mev-share-py

Client library that interacts with MEV-Share node written in Python 3.10.

Based on MEV-Share.

Table of Contents

• Installation
• Usage
• Configuration
• Features
• Examples
• Contributing
• License
• Acknowledgments
• FAQs
• Troubleshooting
• Contact

Installation

This repo assumes Python ^3.8. Preferred way is to use pyenv and poetry for managing Python versions and dependencies. Make sure to have both installed on your system. In case of other environment managers, make sure to install the dependencies listed in pyproject.toml.

Create poetry environment and install dependencies (change directory to the root of the repo):

# If using pyenv and poetry
pyenv install 3.10
pyenv local 3.10
poetry install

Usage

There are two ways to initalize the client:

1) Using the constructor:

(throws an error if any keyword argument is missing):

from client import MevShareClient
client = MevShareClient(api_url='https://relay.flashbots.net/', 
                        sign_key='<your_sign_key>',
                        node_url='https://goerli.infura.io/v3/<your_infura_key>',
                        stream_url='https://mev-share.flashbots.net/')
                        )

2) Using the classmethod from_config which reads from the head dir config.json file:

For this to work, you need to pass the network string (currently either 'goerli' or 'mainnet') and config.json file path to the classmethod. The private_key and to fields are optional, used for easy access by accessing the client.config parameter. The private_key is only used in the example files.

It is NOT advisable to store your PROD private key in the config file.

Add the necessary variables to the config.json file.

{
  "mainnet": {
    "relay_url": "https://relay.flashbots.net",
    "sse_url": "https://mev-share.flashbots.net/",
    "infura_url": "https://mainnet.infura.io/v3/{}"
  },
  "goerli": {
    "relay_url": "https://relay-goerli.flashbots.net/",
    "sse_url": "https://mev-share-goerli.flashbots.net/",
    "infura_url": "https://goerli.infura.io/v3/{}"
  },
  "infura_key": "<your_infura_key>",
  "private_key": "<your_private_key>",
  "sign_key": "<your_sign_key>",
  "to": "<your_wallet_address>",
}

Import the client and create an instance of the client with the desired network.

from client import MevShareClient
client = MevShareClient.from_config('goerli', '../config.json')

Client library uses python typeddict to define the types of the data for static analysis. Those are not enforced at runtime. So make sure to check the types of parameters and return values. The types are defined in api/events.py.

The library consists of two main parts:

• RPC client that interacts with the MEV-Share node
• SSE client that listens for events from the MEV-Share node
• MevShareClient is a wrapper around both clients.

The library exposes the following public methods:

listen_for_events

Subscribe to the event stream and listen for events of a specific type. The method expects type of event (transaction/bundle) and a callback function that will be called when an event is received.

import asyncio
from mev_share_py.client import MevShareClient
from api.events import PendingTransaction


def callback_function(event: PendingTransaction):
    print(event)


client = MevShareClient.from_config('goerli', '../config.json')
res = asyncio.run(
    client.listen_for_events('transaction', callback_function),
)

send_transaction

Send a private transaction to the MEV-Share node. Hints and options are passed as a dictionary.

import asyncio
from mev_share_py.client import MevShareClient

raw_tx = '<raw_tx>'  # Add raw tx here


async def send_tx(tx: str):
    client = MevShareClient.from_config(network='goerli', config_dir='../config.json')
    print(tx)
    return await client.send_transaction(
        tx.rawTransaction.hex(),
        {
            'max_block_number': await client.w3_async.eth.block_number + 10,
            'hints': {
                'calldata': True,
                'contract_address': True,
                'function_selector': True,
                'logs': True
            }
        }
    )


if __name__ == "__main__":
    tx = asyncio.run(send_tx(raw_tx))
    print(tx)

send_bundle

Sends a bundle of transactions to the MEV-Share node. Hints and options are passed as a dictionary. See MEV-Share Docs for detailed descriptions of these parameters.

When sending bundles containing only signed transactions, we can share hints by uncommenting the privacy section.

import asyncio
from mev_share_py.client import MevShareClient
from mev_share_py.api.types import BundleParams



async def build_and_send():
    """
    Generate a bundle with two private transactions and send it.
    :return:
    """
    tx1 = '<raw_tx1>'
    tx2 = '<raw_tx2>'
    client = MevShareClient.from_config(network='goerli', config_dir='../config.json')
    tx1 = tx1
    tx2 = tx2
    block_number = await client.w3_async.eth.block_number
    params = {
        'inclusion': {
            'block': block_number + 1,
            'max_block': block_number + 10,
        },
        'body': [
            {'tx': tx1.rawTransaction.hex()},
            {'tx': tx2.rawTransaction.hex()}],
        'privacy': {
            'hints': {
                'tx_hash': True,
                'calldata': True,
                'logs': True,
                'function_selector': True,
            },
            # 'builders': ['flashbots']
        }
    }
    params = BundleParams(**params)
    print(await client.send_bundle(params))

if __name__ == "__main__":
    asyncio.run(build_and_send())

simulate_bundle

Simulates a bundle. Similar to send_bundle, but also accepts options to modify block header.

import asyncio
from mev_share_py.api.types import BundleParams
from mev_share_py.client import MevShareClient


async def sim_private_tx_backrun():
    """
    Generate a bundle with two private transactions and simulate it.
    The "to" address and "private_key" are read from the config.json file.
    :return:
    """
    tx1 = '<raw_tx1>'
    tx2 = '<raw_tx2>'
    client = MevShareClient.from_config(network='goerli', config_dir='../config.json')
    tx1 = tx1
    tx2 = tx2
    block_number = await client.w3_async.eth.block_number
    params = {
        'inclusion': {
            'block': block_number + 1,
            'max_block': block_number + 10
        },
        'body': [{'tx': tx1.rawTransaction.hex(), 'canRevert': True},
                 {'tx': tx2.rawTransaction.hex(), 'canRevert': True}],
        'privacy': {
            'hints': {
                'tx_hash': True,
                'calldata': True,
                'logs': True,
                'function_selector': True,
            },
            # 'builders': ['flashbots']
        }
    }
    sim_options = {
        'parent_block': block_number,
    }
    params = BundleParams(**params)
    return await client.simulate_bundle(params, sim_options)

if __name__ == "__main__":
    res = asyncio.run(sim_private_tx_backrun())
    print(res)

get_event_history_info

Get information about the event history endpoint for use in get_event_history.

import asyncio
from mev_share_py.client import MevShareClient
client = MevShareClient.from_config('goerli', '../config.json')
his_info = asyncio.run(client.get_event_history_info())

Returns a dictionary:

{
    'count': 2996044,
    'minBlock': 9091377,
    'maxBlock': 9734719,
    'minTimestamp': 1685452445,
    'maxTimestamp': 1695313814,
    'maxLimit': 500
}

get_event_history

Get historical event stream data for last 100 blocks.

params = {"blockStart": his_info['maxBlock'] - 1, "blockEnd": his_info['maxBlock']}
his = asyncio.run(client.get_event_history(params=params))

Examples

All examples are located in the examples directory.

Contributing

License

MIT License

Copyright (c) 2023 Žiga Mrzljak / Flashbots

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Acknowledgments

FAQs

Troubleshooting

Contact

For questions or feedback, contact [email protected]