Build a Flutter AI Voice Agent API

1python -m venv venv
2source venv/bin/activate  # On Windows use `venv\Scripts\activate`
3

1pip install videosdk
2pip install python-dotenv
3

1VIDEOSDK_API_KEY=your_api_key_here
2VIDEOSDK_SECRET_KEY=your_secret_key_here
3

1import asyncio, os
2from videosdk.agents import Agent, AgentSession, CascadingPipeline, JobContext, RoomOptions, WorkerJob, ConversationFlow
3from videosdk.plugins.silero import SileroVAD
4from videosdk.plugins.turn_detector import TurnDetector, pre_download_model
5from videosdk.plugins.deepgram import DeepgramSTT
6from videosdk.plugins.openai import OpenAILLM
7from videosdk.plugins.elevenlabs import ElevenLabsTTS
8from typing import AsyncIterator
9
10# Pre-downloading the Turn Detector model
11pre_download_model()
12
13agent_instructions = "You are a Flutter AI Voice Agent API specializing in providing technical support and guidance for developers using Flutter to build voice-enabled applications. Your persona is that of a knowledgeable and friendly tech assistant. Your capabilities include answering questions about Flutter integration, providing code snippets for common tasks, and guiding users through troubleshooting steps. You can also offer best practices for optimizing voice recognition and handling API requests efficiently. However, you are not a substitute for official documentation or professional developer support. Always encourage users to refer to the official Flutter documentation and community forums for comprehensive guidance. You must include a disclaimer that you are an AI and your responses are based on pre-existing data and algorithms."
14
15class MyVoiceAgent(Agent):
16    def __init__(self):
17        super().__init__(instructions=agent_instructions)
18    async def on_enter(self): await self.session.say("Hello! How can I help?")
19    async def on_exit(self): await self.session.say("Goodbye!")
20
21async def start_session(context: JobContext):
22    # Create agent and conversation flow
23    agent = MyVoiceAgent()
24    conversation_flow = ConversationFlow(agent)
25
26    # Create pipeline
27    pipeline = CascadingPipeline(
28        stt=DeepgramSTT(model="nova-2", language="en"),
29        llm=OpenAILLM(model="gpt-4o"),
30        tts=ElevenLabsTTS(model="eleven_flash_v2_5"),
31        vad=SileroVAD(threshold=0.35),
32        turn_detector=TurnDetector(threshold=0.8)
33    )
34
35    session = AgentSession(
36        agent=agent,
37        pipeline=pipeline,
38        conversation_flow=conversation_flow
39    )
40
41    try:
42        await context.connect()
43        await session.start()
44        # Keep the session running until manually terminated
45        await asyncio.Event().wait()
46    finally:
47        # Clean up resources when done
48        await session.close()
49        await context.shutdown()
50
51def make_context() -> JobContext:
52    room_options = RoomOptions(
53    #  room_id="YOUR_MEETING_ID",  # Set to join a pre-created room; omit to auto-create
54        name="VideoSDK Cascaded Agent",
55        playground=True
56    )
57
58    return JobContext(room_options=room_options)
59
60if __name__ == "__main__":
61    job = WorkerJob(entrypoint=start_session, jobctx=make_context)
62    job.start()
63

1curl -X POST \
2  https://api.videosdk.live/v1/rooms \
3  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
4  -H "Content-Type: application/json" \
5  -d '{"name": "Flutter Voice Agent Room"}'
6

1class MyVoiceAgent(Agent):
2    def __init__(self):
3        super().__init__(instructions=agent_instructions)
4    async def on_enter(self): await self.session.say("Hello! How can I help?")
5    async def on_exit(self): await self.session.say("Goodbye!")
6

1pipeline = CascadingPipeline(
2    stt=DeepgramSTT(model="nova-2", language="en"),
3    llm=OpenAILLM(model="gpt-4o"),
4    tts=ElevenLabsTTS(model="eleven_flash_v2_5"),
5    vad=SileroVAD(threshold=0.35),
6    turn_detector=TurnDetector(threshold=0.8)
7)
8

1def make_context() -> JobContext:
2    room_options = RoomOptions(
3        name="VideoSDK Cascaded Agent",
4        playground=True
5    )
6    return JobContext(room_options=room_options)
7
8async def start_session(context: JobContext):
9    agent = MyVoiceAgent()
10    conversation_flow = ConversationFlow(agent)
11    pipeline = CascadingPipeline(
12        stt=DeepgramSTT(model="nova-2", language="en"),
13        llm=OpenAILLM(model="gpt-4o"),
14        tts=ElevenLabsTTS(model="eleven_flash_v2_5"),
15        vad=SileroVAD(threshold=0.35),
16        turn_detector=TurnDetector(threshold=0.8)
17    )
18    session = AgentSession(
19        agent=agent,
20        pipeline=pipeline,
21        conversation_flow=conversation_flow
22    )
23    try:
24        await context.connect()
25        await session.start()
26        await asyncio.Event().wait()
27    finally:
28        await session.close()
29        await context.shutdown()
30
31if __name__ == "__main__":
32    job = WorkerJob(entrypoint=start_session, jobctx=make_context)
33    job.start()
34

1python main.py
2