Payment Tools

// Server requires payment for API call
app.get('/api/premium-data', async (req, res) => {
  const paymentHeader = req.headers['x-payment'];

  if (!paymentHeader) {
    return res.status(402).json({
      error: 'Payment Required',
      requirements: {
        network: 'solana-devnet',
        maxAmountRequired: '1000000', // 1 USDC
        payTo: 'SERVER_WALLET_ADDRESS',
        asset: 'USDC_MINT'
      }
    });
  }

  // Verify and settle in one call
  const result = await mcp.call('payment_execute', {
    paymentHeader,
    requirements: {
      network: 'solana-devnet',
      maxAmountRequired: '1000000',
      payTo: 'SERVER_WALLET_ADDRESS',
      asset: 'USDC_MINT'
    }
  });

  if (!result.data.settled) {
    return res.status(402).json({ error: 'Payment failed' });
  }

  // Deliver data
  res.json({ data: premiumData });
});

// AI agent autonomously purchases data
async function purchaseDataset(datasetUrl) {
  // 1. Request data (gets 402 error)
  const res = await fetch(datasetUrl);

  if (res.status === 402) {
    const requirements = await res.json();

    // 2. Create payment
    const payment = await mcp.call('payment_create', {
      to: requirements.payTo,
      amount: parseFloat(requirements.maxAmountRequired) / 1_000_000,
      token: 'usdc'
    });

    // 3. Retry with payment header
    const dataRes = await fetch(datasetUrl, {
      headers: {
        'X-Payment': payment.data.paymentHeader
      }
    });

    return await dataRes.json();
  }

  return await res.json();
}