Flash Loan Tutorial

Create an Aave Flash Loan arbitrage smart contract demonstrating both v2 and v3 versions.

Aave v2 Flash Loan Information:

https://aave.com/docs/resources/addresses

Because of the deprecation of Mumbai and Fuji we fork mainnet to test out V2

DAI Forked Mainnet ERC20

(Fund Account for Forked Tenderly Interface):

• 0x6B175474E89094C44Da98b954EedeAC495271d0F

USDC Testnet ERC20

(Fund Account for Forked Tenderly Interface):

• 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48

AAVE PoolAddressProvider

(Forked Mainnet):

• 0xB53C1a33016B2DC2fF3653530bfF1848a515c8c5

The Dex will alway have a profit in the swap when you swap USDC to DAI (10%) so when you do the flashloan the trade will always be beneficial and will have extra USDC to pay the Aave flashloan fee when the transation is completed.

Suggested liquidity to add to Dex.sol:

• USDC 10000
• DAI 10000

Approve:

• USDC 1000000000
• DAI 1000000000000000000000

Note!:

• When swapping USDC, your contract will try to sell the profited DAI which will be a higher amount. You must check how much the profit will be to know how much to approve to swap the DAI back to the USDC. There is a function previewDAISwap that will let you preview the swap amount so you know the amount to approve for the flashloan contract for the dex.

Request Loan - USDC (6 decimal):

0xA2025B15a1757311bfD68cb14eaeFCc237AF5b43,1000000000 // 1,000 USDC 0xA2025B15a1757311bfD68cb14eaeFCc237AF5b43,1000000 // 1 USDC

FlashLoan test Only Steps

Testing just flashloan.sol contract

• Step 1. Deploy your flashloan contract
• Step 2. Fund you flashloan contract with some USDC (need to pay back the Flashloan fee)
• Step 3. Request a loan for any amount of USDC (start with a 1 dollar to make sure it works)

Steps to perform Arbitrage

• Step 1. Deploy your dex
• Step 2. Make sure to add liquidity to your dex (DAI and USDC)
• Step 3. Deploy your flashloan contract
• Step 3. Make sure approvals are set on Flashloan contract
• Step 4. Request a loan for any amount of USDC (not more than your liquidity)
• Step 5. See the results

Aave v3 Flash Loan Information:

https://aave.com/docs/developers/flash-loans https://aave.com/docs/resources/addresses

You can mint tokens from Aave via sepolia testnet https://app.aave.com/faucet/

DAI (ETH Forked Mainnet):

0x6B175474E89094C44Da98b954EedeAC495271d0F

USDC (ETH Forked Mainnet):

0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48

AAVE PoolAddressProvider (Forked Mainnet)

0x2f39d218133AFaB8F2B819B1066c7E434Ad94E9e

Sample Dex.sol deployed (ETH Sepolia Testnet):

Suggested liquidity to add to Dex.sol:

USDC 1500 DAI 1500

Approve:

USDC 1000000000 DAI 1200000000000000000000

Request Loan - USDC (6 decimal):

0xA2025B15a1757311bfD68cb14eaeFCc237AF5b43,1000000000 // 1,000 USDC 0xA2025B15a1757311bfD68cb14eaeFCc237AF5b43,1000000 // 1 USDC

Forked from the work of:

https://github.com/jspruance/aave-flash-loan-tutorial