EasyPost Webhooks API
Asynchronous Event delivery surface. EasyPost POSTs Event objects to subscriber URLs whenever asynchronous objects (batches, trackers, scan forms, refunds, reports, payments, claims, insurance, shipment invoices) change state. Each delivery is signed with an HMAC-SHA256 signature in the X-Hmac-Signature header, derived from a per-webhook secret. Subscribers must return a 2XX status code; non-2XX responses are retried.