Port a TurboModule or Nitro module

TurboModule or Nitro	Lucent
the spec: NativeX.ts, or a Nitro .nitro.ts interface	the module's exports: its functions, types and classes
codegen, or Nitrogen	none: lucent build compiles the module
Objective-C++, Swift, Kotlin or C++ implementations	one .lucent.ts file, with a branch per platform
a Nitro hybrid object	an exported class: its instances cross by reference
Promise<T> methods	async exports; they run on the Lucent thread
events through RCTEventEmitter or listeners	a callback parameter and a stop function
ArrayBuffer	Uint8Array, copied
the library's podspec and Gradle file	lucent.json, if the module needs pods, dependencies or permissions

counter.lucent.ts

/** A Nitro hybrid object becomes a class: JavaScript holds one native instance. */
export class Counter {
  private value = 0;

  increment(by: number): number {
    this.value += by;
    return this.value;
  }

  async reset(): Promise<void> {
    this.value = 0;
  }
}

App.tsx

import { Counter } from "./src/counter.lucent";

const counter = new Counter();
counter.increment(2); // 2

Values that Nitro passes without copying, such as large arrays, are copied here. Keep them in native code across calls, as Design the boundary first shows.

Caution

This guide covers modules. Native views are experimental behind LUCENT_VIEWS=fabric; keep an existing production Fabric component as it is.