Fast API with deta.sh and Paypal IPN (first working test)

main.py

from fastapi import FastAPI, Request
import sys
import urllib.parse
import requests

app = FastAPI()
VERIFY_URL_PROD = 'https://ipnpb.paypal.com/cgi-bin/webscr'
VERIFY_URL_TEST = 'https://ipnpb.sandbox.paypal.com/cgi-bin/webscr'

# Switch as appropriate
VERIFY_URL = VERIFY_URL_TEST

# a POST route for our webhook events
@app.post("/")
def webhook_handler(req: Request):
    # verify signature if needed
    # add logic to handle the request
    
    # Add '_notify-validate' parameter
    params = dict(req.query_params)
    params['cmd']='_notify-validate'

    # Post back to PayPal for validation

    headers = {'content-type': 'application/x-www-form-urlencoded',
            'user-agent': 'Python-IPN-Verification-Script'}
    r = requests.post(VERIFY_URL, params=params, headers=headers, verify=True)
    r.raise_for_status()

    # Check return message and take action as needed
    if r.text == 'VERIFIED':
        """do magic here"""
        return "verified"
    if r.text == 'INVALID':
        return "invalid"
    return "nothing to see here"