WayPay™ Developer Documentation

WayPay is India's sovereign, zero-commission payment reconciliation gateway. It eliminates the 2% + GST fee charged by traditional aggregators (Razorpay, Cashfree, PayU) by allowing customers to pay directly from their UPI app straight into your Indian bank account. WayPay automatically reconciles the payment in under 2 seconds and fires real-time webhooks to fulfill your customer orders.

How the 0% MDR Automatic Gateway Works

Standard payment gateways act as custodians: money sits in their nodal accounts for T+2 business days before reaching you, while they deduct a 2.36% fee. WayPay operates as a pure software reconciliation layer:

5-Minute Quickstart

Accept payments on your website in under 5 minutes with zero backend dependencies.

WayPay.open({
  amount: 499.00,
  orderNumber: 'ORD-' + Date.now(),
  merchantName: 'My Awesome Store',
  vpa: 'yourshop@okaxis', // Your UPI ID
  onSuccess: function(res) {
    console.log('Payment verified! UTR:', res.utr);
    window.location.href = '/order-success?orderId=' + res.orderNumber;
  },
  onFailure: function(err) {
    alert('Payment canceled or expired');
  }
});

Universal Checkout SDK (waypay.js)

waypay.js is a standalone 30KB pure-vector checkout script that generates dynamic SVG QR codes, UPI intent deep-links for Google Pay, PhonePe, Paytm, CRED, BHIM, and polls the reconciliation engine in real time.

WayPay.renderInline('#my-payment-box', {
  amount: 850.00,
  orderNumber: 'ORD-9821',
  merchantName: 'Malabar Spices',
  vpa: 'malabarspices@okaxis',
  successUrl: 'https://mystore.com/thank-you',
  onSuccess: function(res) {
    console.log('Payment reconciled inline:', res);
  }
});

<!-- 1. Include SDK -->
<script src="https://waypay.whatyouwantkerala.in/waypay.js"></script>

<!-- 2. Any HTML Button with data-attributes -->
<button data-waypay-pay
        data-amount="499.00"
        data-name="Artisan Coffee Beans"
        data-vpa="coffee@okaxis"
        data-success-url="https://mystore.com/order-confirmed">
  Buy Now with UPI (0% Fee)
</button>

Webhooks & HMAC-SHA256 Signatures

The millisecond a bank credit alert is validated by your connected phone or bank email inbox, WayPay dispatches an authoritative POST request to your configured webhook URL.

{
  "event": "payment.verified",
  "event_id": "evt_9482049102",
  "timestamp": 1729837200,
  "data": {
    "order_id": "ORD-9921",
    "amount": 499.03,
    "currency": "INR",
    "utr": "628219482014",
    "payer_vpa": "rahul@oksbi",
    "bank": "HDFC_BANK",
    "settlement_type": "DIRECT_PEER_TO_PEER",
    "mdr_fee_deducted": 0.00
  }
}

const crypto = require('crypto');

function verifyWayPaySignature(rawBody, signatureHeader, secret) {
  const parts = signatureHeader.split(',');
  const timestamp = parts.find(p => p.startsWith('t=')).split('=')[1];
  const signature = parts.find(p => p.startsWith('v1=')).split('=')[1];
  
  // Reject replays older than 300 seconds
  if (Math.abs(Date.now() / 1000 - timestamp) > 300) return false;
  
  const payloadToSign = `${timestamp}.${rawBody}`;
  const expectedSig = crypto
    .createHmac('sha256', secret)
    .update(payloadToSign)
    .digest('hex');
    
  return crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expectedSig));
}

Automatic UTR Gateway Engine

WayPay eliminates the need for expensive third-party payment aggregators using redundant, fault-tolerant ingestion pipelines:

Fraud Detection & Fallback Dispute Queue

WayPay is battle-tested against modern UPI fraud techniques, including spoofed APK tools like fake_Upi and synthetic receipt generators.