constructor-argument-detector

🚀 Terminal util to find constructor arguments when creating a contract in ethereum based networks

Get Started

npm install -g constructor-argument-detector

Usage

Usage: constructor-detector [options] <transaction-hash-of-creation-contract>

CLI to find constructor argument in ethereum based chain contracts

Arguments:
  hash                  Tx of creating transactions

Options:
  -e, --endpoint <url>  RPC endpoint url
  -t, --types <string>  Constructor types (Example: uint,string,address)
  -h, --help            display help for command

Example

user@macbook ~ % constructor  -e https://bsc-dataseed1.binance.org \
                              -t address,address \
                              0x1bfbff8411ed44e609d911476b0d35a28284545b690902806ea0a7ff0453e931

(address) 0xcA143Ce32Fe78f1f7019d7d551a6402fC5350c73
(address) 0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c

Or set RRC endpoint to env

user@macbook ~ % export WEB3_ENDPOINT=https://bsc-dataseed1.binance.org
user@macbook ~ % constructor -t address,address,address,address,address,uint 0xc0e636dcebeeed30525f1ca2214b93331fe2263adc87cd467d57d4ff04257d4d
(address) 0x0E09FaBB73Bd3Ade0a17ECC321fD13a19e81cE82
(address) 0xa5f8C5Dbd5F286960b9d90548680aE5ebFf07652
(address) 0x7a2C5c265bDC9724dACe715c5FF60Eea40E07F47
(address) 0xeCc90d54B10ADd1ab746ABE7E83abe178B72aa9E
(address) 0xeCc90d54B10ADd1ab746ABE7E83abe178B72aa9E
(uint) 0

Or using as library

const detector = require("constructor-argument-detector");

detector.parse({
    txHash: "0xc0e636dcebeeed30525f1ca2214b93331fe2263adc87cd467d57d4ff04257d4d",
    endpoint: "https://bsc-dataseed1.binance.org/",
    types: ["address", "address", "address", "address", "address", "uint"]
}).then(result => {
    console.log(result);
})

/* Output:
[
  {
    type: 'address',
    value: '0x0E09FaBB73Bd3Ade0a17ECC321fD13a19e81cE82'
  },
  {
    type: 'address',
    value: '0xa5f8C5Dbd5F286960b9d90548680aE5ebFf07652'
  },
  {
    type: 'address',
    value: '0x7a2C5c265bDC9724dACe715c5FF60Eea40E07F47'
  },
  {
    type: 'address',
    value: '0xeCc90d54B10ADd1ab746ABE7E83abe178B72aa9E'
  },
  {
    type: 'address',
    value: '0xeCc90d54B10ADd1ab746ABE7E83abe178B72aa9E'
  },
  {
    type: 'uint',
    value: BigNumber { _hex: '0x00', _isBigNumber: true }
  }
]
*/

To resolve the issue, we need data from tx.input and the actual smart contract code. You can extract this data yourself

const detector = require('constructor-argument-detector');
const ethers = require('ethers');
const provider = new ethers.providers.JsonRpcProvider("https://bsc-dataseed1.binance.org/");

provider.getTransaction('0xc0e636dcebeeed30525f1ca2214b93331fe2263adc87cd467d57d4ff04257d4d').then(async (tx) => {
    const data = tx.data;
    const addressOfContract = '0x45c54210128a065de780C4B0Df3d16664f7f859e';
    const byteCode = await provider.getCode(addressOfContract);
    
    const result = detector.offchainParse({
        txData: data,
        byteCode,
        types: ["address", "address", "address", "address", "address", "uint"]
    })
    console.log(result);
})