hush-plugin — Macro for building Hush workflow op plugins as cdylib crates.

Provides the hush_plugin! macro that generates the C ABI exports required for hush-serve to load your ops at runtime via libloading.

Usage

// In your Cargo.toml:
// [lib]
// crate-type = ["cdylib"]
//
// [dependencies]
// serde_json = "1"
// hush-plugin = { path = "../../rust/hush-plugin" }

mod math;
mod text;

hush_plugin::hush_plugin! {
    call: {
        "double" => math::double,
        "clean_text" => text::clean_text,
    },
    call_generator: {
        "range_gen" => math::range_gen,
    }
}

C ABI Contract

The macro generates three extern "C" functions:

• hush_call(name, inputs_json) -> *mut c_char — call a regular op
• hush_call_generator(name, inputs_json) -> *mut c_char — call a generator op
• hush_free_str(ptr) — free a string returned by the above

Data crosses the FFI boundary as null-terminated JSON strings. Returns null if the op name is not found.