EIP-712 Typed Data Builder

Compose EIP-712 typed data — domain, types, and message — and get the canonical JSON payload plus the digest hash.

Domain

name

version

chainId

verifyingContract

salt (optional, 32-byte hex)

Types

Types JSON (EIP712Domain is auto-derived from the domain fields)

Primary Type & Message

primaryType

message JSON

Digest Hash

0x4644890d40a2ebb8cbf599801c4412c03f8027f04044d0dd12a0605fbd72bb8b

Canonical Payload (wallet_signTypedData_v4)

{
  "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"
      }
    ],
    "Mail": [
      {
        "name": "from",
        "type": "Person"
      },
      {
        "name": "to",
        "type": "Person"
      },
      {
        "name": "contents",
        "type": "string"
      }
    ]
  },
  "primaryType": "Mail",
  "domain": {
    "name": "Ether Mail",
    "version": "1",
    "chainId": 1,
    "verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
  },
  "message": {
    "from": {
      "name": "Alice",
      "wallet": "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826"
    },
    "to": {
      "name": "Bob",
      "wallet": "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB"
    },
    "contents": "Hello, Bob!"
  }
}

{ "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" } ], "Mail": [ { "name": "from", "type": "Person" }, { "name": "to", "type": "Person" }, { "name": "contents", "type": "string" } ] }, "primaryType": "Mail", "domain": { "name": "Ether Mail", "version": "1", "chainId": 1, "verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC" }, "message": { "from": { "name": "Alice", "wallet": "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826" }, "to": { "name": "Bob", "wallet": "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB" }, "contents": "Hello, Bob!" } }