Automate multi-modal appointment booking via WhatsApp using GPT-4 and Cal.com

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Important notice

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

1. Workflow Overview

Who is this for? This workflow is for healthcare professionals, consultants, coaches, and service businesses who want to completely automate their appointment booking system via WhatsApp — without ...

Best for

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

Tools used

n8n-nodes-base.code, n8n-nodes-base.splitout, n8n-nodes-base.switch, n8n-nodes-base.whatsapp, @n8n/n8n-nodes-langchain.openai, n8n-nodes-base.httprequest, @n8n/n8n-nodes-langchain.agent, @n8n/n8n-nodes-langchain.lmchatopenai

Source and attribution

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

Original n8n.io source

1.1 Workflow description

Title: Automate multi-modal appointment booking via WhatsApp using GPT-4 and Cal.com
Workflow name: Automate multi-modal appointment booking via WhatsApp using GPT-4 and Cal.com

Who is this for?

This workflow is for healthcare professionals, consultants, coaches, and service businesses who want to completely automate their appointment booking system via WhatsApp — without manual intervention for reservations, availability checks, or cancellation management.

What problem is this workflow solving? / Use case

Managing appointments manually via WhatsApp is extremely time-consuming: checking availability, confirmations, rescheduling, cancellations. This workflow automates the entire process — from initial request to final confirmation — allowing your clients to book, modify, or cancel appointments 24/7, in natural language, directly via WhatsApp.

What this workflow does

Processes multi-modal messages (text, audio, images) from WhatsApp Business API
Detects message type and routes to appropriate processing (Whisper for audio, GPT-4 Vision for images)
Uses AI Agent with 5 Cal.com tools to manage complete appointment lifecycle
Checks real-time availability in your Cal.com calendar
Books appointments autonomously without human intervention
Handles cancellations and rescheduling requests
Maintains conversation context with Simple Memory for natural exchanges
Formats responses with Unicode bold for better WhatsApp readability
Sends automated replies directly to the client

The result: a fully automated 24/7 appointment management system via WhatsApp.

Setup

1. WhatsApp Business API

Connect your WhatsApp Business API account in n8n.
Set up the webhook in Facebook Developer Console (Webhook → Messages → Subscribe).
Add your phone_number_id and access token credentials.

2. Cal.com

Create a Cal.com account and configure your calendar.
Generate an API Key from Cal.com settings.
Set up your event types (duration, availability, pricing).
Add your Cal.com API credentials in n8n.

3. OpenAI

Get an OpenAI API key (for GPT-4, Whisper, and Vision).
Add your OpenAI credentials in n8n.
The workflow uses GPT-4 for conversation, Whisper for audio transcription, and GPT-4 Vision for image analysis.

4. Customize the AI Agent

Edit the System Message to define your agent's personality, tone, and business context.
Adjust timezone in tool parameters (default: Europe/Paris).
Configure event type IDs for different appointment types.

5. Test & activate

Test with different message types (text, audio, image) from WhatsApp.
Verify appointments are created correctly in Cal.com.
Switch to production mode and activate the workflow.

This workflow helps you build a fully autonomous AI booking assistant, transforming WhatsApp into a 24/7 appointment management system.

Need help customizing?

Contact me for consulting and support: LinkedIn / Youtube

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 - Code

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 2 - Split out message1

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

Block 3 - Identify and ReRoute Message Types1

Type / Role: n8n-nodes-base.switch - switch
Config choices: Version 3.2

Block 4 - Send message

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

Block 5 - Audio Transcriber

Type / Role: @n8n/n8n-nodes-langchain.openAi - openAi
Config choices: Version 1.8

Block 6 - Analyze image

Type / Role: @n8n/n8n-nodes-langchain.openAi - openAi
Config choices: Version 1.8

Block 7 - Get Audio URL

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

Block 8 - Get Image URL

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

Block 9 - Download Image

Type / Role: n8n-nodes-base.httpRequest - httpRequest
Config choices: Version 4.2

Block 10 - Download Audio

Type / Role: n8n-nodes-base.httpRequest - httpRequest
Config choices: Version 4.2

Block 11 - AI Agent

Type / Role: @n8n/n8n-nodes-langchain.agent - agent
Config choices: Version 2.2

Block 12 - OpenAI Chat Model

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

Block 13 - Simple Memory

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

Block 14 - check_availability

Type / Role: n8n-nodes-base.httpRequestTool - httpRequestTool
Config choices: Version 4.2

Block 15 - book_appointment

Type / Role: @n8n/n8n-nodes-langchain.toolHttpRequest - toolHttpRequest
Config choices: Version 1.1

Block 16 - find_booking

Type / Role: @n8n/n8n-nodes-langchain.toolHttpRequest - toolHttpRequest
Config choices: Version 1.1

Block 17 - cancel_booking

Type / Role: @n8n/n8n-nodes-langchain.toolHttpRequest - toolHttpRequest
Config choices: Version 1.1

Block 18 - reschedule_booking

Type / Role: @n8n/n8n-nodes-langchain.toolHttpRequest - toolHttpRequest
Config choices: Version 1.1

Block 19 - WhatsApp Trigger

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

Block 20 - Edit Fields 1

Type / Role: n8n-nodes-base.set - set
Config choices: Version 3.4

Block 21 - Edit Fields 2

Type / Role: n8n-nodes-base.set - set
Config choices: Version 3.4

Block 22 - Edit Fields 3

Type / Role: n8n-nodes-base.set - set
Config choices: Version 3.4

Block 23 - Sticky Note

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

Block 24 - Sticky Note1

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

Showing the first 24 of 26 workflow blocks. Download the JSON for the full node graph.

3. Summary Table

Workflow	Automate multi-modal appointment booking via WhatsApp using GPT-4 and Cal.com
Complexity	advanced
Nodes	26
Categories	Support Chatbot, AI Chatbot
Author	Stéphane Bordas
Published	24 Nov 2025

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/11188/11188.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 Automate multi-modal appointment booking via WhatsApp using GPT-4 and Cal.com 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.

Stéphane Bordas

2 workflows

Nodes

n8n-nodes-base.code n8n-nodes-base.splitout n8n-nodes-base.switch n8n-nodes-base.whatsapp @n8n/n8n-nodes-langchain.openai n8n-nodes-base.httprequest @n8n/n8n-nodes-langchain.agent @n8n/n8n-nodes-langchain.lmchatopenai

Complexity

advanced

Published 24 Nov 2025

Likes 0

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Install path: /data/workflows/11188/11188.json

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Automate multi-modal appointment booking via WhatsApp using GPT-4 and Cal.com

Workflow preview

Important notice

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

Who is this for?

What problem is this workflow solving? / Use case

What this workflow does

Setup

1. WhatsApp Business API

2. Cal.com

3. OpenAI

4. Customize the AI Agent

5. Test & activate

Need help customizing?

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Code

Block 2 - Split out message1

Block 3 - Identify and ReRoute Message Types1

Block 4 - Send message

Block 5 - Audio Transcriber

Block 6 - Analyze image

Block 7 - Get Audio URL

Block 8 - Get Image URL

Block 9 - Download Image

Block 10 - Download Audio

Block 11 - AI Agent

Block 12 - OpenAI Chat Model

Block 13 - Simple Memory

Block 14 - check_availability

Block 15 - book_appointment

Block 16 - find_booking

Block 17 - cancel_booking

Block 18 - reschedule_booking

Block 19 - WhatsApp Trigger

Block 20 - Edit Fields 1

Block 21 - Edit Fields 2

Block 22 - Edit Fields 3

Block 23 - Sticky Note

Block 24 - Sticky Note1

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