Paypal post data after successful payment

Question

I am trying to create a PHP application that will interact with MySQL. I already have a page that receives POST data, and after receiving it, it gives a "credit" to the user. Can the PayPal button after a successful order send me a message? or is there another way? (most likely easier and safer)

Answer 1

Yes, look at the instant PayPal Prepaid Notification (IPN) - https://www.paypal.com/ipn/
This will cause POST of transaction data to be sent to you whenever a transaction has been started. If you are currently using the Website Payment Standard (HTML buttons), you can simply add

<input type="hidden" name="notify_url" value="http://full-URL-to-the-script-you-set-up-for-IPN">

POST, PayPal, cmd = _notify-validate https://www.paypal.com/cgi-bin/webscr ( https://www.sandbox.paypal.com/cgi-bin/webscr ), IPN-.
INVALID VERIFIED.
INVALID , POST IPN PayPal, VERIFIED , POST IPN PayPal.