Webhooks#

Webhooks send notifications to external URLs when events happen in your system. Use them to integrate with other services, trigger automations, or sync data.

How webhooks work#

1. You register a webhook URL for specific triggers
2. When the trigger occurs, the plugin sends a POST request to your URL
3. Your server processes the data and takes action

Setting up webhooks#

Add a webhook#

1. Go to Events > Settings > Webhooks
2. Click Add Webhook
3. Enter a name for reference
4. Enter the delivery URL
5. Select triggers to listen for
6. Save

Webhook fields#

Field	Description
Name	Reference name for your use
Delivery URL	Where to send the webhook
Status	Active or Paused
Triggers	Which events fire this webhook
Secret	For signature verification

Available triggers#

Event triggers#

Trigger	Fires When
event.created	New event is published
event.updated	Event details change
event.deleted	Event is deleted
event.status_changed	Status changes (cancelled, etc.)

Registration triggers#

Trigger	Fires When
registration.completed	Ticket purchase completes
registration.cancelled	Order is cancelled/refunded

Attendee triggers#

Trigger	Fires When
attendee.checked_in	Attendee checks in
attendee.checked_out	Attendee checks out

Capacity triggers#

Trigger	Fires When
event.sold_out	Event reaches capacity
event.capacity_available	Spots open up

Webhook payload#

Payload structure#

{
  "id": "webhook_123456",
  "trigger": "registration.completed",
  "timestamp": "2025-01-15T10:30:00Z",
  "site_url": "https://yoursite.com",
  "data": {
    // Trigger-specific data
  }
}

Event created payload#

{
  "trigger": "event.created",
  "data": {
    "event_id": 123,
    "title": "Tech Conference",
    "start_date": "2025-03-15",
    "start_time": "09:00",
    "end_date": "2025-03-15",
    "end_time": "17:00",
    "status": "scheduled",
    "type": "in-person",
    "venue": "Convention Center",
    "capacity": 500,
    "link": "https://yoursite.com/events/tech-conference/"
  }
}

Registration completed payload#

{
  "trigger": "registration.completed",
  "data": {
    "attendee_id": 456,
    "event_id": 123,
    "event_name": "Tech Conference",
    "order_id": 789,
    "ticket_code": "EMWC-ABC123DEF",
    "first_name": "John",
    "last_name": "Doe",
    "email": "john@example.com",
    "custom_fields": {
      "company": "Acme Inc"
    }
  }
}

Attendee checked in payload#

{
  "trigger": "attendee.checked_in",
  "data": {
    "attendee_id": 456,
    "event_id": 123,
    "event_name": "Tech Conference",
    "ticket_code": "EMWC-ABC123DEF",
    "name": "John Doe",
    "email": "john@example.com",
    "checked_in_at": "2025-03-15T09:15:00Z",
    "checked_in_by": "admin"
  }
}

Security#

Signature verification#

Each webhook includes a signature header for verification:

X-EMWC-Signature: sha256=abc123...

Verify in your code:

$payload = file_get_contents( 'php://input' );
$signature = $_SERVER['HTTP_X_EMWC_SIGNATURE'];

$expected = 'sha256=' . hash_hmac( 'sha256', $payload, $your_secret );

if ( hash_equals( $expected, $signature ) ) {
    // Valid webhook
}

Secret key#

Set a secret key when creating the webhook. Keep it secure and use it to verify incoming requests.

HTTPS#

Always use HTTPS URLs for webhook delivery to encrypt data in transit.

Delivery#

Retry logic#

If delivery fails:

1. First retry: 1 minute after failure
2. Second retry: 5 minutes after
3. Third retry: 30 minutes after
4. Final retry: 2 hours after

After 4 failures, the webhook is marked as failed.

Timeout#

Requests timeout after 15 seconds. If your server needs more time, return a 200 status immediately and process asynchronously.

Response handling#

Response	Result
2xx	Success, delivery logged
3xx	Failure, will retry
4xx	Failure, will retry
5xx	Failure, will retry
Timeout	Failure, will retry

Managing webhooks#

Viewing webhooks#

Go to Events > Settings > Webhooks to see:

• Webhook name and URL
• Triggers
• Status
• Delivery history

Webhook history#

Click a webhook to see recent deliveries:

• Timestamp
• Trigger type
• Response code
• Payload sent
• Response received

Testing webhooks#

1. Edit a webhook
2. Click Send Test
3. A test payload is sent
4. Check your endpoint received it

Pausing webhooks#

To temporarily stop deliveries:

1. Edit the webhook
2. Change status to Paused
3. Save

Triggers queue but do not deliver until reactivated.

Deleting webhooks#

1. Go to webhook list
2. Hover over the webhook
3. Click Delete
4. Confirm deletion

Use cases#

Slack notifications#

Send event notifications to Slack:

1. Create a Slack Incoming Webhook
2. Add webhook with Slack URL
3. Select registration.completed trigger
4. New registrations post to Slack

Zapier integration#

Connect to thousands of apps:

1. Create a Zapier webhook trigger
2. Add the Zapier URL as a webhook
3. Build Zaps with event data

Custom CRM sync#

Sync attendees to your CRM:

1. Create endpoint in your CRM or middleware
2. Add webhook for registration.completed
3. Process payload to create CRM contacts

Analytics tracking#

Send event data to analytics:

1. Create endpoint for your analytics
2. Add webhooks for desired triggers
3. Log events for reporting

Email marketing#

Add attendees to email lists:

1. Set up endpoint connected to email service
2. Use registration.completed trigger
3. Add attendees to appropriate lists

Troubleshooting#

Webhook not firing#

• Check webhook is Active status
• Verify trigger is selected
• Confirm action should trigger (published event, completed order)

Delivery failures#

• Check URL is accessible
• Verify HTTPS certificate is valid
• Check server is responding within 15 seconds
• Review error messages in delivery history

Wrong data received#

• Verify trigger selection
• Check payload format
• Confirm endpoint is parsing JSON correctly

Signature validation failing#

• Verify secret key matches
• Check payload is not modified
• Confirm hash algorithm (SHA-256)