So you want to become and MEV searcher? The journey to discovering the 'tricks' is often painful, and you will be directly targeted by more experienced searchers. One of the worst ways to get rekt as a new searcher is for your bot to be baited into buying a poisonous token, and they come in many forms.
This repository contains code to build a token whitelist. It is ABSOLUTELY not bulletproof and I'm 100% sure that there are many ways for searchers to sidestep the checks in here, but it is a good starting off point. The grt directory contains code to query all Uniswap V2 pairs from The Graph, and filters for pairs with less than MIN_TX_COUNT transactions. It writes the pairs data to a file. This file is then used to run hardhat simulations which computes the burn fee for each token and writes that data to yet another file. The final file can then be used in-memory for whatever language you use to run your logic for your bot. This is nice because it makes it easy to calculate more accurate profit for your trade as you have token burn fees. There is a contract called BurnCalc.sol that manages the burn calculation. Tokens that are obviously poisonous will cause the simulation to revert, and hence will not be added to the whitelist BUT you will need to add more logic to discover certain classes of poisonous tokens.
I have intentionally left out important logic in the BurnCalc contract that would help avoid other types of poisonous tokens. This is because if you can't understand what needs to be added, then you almost certainly should not be running a bot unless you are willing to lose money for the sake of learning. The current setup will cover simple poison tokens where only the creator of the token is able to sell, leaving you will a worthless pile of ponzi coins.