How to integrate Paytm Payment Gateway :
As we know Paytm is highly popular wallet system in india and Now a days it's growing very fast. So here in this tutorial you will learn how to integrate Paytm payment gateway using PHP on your website.
Step 1: Just go on Paytm site and select SDK to download. In our case we will select PHP.
URL of Paytm : https://business.paytm.com/developers-api#vibDiscussion
Step 2: After clicking on PHP you will be redirect on Github site. Now from git URL download "Paytm Payment Gateway PHP Kit".
Step 3: Copy PaytmKit folder in document root of your server (like /var/www/html)
Step 4: Open config_paytm.php file from the PaytmKit/lib folder and update the below constant values
a) PAYTM_MERCHANT_KEY – Can be downloaded from the Paytm portal. One time downloadable
b) PAYTM_MERCHANT_MID - MID (Merchant ID) can be collected from Paytm team
c) PAYTM_MERCHANT_WEBSITE - Website name can be collected from Paytm team
define('PAYTM_ENVIRONMENT', 'TEST'); // PROD
define('PAYTM_MERCHANT_KEY', 'xxxxxxxxxxxxxxxxxxxxxxxx'); //Change this constant's value with Merchant key downloaded from portal
define('PAYTM_MERCHANT_MID', 'xxxxxxxxxxxxxxxxxxxxxxx'); //Change this constant's value with MID (Merchant ID) received from Paytm
define('PAYTM_MERCHANT_WEBSITE', 'xxxxxxx'); //Change this constant's value with Website name received from Paytm
PaytmKit folder is having following files:
1. TxnTest.php – Testing transaction through Paytm gateway.
2. pgRedirect.php – This file has the logic of checksum generation and passing all required parameters to Paytm PG.
3. pgResponse.php – This file has the logic for processing PG response after the transaction processing.
4. TxnStatus.php – Testing Status Query API
Step 5: Now final step to create a sample html form with required filed, You can also find demo html form in PaytmKit/TxnTest.php.
<?php
header("Pragma: no-cache");
header("Cache-Control: no-cache");
header("Expires: 0");
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Merchant Check Out Page</title>
<meta name="GENERATOR" content="Evrsoft First Page">
</head>
<body>
<h1>Merchant Check Out Page</h1>
<pre>
</pre>
<form method="post" action="pgRedirect.php">
<table border="1">
<tbody>
<tr>
<th>S.No</th>
<th>Label</th>
<th>Value</th>
</tr>
<tr>
<td>1</td>
<td><label>ORDER_ID::*</label></td>
<td><input id="ORDER_ID" tabindex="1" maxlength="20" size="20"
name="ORDER_ID" autocomplete="off"
value="<?php echo "ORDS" . rand(10000,99999999)?>">
</td>
</tr>
<tr>
<td>2</td>
<td><label>CUSTID ::*</label></td>
<td><input id="CUST_ID" tabindex="2" maxlength="12" size="12" name="CUST_ID" autocomplete="off" value="CUST001"></td>
</tr>
<tr>
<td>3</td>
<td><label>INDUSTRY_TYPE_ID ::*</label></td>
<td><input id="INDUSTRY_TYPE_ID" tabindex="4" maxlength="12" size="12" name="INDUSTRY_TYPE_ID" autocomplete="off" value="Retail"></td>
</tr>
<tr>
<td>4</td>
<td><label>Channel ::*</label></td>
<td><input id="CHANNEL_ID" tabindex="4" maxlength="12"
size="12" name="CHANNEL_ID" autocomplete="off" value="WEB">
</td>
</tr>
<tr>
<td>5</td>
<td><label>txnAmount*</label></td>
<td><input title="TXN_AMOUNT" tabindex="10"
type="text" name="TXN_AMOUNT"
value="1">
</td>
</tr>
<tr>
<td></td>
<td></td>
<td><input value="CheckOut" type="submit" onclick=""></td>
</tr>
</tbody>
</table>
* - Mandatory Fields
</form>
</body>
</html>
Step 5: Now above form will post on "pgRedirect.php" file in Paytm kit folder. You may also need to add “CALLBACK_URL” in pgRedirect.php. By default it is commented in thsi file. This is that url on paytm will redirect your user.
$paramList["CALLBACK_URL"] = "http://yourdomain.com/PaytmKit/pgResponse.php";
Here "http://yourdomain.com" will be your website address.
Step 6: Now in "pgResponse.php" file youe can check all status of your transactions.
<?php
header("Pragma: no-cache");
header("Cache-Control: no-cache");
header("Expires: 0");
// following files need to be included
require_once("./lib/config_paytm.php");
require_once("./lib/encdec_paytm.php");
$paytmChecksum = "";
$paramList = array();
$isValidChecksum = "FALSE";
$paramList = $_POST;
$paytmChecksum = isset($_POST["CHECKSUMHASH"]) ? $_POST["CHECKSUMHASH"] : ""; //Sent by Paytm pg
//Verify all parameters received from Paytm pg to your application. Like MID received from paytm pg is same as your application�s MID, TXN_AMOUNT and ORDER_ID are same as what was sent by you to Paytm PG for initiating transaction etc.
$isValidChecksum = verifychecksum_e($paramList, PAYTM_MERCHANT_KEY, $paytmChecksum); //will return TRUE or FALSE string.
if($isValidChecksum == "TRUE") {
echo "<b>Checksum matched and following are the transaction details:</b>" . "<br/>";
if ($_POST["STATUS"] == "TXN_SUCCESS") {
echo "<b>Transaction status is success</b>" . "<br/>";
//Process your transaction here as success transaction.
//Verify amount & order id received from Payment gateway with your application's order id and amount.
}
else {
echo "<b>Transaction status is failure</b>" . "<br/>";
}
if (isset($_POST) && count($_POST)>0 )
{
foreach($_POST as $paramName => $paramValue) {
echo "<br/>" . $paramName . " = " . $paramValue;
}
}
}
else {
echo "<b>Checksum mismatched.</b>";
//Process transaction as suspicious.
}
?>
