Building a Facebook Chatbot with Python and Flask

Introduction

A Facebook chatbot can automate interactions with users, providing instant responses and improving engagement. This tutorial will guide you through building a Facebook Messenger chatbot using Python and Flask.

Requirements

• Basic knowledge of Python and Flask
• A Facebook Developer account
• Access to the Facebook Graph API
• Python libraries: Flask, Requests
• A text editor (e.g., VSCode, PyCharm)

Step 1: Setting Up Facebook API Access

1. Create a Facebook Developer Account: Go to the Facebook for Developers site and create an account.
2. Create an App: In your developer dashboard, create a new app and set up a Facebook Page for your bot.
3. Generate Access Tokens: Obtain the necessary Page Access Token and verify your webhook.

Step 2: Installing Required Python Libraries

Install the necessary Python libraries using pip:

pip install flask requests

Step 3: Writing the Python Script

Import Libraries: Create a Python script named app.py and start by importing the necessary libraries:

from flask import Flask, request
import requests

app = Flask(__name__)

PAGE_ACCESS_TOKEN = 'YOUR_PAGE_ACCESS_TOKEN'
VERIFY_TOKEN = 'YOUR_VERIFY_TOKEN'

Set Up Webhook Verification:

@app.route('/webhook', methods=['GET'])
def verify_webhook():
    if request.args.get('hub.mode') == 'subscribe' and request.args.get('hub.verify_token') == VERIFY_TOKEN:
        return request.args.get('hub.challenge')
    return 'Verification token mismatch', 403

Handling Incoming Messages:

@app.route('/webhook', methods=['POST'])
def handle_messages():
    data = request.get_json()
    for entry in data['entry']:
        for message in entry['messaging']:
            if 'message' in message:
                sender_id = message['sender']['id']
                message_text = message['message']['text']
                send_message(sender_id, message_text)
    return 'EVENT_RECEIVED', 200

def send_message(recipient_id, message_text):
    url = 'https://graph.facebook.com/v12.0/me/messages'
    params = {'access_token': PAGE_ACCESS_TOKEN}
    headers = {'Content-Type': 'application/json'}
    data = {
        'recipient': {'id': recipient_id},
        'message': {'text': message_text}
    }
    requests.post(url, params=params, headers=headers, json=data)

Running the Flask App:

if __name__ == '__main__':
    app.run(debug=True)

Replace 'YOUR_PAGE_ACCESS_TOKEN' and 'YOUR_VERIFY_TOKEN' with your actual tokens.

Step 4: Deploying the Chatbot

Expose Your Local Server: Use Ngrok to expose your local server to the internet:

ngrok http 5000

Set Up Webhook URL: Configure your webhook URL in the Facebook Developer portal using the Ngrok URL.

Test Your Bot: Send messages to your Facebook Page and verify that the bot responds correctly.

Conclusion

Building a Facebook chatbot with Python and Flask can enhance your engagement by providing automated responses to user messages. This tutorial provided a step-by-step guide to setting up and deploying your chatbot.