Sign Typed Data lets you create an EIP-712 signature. Use Case: This command is essential for applications that require structured data to be signed. Example: An insurance platform that requires users to sign typed data to confirm the terms of their insurance policy.
Note: The EIP712Domain must always include chainId. On Worldchain, only custom typed data is permitted.
  • SafeTx and Permit/Permit2 types are not allowed.
On all other chains, any valid EIP-712 structure is supported, including SafeTx and Permit types. 
{
  types: {
    YourTypes: [
      { type: 'bytes', name: 'data' },
      { type: 'uint8', name: 'operation' },
    ],
    EIP712Domain: [
      { type: 'uint256', name: 'chainId' },
      { type: 'address', name: 'verifyingContract' },
    ],
  },
  domain: {
    chainId: 480,
    verifyingContract: "0x1234...",
  },
  primaryType: 'YourTypes',
  message:{ data: '0xffffffff', operation: 15}
}

​
Using the command

​
Sending the command & handling the response

import type { TypedData, TypedDataDomain } from 'abitype'

export type SignTypedDataInput = {
  types: TypedData
  primaryType: string
  message: Record<string, unknown>
  domain: TypedDataDomain
}

type MiniAppSignTypedDataSuccessPayload = {
  status: 'success'
  signature: string
  address: string
  version: number
}
app/page.tsx
import { MiniKit, SignTypedDataInput } from '@worldcoin/minikit-js'

  const signAndVerifyTypedData = async () => {
    if (!MiniKit.isInstalled()) {
      return
    }

    const {finalPayload} = await MiniKit.commandsAsync.signTypedData(
      somePayloadforEIP712 as SignTypedDataInput;
    );

    if (payload.status === 'success') {
      const messageHash = hashSafeMessage(signTypedDataPayload)

      const isValid = await (
        await Safe.init({
          provider: 'https://worldchain-mainnet.g.alchemy.com/v2/your-api-key',
          safeAddress: payload.address,
        })
      ).isValidSignature(messageHash, payload.signature)

      // Checks functionally if the signature is correct
      if (isValid) {
        console.log('Signature is valid')
      }
    }
  };