Voice Appointment Booking Workflow for n8n (LiveKit + Gemini + Google Calendar)

Turn voice calls into instant, bookable appointments—automatically

This n8n workflow lets your LiveKit voice agent hand off a caller’s request to an AI receptionist powered by Google Gemini. The AI checks Google Calendar availability, books the slot, then sends confirmations via Gmail (optional) and WhatsApp (Meta Cloud API).

What this workflow does

• Exposes a webhook that receives a POST request from a LiveKit voice agent with session_id, the caller’s transcribed message, and an optional caller_phone.
• Validates input: if message or session_id is missing, it returns a 400 JSON error.
• Uses Google Gemini with per-session conversation memory to interpret the caller’s intent and manage the dialogue.
• Checks availability: when the caller requests a time, it queries Google Calendar for events in the requested range to confirm whether the slot is free.
• Books the appointment (only if available and confirmed) by creating a new Google Calendar event using the appointment time, summary, description, and attendees.
• Sends confirmations after booking: optionally via Gmail (when an email address is provided) and always via WhatsApp using the Meta Cloud API.
• Returns a response to LiveKit containing the AI’s spoken reply and the same session_id for playback.

Use cases

• Medical or service businesses using a LiveKit voice agent to schedule consultations over the phone.
• SaaS teams launching an “AI receptionist” feature for appointment booking with real calendar availability.
• Operations workflows that need automated follow-ups through WhatsApp and email.

Technical details

• n8n nodes/tools: if, webhook, gmail tool, respond to webhook, n8nn8n-nodes-langchainagent, and a sticky note.
• Integrations: Google Calendar (OAuth2), Gmail (OAuth2), Google Gemini API (API key), and WhatsApp via Meta Graph API (stored as an Authorization: Bearer <token> HTTP header credential).