A label is attached to your parcel, whether we bought it or the floor scanned one in. One event per parcel per seller — three of your items in one box is one event, not three.
Signed with HMAC-SHA256 over the exact request bytes, in the X-Signature header. Respond 2xx; anything else is retried with backoff.
postWebhookshipping_added
Headers
X-Signaturestring required
HMAC-SHA256 of the raw body, keyed with your webhook secret, hex encoded.
Response
Acknowledged.
Changes
Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.