It's mostly straightforward, you just define with #[no_mangle] + extern fn ... The Rust docs cover it in small detail[1]. FWIW you can do the same with JNI and

It's mostly straightforward, you just define with #[no_mangle] + extern fn ... The Rust docs cover it in small detail[1]. FWIW you can do the same with JNI and have direct Java->Rust bindings. If you want to get really clever you can even parse the Rust AST(using syntex) to auto-generate java/headers(there may be libs to do this now, I haven't looked in a while). What's nice about the C FFI is you can pretty much embed Rust anywhere, I've used it in C/C++, Java, C# and Python pretty easily. [1] https://doc.rust-lang.org/book/second-edition/ch19-01-unsafe-rust.html#calling-rust-functions-from-other-languages https://doc.rust-lang.org/book/second-edition/ch19-01-unsafe...