status();
  std::cout << resp->document().text() << "\n";

  return 0;
} catch (google::cloud::Status const& status) {
  std::cerr << "google::cloud::Status thrown: " << status << "\n";
  return 1;

Main classes

The main class in this library is documentai_v1::DocumentProcessorServiceClient. All RPCs are exposed as member functions of this class. Other classes provide helpers, configuration parameters, and infrastructure to mock documentai_v1::DocumentProcessorServiceClient when testing your application.

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