# eth_signTypedData_v4

> Request EIP-712 structured typed data signatures using eth_signTypedData_v4 for human-readable, verifiable signing in MetaMask.

<SimplifiedApiReference
  method="eth_signTypedData_v4"
  description="Signs structured data according to EIP-712, which provides a more secure way to sign data by providing context and structure to the data being signed."
  parameters={[
    {
      name: 'address',
      type: 'string',
      required: true,
      description: 'The address that should sign the data (20 bytes).',
    },
    {
      name: 'typedData',
      type: 'object',
      required: true,
      description: 'The typed structured data to be signed.',
      children: [
        {
          name: 'types',
          type: 'object',
          required: true,
          description: 'An object containing type definitions for the structured data.',
        },
        {
          name: 'primaryType',
          type: 'string',
          required: true,
          description: 'The primary type from the types object that will be signed.',
        },
        {
          name: 'domain',
          type: 'object',
          required: true,
          description: 'The domain separator as defined by EIP-712.',
          children: [
            {
              name: 'name',
              type: 'string',
              required: false,
              description: 'The user-readable name of the signing domain.',
            },
            {
              name: 'version',
              type: 'string',
              required: false,
              description: 'The current major version of the signing domain.',
            },
            {
              name: 'chainId',
              type: 'number',
              required: false,
              description: 'The chain ID of the network.',
            },
            {
              name: 'verifyingContract',
              type: 'string',
              required: false,
              description: 'The address of the contract that will verify the signature.',
            },
            {
              name: 'salt',
              type: 'string',
              required: false,
              description: 'A disambiguating salt for the protocol.',
            },
          ],
        },
        {
          name: 'message',
          type: 'object',
          required: true,
          description: 'The data object to be signed according to the primary type.',
        },
      ],
    },
  ]}
  returns={{
    type: 'string',
    description: 'The signature as a hexadecimal string.',
  }}
  errors={[
    {
      code: 4001,
      message: 'User rejected the request',
      description: 'User denied the signing request',
    },
    {
      code: 4100,
      message: 'Requested method not supported',
      description: 'The method is not supported by the wallet',
    },
    {
      code: -32602,
      message: 'Invalid params',
      description: 'Invalid typed data structure',
    },
  ]}
  exampleRequest={`await provider.request({
    method: 'eth_signTypedData_v4',
    params: [
      '0x3b7252d007059ffc82d16d022da3cbf9992d2f70',
      {
        types: {
          EIP712Domain: [
            { name: 'name', type: 'string' },
            { name: 'version', type: 'string' },
            { name: 'chainId', type: 'uint256' },
            { name: 'verifyingContract', type: 'address' },
          ],
          Person: [
            { name: 'name', type: 'string' },
            { name: 'wallet', type: 'address' },
          ],
        },
        primaryType: 'Person',
        domain: {
          name: 'Example App',
          version: '1',
          chainId: 1,
          verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
        },
        message: {
          name: 'Alice',
          wallet: '0x3b7252d007059ffc82d16d022da3cbf9992d2f70',
        },
      },
    ],
})`}
  exampleResponse={`{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c"
}`}
/>