# YearnMaticUSDCStakingStrategy ## Overview The YearnMaticUSDCStakingStrategy contract is a strategy that supplies USDC into a Yearn V3 Vault and stakes the vault shares to earn additional WMATIC rewards. It manages reward claiming and conversion through Uniswap V3. ## Constants ```solidity address public constant wpol = WPOL_POLYGON; // WMATIC token address IRouter public constant router = IRouter(UNISWAP_V3_ROUTER_POLYGON); // Uniswap V3 router IStakingRewardsMulti public constant yearnStakingRewards = // Yearn staking rewards IStakingRewardsMulti(0x602920E7e0a335137E02DF139CdF8D1381DAdBfD); ``` ## State Variables ```solidity uint256 public minSwapMatic; // Minimum amount of WMATIC to swap ``` ## Functions ### Initialization Functions #### constructor ```solidity constructor() initializer ``` Empty constructor marked as initializer. #### initialize ```solidity function initialize( IMaxApyVault _vault, address[] calldata _keepers, bytes32 _strategyName, address _strategist, IYVaultV3 _yVault ) public override initializer ``` Initializes the strategy with required components. Parameters: * `_vault`: MaxApy vault address * `_keepers`: Array of keeper addresses * `_strategyName`: Name of the strategy * `_strategist`: Strategist address * `_yVault`: Yearn V3 vault address ### Core Functions #### liquidateExact ```solidity function liquidateExact(uint256 amountNeeded) external override checkRoles(VAULT_ROLE) returns (uint256 loss) ``` Withdraws exact amount and re-stakes remaining shares. Parameters: * `amountNeeded`: Amount to withdraw Returns: * `loss`: Amount of realized loss ### Internal Core Functions #### \_beforePrepareReturn ```solidity function _beforePrepareReturn() internal override ``` Claims and processes staking rewards before preparing return. #### \_adjustPosition ```solidity function _adjustPosition(uint256, uint256 minOutputAfterInvestment) internal override ``` Adjusts strategy positions based on available capital. Parameters: * `minOutputAfterInvestment`: Minimum expected output #### \_invest ```solidity function _invest(uint256 amount, uint256 minOutputAfterInvestment) internal override returns (uint256 depositedAmount) ``` Invests assets and stakes received shares. Parameters: * `amount`: Amount to invest * `minOutputAfterInvestment`: Minimum expected shares Returns: * `depositedAmount`: Amount of tokens received #### \_divest ```solidity function _divest(uint256 shares) internal override returns (uint256 withdrawn) ``` Withdraws assets from staking and vault. Parameters: * `shares`: Amount of shares to withdraw Returns: * `withdrawn`: Amount of assets received #### \_liquidatePosition ```solidity function _liquidatePosition(uint256 amountNeeded) internal override returns (uint256 liquidatedAmount, uint256 loss) ``` Liquidates position up to requested amount. Parameters: * `amountNeeded`: Amount to liquidate Returns: * `liquidatedAmount`: Amount actually liquidated * `loss`: Amount of losses incurred #### \_unwindRewards ```solidity function _unwindRewards(IStakingRewardsMulti _yearnStakingRewards) internal ``` Claims WMATIC rewards and converts to USDC. Parameters: * `_yearnStakingRewards`: Staking rewards contract ### Internal View Functions #### \_wpolBalance ```solidity function _wpolBalance() internal view returns (uint256) ``` Returns strategy's WMATIC balance. Returns: * Current WMATIC balance #### \_shareBalance ```solidity function _shareBalance() internal view override returns (uint256 _balance) ``` Returns strategy's staked vault share balance. Returns: * Current staked share balance --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://devs.maxapy.io/maxapy-erc4626/strategies/polygon-usdc.e/yearn/yearnmaticusdcstakingstrategy.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.