🏦Core Markets

The ChainlinkOEVWrapper is used for liquidations in Moonwell's Core lending markets (mToken markets). The liquidator transfers loan tokens to the wrapper, which unlocks the fresh price, executes the liquidation, and splits the seized collateral (mTokens) between the liquidator and the protocol.

Function Signature

function updatePriceEarlyAndLiquidate(
    address borrower,
    uint256 repayAmount,
    address mTokenCollateral,
    address mTokenLoan
) external nonReentrant

Parameter	Type	Description
borrower	address	The underwater borrower to liquidate
repayAmount	uint256	Amount of loan tokens to repay
mTokenCollateral	address	The mToken market for collateral being seized
mTokenLoan	address	The mToken market for the loan being repaid

The OEV wrapper must be registered as the Chainlink feed for the underlying collateral token in Moonwell's ChainlinkOracle. The contract derives the underlying token via MErc20Storage(mTokenCollateral).underlying() and verifies chainlinkOracle.getFeed(underlyingCollateral.symbol()) == address(this). Use the correct wrapper for each collateral asset.

Liquidation Flow

┌─────────────────┐     ┌──────────────────────┐     ┌─────────────────┐
│   Liquidator    │────▶│  ChainlinkOEVWrapper │────▶│  Moonwell Pool  │
│                 │     │                      │     │   (Comptroller) │
└─────────────────┘     └──────────────────────┘     └─────────────────┘
        │                        │                           │
        │  1. Transfer loan      │                           │
        │     tokens             │                           │
        │───────────────────────▶│                           │
        │                        │  2. Update cachedRoundId  │
        │                        │     (unlock fresh price)  │
        │                        │                           │
        │                        │  3. Execute liquidation   │
        │                        │─────────────────────────▶│
        │                        │                           │
        │                        │  4. Receive mToken        │
        │                        │     collateral            │
        │                        │◀─────────────────────────│
        │                        │                           │
        │  5. Receive mToken     │  6. Send protocol fee    │
        │     (repay + bonus)    │     to feeRecipient      │
        │◀───────────────────────│                           │

Collateral Distribution

After liquidation, the seized mTokens are split:

• Liquidator receives: Repayment value + (Profit × liquidatorFeeBps / 10000)

• Protocol receives: Remaining profit (Profit × (10000 − liquidatorFeeBps) / 10000)

Example with liquidatorFeeBps = 4000 (40%):

	Amount
Repayment	1,000 USDC
Collateral seized (10% incentive)	1,100 USDC
Gross profit	100 USDC
Liquidator bonus (40%)	40 USDC
Liquidator total	1,040 USDC worth of mTokens
Protocol total	60 USDC worth of mTokens

Solidity Example

// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IChainlinkOEVWrapper {
    function updatePriceEarlyAndLiquidate(
        address borrower,
        uint256 repayAmount,
        address mTokenCollateral,
        address mTokenLoan
    ) external;
}

contract OEVLiquidator {
    IChainlinkOEVWrapper public oevWrapper;

    constructor(address _oevWrapper) {
        oevWrapper = IChainlinkOEVWrapper(_oevWrapper);
    }

    function liquidate(
        address borrower,
        uint256 repayAmount,
        address mTokenCollateral,
        address mTokenLoan,
        address loanToken
    ) external {
        // 1. Transfer loan tokens from caller
        IERC20(loanToken).transferFrom(msg.sender, address(this), repayAmount);

        // 2. Approve OEV wrapper to spend loan tokens
        IERC20(loanToken).approve(address(oevWrapper), repayAmount);

        // 3. Execute liquidation with early price access
        oevWrapper.updatePriceEarlyAndLiquidate(
            borrower,
            repayAmount,
            mTokenCollateral,
            mTokenLoan
        );

        // 4. mToken collateral is now in this contract
        // Transfer to caller or redeem for underlying
    }
}

Revert Conditions

The following conditions will cause updatePriceEarlyAndLiquidate to revert:

Condition	Error Message
repayAmount == 0	"ChainlinkOEVWrapper: repay amount cannot be zero"
borrower == address(0)	"ChainlinkOEVWrapper: borrower cannot be zero address"
mTokenCollateral == address(0)	"ChainlinkOEVWrapper: mToken collateral cannot be zero address"
mTokenLoan == address(0)	"ChainlinkOEVWrapper: mToken loan cannot be zero address"
Wrong wrapper for collateral	"ChainlinkOEVWrapper: chainlink oracle feed does not match"
Chainlink price ≤ 0	"Chainlink price cannot be lower or equal to 0"
Incomplete round	"Round is in incompleted state"
Stale Chainlink data	"Stale price"
No collateral seized	"ChainlinkOEVWrapper: collateral seized cannot be zero"
Liquidation failed	"ChainlinkOEVWrapper: liquidation failed"

Events

Event	Parameters
PriceUpdatedEarlyAndLiquidated	address indexed borrower, uint256 repayAmount, address mTokenCollateral, address mTokenLoan, uint256 protocolFee, uint256 liquidatorFee
FeeRecipientChanged	address oldFeeRecipient, address newFeeRecipient
LiquidatorFeeBpsChanged	uint16 oldLiquidatorFeeBps, uint16 newLiquidatorFeeBps
MaxRoundDelayChanged	uint256 oldMaxRoundDelay, uint256 newMaxRoundDelay
MaxDecrementsChanged	uint256 oldMaxDecrements, uint256 newMaxDecrements

Deployed Contracts

Base - ChainlinkOEVWrapper

Asset	Address
WETH	0xeb083d234ec636A10325ea42bCbbE09Aa56d1547

WETH Core Market Addresses (Base)

Contract	Address
WETH	0x4200000000000000000000000000000000000006
Moonwell WETH (mToken)	0x628ff693426583D9a7FB391E54366292F509D457

OP Mainnet - ChainlinkOEVWrapper

Asset	Address
WETH	0x531f69127bB04Ebb0Fd321b8092d34a4C2B4E0f1

WETH Core Market Addresses (OP Mainnet)

Contract	Address
WETH	0x4200000000000000000000000000000000000006
Moonwell WETH (mToken)	0xb4104C02BBf4E9be85AAa41a62974E4e28D59A33