[Feature] Ability to prove historical account state (e.g. balance, nonce, codeHash, storageRoot) using Steel

[willemolding]

Feature

Currently the Steel API only supports proving the result of contract calls. It also be useful to be able to prove other historical chain state, in this case the state of accounts/contracts.

Motivation

While a workaround is to deploy a contract that returns the desired values certain applications may wish to read this state directly rather than taking this approach. For example when reading values far into the past such a function may not have been deployed.

Implementation

API

It probably makes sense to follow the function name conventions of alloy providers e.g. get_balance, get_code_at, get_transaction_count on the guest side.

One idea for the host might be to add a include method to EvmEnv which accepts an enum with variants corresponding to the different account state values function calls e.g.

// Host
let mut env = EthViewCallEnv::from_rpc(&args.rpc_url, None)?;
env.include(BalanceOf(address))
env.include(CodeAt(address))

// Guest
let env = input.into_env()
env.get_balance(address)
env.get_code_at(address)

but other ideas also welcome

[linear]

WEB3-276 [Feature] Ability to prove historical account state (e.g. balance, nonce, codeHash, storageRoot) using Steel