signTypedData

Signs typed data and calculates an Ethereum-specific signature in https://eips.ethereum.org/EIPS/eip-712: sign(keccak256("\x19\x01" ‖ domainSeparator ‖ hashStruct(message)))

Usage

example.tsdata.tsconfig.ts

import { account, walletClient } from './config'
import { domain, types } from './data'

const signature = await walletClient.signTypedData({
  account,
  domain,
  types,
  primaryType: 'Mail',
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

// All properties on a domain are optional
export const domain = {
  name: 'Ether Mail',
  version: '1',
  chainId: 1,
  verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
} as const
 
// The named list of all type definitions
export const types = {
  Person: [
    { name: 'name', type: 'string' },
    { name: 'wallet', type: 'address' },
  ],
  Mail: [
    { name: 'from', type: 'Person' },
    { name: 'to', type: 'Person' },
    { name: 'contents', type: 'string' },
  ],
} as const

import { createWalletClient, custom } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { mainnet } from 'viem/chains'

export const walletClient = createWalletClient({
  chain: mainnet,
  transport: custom(window.ethereum)
})

// JSON-RPC Account
export const [account] = await walletClient.getAddresses()
// Local Account
export const account = privateKeyToAccount('0x...')

Account Hoisting

If you do not wish to pass an account to every signTypedData, you can also hoist the Account on the Wallet Client (see config.ts).

Learn more.

example.tsdata.tsconfig.ts (JSON-RPC Account)config.ts (Local Account)

import { walletClient } from './config'
import { domain, types } from './data'

const signature = await walletClient.signTypedData({
  domain,
  types,
  primaryType: 'Mail',
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

// All properties on a domain are optional
export const domain = {
  name: 'Ether Mail',
  version: '1',
  chainId: 1,
  verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
} as const
 
// The named list of all type definitions
export const types = {
  Person: [
    { name: 'name', type: 'string' },
    { name: 'wallet', type: 'address' },
  ],
  Mail: [
    { name: 'from', type: 'Person' },
    { name: 'to', type: 'Person' },
    { name: 'contents', type: 'string' },
  ],
} as const

import { createWalletClient, custom } from 'viem'

// Retrieve Account from an EIP-1193 Provider.
const [account] = await window.ethereum.request({ 
  method: 'eth_requestAccounts' 
})

export const walletClient = createWalletClient({
  account,
  transport: custom(window.ethereum)
})

import { createWalletClient, custom } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'

export const walletClient = createWalletClient({
  account: privateKeyToAccount('0x...'),
  transport: custom(window.ethereum)
})

Returns

0x${string}

The signed data.

Parameters

account

Type: Account | Address

The Account to use for signing.

Accepts a JSON-RPC Account or Local Account (Private Key, etc).

const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266', 
  domain: {
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  types,
  primaryType: 'Mail',
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

domain

Type: TypedDataDomain

The typed data domain.

const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain: { 
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  types,
  primaryType: 'Mail',
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

types

The type definitions for the typed data.

const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain,
  types: { 
    Person: [
      { name: 'name', type: 'string' },
      { name: 'wallet', type: 'address' },
    ],
    Mail: [
      { name: 'from', type: 'Person' },
      { name: 'to', type: 'Person' },
      { name: 'contents', type: 'string' },
    ],
  },
  primaryType: 'Mail',
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

primaryType

Type: Inferred string.

The primary type to extract from types and use in value.

const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain,
  types: {
    Person: [
      { name: 'name', type: 'string' },
      { name: 'wallet', type: 'address' },
    ],
    Mail: [ 
      { name: 'from', type: 'Person' },
      { name: 'to', type: 'Person' },
      { name: 'contents', type: 'string' },
    ],
  },
  primaryType: 'Mail', 
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

message

Type: Inferred from types & primaryType.

const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain,
  types: {
    Person: [
      { name: 'name', type: 'string' },
      { name: 'wallet', type: 'address' },
    ],
    Mail: [
      { name: 'from', type: 'Person' },
      { name: 'to', type: 'Person' },
      { name: 'contents', type: 'string' },
    ],
  },
  primaryType: 'Mail', 
  message: { 
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})

Live Example

Check out the usage of signTypedData in the live Sign Typed Data Example below.

JSON-RPC Methods

JSON-RPC Accounts:
- eth_signTypedData_v4
Local Accounts
- Signs locally. No JSON-RPC request.

signTypedData ​

Usage ​

Account Hoisting ​

Returns ​

Parameters ​

account ​

domain ​

types ​

primaryType ​

message ​

Live Example ​

JSON-RPC Methods ​