Lending Operations

Supply, withdraw, borrow, repay, quote fees, use ERC-4337, and read account data.

This guide walks through supply, withdraw, borrow, repay, quotes, ERC-4337 usage, and reading account data. It assumes an AaveProtocolEvm instance named aave and the USD₮ contract on Ethereum mainnet 0xdAC17F958D2ee523a2206206994597C13D831ec7.

Supply

You can deposit reserves into the pool using supply():

Supply USDT

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const tx = await aave.supply({ token: USDT, amount: 1000000n })
console.log('Supply tx hash:', tx.hash)

Withdraw

You can remove supplied liquidity using withdraw():

Withdraw USDT

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const tx = await aave.withdraw({ token: USDT, amount: 1000000n })
console.log('Withdraw tx hash:', tx.hash)

Borrow

You can draw debt against your collateral using borrow():

Borrow USDT

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const tx = await aave.borrow({ token: USDT, amount: 1000000n })
console.log('Borrow tx hash:', tx.hash)

Repay

You can pay down debt using repay():

Repay USDT

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const tx = await aave.repay({ token: USDT, amount: 1000000n })
console.log('Repay tx hash:', tx.hash)

Quotes before sending

You can estimate the supply fee with quoteSupply():

Quote supply fee

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const supplyQuote = await aave.quoteSupply({ token: USDT, amount: 1000000n })
console.log('Supply fee (wei):', supplyQuote.fee)

You can estimate the withdraw fee with quoteWithdraw():

Quote withdraw fee

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const withdrawQuote = await aave.quoteWithdraw({ token: USDT, amount: 1000000n })
console.log('Withdraw fee (wei):', withdrawQuote.fee)

You can estimate the borrow fee with quoteBorrow():

Quote borrow fee

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const borrowQuote = await aave.quoteBorrow({ token: USDT, amount: 1000000n })
console.log('Borrow fee (wei):', borrowQuote.fee)

You can estimate the repay fee with quoteRepay():

Quote repay fee

const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7'

const repayQuote = await aave.quoteRepay({ token: USDT, amount: 1000000n })
console.log('Repay fee (wei):', repayQuote.fee)

Health factor and collateralization limits still apply. A quote does not guarantee the transaction will succeed if on-chain state changes.

ERC-4337 smart accounts

You can run the same methods through WalletAccountEvmErc4337 and pass a second config argument to override per-call gas payment settings. In v1.0.0-beta.4, the lending methods accept the same override families as the wallet module: paymaster token, sponsorship policy, and native coins. See the ERC-4337 config override section for the full field list.

Supply with paymaster

import { WalletAccountEvmErc4337 } from '@tetherto/wdk-wallet-evm-erc-4337'
import AaveProtocolEvm from '@tetherto/wdk-protocol-lending-aave-evm'

const aa = new WalletAccountEvmErc4337(seedPhrase, "0'/0/0", {
  chainId: 42161,
  provider: 'https://arb1.arbitrum.io/rpc',
  bundlerUrl: process.env.BUNDLER_URL,
  paymasterUrl: process.env.PAYMASTER_URL
})

const aaveAA = new AaveProtocolEvm(aa)

const result = await aaveAA.supply(
  { token: '0xdAC17F958D2ee523a2206206994597C13D831ec7', amount: 1000000n },
  {
    paymasterToken: {
      address: '0xdAC17F958D2ee523a2206206994597C13D831ec7'
    }
  }
)
console.log('Supply hash:', result.hash)

You can use the same second argument to:

override paymaster-token mode with paymasterUrl, paymasterAddress, paymasterToken, or transferMaxFee
switch one call to sponsorship mode with isSponsored, paymasterUrl, and sponsorshipPolicyId
switch one call to native-coin gas mode with useNativeCoins and transferMaxFee

Use token addresses that exist on the same chain as the smart account RPC.

Reading account data

You can inspect collateral, debt, and health using getAccountData():

Read Aave account data

const data = await aave.getAccountData()

console.log({
  totalCollateralBase: data.totalCollateralBase,
  totalDebtBase: data.totalDebtBase,
  availableBorrowsBase: data.availableBorrowsBase,
  currentLiquidationThreshold: data.currentLiquidationThreshold,
  ltv: data.ltv,
  healthFactor: data.healthFactor
})