MEV Sandwich Bot

A maximal extractable value (MEV) bot that monitors the Ethereum mempool for large pending DEX swap transactions and executes sandwich attacks — front-running the target trade to push the price up, then back-running to sell at the inflated price.

What's Included — Full Source Code:

• Complete TypeScript + Solidity source code
• Flashbots integration for private transaction submission
• Gas estimation and profit calculation engine
• Docker deployment with monitoring

Core Features:

• Mempool scanner — monitors pending transactions on Uniswap V2, V3, SushiSwap, and other major DEXes in real time
• Profit calculator — simulates the sandwich trade before execution to determine exact profit after gas costs
• Flashbots bundles — submits front-run + back-run as an atomic bundle via Flashbots, ensuring both execute in the same block or neither does
• Multi-DEX support — works with Uniswap V2, Uniswap V3, SushiSwap, PancakeSwap (BSC), and more
• Dynamic gas pricing — bids just enough gas to get ahead of the target transaction without overpaying
• Token whitelist — only targets high-liquidity tokens to minimise slippage risk

Risk Management:

• Minimum profit threshold (default: $5 after gas)
• Maximum capital per sandwich (configurable)
• Revert protection — Flashbots bundles are atomic, no gas wasted on failed attempts
• Liquidity depth check — ensures enough liquidity to execute without excessive slippage
• Blacklisted contracts — avoids interacting with known malicious contracts

Architecture:

• Mempool listener → Decode pending tx → Simulate sandwich → Calculate profit → Submit Flashbots bundle → Monitor inclusion
• Average execution: 1 block (12 seconds on Ethereum)
• Typical daily opportunities: 50-200 profitable sandwiches

Tech Stack:

• TypeScript + ethers.js v6
• Solidity 0.8.x smart contracts
• Flashbots ethers provider
• WebSocket mempool subscription
• PostgreSQL for trade logging

Supported Chains:

• Ethereum Mainnet (via Flashbots)
• BSC (via private mempool)
• Polygon (via private RPC)

Full source code. Educational and research purposes. Understand MEV extraction mechanics.