Quickstart: Using the Command Line

This page shows you how to send a speech recognition request to Cloud Speech-to-Text using the REST interface and the curl command.

Cloud Speech-to-Text enables easy integration of Google speech recognition technologies into developer applications. You can send audio data to the Speech-to-Text API, which then returns a text transcription of that audio file. For more information about the service, see Cloud Speech-to-Text basics.

Before you begin

  1. Sign in to your Google Account.

    If you don't already have one, sign up for a new account.

  2. Set up a GCP Console project.

    Set up a project

    Click to:

    • Create or select a project.
    • Enable the Speech-to-Text API for that project.
    • Create a service account.
    • Download a private key as JSON.

    You can view and manage these resources at any time in the GCP Console.

  3. Install and initialize the Cloud SDK.
  4. Provide authentication credentials to your application code by running the following command. Replace [PATH] with the location of the JSON file that contains your credentials.

    gcloud auth activate-service-account --key-file=[PATH]

Make an audio transcription request

Now you can use Speech-to-Text to transcribe an audio file to text. Use the following code sample to send a recognize REST request to the Speech-to-Text API.

  1. Create a JSON request file with the following text, and save it as a sync-request.json plain text file:

    {
      "config": {
          "encoding":"FLAC",
          "sampleRateHertz": 16000,
          "languageCode": "en-US",
          "enableWordTimeOffsets": false
      },
      "audio": {
          "uri":"gs://cloud-samples-tests/speech/brooklyn.flac"
      }
    }
      

    This JSON snippet indicates that the audio file has a FLAC encoding format, a sample rate of 16000 Hz, and that the audio file is stored on Google Cloud Storage at the given URI. The audio file is publicly accessible, so you don't need authentication credentials to access the file.

  2. Use curl to make a speech:recognize request, passing it the filename of the JSON request you set up in step 1:

    The sample curl command uses the gcloud auth print-access-token command to get an authentication token.

    curl -s -H "Content-Type: application/json" \
        -H "Authorization: Bearer "$(gcloud auth print-access-token) \
        https://speech.googleapis.com/v1/speech:recognize \
        -d @sync-request.json
      

    Note that to pass a filename to curl you use the -d option (for "data") and precede the filename with an @ sign. This file should be in the same directory in which you execute the curl command.

    You should see a response similar to the following:

    {
      "results": [
        {
          "alternatives": [
            {
              "transcript": "how old is the Brooklyn Bridge",
              "confidence": 0.98267895
            }
          ]
        }
      ]
    }
      

Congratulations! You've sent your first request to Cloud Speech-to-Text !

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Cloud Speech API Documentation