jsi

What problem does it solve?

JSI provides a direct interface for native C++ code to interact with the JavaScript engine in React Native, enabling reading and writing JS values, calling JS functions, and exposing C++ objects to JS without going through the old bridge.

Core Features & Use Cases

• Access and manipulate JS values from C++ using jsi::Value, jsi::Object, and related types.
• Create HostFunction and HostObject bindings to expose native functionality to JavaScript and to implement dynamic object shapes from C++.
• Call JS from native threads safely using CallInvoker, and construct promises or other JS objects from C++.
• Use PropNameID optimization, Scope for temporary values, and NativeState / WeakObject for lifecycle control.

Quick Start

Install JSI bindings during module initialization and expose a minimal HostFunction on the global object, then invoke it from JavaScript to verify end-to-end binding.