Introduction

React Native Native lets you write native components and modules in any compiled language — Rust, C++, Kotlin/Compose, Swift/ObjC — and hot-reload them on a physical device, just like JavaScript.

Why?

React Native's native module system requires you to write Swift/Kotlin wrappers, maintain Xcode/Android Studio projects, and rebuild the entire app for every change. React Native Native removes all of that:

• Write native code in your editor — no IDE switching
• Save and see — Metro compiles, signs, and hot-reloads native code on device
• Full platform SDK access — use any iOS framework or Android API directly
• Works with Expo — drops into any Expo project as a module

How it works

Your native code becomes a React component or module that JS can use like any other:

import { fibonacci } from './rust_math';    // Rust function
import GradientBox from './GradientBox';    // ObjC++ component

<Text>{fibonacci(10)}</Text>
<GradientBox title="Hello!" style={{ width: 300, height: 200 }} />

Development

Metro watches your native files alongside JavaScript. When you save a .cpp, .rs, .swift, or .kt file:

1. Metro compiles it to a signed dynamic library (.dylib on iOS, .dex on Android)
2. Device pulls the compiled library over HTTP — same as a JS bundle refresh
3. Runtime loads it via dlopen (iOS) or DexClassLoader (Android)
4. Hot-reload — your changes appear on device in seconds, no full rebuild

Save .cpp → Metro compiles → device loads .dylib → hot-reload

This works on both simulators and physical devices. Metro auto-detects the target architecture and compiles accordingly.

Production

In release builds, all native code is statically linked into the app binary. No dynamic libraries, no runtime code loading.

iOS — A CocoaPods script phase runs before compilation:

1. Scans your project for native files (.cpp, .mm, .swift, .rs)
2. Generates combined bridge files — one .mm for all C++/ObjC++ bridges, one .swift for all Swift bridges
3. Compiles Rust into a single static library (libnativ_user.a)
4. Xcode compiles and links everything into the app binary

Android — A Gradle pre-build task does the same:

1. Generates per-module bridge files and Kotlin wrappers
2. Compiles Rust for all ABIs (arm64, armv7, x86_64, x86)
3. Gradle compiles and packages everything into the APK

Metro only bundles JavaScript in production — all native code is handled by the platform build system.

# Build for release — native compilation is automatic
npx expo run:ios --configuration Release
npx expo run:android --variant release

See Production Builds for details on EAS Build and CI setup.

Known issues

• Zig support — planned but not yet available.

Language setup

C++, Objective-C++, and Swift work out of the box with no additional setup. Some languages have additional setup steps for your development environment — see the individual language guides for details:

• Rust — install Rust targets and create Cargo.toml
• Kotlin — download the Kotlin compiler toolchain
• Kotlin with Compose — additional Compose compiler toolchain

Next steps