AI Voice Agent with Flutter

import 'dart:convert';
import 'package:http/http.dart' as http;

//Auth token we will use to generate a meeting and connect to it
const token =
    'YOUR_ZRT_AUTH_TOKEN';

// API call to create meeting
Future<String> createMeeting() async {
  final http.Response httpResponse = await http.post(
    Uri.parse('https://api.videosdk.live/v2/rooms'),
    headers: {'Authorization': token},
  );

  //Destructuring the roomId from the response
  return json.decode(httpResponse.body)['roomId'];
}

import 'package:flutter/material.dart';
import 'api_call.dart';
import 'meeting_screen.dart';

class JoinScreen extends StatelessWidget {
  final _meetingIdController = TextEditingController();

  JoinScreen({super.key});

  void onCreateButtonPressed(BuildContext context) async {
    // call api to create meeting and navigate to MeetingScreen with meetingId,token
    await createMeeting().then((meetingId) {
      if (!context.mounted) return;
      Navigator.of(context).push(
        MaterialPageRoute(
          builder:
              (context) => MeetingScreen(meetingId: meetingId, token: token),
        ),
      );
    });
  }

  void onJoinButtonPressed(BuildContext context) {
    // check meeting id is not null or invaild
    // if meeting id is vaild then navigate to MeetingScreen with meetingId,token
    Navigator.of(context).push(
      MaterialPageRoute(
        builder:
            (context) =>
                MeetingScreen(meetingId: "YOUR_MEETING_ID", token: token),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Zero Runtime QuickStart')),
      body: Padding(
        padding: const EdgeInsets.all(12.0),
        child: Center(
          child: ElevatedButton(
            onPressed: () => onJoinButtonPressed(context),
            child: const Text('Join Meeting'),
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';
import 'participant_tile.dart';
import 'meeting_controls.dart';

class MeetingScreen extends StatefulWidget {
  final String meetingId;
  final String token;

  const MeetingScreen({
    super.key,
    required this.meetingId,
    required this.token,
  });

  @override
  State<MeetingScreen> createState() => _MeetingScreenState();
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room _room;
  var micEnabled = true;
  var camEnabled = true;

  Map<String, Participant> participants = {};

  @override
  void initState() {
    // create room
    _room = VideoSDK.createRoom(
      roomId: widget.meetingId,
      token: widget.token,
      displayName: "John Doe",
      micEnabled: micEnabled,
      camEnabled: false,
      defaultCameraIndex:
          1, // Index of MediaDevices will be used to set default camera
    );

    setMeetingEventListener();

    // Join room
    _room.join();

    super.initState();
  }

  // listening to meeting events
  void setMeetingEventListener() {
    _room.on(Events.roomJoined, () {
      setState(() {
        participants.putIfAbsent(
          _room.localParticipant.id,
          () => _room.localParticipant,
        );
      });
    });

    _room.on(Events.participantJoined, (Participant participant) {
      setState(
        () => participants.putIfAbsent(participant.id, () => participant),
      );
    });

    _room.on(Events.participantLeft, (String participantId) {
      if (participants.containsKey(participantId)) {
        setState(() => participants.remove(participantId));
      }
    });

    _room.on(Events.roomLeft, () {
      participants.clear();
      Navigator.popUntil(context, ModalRoute.withName('/'));
    });
  }

  // onbackButton pressed leave the room
  Future<bool> _onWillPop() async {
    _room.leave();
    return true;
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () => _onWillPop(),
      child: Scaffold(
        appBar: AppBar(title: const Text('Zero Runtime QuickStart')),
        body: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            children: [
              Text(widget.meetingId),
              //render all participant
              Expanded(
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: GridView.builder(
                    gridDelegate:
                        const SliverGridDelegateWithFixedCrossAxisCount(
                          crossAxisCount: 2,
                          crossAxisSpacing: 10,
                          mainAxisSpacing: 10,
                          mainAxisExtent: 300,
                        ),
                    itemBuilder: (context, index) {
                      return ParticipantTile(
                        key: Key(participants.values.elementAt(index).id),
                        participant: participants.values.elementAt(index),
                      );
                    },
                    itemCount: participants.length,
                  ),
                ),
              ),
              MeetingControls(
                onToggleMicButtonPressed: () {
                  micEnabled ? _room.muteMic() : _room.unmuteMic();
                  micEnabled = !micEnabled;
                },
                onLeaveButtonPressed: () => _room.leave(),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';

class ParticipantTile extends StatefulWidget {
  final Participant participant;
  const ParticipantTile({super.key, required this.participant});

  @override
  State<ParticipantTile> createState() => _ParticipantTileState();
}

class _ParticipantTileState extends State<ParticipantTile> {
  var pariticpantName;
  @override
  void initState() {
    pariticpantName = widget.participant.displayName;

    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: Container(
        color: Colors.grey.shade800,
        child: Center(
          child: Text(
            '$pariticpantName',
            style: TextStyle(color: Colors.white),
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';

class MeetingControls extends StatelessWidget {
  final void Function() onToggleMicButtonPressed;
  final void Function() onLeaveButtonPressed;

  const MeetingControls({
    super.key,
    required this.onToggleMicButtonPressed,
    required this.onLeaveButtonPressed,
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: [
        ElevatedButton(
          onPressed: onLeaveButtonPressed,
          child: const Text('Leave'),
        ),
        ElevatedButton(
          onPressed: onToggleMicButtonPressed,
          child: const Text('Toggle Mic'),
        ),
      ],
    );
  }
}

# Google API Key for the Gemini Live API
GOOGLE_API_KEY=your_google_api_key_here

# Option A: pre-generated ZRT auth token
ZRT_AUTH_TOKEN=your_zrt_auth_token_here

# Option B: SDK auto-generates the token (omit ZRT_AUTH_TOKEN)
# ZRT_API_KEY=your_zrt_api_key
# ZRT_SECRET_KEY=your_zrt_secret_key

import os
import zrt
from zrt import Agent, Pipeline, Room
from zrt.plugins import GeminiRealtime, GeminiLiveConfig
from zrt.inference import AICousticsDenoise
from dotenv import load_dotenv

load_dotenv()

AGENT_ID = "flutter-voice-agent"

pipeline = Pipeline(
    # Realtime speech-to-speech model goes in the pipeline's llm slot -
    # no separate STT or TTS needed.
    llm=GeminiRealtime(
        # When GOOGLE_API_KEY is set in .env you can omit api_key.
        api_key=os.getenv("GOOGLE_API_KEY"),
        config=GeminiLiveConfig(model="gemini-3.1-flash-live-preview", voice="Leda", response_modalities=["AUDIO"]),
    ),
    denoise=AICousticsDenoise(model_id="quail-vf-2.2-l-16khz"),
)


class MyVoiceAgent(Agent):
    def __init__(self) -> None:
        super().__init__(
            name="MyVoiceAgent",
            agent_id=AGENT_ID,
            instructions="You are a high-energy game-show host guiding the caller to guess a secret number from 1 to 100 to win 1,000,000$.",
            pipeline=pipeline,
        )

    async def on_enter(self) -> None:
        await self.session.say(
            "Welcome to the Zero Runtime AI Agent game show! I'm your host, and we're about to play for 1,000,000$. Are you ready to play?"
        )

    async def on_exit(self) -> None:
        await self.session.say("Goodbye!")


def invoke_agent() -> None:
    # Join the same room the Flutter app created (its meeting ID).
    zrt.invoke(AGENT_ID, room=Room(room_id="YOUR_MEETING_ID"))


if __name__ == "__main__":
    zrt.serve(MyVoiceAgent, on_ready=invoke_agent)