8. Publish the module as a package

package.json

trip-tracker/package.json

{
  "name": "trip-tracker",
  "version": "1.0.0",
  "files": [
    "index.ts",
    "src",
    "lucent.json"
  ],
  "main": "index.ts",
  "lucent": {
    "sources": "src",
    "compatible": ">=0.0.3"
  }
}

lucent.json

trip-tracker/lucent.json

{
  "ios": {
    "infoPlist": {
      "NSLocationWhenInUseUsageDescription": "Trip Tracker records your route while you track a trip."
    }
  }
}

index.ts

trip-tracker/index.ts

export * from "./src/trip.lucent";
export * from "./src/location.lucent";

App.tsx

App.tsx

import { useEffect, useState } from "react";
import { PermissionsAndroid, Platform, Text } from "react-native";
import { requestPermission, stop, watch } from "./src/location.lucent";
import { Trip, type TripSummary } from "./src/trip.lucent";
import { requestPermission, stop, Trip, type TripSummary, watch } from "trip-tracker";

const trip = new Trip();

Move src/ into a folder of its own, trip-tracker/, and add these three files. The package ships the modules as source: an app that installs it compiles them with its own modules, into its one native package.

• lucent.sources names the folder with the modules. lucent.compatible is the range of Lucent versions the package supports.
• index.ts re-exports the modules. Metro swaps each for its proxy, as in an app.
• lucent.json lists what the modules need from the app. Here it's the Info.plist entry, so apps no longer add it by hand.
• The modules are named trip-tracker/trip and trip-tracker/location, so they can't clash with an app's own trip module.

terminal

npm publish

In an app that installs trip-tracker, lucent build finds it and builds its modules. The Expo config plugin writes the Info.plist entry. In a bare app, lucent build names the missing key:

terminal

✓ Native package  .lucent/native
! trip-tracker needs NSLocationWhenInUseUsageDescription in ios/App/Info.plist (the Expo config plugin adds it)

modules  trip-tracker/location  ios android
         trip-tracker/trip      shared

You've built a module with shared logic, async work, errors, platform code, callbacks and permissions, and published it. The examples show more modules built the same way.