Implicit Export

Property	Value
Rule Code	NTX9
Severity	Important

Background

Explicitly listing exported functions improves code clarity and reduces the risk of unintentionally exposing internal functions. It makes the contract's public interface clear and well-defined.

Purpose

Detects when a module exposes all its functions using the __interface__ expression without explicitly listing them.

Example

Consider you have a module erc20.vy:

# erc20


@external
def transfer():
    # ... does something ...
    pass

@external
def mint():
    # ... does something else ...
    pass

And you import it in another contract:

# my_token.vy
import erc20

# Non-compliant - exposes all functions from MyHelperFunctions, including potentially _internal_logic
exports: (erc20.__interface__) # this also exposes the function to mint, which might not always be intended

# my_token.vy
import erc20

# Compliant - explicitly lists the functions to be exposed
exports: (erc20.transfer, erc20.mint) # you can clearly tell that you are exposing a function to mint

Automatic Fix

Natrix can automatically generate the explicit exports for you. Simply run:

natrix codegen exports path/to/erc20.vy

This will output the explicit exports declaration that you can copy into your contract.