Flutter:Custom Voice Bot in Background like Google assistant or SIRI.

 - flutter_tts: ^3.3.3 (use for text to speech) - flutter_background_service: ^2.1.0 (use for handling app in background) - speech_to_text: (use for speech to text) 

 <queries> <intent> <action android:name="android.speech.RecognitionService"/> </intent> </queries> 

 <uses-permission android:name="android.permission.RECORD_AUDIO"/> <uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.BLUETOOTH"/> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/> <uses-permission android:name="android.permission.BLUETOOTH_CONNECT"/> 

 final service = FlutterBackgroundService(); Future initializeService()async{ await service.configure( androidConfiguration: AndroidConfiguration( // this will executed when app is in foreground or background in separated isolate onStart: onStart, // auto start service autoStart: true, isForegroundMode: true, ), iosConfiguration: IosConfiguration( // auto start service autoStart: true, // this will executed when app is in foreground in separated isolate onForeground: onStart, // you have to enable background fetch capability on xcode project onBackground: onIosBackground, ), ); await service.startService(); } bool onIosBackground(ServiceInstance service) { WidgetsFlutterBinding.ensureInitialized(); print('FLUTTER BACKGROUND FETCH'); return true; } void onStart(ServiceInstance service) async { // Only available for flutter 3.0.0 and later DartPluginRegistrant.ensureInitialized(); // For flutter prior to version 3.0.0 // We have to register the plugin manually if (service is AndroidServiceInstance) { service.on('setAsForeground').listen((event) { //set as foreground service.setAsForegroundService(); }); service.on('setAsBackground').listen((event) async { //set as background service.setAsBackgroundService(); }); } service.on('stopService').listen((event) { service.stopSelf(); }); // bring to foreground Timer.periodic(const Duration(seconds:1), (timer) async { if (service is AndroidServiceInstance) { service.setForegroundNotificationInfo( title: "My App Service", content: "Updated at ${DateTime.now()}", ); } /// you can see this log in logcat print('FLUTTER BACKGROUND SERVICE: ${DateTime.now()}'); // test using external plugin service.invoke( 'update', { "current_date": DateTime.now().toIso8601String(), "last_message": '_lastWords', }, ); }); } 

 final SpeechToText _speechToText = SpeechToText(); bool _speechEnabled = false; String _lastWords="Say something"; void _initSpeech() async { _speechEnabled = await _speechToText.initialize(); } void _startListening() async { await _speechToText.listen(onResult: _onSpeechResult); } void _stopListening() async { await _speechToText.stop(); } Future<void> _onSpeechResult(SpeechRecognitionResult result) async { var flutterTts = FlutterTts(); _lastWords=(result.recognizedWords.toString().toLowerCase()); if(_lastWords.contains("hello") || _lastWords.contains('help')) { flutterTts.speak("We are sending help"); } else if(_lastWords.contains('stop')) { _stopListening(); flutterTts.speak("Stopped"); } } 

 import 'dart:async'; import 'package:flutter_background_service/flutter_background_service.dart' show AndroidConfiguration, FlutterBackgroundService, IosConfiguration, ServiceInstance; import 'package:flutter/material.dart'; import 'background_service.dart'; Future<void> main() async { WidgetsFlutterBinding.ensureInitialized(); await initializeService(); runApp( const MyApp()); } class MyApp extends StatefulWidget { const MyApp({Key? key,}) : super(key: key); @override State<MyApp> createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { String text = "Stop Service"; @override Widget build(BuildContext context) { return MaterialApp( debugShowCheckedModeBanner: false, home: Scaffold( appBar: AppBar( title: const Text("Voice Bot"), ), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ //for listen Continuous change in foreground we will be using Stream builder StreamBuilder<Map<String, dynamic>?>( stream: FlutterBackgroundService().on('update'), builder: (context,snapshot){ if (!snapshot.hasData) { return const Center( child: CircularProgressIndicator(), ); } final data = snapshot.data!; String? lastMessage = data["last_message"]; DateTime? date = DateTime.tryParse(data["current_date"]); return Column( mainAxisAlignment: MainAxisAlignment.center, children: [ Text(lastMessage ?? 'Unknown'), Text(date.toString()), ], ); }), Padding( padding: const EdgeInsets.all(8.0), child: GestureDetector( child: Container( padding: const EdgeInsets.symmetric(vertical: 10,horizontal: 20), decoration: BoxDecoration( color: Colors.blueAccent, borderRadius: BorderRadius.circular(16) ), child: const Text("Foreground Mode",style: TextStyle( color: Colors.white ),)), onTap: () { FlutterBackgroundService().invoke("setAsForeground"); }, ), ), Padding( padding: const EdgeInsets.all(8.0), child: GestureDetector( child: Container( padding: const EdgeInsets.symmetric(vertical: 10,horizontal: 20), decoration: BoxDecoration( color: Colors.blueAccent, borderRadius: BorderRadius.circular(16) ), child: const Text("Background Mode",style: TextStyle( color: Colors.white ),)), onTap: () { print('start'); FlutterBackgroundService().invoke("setAsBackground"); }, ), ), Padding( padding: const EdgeInsets.all(8.0), child: GestureDetector( child: Container( padding: const EdgeInsets.symmetric(vertical: 10,horizontal: 20), decoration: BoxDecoration( color: Colors.blueAccent, borderRadius: BorderRadius.circular(16) ), child: Text(text,style: const TextStyle( color: Colors.white ),), ), onTap: () async { final service=FlutterBackgroundService(); var isRunning = await service.isRunning(); if (isRunning) { service.invoke("stopService"); } else { service.startService(); } if (!isRunning) { text = 'Stop Service'; } else { text = 'Start Service'; } setState(() {}); }, ), ), ], ), ), ), ); } }