subway - A practical example on how to perform sandwich attacks on Ethereum

Created at: 2021-12-11 05:01:34
Language: Solidity
License: MIT

Subway

A practical example on how to perform sandwich attacks on UniswapV2 pairs.

Having highly optimized contracts is just one part of the equation, a tech stack is just as important as the contracts to execute on the opportunities.

https://user-images.githubusercontent.com/95674753/145967796-6c2c8925-fb5c-41d4-a64f-a22ce8701ce6.mp4

Overview

The contracts are written in Yul+ and Solidity, and contains the bare minimum needed to perform a sandwich attack (i.e. swap and transfer). They do NOT protect against uncle bandit attacks so use at your own risk.

The goal of this bot is to act as a low barrier of entry, reference source code for aspiring new searchers (hence, JavaScript). This bot contains:

  • read from the mempool
  • decode transaction data
  • simple logging system
  • profit calculation algos
  • gas bribe calculation
  • bundle firing
  • misc
    • doing math in JS
    • calculating next base fee

While the bot is functional, the bot logic is a very simplistic one and does not contain a lot of the features that many advance searchers have (but not including), such as:

  • circuit breakers
  • poison token checker
  • caching system
  • robust logging system (e.g. graphana)
  • various gas saving ALPHAs

As such, this bot is intended as a piece of educational content, and not for production use.