Hyperlane integration

Hyperlane Integration

Hyperlane is a permissionless interoperability protocol. Key distinction from Axelar and LayerZero: anyone can deploy Hyperlane on any chain without protocol permission. This makes it suitable for new L2/L3, appchains, and custom environments where other protocols aren't yet present.

Architecture

Hyperlane consists of:

• Mailbox — smart contract on each chain through which messages are sent and received
• Interchain Security Module (ISM) — customizable message verification. Can use multisig validators, optimistic security, ZK proofs
• Relayers — off-chain agents transmitting messages between chains
• Validators — sign Mailbox state checkpoints

ISM — Custom Security

Hyperlane's uniqueness: each recipient contract defines its own ISM. You decide how to verify incoming messages.

ISM options:

• Multisig ISM — M-of-N signatures from validators (default)
• Aggregation ISM — combination of multiple ISM (AND/OR logic)
• Routing ISM — different ISM for different source chains
• Optimistic ISM — optimistic verification with fraud proof period
• ZK ISM — verification via zero-knowledge proofs (in development)

Sending Messages

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {IMailbox} from "@hyperlane-xyz/core/contracts/interfaces/IMailbox.sol";

contract HyperlaneMessageSender {
    IMailbox public mailbox;
    
    constructor(address _mailbox) {
        mailbox = IMailbox(_mailbox);
    }
    
    function sendMessage(
        uint32 destinationDomain,
        bytes32 recipientAddress,
        bytes calldata messageBody
    ) external payable {
        uint256 fee = mailbox.quoteDispatch(destinationDomain, recipientAddress, messageBody);
        require(msg.value >= fee, "Insufficient gas payment");
        
        bytes32 messageId = mailbox.dispatch{value: fee}(
            destinationDomain,
            recipientAddress,
            messageBody
        );
        
        emit MessageSent(messageId, destinationDomain);
    }
}

Receiving Messages

import {IMessageRecipient} from "@hyperlane-xyz/core/contracts/interfaces/IMessageRecipient.sol";

contract HyperlaneMessageReceiver is IMessageRecipient {
    mapping(uint32 => bytes32) public enrolledSenders;
    
    function handle(
        uint32 origin,
        bytes32 sender,
        bytes calldata message
    ) external payable override {
        require(msg.sender == address(mailbox), "Only mailbox");
        require(enrolledSenders[origin] == sender, "Unknown sender");
        
        (address recipient, uint256 amount) = abi.decode(message, (address, uint256));
        _processMessage(origin, recipient, amount);
    }
}

Domain IDs

Hyperlane integration — 2-3 weeks for basic GMP. Especially valuable for custom L2/L3 and appchains needing fast integration.