n8n Voice Call Appointment Booking to Google Sheets (Claude)

Turn voice-call transcripts into booked appointments—automatically

This n8n workflow receives voice-call transcriptions via a webhook, determines availability in Google Sheets, and books or updates appointments. It then uses Anthropic Claude to rewrite the drafted response into natural spoken wording before replying back with a JSON result.

What this workflow does

• Receives webhook input: Accepts a POST request with sessionId, transcribed caller text, and a turn number.
• Applies abuse controls: Enforces allowed origin, per-session/per-IP turn limits, and input length caps. If blocked, it returns a polite refusal.
• Loads clinic configuration: Pulls in-workflow clinic setup and treatment/service definitions, creates a stable synthetic phone number for the session, and checks for any existing lead in Google Sheets.
• Normalizes caller intent: Converts spoken phrasing into booking-friendly keywords (e.g., mapping “yes please” to “BOOK”) and resolves spoken day/date into offered slot selections.
• Reads and updates appointments: Checks existing appointments in Google Sheets and decides the next action—answer a question, offer available slots, confirm/cancel/reschedule, or create a new booking.
• Uses Anthropic Claude for speech: Sends the drafted reply plus allowed facts to Claude to produce more natural spoken phrasing, with a fallback to the draft if the model response is missing or appears invented.
• Returns results + logs: Responds to the webhook caller with the final reply and diagnostic trace, then upserts the lead, appends any new appointment row, and logs the inbound message and reply to Google Sheets.

Use cases

• Clinic appointment booking from automated voice calls (transcript-based)
• Rescheduling or canceling appointments by interpreting caller confirmations
• Fast slot offering grounded in your live Google Sheets availability

Technical details

• Nodes/stack: webhook, if, set, code, http request, and supporting workflow notes (sticky note)
• Integrations: Google Sheets (leads + appointment rows)
• AI rewrite step: Anthropic Claude to transform the drafted response into spoken-ready language