Across

Across is the fastest, cheapest and most secure cross-chain bridge. It is a system that uses UMA contracts to quickly move tokens across chains. This contains various utilities to support applications on across.

How to use

Get suggested fees from online API

Use across official API to get suggested fees.

>>> import across
>>> a = across.AcrossAPI()
>>> a.suggested_fees("0x7f5c764cbc14f9669b88837ca1490cca17c31607", 10, 1000000000)
{'slowFeePct': '43038790000000000', 'instantFeePct': '5197246000000000'}

Fee Calculator

Calculates lp fee percentages when doing a transfer.

from across.fee_calculator import (
    calculate_apy_from_utilization,
    calculate_realized_lp_fee_pct,
)
from across.utils import toBNWei

rate_model = {
    "UBar": toBNWei("0.65"),
    "R0": toBNWei("0.00"),
    "R1": toBNWei("0.08"),
    "R2": toBNWei("1.00"),
}

interval = { "utilA": 0, "utilB": toBNWei(0.01), "apy": 615384615384600, "wpy": 11830749673498 }
apy_fee_pct = calculate_apy_from_utilization(rate_model, interval["utilA"], interval["utilB"])
assert apy_fee_pct == interval["apy"]

realized_lp_fee_pct = calculate_realized_lp_fee_pct(rate_model, interval["utilA"], interval["utilB"])
assert realized_lp_fee_pct == interval["wpy"]

LP Fee Calculator

Get lp fee calculations by timestamp.

from across import LpFeeCalculator
from web3 import Web3

provider = Web3.WebsocketProvider("{YOUR-PROVIDER-ADDRESS}")
calculator = LpFeeCalculator(provider)
token_address = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2" # WETH on mainnet
bridge_pool_address = "0x7355Efc63Ae731f584380a9838292c7046c1e433" # WETH BridgePool on mainnet
amount = "1000000000000000000" # 1 ETH
timestamp = 1645000000 # timestamp in seconds
percent = calculator.get_lp_fee_pct(
    token_address, bridge_pool_address, amount, timestamp
)
print(percent)

How to build and test

Install poetry and install the dependencies:

pip3 install poetry

poetry install

# test
python -m unittest

# local install and test
pip3 install twine
python3 -m twine upload --repository testpypi dist/*
pip3 install --index-url https://test.pypi.org/simple/ --no-deps across