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

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Important notice

This workflow is provided as-is. Please review and test before using in production.

1. Workflow Overview

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 sc...

Best for

Support Chatbot automation workflows
AI Chatbot automation workflows
advanced n8n builders looking for reusable templates

Tools used

@n8n/n8n-nodes-langchain.vectorstoresupabase, @n8n/n8n-nodes-langchain.embeddingsopenai, n8n-nodes-base.googlecalendartool, n8n-nodes-base.gmailtool, @n8n/n8n-nodes-langchain.mcptrigger, n8n-nodes-base.webhook, n8n-nodes-base.respondtowebhook, n8n-nodes-base.stickynote

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Nabin Bhandari.

Original n8n.io source

1.1 Workflow description

Title: Create a WhatsApp voice assistant with Twilio, VAPI, Google Calendar & OpenAI
Workflow name: 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.

🔎 How it works

WhatsApp → Twilio → VAPI
- A WhatsApp Business number (via TwiML app) receives a voice message.
- Twilio streams the audio into VAPI for processing.
VAPI → n8n Webhook
- VAPI interprets the intent and routes the request to the correct MCP server.
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
n8n → VAPI → WhatsApp
- n8n executes the task and returns the result via VAPI back to the user.

🛠️ 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?”

🎨 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.

📌 Requirements

Twilio WhatsApp-enabled number + TwiML app (verified in WhatsApp Manager)
VAPI project (assistant configured)
n8n instance (Cloud or self-hosted)
Google Calendar & Gmail credentials
Supabase project
OpenAI API key

💡 Good to know

Twilio must have a verified WhatsApp Business number.
VAPI handles voice infra + intent routing; n8n only executes actions.
The design is modular—easy to expand with new MCP servers.
Works best when tested with short, clear commands.

🚀 Use cases

Hands-free scheduling with Google Calendar.
Voice-triggered email confirmations & reminders.
Conversational knowledge base access.
Extendable to CRMs, team chat, or business workflows.

👉 With this setup, you get a scalable voice-first AI agent on WhatsApp that connects seamlessly to your business systems.

1.2 Logical Blocks

This catalog entry is organized from the workflow JSON. The node-level section below shows the executable blocks available for review before importing the template.

2. Block-by-Block Analysis

Block 1 - Supabase Vector Store

Type / Role: @n8n/n8n-nodes-langchain.vectorStoreSupabase - vectorStoreSupabase
Config choices: Version 1.3

Block 2 - Embeddings OpenAI

Type / Role: @n8n/n8n-nodes-langchain.embeddingsOpenAi - embeddingsOpenAi
Config choices: Version 1.2

Block 3 - Create Calendar Event

Type / Role: n8n-nodes-base.googleCalendarTool - googleCalendarTool
Config choices: Version 1.3

Block 4 - Fetch Calendar Events

Type / Role: n8n-nodes-base.googleCalendarTool - googleCalendarTool
Config choices: Version 1.3

Block 5 - Update Calendar Event

Type / Role: n8n-nodes-base.googleCalendarTool - googleCalendarTool
Config choices: Version 1.3

Block 6 - Delete Calendar Event

Type / Role: n8n-nodes-base.googleCalendarTool - googleCalendarTool
Config choices: Version 1.3

Block 7 - Send Email Notification

Type / Role: n8n-nodes-base.gmailTool - gmailTool
Config choices: Version 2.1

Block 8 - MCP Server – Calendar

Type / Role: @n8n/n8n-nodes-langchain.mcpTrigger - mcpTrigger
Config choices: Version 2

Block 9 - MCP Server – Gmail

Type / Role: @n8n/n8n-nodes-langchain.mcpTrigger - mcpTrigger
Config choices: Version 2

Block 10 - MCP Server – Knowledge Base

Type / Role: @n8n/n8n-nodes-langchain.mcpTrigger - mcpTrigger
Config choices: Version 2

Block 11 - Incoming Webhook (VAPI)

Type / Role: n8n-nodes-base.webhook - webhook
Config choices: Version 2.1

Block 12 - Respond to Webhook (VAPI)

Type / Role: n8n-nodes-base.respondToWebhook - respondToWebhook
Config choices: Version 1.4

Block 13 - Sticky Note1

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 14 - Sticky Note2

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 15 - Sticky Note3

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 16 - Sticky Note

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 17 - Sticky Note4

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 18 - Sticky Note5

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

3. Summary Table

Workflow	Create a WhatsApp voice assistant with Twilio, VAPI, Google Calendar & OpenAI
Complexity	advanced
Nodes	18
Categories	Support Chatbot, AI Chatbot
Author	Nabin Bhandari
Published	05 Sept 2025

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/8284/8284.json as the source template for this automation.
2. Import the template into n8n

Open n8n, import the downloaded JSON, and review each node before activating the workflow.
3. Configure credentials and variables

Replace placeholder credentials, API keys, webhook URLs, account IDs, and environment-specific values with your own settings.
4. Test with sample data

Run the workflow manually or in a staging workspace, inspect node output, and confirm downstream systems receive the expected data.
5. Activate and monitor

Enable the workflow only after testing, then monitor executions, errors, and rate limits during the first production runs.

5. General Notes & Resources

Review imported nodes carefully before activation. This catalog entry is intended to help you inspect the workflow structure, understand required services, and find related templates faster.

Node names, credentials, schedules, webhook paths, and external service limits may need adjustment for your workspace.

Download workflow JSON Original n8n.io source Support Chatbot workflows AI Chatbot workflows

Frequently asked questions

What does Create a WhatsApp voice assistant with Twilio, VAPI, Google Calendar & OpenAI do?

What do I need before importing this workflow?

Review the workflow JSON, configure any required credentials in n8n, and test the automation in a safe workspace before using it in production.

Can I customize this workflow?

Yes. Use the block-by-block analysis and the downloadable JSON to inspect each node, then adjust credentials, prompts, schedules, filters, or destinations for your Support Chatbot, AI Chatbot use case.

Nabin Bhandari

7 workflows

Nodes

@n8n/n8n-nodes-langchain.vectorstoresupabase @n8n/n8n-nodes-langchain.embeddingsopenai n8n-nodes-base.googlecalendartool n8n-nodes-base.gmailtool @n8n/n8n-nodes-langchain.mcptrigger n8n-nodes-base.webhook n8n-nodes-base.respondtowebhook n8n-nodes-base.stickynote

Complexity

advanced

Published 05 Sept 2025

Likes 0

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Install path: /data/workflows/8284/8284.json

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

Workflow preview

Important notice

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

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

🔎 How it works

🛠️ How to use

🎨 Customisation ideas

📌 Requirements

💡 Good to know

🚀 Use cases

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Supabase Vector Store

Block 2 - Embeddings OpenAI

Block 3 - Create Calendar Event

Block 4 - Fetch Calendar Events

Block 5 - Update Calendar Event

Block 6 - Delete Calendar Event

Block 7 - Send Email Notification

Block 8 - MCP Server – Calendar

Block 9 - MCP Server – Gmail

Block 10 - MCP Server – Knowledge Base

Block 11 - Incoming Webhook (VAPI)

Block 12 - Respond to Webhook (VAPI)

Block 13 - Sticky Note1

Block 14 - Sticky Note2

Block 15 - Sticky Note3

Block 16 - Sticky Note

Block 17 - Sticky Note4

Block 18 - Sticky Note5

3. Summary Table

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

2. Import the template into n8n

3. Configure credentials and variables

4. Test with sample data

5. Activate and monitor

5. General Notes & Resources

Frequently asked questions