Create a WhatsApp voice assistant with Twilio, VAPI, Google Calendar & OpenAI

WhatsApp Voice Agent with Twilio, VAPI, Google Calendar, Gmail & Supabase

This workflow turns WhatsApp voice messages into an AI assistant using Twilio, VAPI, and modular MCP servers. It handles scheduling, email, and knowledge queries all by voice.

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🔎 How it works 1. WhatsApp → Twilio → VAPI - A WhatsApp Business number (via TwiML app) receives a voice message. - Twilio streams the audio into VAPI for processing. 2. VAPI → n8n Webhook - VAPI interprets the intent and routes the request to the correct MCP server. 3. MCP Servers in n8n - 📅 Calendar MCP → create, fetch, update, delete Google Calendar events - 📧 Gmail MCP → send confirmation or reminder emails - 📚 Knowledge Base MCP → query Supabase Vector Store with OpenAI embeddings 4. n8n → VAPI → WhatsApp - n8n executes the task and returns the result via VAPI back to the user.

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🛠️ How to use - Import this workflow into your n8n instance. - Configure a Twilio WhatsApp-enabled number and connect it to a TwiML app. - Point the TwiML app to your VAPI project. - Add credentials for Google Calendar, Gmail, Supabase, and OpenAI in n8n. - Test by sending a WhatsApp voice command like: - “Book a meeting tomorrow at 3pm” - “Send a confirmation email to the client” - “What’s included in the AI receptionist package?”

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🎨 Customisation ideas - Add more MCP servers (e.g. CRM, Notion, Slack). - Swap Supabase for another vector database. - Extend Gmail flows with templates or multiple senders. - Adjust the VAPI assistant’s tone and role to fit your brand.