Call Platform Code

Start with the highest-level boundary that solves the problem.

Choose The Boundary

Need	Use
Common device capability	Existing plugin
A few app-owned native calls	`MethodChannel`
Larger typed host API	Pigeon
C-compatible native library	FFI
Native UI inside Flutter	Platform view
Browser API on web	JS interop

MethodChannel Shape

Keep the Dart side small and typed at your app boundary:

import 'package:flutter/services.dart';

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

  Future<int> batteryLevel() async {
    final level = await _channel.invokeMethod<int>('batteryLevel');
    if (level == null) {
      throw StateError('Platform returned no battery level');
    }
    return level;
  }
}

Then hide BatteryService behind a repository or view model dependency so tests can fake it.

Rules

Document channel names and method names.
Validate arguments and nulls on both sides.
Keep platform calls asynchronous.
Test missing plugin and unsupported platform paths.
Avoid calling platform code directly from widgets.

Gotcha: Web does not use normal platform channels for browser APIs. Plan a web-specific interop path or mark web unsupported for the feature.