Description
Trigger the workflow when a customer messages your WhatsApp Business number (official Meta Cloud API). One run per incoming message with a fully normalized payload: E.164 sender, profile name, message type (text, interactive button/list reply, image, document, audio, video, sticker, location, reaction), text or caption, media references for Graph API download, and reply context. Fail-closed security on both protocol flows: the GET verification handshake echoes hub.challenge only when the verify token matches (timing-safe), and every POST event is accepted only with a valid X-Hub-Signature-256 HMAC signature. Automatic per-message-id dedup (Meta re-delivers unacknowledged events). Pair with the WhatsApp send node for a full conversational bot: replies fall inside the 24-hour customer-service window, so free-form text needs no pre-approved template.
