# shazow/whatsabi

Extract the ABI (and resolve proxies, and get other metadata) from Ethereum bytecode, even without source code.

Repository: https://github.com/shazow/whatsabi
Canonical: https://ross.abutalabs.com/products/whatsabi
Homepage: https://shazow.github.io/whatsabi/
Language: TypeScript
License: MIT
License Family: permissive
Topics: bytecode, ethereum, evm, web3
Last push: 2026-08-18T12:50:55+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 98, longevity 100
- inputs: {"age_days": 1442, "days_push": 15, "days_rel": 15, "gap_med": 17.5, "n_releases_24m": 21}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1160, forks 92 (observed 2026-08-28T04:03:49.008208+00:00)

## What it is
WhatsABI is a small TypeScript library that guesses an ABI and detects proxy contracts directly from Ethereum bytecode, even for unverified contracts. It works in the browser and embeds in wallets, block explorers, and other web3 tooling, integrating with Ethers.js, Viem, and Web3.js.

## Use cases
- extract an ABI from unverified Ethereum contract bytecode
- resolve proxy contracts behind a contract address
- look up function signatures from selectors
- build a procedural frontend for arbitrary smart contracts
- embed contract analysis in a web3 wallet
- analyze EVM bytecode in a block explorer

## When to choose
- you need ABI info for contracts without verified source code
- you want a tiny, browser-runnable library with minimal dependencies
- you need proxy contract detection
- you work with contracts written in languages other than Solidity, like Vyper

## When to avoid
- you need full decompilation or deep static analysis of EVM bytecode
- you already have verified source code and can compile the ABI yourself
- you need a non-JavaScript environment without a JS runtime

## Facets
- artifact type: library
- maturity: active
- function: parser, developer-tools, sdk
- domain: blockchain, developer-tools, apis
- platform: browser, cross-platform
- tags: ethereum, evm, bytecode-analysis, abi, web3, proxy-detection, smart-contracts, nodejs, typescript

## Member repositories
- shazow/whatsabi (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:49.008208+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:31:49.761768+00:00, confidence not recorded.
  - readme: https://github.com/shazow/whatsabi (fetched 2026-08-28T04:03:49.008208+00:00, sha 6394246aafdd)
  - homepage: https://shazow.github.io/whatsabi/ (fetched 2026-08-29T12:36:37.552960+00:00, sha 4a89276cbcfb)
- Data as of 2026-08-30T08:39:29.467469+00:00.