Webhooks

Webhooks

Receive real-time notifications when events occur in your LH42 account.

Setting Up Webhooks

1. Go to Settings > Webhooks
2. Click "Add Webhook"
3. Enter your endpoint URL
4. Select events to subscribe to
5. Save and copy the signing secret

Event Types

Payload Format

{
  "id": "evt_123abc",
  "type": "document.processed",
  "created_at": "2026-01-20T10:30:00Z",
  "data": {
    "document_id": "doc_xyz",
    "title": "Q4 Report",
    "chunks": 24,
    "processing_time_ms": 1250
  }
}

Verifying Signatures

Always verify webhook signatures:

import hmac
import hashlib

def verify_signature(payload, signature, secret):
    expected = hmac.new(
        secret.encode(),
        payload.encode(),
        hashlib.sha256
    ).hexdigest()
    return hmac.compare_digest(f"sha256={expected}", signature)

Retry Policy

Failed deliveries are retried with exponential backoff:

• Attempt 1: Immediate
• Attempt 2: 1 minute
• Attempt 3: 5 minutes
• Attempt 4: 30 minutes
• Attempt 5: 2 hours

Best Practices

1. Respond quickly - Return 200 within 5 seconds
2. Process async - Queue webhooks for background processing
3. Handle duplicates - Use event IDs for idempotency
4. Monitor failures - Set up alerts for failed deliveries