One Door, Three Modes: Designing a Multi-Channel Appointment Booking System Driven by Conversational Agents

Abstract

Small service businesses such as clinics receive booking requests through WhatsApp, Instagram and Messenger messages, phone calls and web forms, and many have no calendar system at all. We describe the design of ABS, an appointment booking system in which conversational agents take bookings across these channels for many independent businesses. The central decision is that every channel and every booking style passes through one capture operation; three booking modes (a booking link, a fully conversational booking, and an autonomous mode in which the system itself is the business's calendar) differ only in who supplies the fields and in default settings, not in separate pipelines. We describe how availability and conflicts are computed at read time on the business's own clock, why every customer-facing message is editable per business and per language and is never sent with an unresolved variable, how operators can configure agents without being able to read customers' conversations, and four defects that shaped the design, including a language model inventing appointment times and timestamps that silently shifted by the viewer's time zone. This is a design and experience report; we have no controlled evaluation and say so.

Keywords: appointment scheduling, conversational agents, multi-channel messaging, multi-tenancy, privacy by design