A PayPal PHP IPN example

If you're looking for a PayPal IPN example written in PHP, I believe the following code works okay. It's based on the PayPal PHP IPN example (from the PayPal developer site), but I fixed some bugs from their example, added an alternate PHP socket example so you don't have to use SSL to connect to PayPal, and added more variables to the script.

I'm going to add more functionality to this PayPal PHP IPN script, and will keep updating this article as I improve the code. In my next release I hope to include some PHP code here that will let you mail a binary attachment to the customer who pays you. I'm pretty close on that, and I hope to have that done this weekend.

PayPal PHP IPN example

Here's my PayPal PHP IPN code in its current state:

error_reporting(E_ALL ^ E_NOTICE);

// devdaily.com paypal php ipn example.
// version 1.0
// this example built on the paypal php ipn example, with bug fixes,
// and no need for ssl.

$header = "";
$emailtext = "";

// read the post from paypal and add 'cmd'
$req = 'cmd=_notify-validate';
  $get_magic_quotes_exits = true;

// handle escape characters, which depends on setting of magic quotes
foreach ($_POST as $key => $value)
  if($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1)
    $value = urlencode(stripslashes($value));
    $value = urlencode($value);
  $req .= "&$key=$value";

// post back to paypal to validate
$header .= "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";

// here you can use ssl, or not
// $fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);
$fp = fsockopen ('www.sandbox.paypal.com', 80, $errno, $errstr, 30);

// process validation from paypal
// TODO: This sample does not test the http response code.
// All HTTP response codes must be handles or you should use an HTTP
// library, such as cUrl.

if (!$fp)
  fputs ($fp, $header . $req);
  while (!feof($fp))
    $res = fgets ($fp, 1024);
    if (strcmp ($res, "VERIFIED") == 0)
      // get variables from the paypal post to us
      // see these pages for possible variables:
      // https://developer.paypal.com/us/cgi-bin/devscr
      // https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/e_howto_admin_IPNIntro

      // payment info
      $payment_status = $_POST['payment_status'];
      $payment_amount = $_POST['mc_gross'];
      $payment_currency = $_POST['mc_currency'];
      $txn_id = $_POST['txn_id'];

      // product info
      $item_name = $_POST['item_name'];
      $item_number = $_POST['item_number'];

      // buyer info
      $payer_email = $_POST['payer_email'];
      $first_name = $_POST['first_name'];
      $last_name = $_POST['last_name'];
      $address_city = $_POST['address_city'];
      $address_state = $_POST['address_state'];
      $address_country = $_POST['address_country'];

      // receiver_email, that's our email address
      $receiver_email = $_POST['receiver_email'];

      // put your actual email address here
      $our_email = 'foobar@example.com';

      // if all these conditions are true, send the email
      // note: should also verify that $txn_id was not used before
      if (($payment_status == 'Completed') &&
         ($receiver_email == $our_email) &&
         ($payment_amount == $amount_they_should_have_paid ) &&
         ($payment_currency == "USD"))
        foreach ($_POST as $key => $value)
          $emailtext .= $key . " = " .$value ."\n\n";
        mail($payer_email, "Live-VERIFIED IPN", $emailtext . "\n\n" . $req);
    else if (strcmp ($res, "INVALID") == 0)
      // If 'INVALID', send an email. TODO: Log for manual investigation.
      foreach ($_POST as $key => $value)
        $emailtext .= $key . " = " .$value ."\n\n";
      mail($payer_email, "Live-INVALID IPN", $emailtext . "\n\n" . $req);
fclose ($fp);

PayPal IPN

If you haven't heard of "PayPal IPN" before, the "IPN" part stands for "Instant Payment Notification", and it's a way that you can do something in code (PHP, Java, Ruby, Perl, whatever) whenever a customer makes a PayPal purchase (or donation) for your PayPal account.

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There’s just one person behind this website; if this article was helpful (or interesting), I’d appreciate it if you’d share it. Thanks, Al.


Are you sure this will work in live site. Because the url you have given is 'www.sandbox.paypal.com' its sandbox's url then will that work in Live paypal ?

You're right, that URL won't work in production mode, just the PayPal sandbox for testing purposes. Just switch it over to the PayPal URL for production, and it works fine, or at least it has for me.


Thanks a lot, you solved my problem

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