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/ EIP-712 Message Hasher

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EIP-712 Message Hasher

Calculate EIP-712 hashes for typed structured data signing

■ 01

What is EIP-712?

EIP-712 is a standard for hashing and signing typed structured data. It provides a way to sign data that is human-readable and secure, commonly used for permit signatures, meta-transactions, and DAO voting.

■ 02

How does it work?

EIP-712 hashing involves three steps: Calculate the domain separator hash Calculate the message struct hash Combine them: keccak256("\x19\x01" + domainSeparator + messageHash) The domain separator includes information a…

■ 03

Sample Cases

Covers ERC-20 Permit, Meta-transaction, and NFT Order (OpenSea-style) so you can compare common inputs and outputs quickly.

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/ Integration

Source code from the selected tool, shown here alongside the live version on the right.

/ Source Code

TypeScript

typescript

// npm install viem

import { keccak256, encodeAbiParameters, parseAbiParameters } from 'viem';

interface Domain {
  name: string;
  version: string;
  chainId: number;
  verifyingContract: string;
}