searching from scratch

Note: we will have to drastically over-simplify and cut many corners. Writing a decent backrunner from scratch in 2 hours is highly ambitious.

This talk is:

• interactive
• collaborative
• rushed 😅

Ask questions!!

backrunner blueprint

• subscribe to mempool txs on websocket provider
• filter for Uniswap (SwapRouter02) trades
  • filter for multicall
• decode calldata data using abiDecoder
  • filter for exactInputSingle & exactOutputSingle
  • extract trade data from multicall calldata
    • reminder: inner deadline param has to be removed
  • filter for (TOKEN -> WETH) swaps ONLY
  • assume executor will only hold WETH
• write executor contract
  • accept trade data as param to execute function
  • buy tokens (which mempool user will have sold) on Uniswap
  • (my_buy_amount == mempool_user_sell_amount == mempoolTx.amountIn)
  • sell all purchased tokens on Sushiswap
  • return updated WETH balance
• simulation-based profit analysis (not ideal, but quick & easy to implement)
  • blindly/optimistically build backrun bundle
  • simulate on local(-ish) mev-geth
  • use return value to determine whether bundle is worth sending

TODO

• test contract against local mainnet fork
• deploy contract on mainnet & update contracts.ts