EVMole is a powerful library that extracts information from Ethereum Virtual Machine (EVM) bytecode, including function selectors, arguments, state mutability, and storage layout, even for unverified contracts.

Key Features

Multi-language support: Available as JavaScript, Rust, Python, and Go libraries.
High accuracy and performance: Outperforms existing tools.
Broad compatibility: Tested with both Solidity and Vyper compiled contracts.
Lightweight: Clean codebase with minimal external dependencies.
Unverified contract analysis: Extracts information even from unverified bytecode.

Usage

JavaScript

API documentation and usage examples (node, vite, webpack, parcel, esbuild)

$ npm i evmole

import { contractInfo } from 'evmole'

const code = '0x6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256'

console.log( contractInfo(code, {selectors:true, arguments:true, stateMutability:true}) )
// {
//   functions: [
//     {
//       selector: '2125b65b',
//       bytecodeOffset: 52,
//       arguments: 'uint32,address,uint224',
//       stateMutability: 'pure'
//     },
//     ...

Rust

Documentation is available on docs.rs

let code = hex::decode("6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256").unwrap();

println!("{:?}", evmole::contract_info(
    evmole::ContractInfoArgs::new(&code)
        .with_selectors()
        .with_arguments()
        .with_state_mutability()
    )
);
// Contract {
//     functions: Some([
//         Function {
//             selector: [33, 37, 182, 91],
//             bytecode_offset: 52,
//             arguments: Some([Uint(32), Address, Uint(224)]),
//             state_mutability: Some(Pure)
//         },
//         ...

Python

API documentation

$ pip install evmole --upgrade

from evmole import contract_info

code = '0x6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256'

print( contract_info(code, selectors=True, arguments=True, state_mutability=True) )
# Contract(
#     functions=[
#     Function(
#             selector=2125b65b,
#             bytecode_offset=52,
#             arguments=uint32,address,uint224,
#             state_mutability=pure),
#     ...

Go

API documentation

$ go get github.com/cdump/evmole/go

package main

import (
    "context"
    "encoding/hex"
    "fmt"

    "github.com/cdump/evmole/go"
)

func main() {
    code, _ := hex.DecodeString("6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256")

    info, _ := evmole.ContractInfo(context.Background(), code, evmole.Options{
        Selectors:       true,
        Arguments:       true,
        StateMutability: true,
    })

    for _, fn := range info.Functions {
        fmt.Printf("%s: %s @ %d\n", fn.Selector, *fn.Arguments, fn.BytecodeOffset)
    }
    // 2125b65b: uint32,address,uint224 @ 52
    // b69ef8a8:  @ 68
}

Foundry

<a href="https://getfoundry.sh/">Foundry's cast</a> uses the Rust implementation of EVMole


$ cast selectors $(cast code 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2)
0x06fdde03                           view
0x095ea7b3  address,uint256          nonpayable
0x18160ddd                           view
0x23b872dd  address,address,uint256  nonpayable
...

$ cast selectors --resolve $(cast code 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2)
0x06fdde03                           view        name()
0x095ea7b3  address,uint256          nonpayable  approve(address,uint256)
0x18160ddd                           view        totalSupply()
0x23b872dd  address,address,uint256  nonpayable  transferFrom(address,address,uint256)
...

Benchmark

function selectors

FP/FN - False Positive/False Negative errors; smaller is better

<table> <tr> <td>Dataset</td> <td></td> <td>evmole <a href="benchmark/providers/evmole-rs/">rs</a> · <a href="benchmark/providers/evmole-js/">js</a> · <a href="benchmark/providers/evmole-py/">py</a> · <a href="benchmark/providers/evmole-go/">go</a></td> <td><a href="benchmark/providers/whatsabi/">whatsabi</a></td> <td><a href="benchmark/providers/sevm/">sevm</a></td> <td><a href="benchmark/providers/evm-hound-rs/">evmhound</a></td> <td><a href="benchmark/providers/heimdall-rs/">heimdall</a></td> </tr> <tr> <td rowspan="5">largest1k 1000 addresses 24427 functions</td> <td>FP addrs</td> <td>1 🥈</td> <td>0 🥇</td> <td>0 🥇</td> <td>75</td> <td>18</td> </tr> <tr> <td>FN addrs</td> <td>0 🥇</td> <td>0 🥇</td> <td>0 🥇</td> <td>40</td> <td>103</td> </tr> <tr> <td>FP funcs</td> <td>192 🥈</td> <td>0 🥇</td> <td>0 🥇</td> <td>720</td> <td>600</td> </tr> <tr> <td>FN funcs</td> <td>0 🥇</td> <td>0 🥇</td> <td>0 🥇</td> <td>191</td> <td>114</td> </tr> <tr> <td>Time</td> <td>18ms · 0.2s · 22ms · 69ms</td> <td>2.3s</td> <td>30s(*)</td> <td>56ms</td> <td>371s(*)</td> </tr> <tr><td colspan="7"></td></tr> <tr> <td rowspan="5">random50k 50000 addresses 1171102 functions</td> <td>FP addrs</td> <td>1 🥇</td> <td>43</td> <td>1</td> <td>693</td> <td>3</td> </tr> <tr> <td>FN addrs</td> <td>9 🥇</td> <td>11</td> <td>10</td> <td>2903</td> <td>4669</td> </tr> <tr> <td>FP funcs</td> <td>3 🥇</td> <td>51</td> <td>3</td> <td>10798</td> <td>29</td> </tr> <tr> <td>FN funcs</td> <td>10 🥇</td> <td>12</td> <td>11</td> <td>3538</td> <td>4943</td> </tr> <tr> <td>Time</td> <td>0.5s · 3.1s · 0.6s · 3.1s</td> <td>30s</td> <td>440s(*)</td> <td>1.6s</td> <td>8684s(*)</td> </tr> <tr><td colspan="7"></td></tr> <tr> <td rowspan="5">vyper 780 addresses 21244 functions</td> <td>FP addrs</td> <td>0 🥇</td> <td>30</td> <td>0</td> <td>19</td> <td>0</td> </tr> <tr> <td>FN addrs</td> <td>0 🥇</td> <td>780</td> <td>0</td> <td>300</td> <td>780</td> </tr> <tr> <td>FP funcs</td> <td>0 🥇</td> <td>30</td> <td>0</td> <td>19</td> <td>0</td> </tr> <tr> <td>FN funcs</td> <td>0 🥇</td> <td>21244</td> <td>0</td> <td>8273</td> <td>21244</td> </tr> <tr> <td>Time</td> <td>9ms · 99ms · 11ms · 42ms</td> <td>2.0s</td> <td>34s(*)</td> <td>26ms</td> <td>28s(*)</td> </tr> </table>

function arguments

Errors - when at least 1 argument is incorrect: (uint256,string) ≠ (uint256,bytes)

Evmole

Install / Use

README