fs-attestation-safe-eth-py 1.0.0

Modified Safe Ecosystem Foundation utilities for Ethereum projects and FailSafe Attestation Service

Safe-eth-py includes a set of libraries to work with Ethereum and relevant Ethereum projects:

• EthereumClient, a wrapper over Web3.py Web3 client including utilities to deal with ERC20/721 tokens and tracing.

• Gnosis Safe classes and utilities.

• Price oracles for Uniswap, Kyber…

• Django serializers, models and utils.

Quick start

Just run pip install safe-eth-py or add it to your requirements.txt

If you want django ethereum utils (models, serializers, filters…) you need to run pip install safe-eth-py[django]

If you have issues building coincurve maybe you are missing some libraries

Contributing to safe-eth-py

Clone the repo, then to set it up:

python -m venv venv
source venv/bin/activate
pip install -r requirements-dev.txt
pre-commit install -f

Add new address for new chains

If you want to add Safe Smart Account support for a new chain you must open a new issue.

Once the issue is created or edited, an automatic validation will be executed and a Pull Request will be created if everything is ok. Finally, the Safe team will review and merge the automatic Pull Request generated from the issue.

Ethereum utils

gnosis.eth

• class EthereumClient (ethereum_node_url: str): Class to connect and do operations with an ethereum node. Uses web3 and raw rpc calls for things not supported in web3. Only http/https urls are supported for the node url.

EthereumClient has some utils that improve a lot performance using Ethereum nodes, like the possibility of doing batch_calls (a single request making read-only calls to multiple contracts):

from gnosis.eth import EthereumClient
from gnosis.eth.contracts import get_erc721_contract
ethereum_client = EthereumClient(ETHEREUM_NODE_URL)
erc721_contract = get_erc721_contract(self.w3, token_address)
name, symbol = ethereum_client.batch_call([
                    erc721_contract.functions.name(),
                    erc721_contract.functions.symbol(),
                ])

If you want to use the underlying web3.py library:

from gnosis.eth import EthereumClient
ethereum_client = EthereumClient(ETHEREUM_NODE_URL)
ethereum_client.w3.eth.get_block(57)

gnosis.eth.constants

• NULL_ADDRESS (0x000...0): Solidity address(0).

• SENTINEL_ADDRESS (0x000...1): Used for Gnosis Safe’s linked lists (modules, owners…).

• Maximum and minimum values for R, S and V in ethereum signatures.

gnosis.eth.oracles

Price oracles for Uniswap, UniswapV2, Kyber, SushiSwap, Aave, Balancer, Curve, Mooniswap, Yearn… Example:

from gnosis.eth import EthereumClient
from gnosis.eth.oracles import UniswapV2Oracle
ethereum_client = EthereumClient(ETHEREUM_NODE_URL)
uniswap_oracle = UniswapV2Oracle(ethereum_client)
gno_token_mainnet_address = '0x6810e776880C02933D47DB1b9fc05908e5386b96'
weth_token_mainnet_address = '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'
price = uniswap_oracle.get_price(gno_token_mainnet_address, uniswap_oracle.weth_address)

gnosis.eth.utils

Contains utils for ethereum operations:

• mk_contract_address_2(from_: Union[str, bytes], salt: Union[str, bytes], init_code: [str, bytes]) -> str: Calculates the address of a new contract created using the new CREATE2 opcode.

Ethereum django (REST) utils

Django utils are available under gnosis.eth.django. You can find a set of helpers for working with Ethereum using Django and Django Rest framework.

It includes:

• gnosis.eth.django.filters: EthereumAddressFilter.

• gnosis.eth.django.models: Model fields (Ethereum address, Ethereum big integer field).

• gnosis.eth.django.serializers: Serializer fields (Ethereum address field, hexadecimal field).

• gnosis.eth.django.validators: Ethereum related validators.

• gnosis.safe.serializers: Serializers for Gnosis Safe (signature, transaction…).

• All the tests are written using Django Test suite.

Contributors

See contributors