# eip712HashTypedData

Description: eip712HashTypedData cheatcode documentation

Note: This document was authored using MDX

  Source: https://github.com/NomicFoundation/hardhat-website/tree/main/src/content/docs/docs/reference/cheatcodes/Utilities/eip712-hash-typed-data.mdx

### Signature

```solidity
function eip712HashTypedData(
  string calldata jsonData
) external pure returns (bytes32);
```

### Description

Returns the complete EIP-712 digest: `keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash))`.

`jsonData` must be a self-describing EIP-712 JSON payload containing `domain`, `types`, `primaryType`, and `message` fields. This cheatcode is fully self-contained and **does not** require any `eip712Types` configuration in your `hardhat.config.ts`.

### Example

```solidity
string memory json = '{'
    '"domain":{"name":"Ether Mail","version":"1","chainId":1,"verifyingContract":"0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"},'
    '"types":{'
        '"EIP712Domain":[{"name":"name","type":"string"},{"name":"version","type":"string"},{"name":"chainId","type":"uint256"},{"name":"verifyingContract","type":"address"}],'
        '"Mail":[{"name":"from","type":"Person"},{"name":"to","type":"Person"},{"name":"contents","type":"string"}],'
        '"Person":[{"name":"wallet","type":"address"},{"name":"name","type":"string"}]'
    '},'
    '"primaryType":"Mail",'
    '"message":{"from":{"wallet":"0xA","name":"Alice"},"to":{"wallet":"0xB","name":"Bob"},"contents":"hello"}'
'}';

bytes32 digest = cheats.eip712HashTypedData(json);
```

### SEE ALSO

- [eip712HashType](/docs/reference/cheatcodes/utilities/eip712-hash-type)
- [eip712HashStruct](/docs/reference/cheatcodes/utilities/eip712-hash-struct)
- [EIP-712 type hashing guide](/docs/guides/testing/eip712-types)