Packages

uniffi-bindgen-react-native is a command line tool, ubrn, that turns the [uniffi::export] proc-macros in your Rust crate into TypeScript (and, for React Native, C++). The generated code is specific to your library, and leans on a small, fixed runtime — the FFI converters, marshalling, callback dispatch and library loading — that is the same for every library and so is shipped separately.

What a new project installs

The runtime is published under the @ubjs scope. A freshly generated project depends on:

• @ubjs/core is the TypeScript runtime (FFI converters, RustBuffer, polyfills), shared by every target. New generated code imports it.
• @ubjs/node is a single prebuilt N-API addon that loads your compiled cdylib at runtime and calls into it with libffi. Because UniFFI uses a small, fixed set of FFI types, one addon works with any UniFFI library — there is no per-library glue to compile. See the Node.js reference.
• For React Native, the C++/JSI runtime ships inside the uniffi-bindgen-react-native package (the uniffi-bindgen-react-native.podspec and cpp/includes), which the generated turbo-module compiles against. Start with the React Native tutorial; the Web tutorial extends it.

The uniffi-bindgen-react-native package itself is the ubrn command line and the React Native build tooling. On React Native it is a regular dependency (for the C++ runtime above); for a Node.js-only project it is only needed at build time, as a dev dependency.

Existing projects keep working

@ubjs/core is new. Code generated before it existed imports the runtime from uniffi-bindgen-react-native instead, and that package still ships the same runtime bytes under its old name — so projects that haven’t regenerated need no changes. The two are version-locked.