1inch Cross-Chain Resolver Example

A sample implementation of a cross-chain atomic swap resolver using 1inch's cross-chain SDK. This project demonstrates how to implement secure cross-chain token swaps with escrow contracts on both source and destination chains.

Overview

This project implements a cross-chain atomic swap mechanism that allows users to swap tokens across different blockchain networks securely. The system uses:

• Escrow contracts to lock funds on both source and destination chains
• Hash-time-locked contracts (HTLC) for atomic swap execution
• 1inch Limit Order Protocol (LOP) for order execution
• Cross-chain SDK for seamless integration

Architecture

Core Components

1. Resolver Contract (contracts/src/Resolver.sol)

   • Main contract that orchestrates cross-chain swaps
   • Deploys escrow contracts on source and destination chains
   • Handles order execution through 1inch LOP
   • Manages withdrawal and cancellation of escrows

2. Escrow System

   • IBaseEscrow.sol - Base interface for escrow contracts
   • IEscrowFactory.sol - Factory for creating escrow contracts
   • Supports both ERC-20 tokens and native tokens

3. Libraries

   • TakerTraitsLib.sol - Manages taker-specific parameters
   • TimelocksLib.sol - Handles time-based constraints
   • ImmutablesLib.sol - Manages immutable escrow parameters

How It Works

1. Source Chain Deployment: The resolver deploys an escrow contract on the source chain and locks the maker's funds
2. Order Execution: Uses 1inch LOP to execute the swap order
3. Destination Chain Deployment: Deploys a corresponding escrow on the destination chain
4. Atomic Swap: The taker can withdraw funds by providing the secret hash
5. Safety Mechanisms: Includes timelocks and rescue functions for dispute resolution

Prerequisites

• Node.js >= 22
• Yarn or npm
• Tron private keys for mainnet and testnet

Installation

# Install dependencies
yarn install

Configuration

Environment Variables

Create a .env file in the root directory:

# Private keys for Tron networks
PRIVATE_KEY_TRON=0xYourTronPrivateKeyHere
PRIVATE_KEY_NILE=0xYourTronPrivateKeyHere

Network Configuration

The project supports:

• Tron Mainnet - Production network
• Tron Nile Testnet - Test network

Network configurations are defined in tronbox-config.js.

Usage

Compile Contracts

yarn run compile

Deploy Contracts

Tron Mainnet

yarn deploy:tron:main

Tron Nile Testnet

yarn deploy:tron:nile

Contract Functions

deploySrc

Deploys an escrow contract on the source chain and executes the swap order.

function deploySrc(
    IBaseEscrow.Immutables calldata immutables,
    IOrderMixin.Order calldata order,
    bytes32 r,
    bytes32 vs,
    uint256 amount,
    TakerTraits takerTraits,
    bytes calldata args
) external payable

deployDst

Deploys an escrow contract on the destination chain.

function deployDst(
    IBaseEscrow.Immutables calldata dstImmutables, 
    uint256 srcCancellationTimestamp
) external payable

withdraw

Withdraws funds from an escrow using the secret.

function withdraw(
    IEscrow escrow, 
    bytes32 secret, 
    IBaseEscrow.Immutables calldata immutables
) external

cancel

Cancels an escrow and returns funds to the original owner.

function cancel(
    IEscrow escrow, 
    IBaseEscrow.Immutables calldata immutables
) external

Security Features

• Ownable Pattern: Only the contract owner can deploy escrows and make arbitrary calls
• Timelocks: Built-in time constraints for withdrawal and cancellation periods
• Hash Verification: Secure secret-based withdrawal mechanism
• Rescue Functions: Emergency fund recovery mechanisms
• Atomic Operations: Ensures either both chains complete or both fail

Dependencies

Core Dependencies

• @1inch/cross-chain-sdk - Cross-chain functionality
• @1inch/solidity-utils - Utility libraries
• @openzeppelin/contracts - Security and access control
• ethers - Ethereum interaction

Development Dependencies

• tronbox - Tron blockchain development framework
• jest - Testing framework
• eslint - Code linting
• typescript - Type safety

Testing

# Run tests
yarn test

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new functionality
5. Submit a pull request

License

MIT License - see LICENSE file for details

Support

For security issues, contact: security@1inch.io

Disclaimer

This is an example implementation. Use at your own risk and ensure proper security audits before deploying to production.