iPay API Integration - PHP

To integrate iPay's payment gateway into your PHP-based forex CRM platform, follow these steps to enable on-ramp cryptocurrency deposits.

1. Build the Payment URL

Construct a payment URL with required parameters and redirect the user to initiate the payment process.

<?php
// Build iPay payment URL in PHP
$apiKey = 'YOUR_API_KEY';
$depositId = '12345';   // From CRM
$amount = 150;          // Client-entered amount
$onRampProvider = 'provider1';
$defaultFiatCurrency = 'USD';

$baseUrl = 'https://us-central1-nfgdatabasedemo.cloudfunctions.net/app/api/invoice_external?';
$params = http_build_query([
    'apiKey' => $apiKey,
    'customId' => $depositId,
    'onRampProvider' => $onRampProvider,
    'defaultFiatAmount' => $amount,
    'defaultFiatCurrency' => $defaultFiatCurrency
]);
$paymentUrl = $baseUrl . $params;

// Redirect the user to iPay payment page
header("Location: $paymentUrl");
exit();

After the customer completes the payment, they are sent to the redirect URL you registered with iPay. Do not credit the deposit on that page load — credit it only when the server-to-server callback below arrives.

2. Handle the Callback

Set up a callback handler to process the JSON payload sent by iPay when the deposit completes. Callbacks are sent for completed payments only, so there is no status field to check.

<?php
// iPay callback handler (e.g., callback.php)
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $secretToken = 'YOUR_SECRET_TOKEN';  // Optional secret token from iPay

    // Verify the authorization header (if a secret token is configured)
    $headers = array_change_key_case(getallheaders(), CASE_LOWER);
    if ($secretToken !== '' && (($headers['authorization'] ?? '') !== $secretToken)) {
        http_response_code(401);
        exit('Invalid token');
    }

    $payload = json_decode(file_get_contents('php://input'), true);
    if (!is_array($payload) || !isset($payload['customerID'], $payload['transferedAmount'])) {
        http_response_code(400);
        exit('Bad payload');
    }

    // Note the field spellings: transferedAmount (single r), transactionFeePrecent
    $depositId      = (string) $payload['customerID'];      // your customId, returned as a string
    $amountReceived = (float) $payload['transferedAmount']; // net USDT delivered to your wallet
    $txId           = $payload['blockchainTxId'] ?? null;

    // TODO: Update deposit record $depositId in your CRM/database with $amountReceived.
    // Make this idempotent: ignore the callback if $depositId (or $txId) was already credited.

    // Send HTTP 200 OK to iPay
    http_response_code(200);
    exit('OK');
}

Explanation

• Building the URL: The http_build_query function safely encodes parameters like apiKey, customId, and defaultFiatAmount. The resulting URL redirects the user to iPay’s payment page.
• Handling the Callback: The handler verifies the optional authorization header, reads the JSON body, and credits the deposit identified by customerID with transferedAmount. Respond with HTTP 200 to acknowledge receipt.
• Integration Notes: Ensure your CRM can handle HTTP redirects and POST requests. Test the callback endpoint to confirm it receives iPay’s JSON payload correctly — see Testing Your Payment Integration.