Signifyd Webhooks API
Receive asynchronous decision notifications from Signifyd. The primary topic is ORDER_CHECKPOINT_ACTION_UPDATE, covering CHECKOUT, SALE, TRANSACTION, REROUTE, MERCHANT_REVIEW, and SIGNIFYD_REVIEW checkpoints. Each delivery is signed with an HMAC-SHA256 signature in the SIGNIFYD-SEC-HMAC-SHA256 header, keyed by the team's API key, so receivers can verify authenticity.