Webhooks Overview

Webhooks allow you to receive real-time notifications when events occur in your Klen AI account. Instead of polling our API, your server can be notified automatically when events like calls, transcripts, recordings, or calendar events become available.

How Webhooks Work

You create a webhook endpoint on your server that can receive HTTP POST requests.
You register this endpoint URL with Klen AI and specify which events you want to subscribe to.
When an event occurs in your account, Klen AI sends an HTTP POST request to your endpoint with event data in JSON format.
Your server processes the incoming webhook data and takes appropriate actions.

Creating a Webhook Endpoint

From the Dashboard

Log in to your Klen AI dashboard
Navigate to API > Webhooks
Click “Create New Webhook”
Enter a name, your endpoint URL, and select the events you want to subscribe to
Copy the generated secret for signature verification

Via the API

You can also create webhooks programmatically via our API:

curl -X POST 'https://api.klen.ai/api/webhooks/create/' \
  -H 'Authorization: Bearer klen_abcdef123456789' \
  -H 'Content-Type: application/json' \
  -d '{
    "name": "Call Events Webhook",
    "url": "https://example.com/webhooks/klen",
    "subscribed_events": ["call.started", "call.ended", "call.transcript"]
  }'

Available Events

Call Events

Event Name	Description
`call.started`	Triggered when a call begins
`call.ended`	Triggered when a call ends
`call.failed`	Triggered when a call fails to connect
`call.transcript`	Triggered when a call transcript becomes available
`call.recording`	Triggered when a call recording becomes available
`call.summary`	Triggered when a call summary becomes available

Calendar Events

Event Name	Description
`calendar.created`	Triggered when a calendar event is created
`calendar.updated`	Triggered when a calendar event is updated
`calendar.cancelled`	Triggered when a calendar event is cancelled
`calendar.completed`	Triggered when a calendar event is completed
`calendar.reminder`	Triggered when a reminder for a calendar event is sent

Webhook Payload Structure

Call Event Payload

Call event webhooks follow this general structure:

{
  "event_type": "call.ended",
  "call": {
    "id": 123,
    "klen_call_id": "call_abc123",
    "agent_id": 456,
    "agent_name": "Customer Support",
    "status": "completed",
    "type": "inbound",
    "phone_number": "+15551234567",
    "started_at": "2025-04-23T14:30:45Z",
    "ended_at": "2025-04-23T14:35:12Z",
    "duration_seconds": 267,
    "recording_url": "https://storage.example.com/recordings/call_abc123.mp3",
    "summary": "Call summary if available...",
    "contact": {
      "id": 789,
      "name": "John Doe",
      "email": "[email protected]"
    }
  },
  "timestamp": "2025-04-23T14:35:15Z"
}

See Call Events for call event-specific details.

Calendar Event Payload

Calendar event webhooks follow this general structure:

{
  "event_type": "calendar.created",
  "calendar_event": {
    "id": 123,
    "uuid": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
    "title": "Client Meeting",
    "event_type": "meeting",
    "status": "confirmed",
    "start_time": "2025-05-01T14:00:00.000Z",
    "end_time": "2025-05-01T15:00:00.000Z",
    "duration_minutes": 60,
    "location": "Conference Room A",
    "has_video_conference": true,
    "video_conference_url": "https://meet.google.com/abc-defg-hij",
    "created_by_ai_agent": true,
    "ai_agent": {
      "id": 42,
      "name": "Meeting Scheduler",
      "assistant_id": "asst_01234567890"
    },
    "customer": {
      "name": "John Smith",
      "email": "[email protected]",
      "phone": "+15551234567"
    },
    "ics_url": "/calendar/event/f47ac10b-58cc-4372-a567-0e02b2c3d479/calendar.ics"
  },
  "timestamp": "2025-05-01T10:15:30.000Z"
}

See Calendar Events for calendar event-specific details.

Verifying Webhook Signatures

For security, we sign all webhook requests with a signature that you can verify to ensure the request came from Klen AI:

When you create a webhook, you receive a secret.
We include a signature in the X-Klen-Signature header of each webhook request.
You can verify this signature by creating an HMAC-SHA256 hash of the request body using your webhook secret.

Python example for verifying signatures:

import hmac
import hashlib

def verify_webhook_signature(request_body, signature, webhook_secret):
    computed_signature = hmac.new(
        webhook_secret.encode('utf-8'),
        request_body.encode('utf-8'),
        hashlib.sha256
    ).hexdigest()
    
    return hmac.compare_digest(computed_signature, signature)

Handling Webhook Deliveries

Best Practices

Process webhooks asynchronously: Respond quickly to the webhook request (with a 200 status code) and process the data in the background.
Implement idempotency: Use the X-Klen-Delivery-ID header to ensure you don’t process the same webhook multiple times.
Verify signatures: Always verify the webhook signature to ensure the request came from Klen AI.
Handle timeouts: We expect your endpoint to respond within 10 seconds. Process data asynchronously if needed.
Implement proper error handling: If your endpoint fails to process a webhook, we’ll retry with exponential backoff (1 minute, 5 minutes, 30 minutes).

Example Webhook Handler (Express.js)

const express = require('express');
const crypto = require('crypto');
const app = express();

app.use(express.json());

app.post('/webhooks/klen', (req, res) => {
  // Get the signature from the headers
  const signature = req.headers['x-klen-signature'];
  const deliveryId = req.headers['x-klen-delivery-id'];
  const eventType = req.headers['x-klen-event'];
  
  // Verify the signature
  const webhookSecret = 'your_webhook_secret';
  const payload = JSON.stringify(req.body);
  const computedSignature = crypto
    .createHmac('sha256', webhookSecret)
    .update(payload)
    .digest('hex');
  
  if (crypto.timingSafeEqual(
    Buffer.from(computedSignature), 
    Buffer.from(signature)
  )) {
    // Signature is valid, process the webhook
    
    // Always respond with a 200 status quickly
    res.status(200).send('Webhook received');
    
    // Process the webhook data asynchronously
    processWebhook(deliveryId, eventType, req.body);
  } else {
    // Invalid signature
    res.status(401).send('Invalid signature');
  }
});

// Process webhook data asynchronously
function processWebhook(deliveryId, eventType, data) {
  // Check if this webhook has already been processed
  if (hasProcessedWebhook(deliveryId)) {
    console.log(`Webhook ${deliveryId} already processed`);
    return;
  }
  
  // Process based on event type
  switch (eventType) {
    case 'call.started':
      handleCallStarted(data);
      break;
    case 'call.ended':
      handleCallEnded(data);
      break;
    case 'call.transcript':
      handleCallTranscript(data);
      break;
    case 'calendar.created':
      handleCalendarCreated(data);
      break;
    case 'calendar.updated':
      handleCalendarUpdated(data);
      break;
    case 'calendar.cancelled':
      handleCalendarCancelled(data);
      break;
    // Handle other event types...
    default:
      console.log(`Unknown event type: ${eventType}`);
  }
  
  // Mark this webhook as processed
  markWebhookAsProcessed(deliveryId);
}

app.listen(3000, () => {
  console.log('Webhook server running on port 3000');
});

Retries and Failures

If your endpoint fails to respond, Klen AI will retry the webhook delivery with the following schedule:

First retry: After 1 minute
Second retry: After 5 minutes
Final retry: After 30 minutes

If all retries fail, the webhook will be marked as failed. You can view failed webhook deliveries in your Klen AI dashboard.

Managing Webhooks

You can view, update, and delete webhooks from your Klen AI dashboard or via our API:

List webhooks: GET /api/v1/webhooks
Get webhook details: GET /api/v1/webhooks/{webhook_id}
Delete webhook: POST /api/v1/webhooks/{webhook_id}/delete

Testing Webhooks

We recommend using a tool like Webhook.site or Requestbin for testing webhooks during development.

Once you have your endpoint set up, you can trigger test events by making test calls or creating calendar events through your Klen AI dashboard.

Need Help?

If you’re having issues with webhooks, check the webhook delivery logs in your Klen AI dashboard or contact our support team at [email protected].

Overview

Calls

Agents

Contacts

Context Variables

Calendar

Webhooks

Webhooks Overview

Webhooks Overview

How Webhooks Work

Creating a Webhook Endpoint

From the Dashboard

Via the API

Available Events

Call Events

Calendar Events

Webhook Payload Structure

Call Event Payload

Calendar Event Payload

Verifying Webhook Signatures

Handling Webhook Deliveries

Best Practices

Example Webhook Handler (Express.js)

Retries and Failures

Managing Webhooks

Testing Webhooks

Need Help?

Overview

Calls

Agents

Contacts

Context Variables

Calendar

Webhooks

​Webhooks Overview

​How Webhooks Work

​Creating a Webhook Endpoint

​From the Dashboard

​Via the API

​Available Events

​Call Events

​Calendar Events

​Webhook Payload Structure

​Call Event Payload

​Calendar Event Payload

​Verifying Webhook Signatures

​Handling Webhook Deliveries

​Best Practices

​Example Webhook Handler (Express.js)

​Retries and Failures

​Managing Webhooks

​Testing Webhooks

​Need Help?

Webhooks Overview

How Webhooks Work

Creating a Webhook Endpoint

From the Dashboard

Via the API

Available Events

Call Events

Calendar Events

Webhook Payload Structure

Call Event Payload

Calendar Event Payload

Verifying Webhook Signatures

Handling Webhook Deliveries

Best Practices

Example Webhook Handler (Express.js)

Retries and Failures

Managing Webhooks

Testing Webhooks

Need Help?