Integrate WOOFi as a liquidity source on EVM

Contracts

There are two main contracts of WOOFi's Swap:

• WooRouterV2.sol: the router contract that frontend users interact with. It interacts with the lower layer WooPPV2.sol to execute the sell logic and send back users the desired amount of tokens. This contract also implements the logic to route user orders to 3rd party aggregator (e.g. 1inch) when WooPPV2.sol does not have sufficient liquidity.

• WooPPV2.sol: the main swap contract that handles the logic operation, including setting the token info, calculating slippage, calculating the exchange amount and executing trades. it stores all tokens that are supported for trading. In this contract, it defines quote token and base token. Quote token is the reference token (i.e. stablecoins) in the contract and there is only one quote token. The contract can have multiple base tokens and they can be added by the strategist.

Supported assets

Adding IntegrationHelper.sol

WooPPV2.sol has one quote token which is typically the dominant stablecoin of each chain and multiple base tokens. A IntegrationHelper.sol contract is deployed on each supported chain which contains the address of the quote token and the list of tradable base token addresses in WooPPV2.sol.

The latest list of supported tokens can be retrieved via the getSupportTokens() function which will return two values:

• first value: quoteToken address

• second value: array of baseToken addresses

Contract addresses:

Arbitrum: 0x28D2B949024FE50627f1EbC5f0Ca3Ca721148E40

Avalanche: 0x020630613E296c3E9b06186f630D1bF97A2B6Ad1

BSC: 0xAA9c15cd603428cA8ddD45e933F8EfE3Afbcc173

Optimism - 0x96329d66074EB8386Ae8bFD6698B2E3FDA87e15E

Polygon POS - 0x7Ba560eB735AbDCf9a3a5692272652A0cc81850d

zkSync Era - 0x636DfeB023463F176f87D61E3B604231986bd935

Linea - 0x7e1996945eA8866DE873179DC1677E93A4380107

Base - 0xC4E9B633685461E7B7A807D12a246C81f96F31B8

Mantle - 0x86b223E83D2FA43456b433687c8F47A35a9bE24C

Sonic - 0xc8521e41DE46036A61c562062862681f0060CD7E

Berachain - 0x14B435b68e031226ACc4d328a69e294686C3176e

HyperEVM - 0xee8318e9d597bf9df6148e86d4e35a8bc14eea88

Monad - 0xAeE024fAA57C4DB20ac0666a1D5297d5F1c95AfE

Integrate WOOFi as a liquidity source

When integrating WOOFi as a liquidity source, you can either interact with WooRouterV2.sol or WooPPV2.sol.

Integrating WooRouterV2.sol

The straightforward way is interacting with WooRouterV2.sol contract which provides the query and swap for any two specified tokens. It streamlined the logic of swapping native blockchain assets and swapping between any of the two supported assets, which simplifies the integration for apps that do not have an existing aggregation logic.

Contract addresses:

• Same address across Arbitrum, Avalanche, BSC, Optimism, Polygon PoS, Linea, Base, Mantle, Sonic: 0x4c4AF8DBc524681930a27b2F1Af5bcC8062E6fB7

• zkSync: 0x09873bfECA34F1Acd0a7e55cDA591f05d8a75369

Interface

    /// @dev query the amount to swap fromToken -> toToken
    /// @param fromToken the from token
    /// @param toToken the to token
    /// @param fromAmount the amount of fromToken to swap
    /// @return toAmount the predicted amount to receive
    function querySwap(
        address fromToken,
        address toToken,
        uint256 fromAmount
    ) external view returns (uint256 toAmount);
    
    /// @dev query the amount to swap fromToken -> toToken,
    ///      WITHOUT checking the reserve balance; so it
    ///      always returns the quoted amount (for reference).
    /// @param fromToken the from token
    /// @param toToken the to token
    /// @param fromAmount the amount of fromToken to swap
    /// @return toAmount the predicted amount to receive
    function tryQuerySwap(
        address fromToken,
        address toToken,
        uint256 fromAmount
    ) external view returns (uint256 toAmount);
    
    /// @notice Swap `fromToken` to `toToken`.
    /// @param fromToken the from token
    /// @param toToken the to token
    /// @param fromAmount the amount of `fromToken` to swap
    /// @param minToAmount the minimum amount of `toToken` to receive
    /// @param to the destination address
    /// @param rebateTo the rebate address (optional, can be 0)
    /// @return realToAmount the amount of toToken to receive
    function swap(
        address fromToken,
        address toToken,
        uint256 fromAmount,
        uint256 minToAmount,
        address payable to,
        address rebateTo
    ) external payable returns (uint256 realToAmount);

Sample code

// Query Part
address fromToken = 0x2f2a2543B76A4166549F7aaB2e75Bef0aefC5B0f;  // wbtc
address toToken = 0xFF970A61A04b1cA14834A43f5dE4533eBDDB5CC8;    // usdc
uint256 amount1 = wooRouter.querySwap(
  fromToken, 
  toToken,
  100000000  // 1 wbtc amount in decimal 8
)

uint256 amount2 = wooRouter.tryQuerySwap(
  fromToken,
  toToken,
  100000000); // 1 wbtc amount in decimal 8

// NOTE: when the balance reserve is enough for swap, amount1 = amount2;
// otherwise, amount2 is still calculated based on wooracle price and woo market-making
// formula, but the amount1 qeury simply failed with insufficient balance error.


// Swap Part
uint256 amountIn = 100000000;
IERC20(fromToken).safeApprove(address(wooRouter), amountIn);
uint256 realToAmount = wooRouter.swap(
  fromToken,      // wbtc token address
  toToken,        // usdc token address
  amountIn,       // wbtc amount to swap in decimal 8
  19000000000,    // min amount = 19000 usdc (price: 19500)
  address(this),  // the address to receive the swap fund
  address(0)      // the rebateTo address
); 

Integrating WooPPV2.sol

Another way is to integrate directly with WooPPV2.sol. This approach is slightly more gas efficient, but it requires writing the smart contract code and manually send the fromToken to WooPPV2.sol, which a better choice for apps that already have an aggregation logic.

Contract addresses:

• Same address across Arbitrum, Avalanche, BSC, Optimism, Polygon PoS, Linea, Base, Mantle, Sonic: 0x5520385bFcf07Ec87C4c53A7d8d65595Dff69FA4

• zkSync Era: 0xE656d70bc3550e3EEE9dE7dC79367A44Fd13d975

Interface

    /// @notice The quote token address (immutable).
    /// @return address of quote token
    function quoteToken() external view returns (address);

    /// @notice Gets the pool size of the specified token (swap liquidity).
    /// @param token the token address
    /// @return the pool size
    function poolSize(address token) external view returns (uint256);

    /// @notice Query the amount to swap `fromToken` to `toToken`, without checking the pool reserve balance.
    /// @param fromToken the from token
    /// @param toToken the to token
    /// @param fromAmount the amount of `fromToken` to swap
    /// @return toAmount the swapped amount of `toToken`
    function tryQuery(
        address fromToken,
        address toToken,
        uint256 fromAmount
    ) external view returns (uint256 toAmount);

    /// @notice Query the amount to swap `fromToken` to `toToken`, with checking the pool reserve balance.
    /// @dev tx reverts when 'toToken' balance is insufficient.
    /// @param fromToken the from token
    /// @param toToken the to token
    /// @param fromAmount the amount of `fromToken` to swap
    /// @return toAmount the swapped amount of `toToken`
    function query(
        address fromToken,
        address toToken,
        uint256 fromAmount
    ) external view returns (uint256 toAmount);

    /// @notice Swap `fromToken` to `toToken`.
    /// @param fromToken the from token
    /// @param toToken the to token
    /// @param fromAmount the amount of `fromToken` to swap
    /// @param minToAmount the minimum amount of `toToken` to receive
    /// @param to the destination address
    /// @param rebateTo the rebate address (optional, can be address ZERO)
    /// @return realToAmount the amount of toToken to receive
    function swap(
        address fromToken,
        address toToken,
        uint256 fromAmount,
        uint256 minToAmount,
        address to,
        address rebateTo
    ) external returns (uint256 realToAmount);

Sample code

    IWooPPV2 public wooPool; // IWooPPV2 smart contrac
    
    function sampleFunc(...) external {
        ... your business code ..

        // query the trade
        address fromToken = WBTC_ADDR;
        address toToken = USDT_ADDR;
        uint256 amountIn = 10000000; // 0.1 btc
        
        uint256 amountOut = wooPool.query(fromToken, toToken, amountIn);
        // or wooPool.tryQuery if you don't need the swap.
 
        // swap
        IERC20(toToken).safeTransfer(address(wooPool), amountIn);
        uint256 realToAmount = wooPool.swap(
            fromToken,
            toToken,
            amountIn,
            amountOut * 99 / 100, 
            address(this),
            address(0)
        );
        
        ... other business code to deal with `toToken` ...
    }
    

Price check with Wooracle

WOOFi's oracle has a few price checks implemented. You can find the addresses of the wooracle contract in On-chain price feeds.

• checking against the 3rd party oracle price e.g. ChainLink and Pyth

• set the price range a swap can be executed against the current price