Build a Whatsapp Web Chatbot to Send Messages Automatically in Node.js and Automate Whatsapp

How to Build a WhatsApp Web Chatbot Using Node.js to Automate Messages

Automating WhatsApp messages can be useful for tasks like reminders, notifications, or even simple customer support. In this tutorial, we will guide you step-by-step to create a WhatsApp Web chatbot using Node.js and the whatsapp-web.js library.

Step 1: Set Up Your Node.js Environment

Before starting, ensure Node.js is installed on your system. You can download it from Node.js official website.

Next, initialize a new Node.js project:

mkdir whatsapp-chatbot
cd whatsapp-chatbot
npm init -y

mkdir whatsapp-chatbot

cd whatsapp-chatbot

npm init -y

Step 2: Install Required Dependencies

We will use the whatsapp-web.js library for interacting with WhatsApp Web. Install it along with qrcode-terminal for displaying the QR code in the terminal:

npm install whatsapp-web.js qrcode-terminal

1	npm install whatsapp-web.js qrcode-terminal

Step 3: Write the Chatbot Code

Create a file named index.js in your project directory and paste the following code:

const { Client, LocalAuth } = require('whatsapp-web.js');
const qrcode = require('qrcode-terminal');

// Initialize the client with session persistence
const client = new Client({
    authStrategy: new LocalAuth(),
});

// Generate and display QR code
client.on('qr', (qr) => {
    console.log('Scan this QR code with WhatsApp:');
    qrcode.generate(qr, { small: true });
});

// Log successful authentication
client.on('ready', () => {
    console.log('WhatsApp Web Client is ready!');
});

// Listen for incoming messages (optional)
client.on('message', (message) => {
    console.log(`Message received from ${message.from}: ${message.body}`);

    // Example auto-reply
    if (message.body.toLowerCase() === 'hello') {
        message.reply('Hi there! How can I help you?');
    }
});

// Function to send messages
async function sendMessage(to, text) {
    try {
        await client.sendMessage(to, text);
        console.log(`Message sent to ${to}: ${text}`);
    } catch (error) {
        console.error(`Failed to send message to ${to}:`, error);
    }
}

// Start the client
client.initialize();

// Example: Sending a message after the client is ready
client.on('ready', async () => {
    const phoneNumber = '911234567890'; // Replace with recipient's phone number
    const message = 'Hello! This is an automated message.';

    // WhatsApp requires the phone number with country code and no special characters
    const chatId = `${phoneNumber}@c.us`;

    await sendMessage(chatId, message);
});

const { Client, LocalAuth } = require('whatsapp-web.js');

const qrcode = require('qrcode-terminal');

// Initialize the client with session persistence

const client = new Client({

authStrategy: new LocalAuth(),

});

// Generate and display QR code

client.on('qr', (qr) => {

console.log('Scan this QR code with WhatsApp:');

qrcode.generate(qr, { small: true });

});

// Log successful authentication

client.on('ready', () => {

console.log('WhatsApp Web Client is ready!');

});

// Listen for incoming messages (optional)

client.on('message', (message) => {

console.log(`Message received from ${message.from}: ${message.body}`);

// Example auto-reply

if (message.body.toLowerCase() === 'hello') {

message.reply('Hi there! How can I help you?');

}

});

// Function to send messages

async function sendMessage(to, text) {

try {

await client.sendMessage(to, text);

console.log(`Message sent to ${to}: ${text}`);

} catch (error) {

console.error(`Failed to send message to ${to}:`, error);

}

// Start the client

client.initialize();

// Example: Sending a message after the client is ready

client.on('ready', async () => {

const phoneNumber = '911234567890'; // Replace with recipient's phone number

const message = 'Hello! This is an automated message.';

// WhatsApp requires the phone number with country code and no special characters

const chatId = `${phoneNumber}@c.us`;

await sendMessage(chatId, message);

});

Step 4: Run the Chatbot

To run your chatbot, use the following command:

node index.js

Scan the QR code displayed in the terminal with your WhatsApp app. Once authenticated, the bot will be ready to send and receive messages.

Step 5: Automate Messages from a File (Optional)

To send messages in bulk from a file, create a file named contacts.json in the project directory with the following structure:

[
    {
        "phone": "911234567890",
        "message": "Hello, this is a test message!"
    },
    {
        "phone": "919876543210",
        "message": "Good morning! Have a great day."
    }
]

[

{

"phone": "911234567890",

"message": "Hello, this is a test message!"

{

"phone": "919876543210",

"message": "Good morning! Have a great day."

}

]

Modify the script to read from this file and send messages:

const fs = require('fs');

client.on('ready', async () => {
    const contacts = JSON.parse(fs.readFileSync('contacts.json'));

    for (const contact of contacts) {
        const chatId = `${contact.phone}@c.us`;
        await sendMessage(chatId, contact.message);
        await new Promise((resolve) => setTimeout(resolve, 2000)); // Delay to avoid spam
    }
});

const fs = require('fs');

client.on('ready', async () => {

const contacts = JSON.parse(fs.readFileSync('contacts.json'));

for (const contact of contacts) {

const chatId = `${contact.phone}@c.us`;

await sendMessage(chatId, contact.message);

await new Promise((resolve) => setTimeout(resolve, 2000)); // Delay to avoid spam

}

});

Step 6: Best Practices

Avoid Spamming: Add delays between messages to prevent being flagged by WhatsApp.

Session Persistence: Use LocalAuth to persist your session across restarts without needing to scan the QR code repeatedly.
Error Handling: Implement robust error handling for scenarios like unreachable contacts or network issues.
Respect Privacy: Use this bot responsibly and ensure recipients have opted in to receive messages.

Conclusion

You’ve successfully created a WhatsApp Web chatbot using Node.js! This bot can send messages automatically and even handle incoming messages. For more advanced use cases, explore the whatsapp-web.js library’s documentation.

By following these steps, you can easily automate repetitive tasks and improve productivity.