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/v1/speech_client.h"
#include "google/cloud/project.h"
#include <iostream>
int main(int argc, char* argv[]) try {
auto constexpr kDefaultUri = "gs://cloud-samples-data/speech/hello.wav";
if (argc > 2) {
std::cerr << "Usage: " << argv[0] << " [gcs-uri]\n"
<< " The gcs-uri must be in gs://... format. It defaults to "
<< kDefaultUri << "\n";
return 1;
}
auto uri = std::string{argc == 2 ? argv[1] : kDefaultUri};
namespace speech = ::google::cloud::speech_v1;
auto client = speech::SpeechClient(speech::MakeSpeechConnection());
google::cloud::speech::v1::RecognitionConfig config;
config.set_language_code("en-US");
google::cloud::speech::v1::RecognitionAudio audio;
audio.set_uri(uri);
auto response = client.Recognize(config, audio);
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 gRPCserviceas member functions of the class. This library groups multiple gRPC 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.
The library automatically retries requests that fail with transient errors, and usesexponential backoffto backoff between retries. Application developers can override the default policies.
More Information
Error Handling- describes how the library reports errors.
[[["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 for the C++ client library is 2.37.0-rc, and other versions, going as far back as 2.11.0, are also documented and accessible via provided links.\u003c/p\u003e\n"],["\u003cp\u003eThe library uses automatic retries with exponential backoff for requests that encounter transient errors, with the capability for developers to customize these policies.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation covers the \u003ccode\u003eSpeechClient\u003c/code\u003e classes for v1 and v2 of the Speech API, which expose gRPC service RPCs, along with information on error handling and how to customize default endpoints and authentication.\u003c/p\u003e\n"],["\u003cp\u003eThe Cloud Speech-to-Text API C++ client library is in GA, but does not follow Semantic Versioning.\u003c/p\u003e\n"]]],[],null,["Version 2.11.0keyboard_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/v1/speech_client.h\"\n #include \"google/cloud/project.h\"\n #include \u003ciostream\u003e\n\n int main(int argc, char* argv[]) try {\n auto constexpr kDefaultUri = \"gs://cloud-samples-data/speech/hello.wav\";\n if (argc \u003e 2) {\n std::cerr \u003c\u003c \"Usage: \" \u003c\u003c argv[0] \u003c\u003c \" [gcs-uri]\\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 auto uri = std::string{argc == 2 ? argv[1] : kDefaultUri};\n\n namespace speech = ::google::cloud::speech_v1;\n auto client = speech::SpeechClient(speech::MakeSpeechConnection());\n\n google::cloud::speech::v1::RecognitionConfig config;\n config.set_language_code(\"en-US\");\n google::cloud::speech::v1::RecognitionAudio audio;\n audio.set_uri(uri);\n auto response = client.Recognize(config, audio);\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 gRPC `service` as member functions of the class. This library groups multiple gRPC 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::SpeechClient`](/cpp/docs/reference/speech/2.11.0/classgoogle_1_1cloud_1_1speech__v1_1_1SpeechClient)\n- [`speech_v2::SpeechClient`](/cpp/docs/reference/speech/2.11.0/classgoogle_1_1cloud_1_1speech__v2_1_1SpeechClient)\n\n### Retry, Backoff, and Idempotency Policies.\n\nThe library automatically retries requests that fail with transient errors, and uses [exponential backoff](https://en.wikipedia.org/wiki/Exponential_backoff) to backoff between retries. Application developers can override the default policies.\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/2.11.0/speech-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/speech/2.11.0/speech-override-authentication) - describes how to change the authentication credentials used by the library.\n- [Environment Variables](/cpp/docs/reference/speech/2.11.0/speech-env) - describes environment variables that can configure the behavior of the library."]]