Abstract
Defines a new JSON-RPC method which enables apps to ask a wallet to sign EIP-191 messages.
Applications can use this JSON-RPC method to request a signature over any version of signed_data as defined by EIP-191. The new JSON-RPC method allows for support of future EIP-191 signed_data versions.
The new JSON-RPC method also supports EIP-5792-style capabilities, and support for signing capabilities can be discovered using wallet_getCapabilities as defined in EIP-5792.
Motivation
Wallets and developer tools currently support multiple JSON-RPC methods for handling offchain signature requests. This proposal simplifies wallet & tooling implementations by consolidating these requests under a single wallet_sign JSON-RPC method. This also leaves room for new EIP-191 signed_data versions without needing to introduce a new corresponding JSON-RPC method.
Furthermore, this new wallet_sign method introduces new functionalities via EIP-5792-style capabilities.