GoPay Developer API Specification

// Response JSON: All Allowed Channels
{
  "code": 200,
  "status": "SUCCESS",
  "message": "All permitted channel balances fetched successfully.",
  "data": {
    "merchant_id": "MID333255",
    "username": "fastwin",
    "allowed_currencies": "BDT,USDT",
    "channels": {
      "channel_1": { "channel_id": 1, "name": "Channel 1 ", "currency": "BDT", "balance": 1500.00 },
      "channel_2": { "channel_id": 2, "name": "Channel 2 ", "currency": "BDT", "balance": 3200.50 },
      "channel_3": { "channel_id": 3, "name": "Channel 3 ", "currency": "BDT", "balance": 500.00 },
      "channel_5": { "channel_id": 5, "name": "Channel 5 ", "currency": "USDT", "balance": 250.00 }
    },
    "total_bdt_balance": 5200.50,
    "total_usdt_balance": 250.00,
    "main_account_balance": 36950.50
  },
  "timestamp": "2026-09-29 18:30:00"
}

<!-- Direct Form Auto-Submit Example -->
<form id="gopay_checkout" action="https://api-pay.go-pay.pro/v1/Collect/bdt/" method="POST">
    <input type="hidden" name="appId" value="GP_xxxxxxxx">
    <input type="hidden" name="merOrderNo" value="ORD_<?php echo time(); ?>">
    <input type="hidden" name="amount" value="500.00">
    <input type="hidden" name="payMethod" value="NAGAD">
    <input type="hidden" name="notifyUrl" value="https://yourdomain.com/gopay_notify.php">
    <input type="hidden" name="returnUrl" value="https://yourdomain.com/payment_success.php">
</form>
<script>document.getElementById('gopay_checkout').submit();</script>

<!-- India Pay-In Form Post -->
<form id="indian_checkout" action="https://api-pay.go-pay.pro/indian_pay.php" method="POST">
    <input type="hidden" name="appId" value="GP_xxxxxxxx">
    <input type="hidden" name="merOrderNo" value="INR_<?php echo time(); ?>">
    <input type="hidden" name="amount" value="1000.00">
    <input type="hidden" name="payMethod" value="UPI">
    <input type="hidden" name="customer_name" value="Amit Sharma">
    <input type="hidden" name="notifyUrl" value="https://yourdomain.com/indian_notify.php">
    <input type="hidden" name="returnUrl" value="https://yourdomain.com/payment_done.php">
</form>
<script>document.getElementById('indian_checkout').submit();</script>

{
  "appId": "GP_xxxxxxxx",
  "secret_key": "YOUR_MERCHANT_SECRET_KEY",
  "order_id": "2026092917882299"
}

<?php
/**
 * Universal Webhook Listener (PHP)
 */
define('MY_GOPAY_SECRET', 'YOUR_MERCHANT_SECRET_KEY');

$rawPayload = file_get_contents("php://input");
$data = json_decode($rawPayload, true) ?: $_POST;

$receivedSecret = $data['secret_key'] ?? '';
$orderNo        = $data['merOrderNo'] ?? ($data['order_id'] ?? '');
$amount         = floatval($data['amount'] ?? 0);
$status         = strtoupper($data['orderStatus'] ?? ($data['status'] ?? ''));

// 1. Verify Secret Key Authenticity
if ($receivedSecret !== MY_GOPAY_SECRET) {
    http_response_code(403);
    echo "fail";
    exit;
}

// 2. Process Successful Transaction
if (!empty($orderNo) && ($status === 'SUCCESS' || $status === '1')) {
    // Check if order is already processed in your DB
    // Credit user account: $amount
    // Mark order status as Paid in your DB

    echo "ok"; // Mandatory: Echo exactly 'ok'
    exit;
}

echo "fail";
?>

{
  "appId": "GP_xxxxxxxx",
  "secret_key": "YOUR_MERCHANT_SECRET_KEY",
  "channel": 5,
  "amount": 20.00,
  "method": "usdt_trc20",
  "usdt_address": "TLNVbJs71RVpZavaNSFxH3uuegrqJnum91"
}

{
  "appId": "GP_xxxxxxxx",
  "secret_key": "YOUR_MERCHANT_SECRET_KEY",
  "payout_id": "DF2026092918451198"
}