Deepgram Webhooks Skill

When to Use This Skill

• Setting up Deepgram callback handlers for transcription results
• Processing asynchronous transcription results from Deepgram
• Implementing webhook authentication for Deepgram callbacks
• Handling transcription completion events

Essential Code

Deepgram webhooks (callbacks) are used to receive transcription results asynchronously. When you provide a callback URL in your transcription request, Deepgram immediately responds with a request_id and sends the transcription results to your callback URL when processing is complete.

Basic Webhook Handler

// Express.js example
const crypto = require('crypto');

function safeEqual(a, b) {
  const ab = Buffer.from(a || '', 'utf8');
  const bb = Buffer.from(b || '', 'utf8');
  return ab.length === bb.length && crypto.timingSafeEqual(ab, bb);
}

app.post('/webhooks/deepgram', express.raw({ type: 'application/json' }), (req, res) => {
  // 1. Primary check: Basic Auth credentials you embedded in the callback URL
  //    (https://user:pass@your-domain.com/webhooks/deepgram)
  const auth = req.headers['authorization'] || '';
  const decoded = auth.startsWith('Basic ')
    ? Buffer.from(auth.slice(6), 'base64').toString('utf8')
    : '';
  const sep = decoded.indexOf(':');
  if (
    sep === -1 ||
    !safeEqual(decoded.slice(0, sep), process.env.DEEPGRAM_CALLBACK_USERNAME) ||
    !safeEqual(decoded.slice(sep + 1), process.env.DEEPGRAM_CALLBACK_PASSWORD)
  ) {
    return res.status(401).send('Unauthorized');
  }

  // 2. Supplementary check: dg-token is NOT sent on every callback,
  //    so only compare it when it is present
  const dgToken = req.headers['dg-token'];
  if (dgToken && process.env.DEEPGRAM_API_KEY_ID && !safeEqual(dgToken, process.env.DEEPGRAM_API_KEY_ID)) {
    return res.status(403).send('Invalid dg-token');
  }

  // The callback body is the normal /v1/listen response: { metadata, results }
  const payload = JSON.parse(req.body.toString());
  const requestId = payload.metadata?.request_id;
  const transcript = payload.results?.channels?.[0]?.alternatives?.[0]?.transcript;
  console.log('Received transcription:', requestId, transcript);

  // Return success to prevent retries
  res.status(200).send('OK');
});

Authentication Methods

Deepgram documents two ways to authenticate callbacks:

1. Basic Auth (primary): Embed credentials in the callback URL; Deepgram sends them as an Authorization: Basic header
2. dg-token Header (supplementary): When present, contains the API Key Identifier of the key that submitted the request. Deepgram's docs state it "is not guaranteed on every callback request", so never rely on it alone

// Basic Auth in callback URL (percent-encode special characters in the credentials)
// https://username:password@your-domain.com/webhooks/deepgram

// dg-token: check only when present
const dgToken = req.headers['dg-token'];
if (dgToken && dgToken !== process.env.DEEPGRAM_API_KEY_ID) {
  return res.status(403).send('Invalid dg-token');
}

Making a Request with Callback

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

Common Event Types

Deepgram callbacks carry no event-type field. The body is the same JSON a synchronous /v1/listen request returns: a metadata object and a results object. The structure of results varies based on the features enabled in your request:

Environment Variables

# Your Deepgram API Key (for making requests)
DEEPGRAM_API_KEY=your_api_key_here

# Basic Auth credentials you embed in the callback URL (primary check)
DEEPGRAM_CALLBACK_USERNAME=your_callback_username
DEEPGRAM_CALLBACK_PASSWORD=your_callback_password

# Optional: API Key Identifier, used to check the dg-token header when present
# Note: This is NOT your API Key secret - it's a unique identifier shown
# in the Deepgram console that identifies which API key was used for a request
DEEPGRAM_API_KEY_ID=your_api_key_id_here

# Your webhook endpoint URL
WEBHOOK_URL=https://your-domain.com/webhooks/deepgram

Local Development

For local webhook testing, install Hookdeck CLI:

# Create a local tunnel (no account required)
npx hookdeck-cli listen 3000 deepgram --path /webhooks/deepgram

# Use the provided URL as your callback URL when making Deepgram requests

This provides:

• Local tunnel URL for testing
• Web UI for inspecting webhook payloads
• Request history and debugging tools

Important Notes

Retry Behavior

• Deepgram retries failed callbacks (non-200-299 status) up to 10 times
• 30-second delay between retry attempts
• Always return 200-299 status for successfully processed webhooks

Port Restrictions

• Only ports 80, 443, 8080, and 8443 are allowed for callbacks
• Ensure your webhook endpoint uses one of these ports

No Signature Verification

• Deepgram does not sign callbacks (no HMAC, no timestamp)
• Authenticate with Basic Auth credentials embedded in the callback URL; treat the dg-token header as a supplementary check because it is not sent on every callback
• Always use HTTPS for webhook endpoints

Resources

• overview.md - What Deepgram webhooks are, transcription events
• setup.md - Configure callbacks in Deepgram API requests
• verification.md - Authentication methods and security considerations
• examples/ - Complete implementations for Express, Next.js, and FastAPI