Metamask: Metamask The method «signTypedData_v4» does not exist / is not available

Bug with Metamask and Signed Data Version 4 (v3)

Since my last update, Metamask has a limitation regarding 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 will provide some workarounds and explanations of how this limitation affects you:

What does «signTypedData_v4» do?

signedTypedData_v4 is a method used by Ethereum 2.0 to transfer signed type data between the Ethereum Virtual Machine (EVM) and the signer contract in Metamask.

Why is «signTypedData_v4» not available in the latest protocol standards?

The latest protocol standards for Signed Type Data version 4 do not include the signTypedData_v4 method. This change may 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 typed data version 3 (v2): You can still use typed data with a metamask if you specify the SignedTypedData_v2 format instead. This will allow you to transfer signed data between the EVM and the Contract Signer.

const typedData = new TypedData.SignedTypedDataV2({
type: ' SignedTypedData_v2',
value: {
// Your signed typed data here
}
});

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

• Consider upgrading to Ethereum 2.0

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

If you are looking for more information on how to get around this limitation, let me know!