# signTypedData

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

## Usage

:::code-group

```ts twoslash [example.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!',
  },
})
```

```ts twoslash [data.ts]
// 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
```

```ts twoslash [config.ts] filename="config.ts"
// [!include ~/snippets/walletClient.ts]

export const [account] = await walletClient.getAddresses()
// @log: ↑ JSON-RPC Account

// export const account = privateKeyToAccount(...)
// @log: ↑ Local Account
```

:::

### 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](/docs/clients/wallet#withaccount).

:::code-group

```ts twoslash [example.ts]
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!',
  },
})
```

```ts twoslash [data.ts]
// 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
```

```ts [config.ts (JSON-RPC Account)]
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!)
})
```

```ts twoslash [config.ts (Local Account)] filename="config.ts"
import { createWalletClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'

export const walletClient = createWalletClient({
  account: privateKeyToAccount('0x...'),
  transport: http()
})
```

:::

## Returns

`0x${string}`

The signed data.

## Parameters

### account

* **Type:** `Account | Address`

The Account to use for signing.

Accepts a [JSON-RPC Account](/docs/clients/wallet#json-rpc-accounts) or [Local Account (Private Key, etc)](/docs/clients/wallet#local-accounts-private-key-mnemonic-etc).

```ts twoslash
// [!include ~/snippets/walletClient.ts]
// ---cut---
const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266', // [!code focus]
  domain: {
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  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!',
  },
})
```

### domain

**Type:** `TypedDataDomain`

The typed data domain.

```ts twoslash
// [!include ~/snippets/walletClient.ts]
// ---cut---
const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain: { // [!code focus:6]
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  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!',
  },
})
```

### types

The type definitions for the typed data.

```ts twoslash
// [!include ~/snippets/walletClient.ts]
// ---cut---
const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain: { 
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  types: { // [!code focus:11]
    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`.

```ts twoslash
// [!include ~/snippets/walletClient.ts]
// ---cut---
const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain: { 
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  types: {
    Person: [
      { name: 'name', type: 'string' },
      { name: 'wallet', type: 'address' },
    ],
    Mail: [ // [!code focus:5]
      { name: 'from', type: 'Person' },
      { name: 'to', type: 'Person' },
      { name: 'contents', type: 'string' },
    ],
  },
  primaryType: 'Mail', // [!code focus]
  message: {
    from: {
      name: 'Cow',
      wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
    },
    to: {
      name: 'Bob',
      wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
    },
    contents: 'Hello, Bob!',
  },
})
```

### message

**Type:** Inferred from `types` & `primaryType`.

```ts twoslash
// [!include ~/snippets/walletClient.ts]
// ---cut---
const signature = await walletClient.signTypedData({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  domain: { 
    name: 'Ether Mail',
    version: '1',
    chainId: 1,
    verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
  },
  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: { // [!code focus:11]
    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](https://stackblitz.com/github/wevm/viem/tree/main/examples/signing_typed-data) below.

<iframe frameBorder="0" width="100%" height="500px" src="https://stackblitz.com/github/wevm/viem/tree/main/examples/signing_typed-data?embed=1&file=index.ts&hideNavigation=1&hideDevTools=true&terminalHeight=0&ctl=1" />

## JSON-RPC Methods

* JSON-RPC Accounts:
  * [`eth_signTypedData_v4`](https://docs.metamask.io/guide/signing-data#signtypeddata-v4)
* Local Accounts
  * Signs locally. No JSON-RPC request.