The template generated with bundle gem —-ext=rust uses the Magnus[1] library that provides a high-level friendly Rust wrapper over the Ruby C API, but you can a

The template generated with bundle gem —-ext=rust uses the Magnus[1] library that provides a high-level friendly Rust wrapper over the Ruby C API, but you can also use rb-sys[2] which is lower level bindings direct to the Ruby C API. [1]: https://github.com/matsadler/magnus https://github.com/matsadler/magnus [2]: https://github.com/oxidize-rb/rb-sys https://github.com/oxidize-rb/rb-sys