The payment gateway built with precision.

$gateway = new \S_PayWay\Gateway($merchantId, $apiKey, $privateKey);

$result = $gateway->createINV([
    'goods' => [
        'reference_id' => 'ORDER-10492',
        'name'         => 'Premium plan',
        'description'  => '12 months',
        'quantity'     => 1,
        'unit_price'   => 25.00,
    ],
    'customer' => [
        'id'       => '1042',
        'fullname' => 'Sok Dara',
        'email'    => '[email protected]',
    ],
    'paid_url'   => 'https://yourshop.com/paid',
    'cancel_url' => 'https://yourshop.com/cart',
]);

header('Location: ' . $result['payment_url']);

POST https://api.s-payway.com/v3/invoices/
Content-Type: application/json
S-PayWay-Merchant-ID: 100245
S-PayWay-API-KEY: SAPI-...
S-PayWay-Timestamp: 1767225600000
S-PayWay-Request-ID: a1b2c3d4...
S-PayWay-Signature: 7c1e...a94f

{ "goods": { ... }, "customer": { ... },
  "paid_url": "...", "cancel_url": "...",
  "timestamp": 1767225600000 }

Timestamp in milliseconds. Signature = HMAC-SHA256(merchant_id:timestamp:body, private key)

$raw       = file_get_contents('php://input');
$timestamp = $_SERVER['HTTP_S_PAYWAY_TIMESTAMP'] ?? '';
$signature = strtolower($_SERVER['HTTP_S_PAYWAY_SIGNATURE'] ?? '');

$expected = hash_hmac('sha256', $timestamp . ':' . $raw, $privateKey);
if (!hash_equals($expected, $signature)) {
    http_response_code(401);
    exit;
}

$call = json_decode($raw, true);

S-PayWay sends every paid transaction to your webhook:
POST, event payment.completed, headers S-PayWay-Event, S-PayWay-Event-ID,
S-PayWay-Timestamp, S-PayWay-Signature. Answer 200 within 20 seconds.

$raw       = file_get_contents('php://input');
$timestamp = $_SERVER['HTTP_S_PAYWAY_TIMESTAMP'] ?? '';
$signature = $_SERVER['HTTP_S_PAYWAY_SIGNATURE'] ?? '';
$eventId   = $_SERVER['HTTP_S_PAYWAY_EVENT_ID'] ?? '';

$expected = hash_hmac('sha256', $timestamp . ':' . $raw, $webhookSecret);
if (!hash_equals($expected, $signature)
    || abs(time() - (int) $timestamp) > 300) {
    http_response_code(401);
    exit;
}
if (alreadyHandled($eventId)) { http_response_code(200); exit; }

$event = json_decode($raw, true);
$event['data']['invoice_id'], ['total_usd'], ['goods']['reference_id'] ...
http_response_code(200);

Read your transactions from your server with your access token (SAT).

GET https://api.s-payway.com/transactions/?page=1
Authorization: Bearer SAT_...

?id=883660               one transaction
?reference=ORDER-10492   your own order number
?page=1                  20 a page, newest first

{ "success": true, "count": 1, "data": [{
    "invoice_id": 883660, "reference_id": "ORDER-10492",
    "total_usd": "25.00", "status": "Paid",
    "payment": { ... }, "created_at": "1791704100" }] }