ZetaChain - Omnichain Smart Contract Platform

// Example: Omnichain DEX Contract
pragma solidity 0.8.7;

import "@zetachain/protocol-contracts/contracts/zevm/SystemContract.sol";
import "@zetachain/protocol-contracts/contracts/zevm/interfaces/IZRC20.sol";

contract OmnichainDEX {
    SystemContract public systemContract;

    constructor(address systemContractAddress) {
        systemContract = SystemContract(systemContractAddress);
    }

    // Swap tokens across any chain
    function crossChainSwap(
        address zrc20From,
        address zrc20To,
        uint256 amount,
        bytes calldata recipient
    ) external {
        // Transfer from user
        IZRC20(zrc20From).transferFrom(msg.sender, address(this), amount);

        // Perform swap logic
        uint256 amountOut = calculateSwapAmount(zrc20From, zrc20To, amount);

        // Send to recipient on destination chain
        IZRC20(zrc20To).withdraw(recipient, amountOut);
    }
}

// Send cross-chain message from Ethereum to Bitcoin
const connector = new ethers.Contract(connectorAddress, connectorABI, signer);

const tx = await connector.send({
    destinationChainId: "18332", // Bitcoin testnet
    destinationAddress: bitcoinAddress,
    destinationGasLimit: 100000,
    message: ethers.utils.defaultAbiCoder.encode(
        ["string"],
        ["Hello from Ethereum!"]
    ),
    zetaValueAndGas: ethers.utils.parseEther("0.1"),
    zetaParams: "0x"
});

console.log('Cross-chain message sent:', tx.hash);

// Implement retry logic for resilience
async function createProvider() {
  const provider = new ethers.JsonRpcProvider(
    'https://api-zetachain-mainnet.n.dwellir.com/YOUR_API_KEY'
  );

  // Set custom timeout
  provider._getConnection().timeout = 10000;

  // Verify connection
  try {
    await provider.getNetwork();
    return provider;
  } catch (error) {
    console.error('Connection failed, retrying...');
    await new Promise(r => setTimeout(r, 1000));
    return createProvider();
  }
}

// Optimize gas for cross-chain transactions
async function estimateCrossChainGas(contract, method, params) {
  // Get current gas price
  const gasPrice = await provider.getGasPrice();

  // Estimate gas with buffer for cross-chain
  const estimatedGas = await contract.estimateGas[method](...params);
  const gasLimit = estimatedGas.mul(120).div(100); // 20% buffer

  return {
    gasLimit,
    gasPrice: gasPrice.mul(110).div(100) // 10% above current
  };
}

// Monitor cross-chain events efficiently
function watchCrossChainEvents(contract) {
  const filter = contract.filters.CrossChainCall();

  contract.on(filter, (from, to, amount, destinationChain, event) => {
    console.log(`Cross-chain transfer: ${from} → ${to}`);
    console.log(`Amount: ${amount}, Chain: ${destinationChain}`);
    console.log(`Transaction: ${event.transactionHash}`);
  });
}

// Secure cross-chain transfer
modifier validateCrossChain(uint256 chainId) {
    require(
        systemContract.isValidChainId(chainId),
        "Invalid destination chain"
    );
    _;
}

function secureCrossChainTransfer(
    uint256 destinationChainId,
    bytes calldata recipient,
    uint256 amount
) external validateCrossChain(destinationChainId) {
    // Implementation
}