OpenMevRouter

Optimal MEV router contract (IUniswapV2Router compatible)

For the User it aims to offer:

1. Better order routing for minimal slippage
2. At source MEV
3. Lower gas costs for swaps and liquidity changes

For the Liquidity providers:

1. Inclusive rewards
2. Reduced impermanent loss

For the Exchange providers:

1. Inclusive rewards
2. Increased adoption

For the Ethereum environment:

1. Reduced MEV attacks and fee spikes
2. Healthy growth in MEV space with inclusive incentives

Version 1 MEV Strategies

• cross-dex backruns for swaps
• reduced slippage fallback router The contract leverages and depends on 3 external protocols:

1. Uniswap V2 (or equivalent on another network) for backrun completion and fallback swaps
2. BentoBox for flashloan backruns
3. Aave V2 for flashloan backruns that require more liquidity than BentoBox has

Business logic

• Profits from backruns are retained on the contract to improve efficiency (gas cost and profit) of future backruns The contract should therefore be deployed or ownership transferred to a multisig address
• Harvest function can be called from the multisig owners to distribute profits by consensus

Dev Notes

• Normal sushiswap router functions. Swaps have 2 material changes:
  1. slippage fallback router (uniswap v2)
  2. backruns after user swap
• For gas and size efficiency, requirements are modified to revert with custom errors
• Factory hash is now passed to library functions because we are working with 2 factories
• Other changes are trade-offs for reducing contract size and / or gas usage and stack too deep errors

Methods

Returns

Name	Type	Description
_0	address	undefined

acceptOwnership

acceptOwnership

function acceptOwnership() external nonpayable

acceptOwnership

Details Transfers ownership of the contract to the caller. Can only be called by a new potential owner set by the current owner.

addLiquidity

Adds liquidity to an ERC-20⇄ERC-20 pool. msg.sender should have already given the router an allowance of at least amountADesired/amountBDesired on tokenA/tokenB

addLiquidity

function addLiquidity(address tokenA, address tokenB, uint256 amountADesired, uint256 amountBDesired, uint256 amountAMin, uint256 amountBMin, address to, uint256 deadline) external nonpayable returns (uint256 amountA, uint256 amountB, uint256 liquidity)

Parameters

Name	Type	Description
tokenA	address	Token in pool
tokenB	address	Token in pool
amountADesired	uint256	Amount of token A desired to add to pool
amountBDesired	uint256	Amount of token B desired to add to pool
amountAMin	uint256	Minimum amount of token A, can be 0
amountBMin	uint256	Minimum amount of token B, can be 0
to	address	Address to receive liquidity token
deadline	uint256	Unix timestamp in seconds after which the transaction will revert

Returns

Name	Type	Description
amountA	uint256	exact amount of token A added to pool
amountB	uint256	exact amount of token B added to pool
liquidity	uint256	amount of liquidity token received

addLiquidityETH

Adds liquidity to an ERC-20⇄WETH pool with ETH. msg.sender should have already given the router an allowance of at least amountTokenDesired on token. msg.value is treated as a amountETHDesired. Leftover ETH, if any, is returned to msg.sender

Solidity

function addLiquidityETH(address token, uint256 amountTokenDesired, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline) external payable returns (uint256 amountToken, uint256 amountETH, uint256 liquidity)

Parameters

Name	Type	Description
token	address	Token in pool
amountTokenDesired	uint256	Amount of token desired to add to pool
amountTokenMin	uint256	Minimum amount of token, can be 0
amountETHMin	uint256	Minimum amount of ETH, can be 0
to	address	Address to receive liquidity token
deadline	uint256	Unix timestamp in seconds after which the transaction will revert

Returns

Name	Type	Description
amountToken	uint256	exact amount of token added to pool
amountETH	uint256	exact amount of ETH added to pool
liquidity	uint256	amount of liquidity token received

cancelOwnershipTransfer

Solidity

function cancelOwnershipTransfer() external payable

note

Details Cancel a transfer of ownership to a new account. Can only be called by the current owner.

executeOperation

Called from Aave Lending pool after the contract has received the flash loaned amount ¹

Solidity

function executeOperation(address[] assets, uint256[] amounts, uint256[] premiums, address initiator, bytes params) external nonpayable returns (bool)

note

Details Reverts if not profitable.

Parameters

Name	Type	Description
assets	address[]	Array of tokens to loan
amounts	uint256[]	Array of amounts to loan
premiums	uint256[]	Array of premiums to repay on loan amounts
initiator	address	Address of flashloan initiator
params	bytes	Encoded factories and tokens

Returns

Name	Type	Description
_0	bool	success indicating success

Events

LoanError

Solidity

event LoanError(bool indexed isAave, address indexed token, uint256 amountIn)

Parameters

Name	Type	Description
isAave indexed	bool	undefined
token indexed	address	undefined
amountIn	uint256	undefined

OpenMEV

Solidity

event OpenMEV(address indexed user, address indexed token, uint256 value)

Parameters

Name	Type	Description
user indexed	address	undefined
token indexed	address	undefined
value	uint256	undefined

OwnershipTransferred

Solidity

event OwnershipTransferred(address indexed previousOwner, address indexed newOwner)

Parameters

Name	Type	Description
previousOwner indexed	address	undefined
newOwner indexed	address	undefined

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1. see the Aave documentation for more information: https://docs.aave.com/developers/v/2.0/guides/flash-loans↩