Cross-Chain Swap Optimization Hook for Uniswap V4

This is a Uniswap V4 hook implementation that optimizes swaps across multiple blockchains, automatically routing users to the most profitable execution venue.

Project Structure

src/
├── CrossChainSwapHook.sol          # Main contract
├── interfaces/
│   ├── IPythOracle.sol            # Pyth oracle interface
│   └── IBridgeProtocol.sol        # Bridge protocol interface
└── libraries/
    ├── PriceCalculator.sol        # Price calculation utilities
    └── VenueComparator.sol        # Venue comparison logic

Contracts Overview

CrossChainSwapHook.sol

The main Uniswap V4 hook contract that handles cross-chain swap optimization. It inherits from Uniswap V4's BaseHook and OpenZeppelin's Ownable, ReentrancyGuard, and Pausable.

Hook Implementation:

• Implements beforeSwap and afterSwap hooks from Uniswap V4
• Automatically analyzes cross-chain opportunities before each swap
• Routes users to the most profitable execution venue

Key State Variables:

• pythOracle: IPythOracle instance for price feeds
• bridgeProtocol: IBridgeProtocol instance for cross-chain operations
• venues[]: Array of configured execution venues
• tokenPriceData[]: Mapping of tokens to their price feed configurations
• maxSlippageBps: Maximum allowed slippage (default: 300 = 3%)
• protocolFeeBps: Protocol fee in basis points (default: 10 = 0.1%)
• crossChainThresholdBps: Minimum improvement threshold for cross-chain (default: 200 = 2%)

Hook Functions:

• _beforeSwap(): Analyzes cross-chain opportunities and executes if profitable
• _afterSwap(): Handles post-swap logic and emits events
• getHookPermissions(): Returns hook permissions for V4 validation

Admin Functions:

• addVenue(): Adds new execution venue
• configurePriceData(): Configures token price feeds
• simulateSwap(): Returns quotes without executing

Structs:

struct CrossChainSwapData {
    uint256 minAmountOut;
    address recipient;
    uint256 deadline;
    bytes32 tokenInPriceId;
    bytes32 tokenOutPriceId;
    uint256 maxGasPrice;
    bool forceLocal;
    uint256 thresholdBps; // Minimum improvement threshold in basis points
}

struct SwapVenue {
    uint256 chainId;
    address venueAddress;
    string name;
    bool isActive;
    uint256 baseGasEstimate;
    uint256 lastUpdateTime;
    uint8 reliabilityScore;
}

struct ExecutionQuote {
    uint256 outputAmount;
    uint256 totalCost;
    uint256 netOutput;
    uint256 venueIndex;
    uint256 executionTime;
    bool requiresBridge;
    bytes bridgeData;
    uint8 confidenceScore;
}

IPythOracle.sol

Interface for Pyth Network price oracles.

Key Functions:

• getPrice(bytes32 id): Returns current price for a price ID
• updatePriceFeeds(bytes[] calldata updateData): Updates price feeds
• getUpdateFee(bytes[] calldata updateData): Gets required fee for updates

Structs:

struct Price {
    int64 price;
    uint64 conf;
    int32 expo;
    uint publishTime;
}

IBridgeProtocol.sol

Interface for cross-chain bridge protocols.

Key Functions:

• getQuote(address tokenIn, address tokenOut, uint256 amountIn, uint256 destinationChainId): Gets bridge quote
• bridge(address tokenIn, uint256 amountIn, uint256 destinationChainId, address recipient, bytes calldata bridgeData): Executes bridge

Structs:

struct BridgeQuote {
    uint256 outputAmount;
    uint256 bridgeFee;
    uint256 estimatedTime;
    bytes bridgeData;
    uint256 destinationChainId;
    uint256 minAmount;
    uint256 maxAmount;
    uint256 validUntil;
}

PriceCalculator.sol

Library for price calculations using Pyth oracle data.

Key Functions:

• calculateOutputAmount(Price memory priceIn, Price memory priceOut, uint256 amountIn): Calculates output amount
• calculateOutputAmountWithConfidence(...): Calculates with confidence scoring
• applySlippage(uint256 outputAmount, uint256 slippageBps): Applies slippage protection
• calculatePriceImpact(uint256 basePrice, uint256 tradeSize, uint256 liquidityDepth): Calculates price impact

Constants:

• MAX_PRICE_STALENESS = 600: Maximum price staleness (10 minutes)
• MIN_CONFIDENCE_SCORE = 20: Minimum confidence score
• PRICE_PRECISION = 1e18: Price precision for calculations

VenueComparator.sol

Library for comparing and ranking execution venues.

Key Functions:

• calculateVenueScore(ComparisonData memory data, ScoringWeights memory weights, ComparisonData memory referenceData): Calculates venue score
• compareVenues(ComparisonData memory venue1, ComparisonData memory venue2, ScoringWeights memory weights, ComparisonData memory referenceData): Compares two venues
• rankVenues(ComparisonData[] memory venues, ScoringWeights memory weights, ComparisonData memory referenceData): Ranks all venues

Scoring Weights:

struct ScoringWeights {
    uint8 outputWeight;        // 35% - Net output amount
    uint8 costWeight;          // 20% - Execution costs
    uint8 timeWeight;          // 15% - Execution speed
    uint8 reliabilityWeight;   // 10% - Venue reliability
    uint8 confidenceWeight;    // 10% - Price confidence
    uint8 liquidityWeight;     // 5% - Available liquidity
    uint8 performanceWeight;   // 5% - Historical performance
}

Usage Example

// Deploy the hook contract
CrossChainSwapHook hook = new CrossChainSwapHook(
    poolManagerAddress,
    pythOracleAddress,
    bridgeProtocolAddress,
    feeRecipientAddress
);

// Add execution venues
hook.addVenue(137, polygonVenueAddress, "Polygon Uniswap", 200000);
hook.addVenue(42161, arbitrumVenueAddress, "Arbitrum Uniswap", 150000);

// Configure price feeds
hook.configurePriceData(WETH, ETH_PRICE_ID, 600);
hook.configurePriceData(USDC, USDC_PRICE_ID, 300);

// Create a Uniswap V4 pool with the hook
PoolKey memory poolKey = PoolKey({
    currency0: Currency.wrap(WETH),
    currency1: Currency.wrap(USDC),
    fee: 3000,
    tickSpacing: 60,
    hooks: IHooks(address(hook))
});

poolManager.initialize(poolKey, sqrtPriceX96);

// Users can now swap through the pool, and the hook will automatically
// analyze cross-chain opportunities and route to the best venue

Events

The contract emits several events for monitoring:

• CrossChainSwapExecuted: When a cross-chain swap is executed
• LocalSwapOptimized: When local execution is chosen
• VenueConfigured: When venues are added or updated
• PriceOracleUpdated: When oracle is changed
• BridgeProtocolUpdated: When bridge protocol is changed
• SwapParametersUpdated: When parameters are updated
• EmergencyWithdraw: When emergency withdrawal occurs

Admin Functions

Owner-only functions for configuration:

• addVenue(): Add new execution venue
• updateVenueStatus(): Enable/disable venues
• configurePriceData(): Configure token price feeds
• updatePythOracle(): Change oracle address
• updateBridgeProtocol(): Change bridge protocol
• updateSwapParameters(): Update slippage and limits
• updateFeeParameters(): Update fee settings
• pause()/unpause(): Emergency pause functionality
• emergencyWithdraw(): Recover stuck tokens

Security Features

• ReentrancyGuard: Prevents reentrancy attacks
• Pausable: Emergency pause functionality
• Ownable2Step: Two-step ownership transfer
• Slippage Protection: Configurable slippage limits
• Price Validation: Staleness and confidence checks
• Bridge Validation: Quote validation before execution

Development

Setup

# Install dependencies
forge install

# Build contracts
forge build

# Run tests
forge test

# Run tests with verbose output
forge test -vvv

Testing

The project includes basic tests in test/Counter.t.sol. Additional tests should be added for the main contract functionality.

Deployment

# Set environment variables
export PRIVATE_KEY="your_private_key"
export POOL_MANAGER="0x..."
export PYTH_ORACLE="0x..."
export BRIDGE_PROTOCOL="0x..."
export FEE_RECIPIENT="0x..."

# Deploy the hook
forge script script/DeployCrossChainHook.s.sol --rpc-url <RPC_URL> --broadcast

# Verify on block explorer
forge verify-contract <CONTRACT_ADDRESS> src/CrossChainSwapHook.sol:CrossChainSwapHook --chain-id <CHAIN_ID>

Dependencies

• Uniswap V4 Core (v4-core)
• Uniswap V4 Periphery (v4-periphery)
• OpenZeppelin Contracts v5.4.0
• Foundry (forge, cast, anvil)
• Solidity ^0.8.24

License

MIT