1. Documentation
  2. Features
  3. Callback

Callback

PRE-RECORDED
STREAMING

Deepgram’s Callback feature allows you to supply a callback URL to which transcriptions can be returned. When passed, Deepgram will immediately respond with a request_id before processing your audio asynchronously.

Use Cases

Some examples of use cases for Callback include:

  • Customers with large amounts of audio that may be slow to process.
  • Customers who don't require immediate results.

Enable Feature

To enable Callback, when you call Deepgram’s API, add a callback parameter in the query string and set it to the URL to which you would like transcriptions sent:

callback=URL

To transcribe audio from a file on your computer, run the following cURL command in a terminal or your favorite API client.

Be sure to replace the placeholder URL with your chosen callback URL and YOUR_DEEPGRAM_API_KEY with your Deepgram API Key. You can create an API Key in the Deepgram Console.

curl \
  --request POST \
  --header 'Authorization: Token YOUR_DEEPGRAM_API_KEY' \
  --header 'Content-Type: audio/wav' \
  --data-binary @youraudio.wav \
  --url 'https://api.deepgram.com/v1/listen?callback=URL'

URL Structure

An example URL is https://example.com/callback.

Your callback URLs may reference the following protocols:

  • For pre-recorded audio: http or https
  • For streaming audio, http, https, ws, or wss:

If a WebSocket callback connection is disconnected at any point, the entire real-time transcription stream is killed; this maintains the strong guarantee of a one-to-one relationship between incoming real-time connections and outgoing WebSocket callback connections.

You may embed basic authentication credentials in the callback URL.

Only ports 80, 443, 8080, and 8443 may be used for callbacks.

Results

Depending on the type of submitted audio, the response will vary.

Pre-recorded Audio

When Deepgram has finished analyzing the audio, it will send a POST request to the provided callback URL with an appropriate HTTP status code.

Streaming Audio

As Deepgram analyzes the audio, the way in which it sends requests back to the provided callback URL varies:

  • If your callback URL begins with http:// or https://, then Deepgram will send POST requests to the callback server for each streaming response.
  • If your callback URL begins with ws:// or wss://, then Deepgram will establish a WebSocket connection with the callback server and send WebSocket text messages that contain the streaming responses.

If a WebSocket callback connection is disconnected at any point, the entire real-time transcription stream is killed; this maintains the strong guarantee of a one-to-one relationship between incoming real-time connections and outgoing WebSocket callback connections.