NetPayBD API Documentation

Introduction

Welcome to the NetPayBD API documentation. This guide will walk you through the process of integrating our payment gateway into your website. The process is straightforward and involves redirecting the user to our payment page with specific parameters.

Getting Started

To start using our API, you need two essential credentials which will be provided to you upon registration:

Username: Your unique merchant username.
API Key: Your secret key for authenticating requests.

1. Initiating a Payment

To initiate a payment, you need to redirect the user to our payment gateway URL with the required parameters. The request should be a simple `GET` request.

Base URL

https://pay.netpaybd.com/

Request Parameters

Parameter	Type	Required	Description
`username`	String	Yes	Your unique merchant username.
`api`	String	Yes	Your merchant API Key.
`amount`	Number	Yes	The amount to be paid (e.g., 50.00).
`success_url`	URL	Yes	The URL to which the user will be redirected after a successful payment.
`callback_url`	URL	Yes	The URL our server will send a `POST` request to (IPN) after a successful payment.

Example: Building the Payment URL in PHP

Here's how you can construct the full payment URL and redirect the user.

<?php
$username = 'YOUR_USERNAME';
$api_key = 'YOUR_API_KEY';
$amount = 50.00;
$success_url = 'https://yourwebsite.com/payment_success.php';
$callback_url = 'https://yourwebsite.com/payment_callback.php';
$gateway_url = "https://pay.netpaybd.com/";
$payment_params = [
    'username' => $username,
    'api' => $api_key,
    'amount' => $amount,
    'success_url' => $success_url,
    'callback_url' => $callback_url
];
$redirect_url = $gateway_url . '?' . http_build_query($payment_params);
header('Location: ' . $redirect_url);
exit;
?>

2. Handling the Callback (IPN)

After a payment is successfully verified, our server will send an automated `POST` request to your callback_url. This is known as an Instant Payment Notification (IPN). This is the most reliable way to confirm a payment and update your database (e.g., mark an order as paid).

Your callback script should be prepared to receive the following `POST` data:

Callback Parameters

Parameter	Type	Description
`status`	String	Will always be "success" for a successful transaction.
`transaction_id`	String	The unique transaction ID (TrxID) from our system.
`amount`	Number	The amount that was paid.
`payment_type`	String	The payment method used (e.g., 'bKash', 'NAGAD').
`username`	String	The merchant username who received the payment.
`timestamp`	Unix Timestamp	The time the transaction was completed.

Example: Callback Handler in PHP

Create a file at your callback_url (e.g., payment_callback.php) to process the data.

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $status = $_POST['status'];
    $transaction_id = $_POST['transaction_id'];
    $amount = $_POST['amount'];
    
    $log_data = json_encode($_POST, JSON_PRETTY_PRINT);
    file_put_contents('payment_log.txt', $log_data . "\n", FILE_APPEND);
    
    http_response_code(200);
    echo "Callback received successfully.";

} else {
    http_response_code(405);
    echo "Method Not Allowed.";
}
?>

3. Handling the Success Redirect

After the user completes the payment, their browser will be redirected to your success_url. We will append the transaction ID and amount as `GET` parameters to this URL, so you can display a confirmation message to the user.

Example Success URL

https://yourwebsite.com/payment_success.php?trx_id=TXN1234567890&amount=50.00

Example: Success Page in PHP

At your success_url, you can retrieve the data to show a message.

<?php
if (isset($_GET['trx_id']) && isset($_GET['amount'])) {
    $transaction_id = htmlspecialchars($_GET['trx_id']);
    $amount = htmlspecialchars($_GET['amount']);

    echo "<h1>Payment Successful!</h1>";
    echo "<p>Thank you for your payment.</p>";
    echo "<p>Transaction ID: " . $transaction_id . "</p>";
    echo "<p>Amount Paid: ৳" . $amount . "</p>";

} else {
    echo "<h1>Thank you!</h1>";
}
?>