An idiomatic C++ client library for theCloud Speech-to-Text API, a service which converts audio to text by applying powerful neural network models.
While this library isGA, please note Google Cloud C++ client libraries donotfollowSemantic Versioning.
Quickstart
The following shows the code that you'll run in thegoogle/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*Clientclasses, 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*Clientclasses 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 2025-09-04 UTC."],[[["\u003cp\u003eThis webpage provides documentation for the Cloud Speech-to-Text API C++ client library, which allows converting audio to text using neural network models.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate version of the library is 2.37.0-rc, and the page lists a range of prior versions from 2.36.0 back to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eThe library offers multiple client classes, including \u003ccode\u003espeech_v1::AdaptationClient\u003c/code\u003e, \u003ccode\u003espeech_v1::SpeechClient\u003c/code\u003e, and \u003ccode\u003espeech_v2::SpeechClient\u003c/code\u003e, which expose RPCs for service interactions.\u003c/p\u003e\n"],["\u003cp\u003eThe library is generally available (GA), but does not adhere to Semantic Versioning, as indicated by Google Cloud's C++ client libraries.\u003c/p\u003e\n"],["\u003cp\u003eThe page offers links for error handling and instructions on how to override the default endpoint, authentication credentials, retry policies, as well as environment variables that configure the behavior of the library.\u003c/p\u003e\n"]]],[],null,["Version 2.31.0keyboard_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/2.31.0/classgoogle_1_1cloud_1_1speech__v1_1_1AdaptationClient)\n- [`speech_v1::SpeechClient`](/cpp/docs/reference/speech/2.31.0/classgoogle_1_1cloud_1_1speech__v1_1_1SpeechClient)\n- [`speech_v2::SpeechClient`](/cpp/docs/reference/speech/2.31.0/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/2.31.0/speech-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/speech/2.31.0/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/2.31.0/speech-override-retry) - describes how to change the default retry policies.\n- [Environment Variables](/cpp/docs/reference/speech/2.31.0/speech-env) - describes environment variables that can configure the behavior of the library."]]