Integrating a crypto payment gateway requires a shift in how engineers think about transaction states. Unlike traditional card networks where transactions are immediately approved or declined, blockchain transactions involve network propagation, block confirmations, and varying gas fees.
Handling Asynchronous Transaction States
When a customer initiates a stablecoin payment, the payment gateway must listen for on-chain events. Since blockchain finality is asynchronous, relying on polling is inefficient and non-scalable. Engineers should utilize robust webhook systems to listen for confirm events:
// Example webhook handler
app.post('/webhooks/flashtle', (req, res) => {
const signature = req.headers['flashtle-signature'];
const event = verifyWebhookSignature(req.body, signature);
if (event.type === 'payment.confirmed') {
updateOrderStatus(event.data.orderId, 'paid');
}
res.status(200).send();
});Designing Robust Failbacks
Network congestion can lead to delayed block confirmations. To prevent checkout drop-offs, a payment gateway must implement automatic routing fallbacks. If stablecoin network gas fees spike, Flashtle’s intelligent router can fallback to alternative high-speed chains or traditional instant transfer rails, ensuring the user experience remains seamless.