cross-chain

# Cross-Chain Development Skill Expert cross-chain bridge development and multi-chain integration. ## Capabilities - **LayerZero**: Omnichain messaging and OFT tokens - **Chainlink CCIP**: Cross-chain interoperability protocol - **Bridge Verification**: Implement verification logic - **Finality Handling**: Handle chain finality differences - **Wormhole/Axelar**: Alternative bridge protocols - **Canonical Bridges**: Token bridge implementations - **State Verification**: Cross-chain state proofs ## LayerZero Integration ### OFT Token (Omnichain Fungible Token) ```solidity // SPDX-License-Identifier: MIT pragma solidity ^0.8.20; import { OFT } from "@layerzerolabs/lz-evm-oapp-v2/contracts/oft/OFT.sol"; contract MyOFT is OFT { constructor( string memory _name, string memory _symbol, address _lzEndpoint, address _delegate ) OFT(_name, _symbol, _lzEndpoint, _delegate) { _mint(msg.sender, 1000000 * 10 ** decimals()); } } ``` ### OApp (Omnichain Application) ```solidity import { OApp } from "@layerzerolabs/lz-evm-oapp-v2/contracts/oapp/OApp.sol"; import { Origin } from "@layerzerolabs/lz-evm-oapp-v2/contracts/oapp/interfaces/IOAppReceiver.sol"; contract CrossChainCounter is OApp { uint256 public count; constructor(address _endpoint, address _owner) OApp(_endpoint, _owner) {} function increment( uint32 _dstEid, bytes calldata _options ) external payable { bytes memory payload = abi...