Platform Integration

Flutter covers most UI and logic in Dart, but sometimes you need a platform feature it doesn't provide directly — a device sensor, a platform SDK, or an existing native library.

Plugins first

Most platform features are already wrapped as plugins on pub.dev: camera, geolocator, url_launcher, shared_preferences, local_auth, and many more. Each plugin contains Dart code plus native code for each platform. Always check pub.dev before writing your own.

Platform channels

To call your own native code, send messages over a method channel:

import 'package:flutter/services.dart';

class BatteryService {
  static const _channel = MethodChannel('com.example.app/battery');

  Future<int?> batteryLevel() async {
    try {
      return await _channel.invokeMethod<int>('getBatteryLevel');
    } on PlatformException catch (e) {
      print('Failed: ${e.message}');
      return null;
    }
  }
}

On Android, Kotlin code handles the call:

MethodChannel(flutterEngine.dartExecutor.binaryMessenger, "com.example.app/battery")
    .setMethodCallHandler { call, result ->
        if (call.method == "getBatteryLevel") {
            val manager = getSystemService(BATTERY_SERVICE) as BatteryManager
            result.success(manager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY))
        } else {
            result.notImplemented()
        }
    }

and Swift code does the same on iOS. Messages are asynchronous, so the Dart side awaits the result.

The pigeon package generates type-safe channel code for both sides from a single Dart definition, avoiding hand-written string method names.

FFI: calling C directly

dart:ffi calls C functions directly — with no message passing — which suits performance-critical native libraries (image codecs, crypto, databases like SQLite). The ffigen package generates Dart bindings from C header files.

Web

On the web, Dart talks to JavaScript through dart:js_interop and the package:web browser APIs, using extension types to describe JavaScript objects.

Which to use