app.py

import requests
import os, signal
from flask import Flask, request
import openai
app = Flask(__name__)

#This is API key for OpenAI
openai.api_key = os.environ.get("OPENAI_KEY")
# This is page access token that you get from facebook developer console.
PAGE_ACCESS_TOKEN = os.environ.get("PAGE_TOKEN")
# This is API key for facebook messenger.
API="https://graph.facebook.com/v16.0/me/messages?access_token="+PAGE_ACCESS_TOKEN

@app.route('/', methods=['GET'])
def verify():
    # Verify the webhook subscription with Facebook Messenger
    if request.args.get("hub.mode") == "subscribe" and request.args.get("hub.challenge"):
        if not request.args.get("hub.verify_token") == os.environ.get("ACCESS_TOKEN"):
            return "Verification token missmatch", 403
        return request.args['hub.challenge'], 200
    return "MessengerGPT: https://facebook.com/MessengerBotGPT", 200

@app.route("/", methods=['POST'])
def fbwebhook():
    data = request.get_json()
    try:
        if data['entry'][0]['messaging'][0]['sender']['id']:
            message = data['entry'][0]['messaging'][0]['message']
            sender_id = data['entry'][0]['messaging'][0]['sender']['id']
            chat_gpt_input=message['text']
            print(chat_gpt_input)
            completion = openai.ChatCompletion.create(
                            model="gpt-4o-mini",
                            messages=[{"role": "user", "content": chat_gpt_input}])          
            chatbot_res = completion['choices'][0]['message']['content']
            print("ChatGPT Response=>",chatbot_res)
            response = {
                'recipient': {'id': sender_id},
                'message': {'text': chatbot_res}
            }
            requests.post(API, json=response)
    except Exception as e:
        print(e)
        pass
    return '200 OK HTTPS.'
  # Run the Flask app
if __name__ == '__main__':
    app.run(host='0.0.0.0', debug=False, port=5000)