Metamask: Metamask The method “signTypedData_v4” does not exist / is not available

Error with Metamask and Signed Type Data Version 4 (v3)

As of my last update, Metamask has a limitation regarding its support for Signed Type Data version 4. The “signTypedData_v4” method is indeed not available in the latest protocol standards.

This means that when you try to use signed type data with metamask, you will encounter an error message indicating that it does not exist. However, I’ll provide some workarounds and explanations for how this limitation affects you:

What does “signTypedData_v4” do?

signedTypedData_v4 is a method used by Ethereum 2.0 to transmit signed type data between the Ethereum Virtual Machine (EVM) and the Signer contract in metamask.

Why is “signTypedData_v4” not available in latest protocol standards?

The latest protocol standards for Signed Type Data version 4 do not include the signTypedData_v4 method. This change might have been made to accommodate new features or improve performance.

Workarounds and Solutions

Since the signTypedData_v4 method is no longer supported, you can use one of the following alternatives:

• Use Signed Type Data version 3 (v2): You can still use signed type data with metamask by specifying the SignedTypedData_v2 format instead. This will allow you to transmit signed type data between the EVM and the Signer contract.

const typedData = new TypedData.SignedTypedDataV2({

  type: 'SignedTypedData_v2',

  value: {

    // Your signed type data here

  }

});

• Use a library or module that supports Signed Type Data: There are libraries and modules available that provide support for Signed Type Data, such as metamask-unsigned-typedata. These libraries might offer more features and flexibility than metamask’s built-in support.

• Consider upgrading to Ethereum 2.0

  

  : If you plan on using Ethereum 2.0 or its associated software (such as Metamask), you should be aware that signed type data is currently supported in the latest protocol standards.

Conclusion

In summary, due to the limitation of the signTypedData_v4 method, you cannot use it with metamask’s Signed Type Data version 4. You can still use signed type data with metamask by specifying the SignedTypedData_v2 format or using a library that supports it.

If you’re looking for more information on how to work around this limitation, please let me know!