Webhook Simulator

Test your webhook endpoints with sample payloads before going live

Configuration

Enter your webhook URL and select an event type to test

Webhook URL

We'll send a POST request with JSON payload to this URL

Event Type

Triggered when the page title changes

Payload Preview

This is the JSON payload that will be sent to your webhook

{
  "event": "title_change",
  "timestamp": "2025-12-28T16:34:37.024Z",
  "monitor": {
    "id": "mon_abc123xyz",
    "name": "My Website",
    "url": "https://example.com"
  },
  "changes": {
    "field": "title",
    "previous": "Old Title - My Website",
    "current": "New Title - My Website"
  }
}

Request Headers

Content-Type: application/json

User-Agent: Katsau-Webhook/1.0

X-Katsau-Event: title_change

X-Katsau-Signature: sha256=...

Webhook Best Practices

Respond quickly - Return a 2xx status within 5 seconds
Verify signatures - Check the X-Katsau-Signature header to verify authenticity
Handle duplicates - Use the event ID to deduplicate in case of retries
Process async - Queue the webhook and process in the background