Client library that interacts with MEV-Share node written in Python 3.10.
Based on MEV-Share Spec.
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 installfrom 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/')
)Prints a warning if any keyword argument is missing:
UserWarning: No api_url parameter provided.
warnings.warn("No api_url parameter provided.")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 three main parts:
- RPC client that interacts with the MEV-Share node
- SSE client that listens for events from the MEV-Share Event Stream
- MevShareClient is a child class and inherits from both.
The library exposes the following public methods:
Subscribe to the event stream and listen for events of a specific type. The method expects type of event (string: 'transaction' or 'bundle') and a callback function that will be called when an event is received.
Callback function also receives a reference to the client object, so that it can be used to send transactions or bundles.
import asyncio
from mev_share_py.client import MevShareClient
from api.events import PendingTransaction
def callback_function(event: PendingTransaction, client: MevShareClient):
print(event)
STREAM_URL = "https://mev-share-goerli.flashbots.net/" # Goerli
client = MevShareClient(stream_url=STREAM_URL)
res = asyncio.run(
client.listen_for_events('transaction', callback_function),
)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(api_url='<RPC_url>', # "https://relay-goerli.flashbots.net/",
stream_url='<SSE_url>', # "https://mev-share-goerli.flashbots.net/",
sign_key='<sign_key>', # Private key to sign the bundle
node_url='<node_url>' # Geth node url
)
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)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:
"""
user_tx_hash = '<user_tx_hash>'
backrun_signed_tx = '<raw_signed_tx>'
client = MevShareClient(api_url='<RPC_url>', # "https://relay-goerli.flashbots.net/",
stream_url='<SSE_url>', # "https://mev-share-goerli.flashbots.net/",
sign_key='<sign_key>', # Private key to sign the bundle
node_url='<node_url>' # Geth node url
)
block_number = await client.w3_async.eth.block_number
params = {
'inclusion': {
'block': block_number + 1,
'max_block': block_number + 10,
},
'body': [
{'hash': user_tx_hash},
{'tx': backrun_signed_tx.hex(), 'can_revert': True}],
'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())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:
"""
user_tx_hash = '<user_tx_hash>'
backrun_signed_tx = '<raw_signed_tx>'
client = MevShareClient(api_url='<RPC_url>', # "https://relay-goerli.flashbots.net/",
stream_url='<SSE_url>', # "https://mev-share-goerli.flashbots.net/",
sign_key='<sign_key>', # Private key to sign the bundle
node_url='<node_url>' # Geth node url
)
block_number = await client.w3_async.eth.block_number
params = {
'inclusion': {
'block': block_number + 1,
'max_block': block_number + 10
},
'body': [
{'hash': user_tx_hash},
{'tx': backrun_signed_tx.hex(), 'can_revert': 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 information about the event history endpoint for use in get_event_history.
import asyncio
from mev_share_py.client import MevShareClient
client = MevShareClient(api_url='<RPC_url>', # "https://relay-goerli.flashbots.net/",
stream_url='<SSE_url>', # "https://mev-share-goerli.flashbots.net/",
sign_key='<sign_key>', # Private key to sign the bundle
node_url='<node_url>' # Geth node url
)
history_info = asyncio.run(client.get_event_history_info())Returns a dictionary:
{
'count': 2996044,
'minBlock': 9091377,
'maxBlock': 9734719,
'minTimestamp': 1685452445,
'maxTimestamp': 1695313814,
'maxLimit': 500
}Get historical event stream data for last 100 blocks.
params = {"blockStart": history_info['maxBlock'] - 1, "blockEnd": history_info['maxBlock']}
his = asyncio.run(client.get_event_history(params=params))All examples are located in the examples directory.
Before running the scripts, make sure to set the environment variables.
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.
I would like to express my gratitude to the following individuals and organizations who have contributed to this project:
- Brock Smedley (@zeroXbrock) - Oversaw the project and provided valuable feedback.
- Flashbots (@flashbots Organization that provided the initial idea and specifications for the project.
- aiohttp-sse-client - By Jason Hu
- web3.py - By Ethereum Foundation
For questions or feedback, contact ziga.mrzljak@gmail.com or ask in Flashbots Discord