Macro export_interface_spec 

export_interface_spec!() { /* proc-macro */ }

Anchor a #[contract] trait’s spec for inclusion. Spec shaking drops a trait’s (candidate) interface spec unless something anchors it — normally a #[contract] impl. Use this in an interface crate’s spec-carrier main.rs so building that crate on its own emits the interface’s full spec:

thruput_sdk::export_interface_spec!(thruput_erc20_if::ERC20);