Notification of an inbound message sent by a user to your WhatsApp Business number (type: message).
The message object includes the content type (text, image, video, document, audio, button, location, contacts) and its data, along with the sender (from, from_user_id). The context field is only included when the message is a reply to a message you previously sent, and indicates the original message_id it replies to.
For contacts messages (a user shares one or more contacts as vCards), message.contacts carries the shared contacts. Every field is optional — Meta omits the ones the user did not have in their address book — and any extra field Meta sends (e.g. vcard, origin) is propagated as-is: do not assume a closed shape.
reply when the message replies to a message you previously sent (message.context carries the original id); no_active_session when it arrived outside an active session.