TTS Callback

A text-to-speech Callback allows you to have your submitted text processed asynchronously.

callback stringEnglish

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

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:


To synthesize text-to-speech and generate an audio file, run the following cURL command in a terminal or your favorite API client:

curl \
  --request POST \
  --header 'Authorization: Token YOUR_DEEPGRAM_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{"text": "Hello, how can I help you today?"}'
  --url ''

URL Structure

An example URL is

Your callback URLs may reference the http or https protocols.

Authenticating Callback Requests

Authentication ensures the security and integrity of callback requests. There are two main methods for authenticating callback requests: using Basic Auth and utilizing the dg-token request header.

Using Basic Auth

You may embed username-password authentication credentials in the callback URL in the format https://username:[email protected]. However, it's important to note that only ports 80, 443, 8080, and 8443 are permitted for callbacks.


Only ports 80, 443, 8080, and 8443 are permitted for callbacks.

Using the dg-token Request Header

Alternatively, the callback request itself contains a header named dg-token. This header is automatically set to the API Key Identifier associated with the API Key used to submit the original request. This method provides a secure and straightforward means of authentication.


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

If the HTTP status code of the response to the callback POST request is unsuccessful (not 200-299), Deepgram will retry the callback up to 10 times with a 30 second delay between attempts.

If you would like Deepgram to make a PUT request rather than a POST request to your callback URL, you can add the callback_method=put query parameter in addition to callback=URL. Refer to the AWS S3 Presigned URLs and Deepgram guide for more information.


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