Repay

Learn how to repay a debt on Morpho, onchain via a smart contract & offchain via ethers.js.

Repay the debt of anyone, offchain through Etherscan or with ethers.js, or onchain using a smart contract. Here are concrete examples 👇

Morpho AaveV2 Optimizer

Solidity

// SPDX-License-Identifier: GNU AGPLv3
pragma solidity ^0.8.16;

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

interface IWETH9 {
    function deposit() external payable;
}

contract MorphoAaveV2Repayer {
    address public constant WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address public constant AWETH = 0x030bA81f1c18d280636F32af80b9AAd02Cf0854e;

    address public constant DAI = 0x6B175474E89094C44Da98b954EedeAC495271d0F;
    address public constant ADAI = 0x028171bCA77440897B824Ca71D1c56caC55b68A3;

    address public constant MORPHO = 0x777777c9898D384F785Ee44Acfe945efDFf5f3E0;

    function _repayERC20(
        address _aToken,
        address _underlying,
        uint256 _amount
    ) internal {
        IERC20(_underlying).approve(MORPHO, _amount);
        IMorpho(MORPHO).repay(
            _aToken,
            address(this), // the address of the user you want to repay on behalf of
            _amount
        );
    }

    function repayDAI(uint256 _amount) public {
        _repayERC20(
            ADAI, // the DAI market, represented by the aDAI ERC20 token
            DAI,
            _amount
        );
    }

    function repayETH() public payable {
        // first wrap ETH into WETH
        IWETH9(WETH).deposit{value: msg.value}();

        _repayERC20(
            AWETH, // the WETH market, represented by the aWETH ERC20 token
            WETH,
            msg.value
        );
    }
}

ethers.js

import ethers from "ethers";

const signer = new ethers.Wallet(
  process.env.PRIVATE_KEY,
  new ethers.providers.JsonRpcBatchProvider(process.env.RPC_URL)
);

const signerAddress = await signer.getAddress();

const aWethAddress = "0x030bA81f1c18d280636F32af80b9AAd02Cf0854e";
const aDaiAddress = "0x028171bCA77440897B824Ca71D1c56caC55b68A3";

const daiDecimals = 18;

const weth = new ethers.Contract(
  "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
  [
    "function deposit() external payable",
    "function approve(address, uint256) external returns (bool)",
  ],
  signer
);

const dai = new ethers.Contract(
  "0x6B175474E89094C44Da98b954EedeAC495271d0F",
  ["function approve(address, uint256) external returns (bool)"],
  signer
);

const morpho = new ethers.Contract(
  "0x777777c9898d384f785ee44acfe945efdff5f3e0",
  ["function repay(address, address, uint256) external"],
  signer
);

async function repayERC20(aTokenAddress, underlying, amount) {
  await underlying.approve(morpho.address, amount);
  await morpho.repay(
    aTokenAddress,
    signerAddress, // the address of the user you want to supply on behalf of
    amount
  );
}

async function repayDAI(amount) {
  return repayERC20(
    aDaiAddress, // the DAI market, represented by the aDAI ERC20 token
    dai,
    amount
  );
}

async function repayETH(amount) {
  // first wrap ETH into WETH
  await weth.deposit({ value: amount });

  return repayERC20(
    aWethAddress, // the WETH market, represented by the cETH ERC20 token
    weth,
    amount
  );
}

// repayDAI(ethers.utils.parseUnits(100, 18)); // DAI has 18 decimals
// repayETH(ethers.utils.parseEther(1));

Morpho CompoundV2 Optimizer

Solidity

// SPDX-License-Identifier: GNU AGPLv3
pragma solidity ^0.8.16;

import {IMorpho} from "@morpho-org/morpho-core-v1/contracts/compound/interfaces/IMorpho.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IWETH9 {
    function deposit() external payable;
}

contract MorphoCompoundRepayer {
    address public constant WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address public constant CETH = 0x4Ddc2D193948926D02f9B1fE9e1daa0718270ED5;

    address public constant DAI = 0x6B175474E89094C44Da98b954EedeAC495271d0F;
    address public constant CDAI = 0x5d3a536E4D6DbD6114cc1Ead35777bAB948E3643;

    address public constant MORPHO = 0x8888882f8f843896699869179fB6E4f7e3B58888;

    function _repayERC20(
        address _cToken,
        address _underlying,
        uint256 _amount
    ) internal {
        IERC20(_underlying).approve(MORPHO, _amount);
        IMorpho(MORPHO).repay(
            _cToken,
            address(this), // the address of the user you want to repay on behalf of
            _amount
        );
    }

    function repayDAI(uint256 _amount) external {
        _repayERC20(
            CDAI, // the DAI market, represented by the cDAI ERC20 token
            DAI,
            _amount
        );
    }

    function repayETH() external payable {
        // first wrap ETH into WETH
        IWETH9(WETH).deposit{value: msg.value}();

        _repayERC20(
            CETH, // the WETH market, represented by the cETH ERC20 token
            WETH,
            msg.value
        );
    }
}

ethers.js

import ethers from "ethers";

const signer = new ethers.Wallet(
  process.env.PRIVATE_KEY,
  new ethers.providers.JsonRpcBatchProvider(process.env.RPC_URL)
);

const signerAddress = await signer.getAddress();

const cEthAddress = "0x4Ddc2D193948926D02f9B1fE9e1daa0718270ED5";
const cDaiAddress = "0x5d3a536E4D6DbD6114cc1Ead35777bAB948E3643";

const daiDecimals = 18;

const weth = new ethers.Contract(
  "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
  [
    "function deposit() external payable",
    "function approve(address, uint256) external returns (bool)",
  ],
  signer
);

const dai = new ethers.Contract(
  "0x6B175474E89094C44Da98b954EedeAC495271d0F",
  ["function approve(address, uint256) external returns (bool)"],
  signer
);

const morpho = new ethers.Contract(
  "0x8888882f8f843896699869179fB6E4f7e3B58888",
  ["function repay(address, address, uint256) external"],
  signer
);

async function repayERC20(cTokenAddress, underlying, amount) {
  await underlying.approve(morpho.address, amount);
  await morpho.repay(
    cTokenAddress,
    signerAddress, // the address of the user you want to supply on behalf of
    amount
  );
}

async function repayDAI(amount) {
  return repayERC20(
    cDaiAddress, // the DAI market, represented by the cDAI ERC20 token
    dai,
    amount
  );
}

async function repayETH(amount) {
  // first wrap ETH into WETH
  await weth.deposit({ value: amount });

  return repayERC20(
    cEthAddress, // the WETH market, represented by the cETH ERC20 token
    weth,
    amount
  );
}

// repayDAI(ethers.utils.parseUnits(100, 18)); // DAI has 18 decimals
// repayETH(ethers.utils.parseEther(1));