This old helper looks similar to TransactionBuilder trait's build_unsigned, but it fills silently some fields while the latest returns an error with the list of missing fields.

So the remplacement is not "drop-in" - but I think - it is very beneficial. For now it used in 3 places:

• ‎EthApi::build_typed_tx_request, imo the whole method should be refactored, by prefilling request and then building typed tx.
  

  foundry/crates/anvil/src/eth/api.rs

  Line 3412 in b4d888b

  let request = match transaction_request_to_typed(request) {

• determine_base_gas_by_kind helper, I think we don’t need to build typed tx here as we can simply rely on TransactionBuilder fns to determine type, kind, and access list len.
  

  foundry/crates/anvil/src/eth/api.rs

  Line 3621 in b4d888b

  match transaction_request_to_typed(request.clone()) {

• ‎Backend::simulate‎, we can determine proactively tx type and fill missing fields using TransactionBuilder trait fns, or handle build_unsigned error, filling the fields we can then retry. btw this may be wrap into an helper providing similar service as original transaction_request_to_typed.
  

  foundry/crates/anvil/src/eth/backend/mem/mod.rs

  Line 1764 in b4d888b

  let request = transaction_request_to_typed(WithOtherFields::new(request))