Booking Concierge

Problem

Small businesses lose bookings to slow replies. Naive booking bots confirm slots that are already taken.

Try it live

Book a cupping session in the phone frame, in English or a second language. Watch the slot move from held to booked on the live calendar. Open a second tab and try to take the same slot.

Proves

Tool calling under strict schemas, real-time systems, and concurrency handled by the database.

Signal chain

1. detect language
2. collect details
3. check availability
4. hold slot, 5 min
5. confirm
6. send confirmation

Stack

Django Channels · WebSockets · Postgres range types · Redis · Vue · installable PWA

Engineering highlights

• A Postgres exclusion constraint on booking time ranges makes a double booking impossible, even if the model calls the tool twice.
• A state machine decides which tools the model may call at each step, so it cannot confirm a slot it never held.
• Idempotency keys on confirm, automatic hold expiry, and a handoff to a person with the full transcript.