Clinics get the same message all day: "Is the doctor available tomorrow?" Then begins a back-and-forth of slot suggestions that ties up the front desk.

WhatsApp interactive list messages fix this. The patient taps a button, picks a slot from a list, and your server books it. In this post we'll build that flow with Node.js, Express and the WhatsApp Cloud API.

How the flow works

Patient messages the clinic ("Hi", "Book appointment")

Server replies with a list message of available slots

Patient picks a slot; the reply arrives at your webhook as list_reply

Server confirms the booking (and later sends a reminder template)

Because the patient messages first, steps 2–4 happen inside the 24-hour customer service window, so free-form interactive messages are allowed.

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