WhatsApp N8N Server – Automate WhatsApp Messaging via REST API + N8N

A Node.js server that integrates with WhatsApp Web via whatsapp-web.js, enabling automated message sending through a REST API. Built with Clean Architecture principles.

✨ Features

• WhatsApp Web integration using whatsapp-web.js
• REST API endpoint for sending messages
• QR code authentication
• Session persistence with LocalAuth
• Clean Architecture

⚙️ Prerequisites

• Node.js v18 or higher
• A WhatsApp account
• A smartphone with WhatsApp installed
• Package manager: Bun (recommended)

Note

This project uses Bun for local development and scripting, but is fully compatible with any Node.js-compatible package manager.

🚀 Installation

Clone the repository:

git clone https://github.com/nicolasdelrosario/whatsapp-n8n-server.git
cd whatsapp-n8n-server

Install dependencies

bun install

🧪 Usage

Start development mode

bun dev

• On first run, a QR code will appear in the terminal.
• Scan it using WhatsApp on your phone to authenticate.
• Once authenticated, your session will be saved.

Server will run on:

http://localhost:3000

📡 API

POST /api/v1/send-message

Sends a WhatsApp message to a phone number.

🔸 Request Body (JSON)

{
    "number": "51123456789",
    "content": "Hello from WhatsApp N8N Server"
}

number: Phone number in international format (without +)

content: The message to send

🔸 Response

{
    "message": "OK"
}

🧑‍💻 Author

Developed by Nicolas Del Rosario

📜 License

MIT