Webhooks for pre-recorded audio

Webhooks are custom HTTP callbacks that you can define to get notified when your pre-recorded audio transcripts are ready.

To use webhooks, you need to set up your own webhook receiver to handle webhook deliveries.

Create a webhook for a transcription

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import requests
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import time
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base_url = "https://api.assemblyai.com"
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headers = {
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    "authorization": "<YOUR_API_KEY>"
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}
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with open("./my-audio.mp3", "rb") as f:
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  response = requests.post(base_url + "/v2/upload",
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                          headers=headers,
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                          data=f)
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upload_url = response.json()["upload_url"]
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data = {
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    "audio_url": upload_url,
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    "webhook_url": "https://example.com/webhook"
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}
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url = base_url + "/v2/transcript"
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response = requests.post(url, json=data, headers=headers)

Handle webhook deliveries

When the transcript is ready, AssemblyAI will send a POST HTTP request to the URL that you specified.

Your webhook endpoint must return a 2xx HTTP status code within 10 seconds to indicate successful receipt. If a 2xx status is not received within 10 seconds, AssemblyAI will retry the webhook call up to a total of 10 attempts. If at any point your endpoint returns a 4xx status code, the webhook call is considered failed and will not be retried.

Delivery payload

The webhook delivery payload contains a JSON object with the following properties:

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{
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  "transcript_id": "5552493-16d8-42d8-8feb-c2a16b56f6e8",
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  "status": "completed"
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}

The webhook payload only contains the transcript_id and status. It doesn’t include the transcript text or error details. If the status is "error", make a GET /v2/transcript/{transcript_id} request to retrieve the error message from the error field in the response. See Retrieve a transcript with the transcript ID below.

Webhook status code

When you retrieve the transcript using the transcript ID, the JSON response will include a webhook_status_code field. This field contains the HTTP status code that AssemblyAI received when calling your webhook endpoint, allowing you to verify that the webhook was delivered successfully.

Retrieve a transcript with the transcript ID

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import requests
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import time
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base_url = "https://api.assemblyai.com"
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headers = {
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    "authorization": "<YOUR_API_KEY>"
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}
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transcript_id = "<TRANSCRIPT_ID>"
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polling_endpoint = f"https://api.assemblyai.com/v2/transcript/{transcript_id}"
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transcription_result = requests.get(polling_endpoint, headers=headers).json()
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if transcription_result['status'] == 'completed':
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  print(f"Transcript ID: {transcript_id}")
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elif transcription_result['status'] == 'error':
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  raise RuntimeError(f"Transcription failed: {transcription_result['error']}")

Authenticate webhook deliveries

You can authenticate webhook deliveries from AssemblyAI by including a custom HTTP header in the request.

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config = aai.TranscriptionConfig().set_webhook(
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    "https://example.com/webhook", "X-My-Webhook-Secret", "secret-value"
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)
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aai.Transcriber().submit(audio_url, config)

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import requests
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import time
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base_url = "https://api.assemblyai.com"
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headers = {
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    "authorization": "<YOUR_API_KEY>"
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}
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with open("./my-audio.mp3", "rb") as f:
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  response = requests.post(base_url + "/v2/upload",
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                          headers=headers,
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                          data=f)
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upload_url = response.json()["upload_url"]
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data = {
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    "audio_url": upload_url,
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    "webhook_url": "https://example.com/webhook",
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    "webhook_auth_header_name": "X-My-Webhook-Secret",
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    "webhook_auth_header_value": "secret-value"
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}
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url = base_url + "/v2/transcript"
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response = requests.post(url, json=data, headers=headers)

Add metadata to webhook deliveries

To associate metadata for a specific transcription request, you can add your own query parameters to the webhook URL.

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https://example.com/webhook?customer_id=1234&order_id=5678

Now, when you receive the webhook delivery, you’ll know the customer who requested it.

Failed webhook deliveries

Webhook deliveries can fail for multiple reasons. For example, if your server is down or takes more than 10 seconds to respond.

If a webhook delivery fails, AssemblyAI will attempt to redeliver it up to 10 times, waiting 10 seconds between each attempt. If all attempts fail, AssemblyAI considers the delivery as permanently failed.