FlexPay: Solana Merchant Checkout SDK & Swap Gateway

I engineered FlexPay to solve multi-token payment routing by embedding real-time DEX aggregation directly into the checkout SDK:

1. Real-Time Routing via Jupiter Swap V2 Engine

When a customer selects an arbitrary token to pay with, FlexPay queries Jupiter Swap V2 API to identify the optimal swap path, calculates slippage protection, and builds an atomic transaction combining the token swap and USDC transfer into a single wallet approval prompt.

2. Client-Side Checkout React Hook (

Terminal Workspace

useFlexPay

)

Terminal Workspace
// FlexPay React Hook for Instant E-Commerce Checkout Integration
export function useFlexPay({ merchantAddress, targetAmountUSDC }: FlexPayConfig) {
  const [loading, setLoading] = useState(false);

  const executeCheckout = async (inputToken: string) => {
    setLoading(true);
    const swapRoute = await fetchJupiterRoute(inputToken, 'USDC', targetAmountUSDC);
    const transaction = await buildAtomicPaymentTx(swapRoute, merchantAddress);
    const txHash = await sendTransaction(transaction);
    return txHash;
  };

  return { executeCheckout, loading };
}

3. Merchant Transaction Verification Dashboard

Built an analytics dashboard for merchants to track transaction volume, inspect conversion rates, and verify settlement status in real time.