multi_agent.py

import logging
from dataclasses import dataclass

from dotenv import load_dotenv

from livekit import api
from livekit.agents import (
    Agent,
    AgentServer,
    AgentSession,
    ChatContext,
    JobContext,
    JobProcess,
    RunContext,
    cli,
    metrics,
)
from livekit.agents.job import get_job_context
from livekit.agents.llm import function_tool
from livekit.agents.voice import MetricsCollectedEvent
from livekit.plugins import deepgram, openai, silero

# uncomment to enable Krisp BVC noise cancellation, currently supported on Linux and MacOS
# from livekit.plugins import noise_cancellation

## The storyteller agent is a multi-agent that can handoff the session to another agent.
## This example demonstrates more complex workflows with multiple agents.
## Each agent could have its own instructions, as well as different STT, LLM, TTS,
## or realtime models.

logger = logging.getLogger("multi-agent")

load_dotenv()

common_instructions = (
    "Your name is Echo. You are a story teller that interacts with the user via voice."
    "You are curious and friendly, with a sense of humor."
)


@dataclass
class StoryData:
    # Shared data that's used by the storyteller agent.
    # This structure is passed as a parameter to function calls.

    name: str | None = None
    location: str | None = None


class IntroAgent(Agent):
    def __init__(self) -> None:
        super().__init__(
            instructions=f"{common_instructions} Your goal is to gather a few pieces of "
            "information from the user to make the story personalized and engaging."
            "You should ask the user for their name and where they are from."
            "Start the conversation with a short introduction.",
        )

    async def on_enter(self):
        # when the agent is added to the session, it'll generate a reply
        # according to its instructions
        self.session.generate_reply()

    @function_tool
    async def information_gathered(
        self,
        context: RunContext[StoryData],
        name: str,
        location: str,
    ):
        """Called when the user has provided the information needed to make the story
        personalized and engaging.

        Args:
            name: The name of the user
            location: The location of the user
        """

        context.userdata.name = name
        context.userdata.location = location

        story_agent = StoryAgent(name, location)
        # by default, StoryAgent will start with a new context, to carry through the current
        # chat history, pass in the chat_ctx
        # story_agent = StoryAgent(name, location, chat_ctx=self.chat_ctx)

        logger.info(
            "switching to the story agent with the provided user data: %s", context.userdata
        )
        return story_agent


class StoryAgent(Agent):
    def __init__(self, name: str, location: str, *, chat_ctx: ChatContext | None = None) -> None:
        super().__init__(
            instructions=f"{common_instructions}. You should use the user's information in "
            "order to make the story personalized."
            "create the entire story, weaving in elements of their information, and make it "
            "interactive, occasionally interating with the user."
            "do not end on a statement, where the user is not expected to respond."
            "when interrupted, ask if the user would like to continue or end."
            f"The user's name is {name}, from {location}.",
            # each agent could override any of the model services, including mixing
            # realtime and non-realtime models
            llm=openai.realtime.RealtimeModel(voice="echo"),
            tts=None,
            chat_ctx=chat_ctx,
        )

    async def on_enter(self):
        # when the agent is added to the session, we'll initiate the conversation by
        # using the LLM to generate a reply
        self.session.generate_reply()

    @function_tool
    async def story_finished(self, context: RunContext[StoryData]):
        """When you are fininshed telling the story (and the user confirms they don't
        want anymore), call this function to end the conversation."""
        # interrupt any existing generation
        self.session.interrupt()

        # generate a goodbye message and hang up
        # awaiting it will ensure the message is played out before returning
        await self.session.generate_reply(
            instructions=f"say goodbye to {context.userdata.name}", allow_interruptions=False
        )

        job_ctx = get_job_context()
        await job_ctx.api.room.delete_room(api.DeleteRoomRequest(room=job_ctx.room.name))


server = AgentServer()


def prewarm(proc: JobProcess):
    proc.userdata["vad"] = silero.VAD.load()


server.setup_fnc = prewarm


@server.rtc_session()
async def entrypoint(ctx: JobContext):
    session = AgentSession[StoryData](
        vad=ctx.proc.userdata["vad"],
        # any combination of STT, LLM, TTS, or realtime API can be used
        llm=openai.LLM(model="gpt-4.1-mini"),
        stt=deepgram.STT(model="nova-3"),
        tts=openai.TTS(voice="echo"),
        userdata=StoryData(),
    )

    # log metrics as they are emitted, and total usage after session is over
    @session.on("metrics_collected")
    def _on_metrics_collected(ev: MetricsCollectedEvent):
        metrics.log_metrics(ev.metrics)

    async def log_usage():
        logger.info(f"Usage: {session.usage}")

    ctx.add_shutdown_callback(log_usage)

    await session.start(
        agent=IntroAgent(),
        room=ctx.room,
    )


if __name__ == "__main__":
    cli.run_app(server)