Facebook Messenger Bot Development Guide

Facebook Messenger Bot Development Guide

Overview

Facebook Messenger bots allow you to create interactive experiences for your customers. This guide covers everything from setup to advanced features.

Prerequisites

Facebook Developer Account

Node.js and npm

ngrok for local development

Step 1: Create Facebook App

1. Go to Facebook Developers
2. Create a new app
3. Add Messenger product
4. Generate access token

Step 2: Setup Webhook

const express = require('express');
const app = express();

app.get('/webhook', (req, res) => {
  const VERIFY_TOKEN = process.env.VERIFY_TOKEN;
  const mode = req.query['hub.mode'];
  const token = req.query['hub.verify_token'];
  const challenge = req.query['hub.challenge'];

  if (mode && token) {
    if (mode === 'subscribe' && token === VERIFY_TOKEN) {
      res.status(200).send(challenge);
    } else {
      res.sendStatus(403);
    }
  }
});

Step 3: Handle Messages

app.post('/webhook', (req, res) => {
  const body = req.body;

  if (body.object === 'page') {
    body.entry.forEach(entry => {
      const webhookEvent = entry.messaging[0];
      
      if (webhookEvent.message) {
        handleMessage(webhookEvent);
      }
    });
    
    res.status(200).send('EVENT_RECEIVED');
  } else {
    res.sendStatus(404);
  }
});

Advanced Features

Quick Replies

Persistent Menu

Typing Indicators

Rich Media

Conclusion

You now have a fully functional Facebook Messenger bot!