generates a clean .sol interface file for any solidity contract address verified on etherscan

generate_interface.py

import os
import re
import requests
import sys

from dotenv import load_dotenv


# https://etherscan.io/contract-license-types
# https://spdx.org/licenses/
ETHERSCAN_TO_SPDX= {
    'Unlicense': 'Unlicense',
    'MIT': 'MIT',
    'GNU GPLv2': 'GPL-2.0',
    'GNU GPLv3': 'GPL-3.0',
    'GNU LGPLv2.1': 'LGPL-2.1',
    'GNU LGPLv3': 'LGPL-3.0',
    'BSD-2-Clause': 'BSD-2-Clause',
    'BSD-3-Clause': 'BSD-3-Clause',
    'MPL-2.0': 'MPL-2.0',
    'OSL-3.0': 'OSL-3.0',
    'Apache-2.0': 'Apache-2.0',
    'GNU AGPLv3': 'AGPL-3.0',
    'BSL 1.1': 'BUSL-1.1',
}


def get_from_etherscan(address):
    r = requests.get('https://api.etherscan.io/api', params={
        'module': 'contract',
        'action': 'getsourcecode',
        'address': address,
        'apikey': os.getenv('ETHERSCAN_TOKEN'),
    }).json()
    if r['status'] != '1':
        raise Exception(r['result'])

    result = r['result'][0]

    if result['Proxy'] != '0':
        return get_from_etherscan(result['Implementation'])

    contract = {}
    contract['name'] = result['ContractName']
    try:
        contract['license'] = ETHERSCAN_TO_SPDX[result['LicenseType']]
    except KeyError:
        contract['license'] = None
    contract['version'] = re.findall(
        r'v(\d+\.\d+\.\d+)\+', result['CompilerVersion']
    )[0]
    contract['abi'] = result['ABI']

    return contract


def main(address):
    load_dotenv()

    dump_dir = 'interfaces/autogenerated/'
    os.makedirs(dump_dir, exist_ok=True)

    contract = get_from_etherscan(address)

    dump_tmp = f'{dump_dir}I{contract["name"]}.tmp'
    with open(dump_tmp, 'w') as f:
        f.write(contract['abi'])

    command = f'cat {dump_tmp} | abi-to-sol --validate -S -A'
    if contract['license']:
        command += f' -L={contract["license"]}'
    if contract['version']:
        command += f' -V=^{contract["version"]}'
    command += f' I{contract["name"]} > {dump_dir}I{contract["name"]}.sol'

    print(command)
    os.system(command)
    os.remove(dump_tmp)

if __name__ == '__main__':
    main(sys.argv[1])

INSTALLATION

• copypasta generate_interface.py to your brownie dir
• install the excellent abi-to-sol:

npm install abi-to-sol

• make sure to have installed prettier and its solidity plugin alongside abi-to-sol:

npm install --save-dev prettier prettier-plugin-solidity

USAGE

python generate_interface.py 0xb2Bf1d48F2C2132913278672e6924efda3385de2

it will generate a clean .sol interface file in interfaces/autogenerated/.

TODO

• support vyper contracts (eg 0x1Ba86c33509013c937344f6e231DA2E63ea45197)