readSignedInvoice

import { readSignedInvoice } from '@taprails/tap-to-pay';

async function readSignedInvoice(): Promise<PaymentRequest>

interface PaymentRequest {
  paymentId: string;         // Payment ID (same as NFC tag's `id`)
  merchantWallet: string;    // Merchant wallet address
  amount: string;            // USDC decimal string, e.g. "25.00"
  currency: 'USDC';
  network: 'base';
  timestamp: number;         // Unix ms timestamp from invoice
  transactionId: string;     // Alias for paymentId
}

import { readSignedInvoice, NFCPaymentError, NFCErrorCode } from '@taprails/tap-to-pay';

const handleScan = async () => {
  try {
    const payment = await readSignedInvoice();
    console.log('Amount:', payment.amount, 'USDC');
    console.log('Merchant:', payment.merchantWallet);
    // Proceed to processPayment...
  } catch (err) {
    if (err instanceof NFCPaymentError) {
      if (err.code === NFCErrorCode.TIMEOUT) {
        Alert.alert('Timed out', 'Move your phone closer and try again');
      } else {
        Alert.alert('Scan failed', err.message);
      }
    }
  }
};