NAC Gateway

NAC (Cross-Runtime Atomic Calls) is the Tezos X mechanism for atomically forwarding EVM transactions to the Tezos L1 Michelson layer.

Entrypoints

Context	Entrypoint	Use case
Native transfer (tez)	default	Send XTZ to a Tezos address
Smart contract call (EVM→Michelson)	callMichelson	Call a Michelson contract from EVM
Smart contract call (Michelson→EVM)	call_evm	Call an EVM contract from Michelson

Micheline structure

For a callMichelson call, the relayer builds:

Pair(
  destination_kt1,
  Pair(
    entrypoint_name,
    calldata_bytes
  )
)

Flow

Sender identity

When a transaction passes through NAC:

• Tezos.get_sender inside a Michelson contract = the user's mapped tz1 address
• The kernel resolves the EVM caller's identity and forwards it as the sender to the Michelson contract

info

Tezos.get_sender returns the original caller's tz1 address (mapped from the EVM alias), not the NAC gateway address.