Fixed Rate Swap

const params = new URLSearchParams({
  amount: '1',
  from: '6689b73ec90e45f3b3e51566',       // ETH token id from /tokens
  to:   '6689b73ec90e45f3b3e51558',       // USDC token id from /tokens
  fixed: 'true',                          // request fixed-rate quotes
  refundAddress: '0xYourRefundWallet',    // source-chain wallet for refunds
});

const response = await fetch(
  `https://api-partner.houdiniswap.com/v2/quotes?${params}`,
  {
    headers: {
      'Authorization': `${API_KEY}:${API_SECRET}`,
      'x-user-ip': userIp,
      'x-user-agent': userAgent,
      'x-user-timezone': userTimezone
    }
  }
);

const { quotes } = await response.json();

// All returned quotes will be fixed-rate standard quotes
const quote = quotes[0];
console.log('Guaranteed out:', quote.amountOut);
console.log('Rate locked until:', quote.validUntil);
console.log('Quote ID:', quote.quoteId);  // needed for /exchanges

// Always check the rate is still valid before submitting
if (Date.now() >= new Date(quote.validUntil).getTime()) {
  throw new Error('Rate expired — fetch a new quote');
}

const response = await fetch('https://api-partner.houdiniswap.com/v2/exchanges', {
  method: 'POST',
  headers: {
    'Authorization': `${API_KEY}:${API_SECRET}`,
    'Content-Type': 'application/json',
    'x-user-ip': userIp,
    'x-user-agent': userAgent,
    'x-user-timezone': userTimezone
  },
  body: JSON.stringify({
    quoteId: '69af9e02f9c5affabcaccc14',       // from /quotes
    addressTo: '0x742d35Cc6634C0532925a3b844Bc454e4438f44e',
    refundAddress: '0xYourRefundWallet'         // required for fixed rate
  })
});

const order = await response.json();
console.log('Order ID:', order.houdiniId);
console.log('Deposit to:', order.depositAddress);
console.log('Send:', order.inAmount, order.inSymbol);
console.log('Rate locked:', order.fixed, '— guaranteed out:', order.outAmount);

const response = await fetch(
  `https://api-partner.houdiniswap.com/v2/orders/${order.houdiniId}`,
  {
    headers: {
      'Authorization': `${API_KEY}:${API_SECRET}`,
      'x-user-ip': userIp,
      'x-user-agent': userAgent,
      'x-user-timezone': userTimezone
    }
  }
);

const status = await response.json();
console.log('Status:', status.statusLabel);
// WAITING     — awaiting deposit
// CONFIRMING  — deposit detected, awaiting confirmations
// EXCHANGING  — CEX processing the swap at locked rate
// FINISHED    — swap complete, guaranteed amount sent
// FAILED      — swap failed
// REFUNDED    — swap failed; refund handling depends on provider