Rito for React Native

React Native bindings for the Rito EPUB engine, published as @umbrae-labs/rito-rn.

Important

This is an unofficial, community-maintained adaptation of Rito, maintained by Umbrae Labs for Lunar.

Precompiled Rust engine

The release pipeline builds the Rust engine before publishing and includes the libraries in the npm package. Application builds link these libraries and compile the Nitro C++ bridge against the application's React Native and Nitro versions. Consumers of binary releases can build their applications without installing Rust or cargo-ndk. Standard Android or Xcode build tools are still required.

Platform	Included Rust library	Architectures
Android	librito_ffi.a	arm64-v8a
iOS device	Static library in RitoFFI.xcframework	ARM64
iOS simulator	Static library in RitoFFI.xcframework	ARM64 and x86_64

Note

Version 0.2.0 was published as a source-only package. Precompiled libraries become available in releases built with this publishing configuration. Upgrade the npm dependency to such a release to use them.

Installation

pnpm add @umbrae-labs/rito-rn react-native-nitro-modules@0.37.0

npm tag	Engine
latest	Rito upstream release (master)
canary	Rito upstream development (dev)
lunar	Rito dev with Lunar kernel changes and bindings

Use a native application build after installing or upgrading this package so the native library changes are included.

Component	Development baseline
React Native	0.86.3 with the New Architecture
React	19.2.3
Nitro Modules	0.37.0
Expo integration	SDK 57
Node.js	22 or newer

Android

For Expo projects, add the plugin to the existing plugins array in the app configuration. The plugin sets reactNativeArchitectures to arm64-v8a.

{
  "expo": {
    "plugins": ["@umbrae-labs/rito-rn"]
  }
}

pnpm exec expo prebuild --platform android
pnpm exec expo run:android

For plain React Native projects, autolinking discovers the package. Set reactNativeArchitectures=arm64-v8a in android/gradle.properties.

Configure the Android SDK, NDK and JDK for the host React Native version. The bundled Rust library is built with NDK 27.1.12297006 and API 23; the application must also meet React Native's minimum SDK requirement. Android x86_64 emulators and 32-bit targets are outside the current package's supported architectures.

iOS

On macOS, install pods using the application's usual CocoaPods command after adding the package. Autolinking loads the podspec, which validates RitoFFI.xcframework; CocoaPods selects the device or simulator library.

The Rust libraries target iOS 15.1 or newer. The application's minimum iOS version must also satisfy its React Native version. The default pod configuration links the bundled library without adding a Rust compilation phase.

Source development

To modify the engine or use a source-only archive, enable RITO_BUILD_FROM_SOURCE=1. Android also accepts ritoBuildFromSource=true in Gradle properties. On iOS, set the environment variable when running pod install and when building; rerun pod installation without it to return to precompiled mode.

Source builds require Rust 1.95.0 and the appropriate target toolchains. Android also requires cargo-ndk 4.1.2. RITO_FFI_SOURCE_DIR selects a custom Rust workspace and enables source mode. See CONTRIBUTING.md for kernel branches, tooling checks and packaging commands.

Directory	Purpose
src	TypeScript API, reader sessions and protocol handling
cpp, android, ios	Nitro bridge and platform integration
upstream/rito	Rito fork submodule for engine development
native/rito	Generated Rust source included in npm packages
prebuilt	Generated Rust binaries and verification manifests

License

AGPL-3.0-only. Rito and vendored Parley retain their license files. See NOTICE for attribution.