This library works by injecting a new module in the Web3.py instance, which allows submitting "bundles" of transactions directly to miners. This is done by also creating a middleware which captures calls to eth_sendBundle and eth_callBundle, and sends them to an RPC endpoint which you have specified, which corresponds to mev-geth. To apply correct headers we use FlashbotProvider which injects the correct header on post


from eth_account.signers.local import LocalAccount
from web3 import Web3, HTTPProvider
from flashbots import flashbot
from eth_account.account import Account
import os

ETH_ACCOUNT_SIGNATURE: LocalAccount = Account.from_key(os.environ.get("ETH_SIGNATURE_KEY"))

w3 = Web3(HTTPProvider("http://localhost:8545"))

Now the w3.flashbots.sendBundle method should be available to you. Look in examples/simple.py for usage examples

Development and testing

Setup and run (mev-)geth with Websocket support:

geth --http --http.api eth,net,web3,txpool --syncmode full

Install poetry

Poetry will automatically fix your venv and all packages needed

poetry install

Tips: PyCharm has a poetry plugin


It's advisable to run black with default rules for linting

sudo pip install black # Black should be installed with a global entrypoint
black .