Integrate

import { quais } from 'quais';

const RPC_URL = 'https://rpc.quai.network/cyprus1';
const RELAY_ADDRESS = '0x003D2EC4C1Ff5e98898fEa6C6D1AAaA48FaDc11A';
const RELAY_ABI = ['function sendTo(address payable to) external payable'];

// quais.getAddress() checksums — Quai's RPC rejects a lowercase address outright.
async function sendThroughRelay(signer, destination, valueWei) {
  const to = quais.getAddress(String(destination).toLowerCase());
  if (!to.startsWith('0x00')) {
    throw new Error('destination is not a Cyprus-1 address — QUAI sent there is unreachable');
  }
  if (parseInt(to.slice(4, 6), 16) >= 0x80) {
    throw new Error('destination is a Qi-ledger address — QUAI cannot be sent to it');
  }

  const relay = new quais.Contract(RELAY_ADDRESS, RELAY_ABI, signer);
  const tx = await relay.sendTo(to, { value: valueWei });
  await tx.wait();
  return tx.hash;
}

import { quais } from 'quais';

const provider = new quais.JsonRpcProvider('https://rpc.quai.network/cyprus1', undefined, {
  usePathing: false, // RPC_URL already ends in /cyprus1 — do not let the SDK append it again
});

async function maxSendable(accountAddress) {
  const address = quais.getAddress(String(accountAddress).toLowerCase());
  const [balance, feeData] = await Promise.all([
    provider.getBalance(address),
    provider.getFeeData(quais.Zone.Cyprus1), // getFeeData needs the zone on Quai
  ]);

  // A sendTo to a never-used recipient estimates ~98,000 gas (2026-11-02); 60,000 is too low and
  // reverts. Use a live provider.estimateGas(...) + 20% where you can.
  const gasLimit = 130_000n;
  const gasPrice = BigInt(feeData.gasPrice ?? feeData.maxFeePerGas ?? 0n);
  const gasCost = (gasLimit * gasPrice * 125n) / 100n; // 25% headroom

  if (gasCost >= balance) return 0n; // balance can't cover its own fee
  return balance - gasCost;
}

POST https://rpc.quai.network/cyprus1
Content-Type: application/json

{"jsonrpc":"2.0","id":1,"method":"quai_getCode","params":["0x003D2EC4C1Ff5e98898fEa6C6D1AAaA48FaDc11A","latest"]}

POST https://rpc.quai.network/cyprus1
Content-Type: application/json

{"jsonrpc":"2.0","id":1,"method":"quai_getBalance","params":["0x<your-checksummed-address>","latest"]}

// selector for sendTo(address), keccak-256("sendTo(address)")[0..4]
const SELECTOR = '0xe6d25245';

function encodeSendTo(toChecksummed) {
  const body = toChecksummed.slice(2).toLowerCase().padStart(64, '0');
  return SELECTOR + body;
}

const tx = {
  from: accountAddress,
  to: '0x003D2EC4C1Ff5e98898fEa6C6D1AAaA48FaDc11A',
  value: '0x' + valueWei.toString(16),
  data: encodeSendTo(destinationChecksummed),
  // A never-used recipient needs ~98,000 gas; use a live quai_estimateGas + 20%, or 130,000.
  gas: '0x' + (130_000n).toString(16),
};
// wallet.request({ method: 'quai_sendTransaction', params: [tx] })