SMS appointment scheduling bot with automated follow-ups

How it works

1. 1.A Twilio Trigger receives inbound SMS and a Switch node checks whether the body contains STOP.
2. 2.STOP messages update the Airtable record status to STOP and send a confirmation SMS.
3. 3.The existing chat session is fetched from the Lead Tracker table and passed to the AI agent as context.
4. 4.The agent (GPT-4o-mini) uses Cal.com HTTP tools for availability, booking creation, lookup, reschedule and cancel, with a structured output parser plus auto-fixing parser.
5. 5.The Airtable record is updated (name, summary, appointment, chat log) and the agent reply is sent back via Twilio.
6. 6.A daily schedule trigger searches Airtable for leads with no appointment, status not STOP, fewer than 3 follow-ups and 3+ days since last follow-up, generates an AI follow-up message, updates counters and sends it via Twilio.

Use cases

• Scheduling PC/laptop repair appointments through an SMS chatbot.
• Letting customers check, reschedule or cancel existing bookings by SMS.
• Re-engaging leads who never completed a booking with capped follow-ups.
• Handling opt-out requests via the STOP keyword.

Requirements

• Twilio credentials for both the trigger and SMS sending, with a Twilio number wired to n8n.
• Airtable credentials and a base/table (Lead Tracker) containing fields such as session_id, status, chat_messages, followup_count, last_followup_at and appointment_id.
• An OpenAI API key for the agent chat model, follow-up chain and parser auto-fixing model.
• Cal.com API v2 credentials (header auth or calApi) and replacing eventTypeId 648297 with your own event type ID.

Setup and testing in n8n

1. Send an SMS containing STOP and verify the Airtable status changes and the confirmation arrives.
2. Start a new enquiry, complete a booking and confirm it appears in Cal.com and Airtable.
3. Ask about an existing booking, then reschedule or cancel it to exercise the Cal.com tools.
4. Create a lead record with no appointment and an old follow-up date, run the follow-up branch manually, and verify the message and counter update.

Service Value

Ideal as a smart automation service combining integrations and AI to produce ready-to-use results.