Fired when a human clicks Send test event in the admin UI. Carries a fixed synthetic payload — your verification code should treat it exactly like a real event.
{
"event_id": "00000000-0000-4000-8000-000000000000",
"event_type": "webhook.test",
"delivered_at": "2026-05-20T09:30:00Z",
"data": {
"subscription_id": 42,
"message": "This is a test webhook from Mercura.",
"sent_at": "2026-05-20T09:30:00Z"
}
}