mkdir whatsapp-bot
cd whatsapp-bot
npm init -y
npm install express twilio body-parser
const express = require('express');
const bodyParser = require('body-parser');
const twilio = require('twilio');

const app = express();
const port = process.env.PORT || 3000;

const accountSid = 'your_twilio_account_sid';
const authToken = 'your_twilio_auth_token';
const client = twilio(accountSid, authToken);

app.use(bodyParser.urlencoded({ extended: false }));

app.post('/whatsapp', (req, res) => {
const incomingMessage = req.body.Body;
const from = req.body.From;

let responseMessage = 'Hello!';

if (incomingMessage.toLowerCase() === 'hi') {
responseMessage = 'Hi there! How can I help you today?';
}

client.messages
.create({
body: responseMessage,
from: 'whatsapp:+14155238886', // Twilio sandbox number
to: from
})
.then(message => console.log(message.sid))
.catch(err => console.error(err));

res.sendStatus(200);
});

app.listen(port, () => {
console.log(Server running on port ${port});
});