Webhook Events Reference

Overview#

AcelleMail fires webhooks to your URL when key events occur. Configure endpoints at Settings → Webhooks → Add.

Event Types#

Payload Example#

All events share a common envelope:

{
  "event": "subscriber.created",
  "fired_at": "2026-03-15T10:23:00Z",
  "data": {
    "subscriber": {
      "uid": "sub_abc123",
      "email": "user@example.com",
      "first_name": "Jane",
      "status": "subscribed",
      "list_uid": "list_xyz"
    }
  }
}

Verifying Webhook Signatures#

AcelleMail signs each webhook with HMAC-SHA256. Verify in PHP:

$secret = 'your_webhook_secret';
$signature = $_SERVER['HTTP_X_ACELLE_SIGNATURE'] ?? '';
$payload = file_get_contents('php://input');

$expected = hash_hmac('sha256', $payload, $secret);
if (!hash_equals($expected, $signature)) {
    http_response_code(401);
    exit('Invalid signature');
}

Retry Logic#

If your endpoint returns a non-2xx status, AcelleMail retries up to 5 times with exponential backoff (1 min, 5 min, 30 min, 2 hrs, 8 hrs). After 5 failures the webhook is marked inactive.