ProphetSwap

ProphetSwap is a router contract built to route all trade done through the bot and take a revshare fee that is withdrawable by the team

Usage

Build

$ forge build

Test

$ forge test

Format

$ forge fmt

Gas Snapshots

$ forge snapshot

Serve Docs

forge doc --build
forge doc --serve

ProphetSwap

Git Source

Inherits: Ownable2Step

This contract interacts with Uniswap V2 to facilitate token swaps and collects a fee on each transaction.

State Variables

totalFeeCollected

uint256 public totalFeeCollected;

UNISWAP_V2_ROUTER

address private constant UNISWAP_V2_ROUTER = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;

WETH

address private constant WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;

Functions

constructor

constructor();

ProphetBuy

Buys tokens on Uniswap V2 and collects a fee

function ProphetBuy(uint256 amountOutMin, address tokenAddress, uint256 _fee) external payable;

Parameters

Name	Type	Description
amountOutMin	uint256	Minimum amount of tokens to receive from the swap
tokenAddress	address	The address of the token to buy
_fee	uint256	The fee percentage to be collected

ProphetSell

Sells tokens on Uniswap V2 and collects a fee

function ProphetSell(uint256 amountIn, uint256 amountOutMin, address tokenAddress, uint256 _fee) external;

Parameters

Name	Type	Description
amountIn	uint256	Amount of tokens to sell
amountOutMin	uint256	Minimum amount of ETH to receive from the swap
tokenAddress	address	The address of the token to sell
_fee	uint256	The fee percentage to be collected

ProphetSmartSell

Sells tokens on Uniswap V2 for a specified amount of ETH, collects a fee

function ProphetSmartSell(uint256 amountOut, uint256 amountInMax, address tokenAddress, uint256 _fee) external;

Parameters

Name	Type	Description
amountOut	uint256	The exact amount of ETH to receive from the swap
amountInMax	uint256	The maximum amount of tokens to sell
tokenAddress	address	The address of the token to sell
_fee	uint256	The fee percentage to be collected in BPS

getPathForTokenToToken

Helper function to get the swap path for token to token or ETH to token swaps

function getPathForTokenToToken(bool swapETH, address _tokenOut) private pure returns (address[] memory);

Parameters

Name	Type	Description
swapETH	bool	Indicates whether the swap involves ETH
_tokenOut	address	The address of the output token

Returns

Name	Type	Description
<none>	address[]	path The swap path as an array of addresses

withdraw

Allows the contract owner to withdraw tokens from the contract

function withdraw(address _token) external onlyOwner;

Parameters

Name	Type	Description
_token	address	The token address to withdraw

withdrawETH

Allows the contract owner to withdraw ETH from the contract

function withdrawETH() external;

receive

Fallback function to receive ETH

receive() external payable;

Events

ProphetFee

Event emitted after collecting a fee

event ProphetFee(address indexed sender, uint256 amount);

Errors

InvalidAmount

Custom Errors for the contract

error InvalidAmount();

InvalidOutputAmount

error InvalidOutputAmount();

InvalidFeeAmount

error InvalidFeeAmount();

InvalidToken

error InvalidToken();

TransferFailed

error TransferFailed();

Security Risks

• Potential Issues with Using block.timestamp as the Deadline for AMM Swaps
• Centralizaiont risks if keys are compromised

Deadline check

Summary:

Frontrunning and Sandwich attacks a threat to the security of an AMMs. In the current implementation, the block.timestamp is used as the deadline parameter.

Since block.timestamp aligns with the current timestamp when included in a block by the miner, this opens an opportunity for miners game the system as the cost of a user. A malicious miner can withhold the transaction from being mined until it incurs the maximum slippage. Alternatively, they may exploit the transaction later to execute a sandwich attack.

Similar instances have been reported in auditing contests:

Code 423n4 - 2022-11-paraspace-findings

Sherlock Audit - 2023-01-ajna-judging

Recommendation:

It is advisable that the deadline parameter of 3600 + block.timestamp be revised to deem if it is necessary or not. The deadline could be calculated on the frontend and sent to the contract as an argument. For example you can get the current time using the js date() method add 3600 to and it pass it as the deadline parameter. This way it cannot be manipulate by a miner.

Compromised Keys

Summary:

Many core functions including withdrawETH and withdrawTokens withdraw all the funds from fees to a revShare address. If for whatever reason this address is compromised it could lead to loss of funds to the team.

Currently there aren't many way to mitigate against this besides ensuring that this address is a multi sig. If one of the keys get compromised the funds will still be safe and retrievable by the owners.