How to Auto-Reply on WhatsApp Using OpenAI API and Node.js

Have you ever wished your WhatsApp could automatically reply to messages just like a chatbot? In this post, we’ll walk you through how to connect your personal WhatsApp account to an auto-responder bot powered by OpenAI API. This solution is built using Node.js and a library called whatsapp-web.js. The final bot reads incoming messages and responds intelligently using OpenAI's ChatGPT.

What You Need

• Node.js installed on your computer
• A terminal or Termux (for mobile)
• An OpenAI API key
• Your WhatsApp account

Step 1: Set Up Your Project

Create a new folder for your project and initialize Node.js:

Copy Codemkdir whatsapp-ai-bot
cd whatsapp-ai-bot
npm init -y

Step 2: Install Required Packages

Copy Codenpm install whatsapp-web.js qrcode-terminal openai dotenv

Step 3: Create Your Bot Script

Copy Codeconst { Client } = require('whatsapp-web.js');
const qrcode = require('qrcode-terminal');
const { OpenAI } = require('openai');
require('dotenv').config();
const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
const client = new Client();

client.on('qr', qr => {
  qrcode.generate(qr, { small: true });
});

client.on('ready', () => {
  console.log('WhatsApp bot is ready!');
});

client.on('message', async message => {
  if (message.fromMe) return;
  try {
    const chatCompletion = await openai.chat.completions.create({
      messages: [{ role: "user", content: message.body }],
      model: "gpt-3.5-turbo"
    });
    const reply = chatCompletion.choices[0].message.content;
    message.reply(reply);
  } catch (err) {
    message.reply("Sorry, something went wrong.");
    console.error(err);
  }
});

client.initialize();

Step 4: Set Up Environment Variables

Copy CodeOPENAI_API_KEY=your_openai_key_here

Step 5: Run Your Bot

Copy Codenode index.js

Scan the QR code with your WhatsApp. Once connected, the bot will auto-reply to any message it receives.

Important Notes

• This method is best for personal or testing use.
• Keep the terminal open or use pm2.
• Respect WhatsApp's terms of service.

Demo Video

Final Thoughts

You now have a working system that lets your WhatsApp auto-reply to messages using AI. You can extend this to filter replies, respond to specific commands, or integrate your own database. Use pm2 or a cloud server to keep it running without interruption.

Would you like this as a downloadable template or app? Leave a comment below!