Signed, retried, idempotent. Hook up your CRM, ERP, or notification pipeline.
Subscribe an HTTPS endpoint. We POST a signed JSON envelope when something happens. Retries are exponential up to 24h. Signatures use HMAC-SHA256 of the raw body, checked with your secret.
{
"id": "evt_01HQ4...",
"type": "order.shipped",
"created": "2026-05-03T20:14:11Z",
"data": {
"order_id": 18432,
"carrier": "DHL",
"tracking_number": "JD0149...",
"ship_eta": "2026-05-09"
}
}const sig = req.get('X-Listing-Signature');
const expected = crypto.createHmac('sha256', SECRET).update(rawBody).digest('hex');
if (sig !== expected) return res.sendStatus(400);Full API docs