An idiomatic C++ client library for the Cloud Speech-to-Text API, a service which converts audio to text by applying powerful neural network models.
While this library is GA, please note Google Cloud C++ client libraries do not follow Semantic Versioning.
Quickstart
The following shows the code that you'll run in the google/cloud/speech/quickstart/ directory, which should give you a taste of the Cloud Speech-to-Text API C++ client library API.
#include "google/cloud/speech/v2/speech_client.h"
#include "google/cloud/project.h"
#include <iostream>
// Configure a simple recognizer for en-US.
void ConfigureRecognizer(google::cloud::speech::v2::RecognizeRequest& request) {
*request.mutable_config()->add_language_codes() = "en-US";
request.mutable_config()->set_model("short");
*request.mutable_config()->mutable_auto_decoding_config() = {};
}
int main(int argc, char* argv[]) try {
auto constexpr kDefaultUri = "gs://cloud-samples-data/speech/hello.wav";
if (argc != 3 && argc != 4) {
std::cerr << "Usage: " << argv[0] << " project <region>|global [gcs-uri]\n"
<< " Specify the region desired or \"global\"\n"
<< " The gcs-uri must be in gs://... format. It defaults to "
<< kDefaultUri << "\n";
return 1;
}
std::string const project = argv[1];
std::string location = argv[2];
auto const uri = std::string{argc == 4 ? argv[3] : kDefaultUri};
namespace speech = ::google::cloud::speech_v2;
std::shared_ptr<speech::SpeechConnection> connection;
google::cloud::speech::v2::RecognizeRequest request;
ConfigureRecognizer(request);
request.set_uri(uri);
request.set_recognizer("projects/" + project + "/locations/" + location +
"/recognizers/_");
if (location == "global") {
// An empty location string indicates that the global endpoint of the
// service should be used.
location = "";
}
auto client = speech::SpeechClient(speech::MakeSpeechConnection(location));
auto response = client.Recognize(request);
if (!response) throw std::move(response).status();
std::cout << response->DebugString() << "\n";
return 0;
} catch (google::cloud::Status const& status) {
std::cerr << "google::cloud::Status thrown: " << status << "\n";
return 1;
}
Main classes
This library offers multiple *Client classes, which are listed below. Each one of these classes exposes all the RPCs for a service as member functions of the class. This library groups multiple services because they are part of the same product or are often used together. A typical example may be the administrative and data plane operations for a single product.
The library also has other classes that provide helpers, configuration parameters, and infrastructure to mock the *Client classes when testing your application.
[[["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 2025-08-28 UTC."],[[["\u003cp\u003eThe Cloud Speech-to-Text API C++ Client Library enables the conversion of audio to text using neural network models.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version of this library is 2.37.0-rc, though note that Google Cloud C++ client libraries do not adhere to Semantic Versioning.\u003c/p\u003e\n"],["\u003cp\u003eThis library includes \u003ccode\u003eAdaptationClient\u003c/code\u003e and \u003ccode\u003eSpeechClient\u003c/code\u003e classes, each exposing RPCs for their respective services, and it is designed for ease of integration and use.\u003c/p\u003e\n"],["\u003cp\u003eThe quickstart guide demonstrates how to use the library with a provided code example that includes configuring a recognizer and initiating a speech recognition request.\u003c/p\u003e\n"],["\u003cp\u003eThe library offers information on error handling, endpoint and authentication overrides, retry policies, and configurable environment variables for advanced usage.\u003c/p\u003e\n"]]],[],null,["Version latestkeyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/speech/latest)\n- [2.41.0](/cpp/docs/reference/speech/2.41.0)\n- [2.40.0](/cpp/docs/reference/speech/2.40.0)\n- [2.39.0](/cpp/docs/reference/speech/2.39.0)\n- [2.38.0](/cpp/docs/reference/speech/2.38.0)\n- [2.37.0](/cpp/docs/reference/speech/2.37.0)\n- [2.36.0](/cpp/docs/reference/speech/2.36.0)\n- [2.35.0](/cpp/docs/reference/speech/2.35.0)\n- [2.34.0](/cpp/docs/reference/speech/2.34.0)\n- [2.33.0](/cpp/docs/reference/speech/2.33.0)\n- [2.32.0](/cpp/docs/reference/speech/2.32.0)\n- [2.31.0](/cpp/docs/reference/speech/2.31.0)\n- [2.30.0](/cpp/docs/reference/speech/2.30.0)\n- [2.29.0](/cpp/docs/reference/speech/2.29.0)\n- [2.28.0](/cpp/docs/reference/speech/2.28.0)\n- [2.27.0](/cpp/docs/reference/speech/2.27.0)\n- [2.26.0](/cpp/docs/reference/speech/2.26.0)\n- [2.25.1](/cpp/docs/reference/speech/2.25.1)\n- [2.24.0](/cpp/docs/reference/speech/2.24.0)\n- [2.23.0](/cpp/docs/reference/speech/2.23.0)\n- [2.22.1](/cpp/docs/reference/speech/2.22.1)\n- [2.21.0](/cpp/docs/reference/speech/2.21.0)\n- [2.20.0](/cpp/docs/reference/speech/2.20.0)\n- [2.19.0](/cpp/docs/reference/speech/2.19.0)\n- [2.18.0](/cpp/docs/reference/speech/2.18.0)\n- [2.17.0](/cpp/docs/reference/speech/2.17.0)\n- [2.16.0](/cpp/docs/reference/speech/2.16.0)\n- [2.15.1](/cpp/docs/reference/speech/2.15.1)\n- [2.14.0](/cpp/docs/reference/speech/2.14.0)\n- [2.13.0](/cpp/docs/reference/speech/2.13.0)\n- [2.12.0](/cpp/docs/reference/speech/2.12.0)\n- [2.11.0](/cpp/docs/reference/speech/2.11.0) \n\nCloud Speech-to-Text API C++ Client Library\n===========================================\n\nAn idiomatic C++ client library for the [Cloud Speech-to-Text API](https://cloud.google.com/speech), a service which converts audio to text by applying powerful neural network models.\n\nWhile this library is **GA** , please note Google Cloud C++ client libraries do **not** follow [Semantic Versioning](https://semver.org/).\n\n### Quickstart\n\nThe following shows the code that you'll run in the `google/cloud/speech/quickstart/` directory, which should give you a taste of the Cloud Speech-to-Text API C++ client library API. \n\n #include \"google/cloud/speech/v2/speech_client.h\"\n #include \"google/cloud/project.h\"\n #include \u003ciostream\u003e\n\n // Configure a simple recognizer for en-US.\n void ConfigureRecognizer(google::cloud::speech::v2::RecognizeRequest& request) {\n *request.mutable_config()-\u003eadd_language_codes() = \"en-US\";\n request.mutable_config()-\u003eset_model(\"short\");\n *request.mutable_config()-\u003emutable_auto_decoding_config() = {};\n }\n\n int main(int argc, char* argv[]) try {\n auto constexpr kDefaultUri = \"gs://cloud-samples-data/speech/hello.wav\";\n if (argc != 3 && argc != 4) {\n std::cerr \u003c\u003c \"Usage: \" \u003c\u003c argv[0] \u003c\u003c \" project \u003cregion\u003e|global [gcs-uri]\\n\"\n \u003c\u003c \" Specify the region desired or \\\"global\\\"\\n\"\n \u003c\u003c \" The gcs-uri must be in gs://... format. It defaults to \"\n \u003c\u003c kDefaultUri \u003c\u003c \"\\n\";\n return 1;\n }\n std::string const project = argv[1];\n std::string location = argv[2];\n auto const uri = std::string{argc == 4 ? argv[3] : kDefaultUri};\n namespace speech = ::google::cloud::speech_v2;\n\n std::shared_ptr\u003cspeech::SpeechConnection\u003e connection;\n google::cloud::speech::v2::RecognizeRequest request;\n ConfigureRecognizer(request);\n request.set_uri(uri);\n request.set_recognizer(\"projects/\" + project + \"/locations/\" + location +\n \"/recognizers/_\");\n\n if (location == \"global\") {\n // An empty location string indicates that the global endpoint of the\n // service should be used.\n location = \"\";\n }\n\n auto client = speech::SpeechClient(speech::MakeSpeechConnection(location));\n auto response = client.Recognize(request);\n if (!response) throw std::move(response).status();\n std::cout \u003c\u003c response-\u003eDebugString() \u003c\u003c \"\\n\";\n\n return 0;\n } catch (google::cloud::Status const& status) {\n std::cerr \u003c\u003c \"google::cloud::Status thrown: \" \u003c\u003c status \u003c\u003c \"\\n\";\n return 1;\n }\n\n### Main classes\n\nThis library offers multiple `*Client` classes, which are listed below. Each one of these classes exposes all the RPCs for a service as member functions of the class. This library groups multiple services because they are part of the same product or are often used together. A typical example may be the administrative and data plane operations for a single product.\n\nThe library also has other classes that provide helpers, configuration parameters, and infrastructure to mock the `*Client` classes when testing your application.\n\n- [`speech_v1::AdaptationClient`](/cpp/docs/reference/speech/latest/classgoogle_1_1cloud_1_1speech__v1_1_1AdaptationClient)\n- [`speech_v1::SpeechClient`](/cpp/docs/reference/speech/latest/classgoogle_1_1cloud_1_1speech__v1_1_1SpeechClient)\n- [`speech_v2::SpeechClient`](/cpp/docs/reference/speech/latest/classgoogle_1_1cloud_1_1speech__v2_1_1SpeechClient)\n\n### More Information\n\n- [Error Handling](https://cloud.google.com/cpp/docs/reference/common/latest/common-error-handling.html) - describes how the library reports errors.\n- [How to Override the Default Endpoint](/cpp/docs/reference/speech/latest/speech-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/speech/latest/speech-override-authentication) - describes how to change the authentication credentials used by the library.\n- [Override Retry, Backoff, and Idempotency Policies](/cpp/docs/reference/speech/latest/speech-override-retry) - describes how to change the default retry policies.\n- [Environment Variables](/cpp/docs/reference/speech/latest/speech-env) - describes environment variables that can configure the behavior of the library."]]