Agent skill · software engineering · affaan-m
nodejs-keccak256
Prevent Ethereum hashing bugs in JavaScript and TypeScript. Node's sha3-256 is NIST SHA3, not Ethereum Keccak-256, and silently breaks selectors, signatures, storage slots, and address derivation. Use when hashing for Ethereum in JavaScript or TypeScript, or when a selector, signature, storage slot, or derived address is wrong.
Why this skill is useful
Provides specific implementation patterns and examples for using Keccak-256 in Ethereum contexts, which the AI may not reliably generate on its own.
What it needs
About 1k tokens when loaded. Last updated 2026-08-06. 238,342 stars on the source repository.
What this skill does
Node.js Keccak-256 Ethereum uses Keccak-256, not the NIST-standardized SHA3 variant exposed by Node's crypto.createHash('sha3-256'). When to Use Computing Ethereum function selectors or event topics Building EIP-712, signature, Merkle, or storage-slot helpers in JS/TS Reviewing any code that hashes Ethereum data with Node crypto directly How It Works The two algorithms produce different outputs for the same input, and Node will not warn you. Examples ethers v6 viem web3.js Common patterns Address from public key Audit your codebase Rule For Ethereum contexts, never use crypto.createHash('sha3-256'). Use Keccak-aware helpers from ethers, viem, web3, or another explicit Keccak implementation.
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills affaan-m/nodejs-keccak256--fa0132