signMessage

Calculates an Ethereum-specific signature in EIP-191 format: keccak256("\x19Ethereum Signed Message:\n" + len(message) + message)).

With the calculated signature, you can:

use verifyMessage to verify the signature,
use recoverMessageAddress to recover the signing address from a signature.

Usage

example.tsconfig.ts

import { account, walletClient } from './config'
 
const signature = await walletClient.signMessage({ 
  account,
  message: 'hello world',
})
// "0xa461f509887bd19e312c0c58467ce8ff8e300d3c1a90b608a760c5b80318eaf15fe57c96f9175d6cd4daad4663763baa7e78836e067d0163e9a2ccf2ff753f5b1b"

const signature = await walletClient.signMessage({
  account,
  // Hex data representation of message.
  message: { raw: '0x68656c6c6f20776f726c64' },
})
// "0xa461f509887bd19e312c0c58467ce8ff8e300d3c1a90b608a760c5b80318eaf15fe57c96f9175d6cd4daad4663763baa7e78836e067d0163e9a2ccf2ff753f5b1b"

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(...)

Account Hoisting

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

Learn more.

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

import { walletClient } from './config'
 
const signature = await walletClient.signMessage({ 
  message: 'hello world',
})
// "0xa461f509887bd19e312c0c58467ce8ff8e300d3c1a90b608a760c5b80318eaf15fe57c96f9175d6cd4daad4663763baa7e78836e067d0163e9a2ccf2ff753f5b1b"

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

Hex

The signed message.

Parameters

account

Type: Account | Address

Account to use for signing.

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

const signature = await walletClient.signMessage({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266', 
  message: 'hello world',
})

data

Type: string | { raw: Hex | ByteArray }

Message to sign.

By default, viem signs the UTF-8 representation of the message.

const signature = await walletClient.signMessage({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  message: 'hello world', 
})

To sign the data representation of the message, you can use the raw attribute.

const signature = await walletClient.signMessage({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  message: { raw: '0x68656c6c6f20776f726c64' }, 
})

JSON-RPC Methods

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

signMessage ​

Usage ​

Account Hoisting ​

Returns ​

Parameters ​

account ​

data ​

JSON-RPC Methods ​