Find an SDK class

lucent sdk search finds classes and members with the import to copy; lucent sdk show prints what Lucent code sees.

npx lucent sdk search BatteryManager

android  android.os
  class  BatteryManager  import { BatteryManager } from "lucent:android/android.os";

searched 297 modules of 299 (your imports and the SDK cache; lucent sdk prefetch --all to search every module)

The search matches classes and members, in the modules you import and those already cached. The import line is ready to copy. To search everything, run lucent sdk prefetch --all once.

npx lucent sdk show UIKit.UIDevice.batteryLevel

// lucent:ios/UIKit
export declare class UIDevice extends NSObject {
  readonly batteryLevel: number;
}

sdk show prints what Lucent code sees: a class, or one member. Name it as <module>.<Class>, such as UIKit.UIDevice or android.os.BatteryManager. Doc comments say when a class is main-thread only, and the OS version each member needs.

Your editor shows the same declarations, since lucent build writes them to .lucent/native/types/.

Start

What is Lucent Install Lucent Your first module

Tutorial: a trip tracker

1. Measure a trip in shared code 2. Keep the trip in native code 3. Simplify the route off the JS thread 4. Throw errors JavaScript can handle 5. Read the position from iOS and Android 6. Send live positions to JavaScript 7. Ask for the location permission 8. Publish the module as a package

How Lucent works

How a module becomes native code How a call reaches native code How an SDK call reaches iOS and Android

Thinking in Lucent

Three places your code runs Design the boundary first Write shared code first, platform code last Which thread your code runs on When memory is freed What changes from JavaScript Coming from Swift or Kotlin

Guides

Call an iOS API Call an Android API Find an SDK class Implement a delegate or listener Send events to JavaScript Accept a JS callback Run work off the JS thread Cancel work Run code on the main thread Present a view controller Throw and handle errors Check the OS version Share code between iOS and Android Add permissions and native config Use a third-party SDK Publish a Lucent library Use a Lucent library Port an Expo Module Port a TurboModule or Nitro module Test a module Debug a crash Measure performance Upgrade Xcode, the Android SDK or Lucent

Reference

Language features Built-ins Types across the boundary SDK types The lucent:* modules CLI lucent.json Metro, Expo and editor options Diagnostics Compatibility

Examples

Examples that call iOS and Android Clipboard Location Network state Local authentication Secure store Haptics

More

Lucent, Expo Modules, Nitro and Turbo Native Modules Frequently asked questions Roadmap