From 7c4294b7f61096843a5cda3cd98077368843c0f6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Aleix=20Conchillo=20Flaqu=C3=A9?= Date: Wed, 13 May 2026 23:26:27 -0700 Subject: [PATCH] Add local-handoff-two-agents-tts example Variant of the local handoff example with per-task TTS voices. Each child task wraps the LLM with its own `CartesiaTTSService` in a custom pipeline override, so the main task has no TTS and audio comes from whichever child is active over the bus. --- .../local-handoff-two-agents-tts.py | 268 ++++++++++++++++++ 1 file changed, 268 insertions(+) create mode 100644 examples/multi-task/local-handoff/local-handoff-two-agents-tts.py diff --git a/examples/multi-task/local-handoff/local-handoff-two-agents-tts.py b/examples/multi-task/local-handoff/local-handoff-two-agents-tts.py new file mode 100644 index 000000000..aeee2358b --- /dev/null +++ b/examples/multi-task/local-handoff/local-handoff-two-agents-tts.py @@ -0,0 +1,268 @@ +# +# Copyright (c) 2026, Daily +# +# SPDX-License-Identifier: BSD 2-Clause License +# + +"""Two LLM tasks with per-task TTS voices. + +Same shape as ``local-handoff-two-agents.py``, but each child task +runs its own TTS with a distinct voice. The main task has no TTS — +audio comes from the child tasks via the bus and is played by the +main task's transport. Tasks announce the transfer ("let me connect +you with...") before handing off. + +Architecture:: + + Main task (no TTS): + transport.in → STT → user_agg → BusBridge → transport.out → assistant_agg + + Child task (with TTS): + bridge_in → LLM → TTS → bridge_out + +Requirements: + +- OPENAI_API_KEY +- DEEPGRAM_API_KEY +- CARTESIA_API_KEY +- DAILY_API_KEY (for Daily transport) +""" + +import os + +from dotenv import load_dotenv +from loguru import logger + +from pipecat.audio.vad.silero import SileroVADAnalyzer +from pipecat.bus import BusBridgeProcessor +from pipecat.pipeline.pipeline import Pipeline +from pipecat.pipeline.runner import PipelineRunner +from pipecat.pipeline.task import PipelineParams, PipelineTask +from pipecat.processors.aggregators.llm_context import LLMContext +from pipecat.processors.aggregators.llm_response_universal import ( + LLMContextAggregatorPair, + LLMUserAggregatorParams, +) +from pipecat.runner.types import RunnerArguments +from pipecat.runner.utils import create_transport +from pipecat.services.cartesia.tts import CartesiaTTSService +from pipecat.services.deepgram.stt import DeepgramSTTService +from pipecat.services.llm_service import FunctionCallParams +from pipecat.services.openai.llm import OpenAILLMService +from pipecat.tasks.llm import LLMTask, LLMTaskActivationArgs, tool +from pipecat.transports.base_transport import BaseTransport, TransportParams +from pipecat.transports.daily.transport import DailyParams + +load_dotenv(override=True) + +MAIN_NAME = "acme" + + +transport_params = { + "daily": lambda: DailyParams( + audio_in_enabled=True, + audio_out_enabled=True, + ), + "webrtc": lambda: TransportParams( + audio_in_enabled=True, + audio_out_enabled=True, + ), +} + + +class AcmeTTSTask(LLMTask): + """Child task with its own LLM + TTS, bridged to the main task. + + Each child wraps the standard ``Pipeline([llm])`` with an extra + TTS processor so audio is produced locally by each child and + shipped to the main task over the bus. + """ + + def __init__(self, name: str, *, llm: OpenAILLMService, voice_id: str): + """Initialize the child task. + + Args: + name: Unique task name. + llm: The LLM service for this child. + voice_id: Cartesia voice id for this child's TTS. + """ + tts = CartesiaTTSService( + api_key=os.environ["CARTESIA_API_KEY"], + settings=CartesiaTTSService.Settings(voice=voice_id), + ) + super().__init__( + name, + llm=llm, + pipeline=Pipeline([llm, tts]), + bridged=(), + ) + + @tool(cancel_on_interruption=False) + async def transfer_to_agent(self, params: FunctionCallParams, agent: str, reason: str): + """Transfer the user to another agent. + + Args: + agent (str): The agent to transfer to (e.g. 'greeter', 'support'). + reason (str): Why the user is being transferred. + """ + logger.info(f"Task '{self.name}': transferring to '{agent}' ({reason})") + await self.handoff_to( + agent, + messages=[ + { + "role": "developer", + "content": f"Tell the user about the transfer ({reason}).", + } + ], + activation_args=LLMTaskActivationArgs( + messages=[{"role": "developer", "content": reason}], + ), + result_callback=params.result_callback, + ) + + @tool + async def end_conversation(self, params: FunctionCallParams, reason: str): + """End the conversation when the user says goodbye. + + Args: + reason (str): Why the conversation is ending. + """ + logger.info(f"Task '{self.name}': ending conversation ({reason})") + await self.end( + reason=reason, + messages=[{"role": "developer", "content": reason}], + result_callback=params.result_callback, + ) + + +def _build_greeter() -> AcmeTTSTask: + """Greeter: routes the user to support when they pick a product.""" + llm = OpenAILLMService( + api_key=os.environ["OPENAI_API_KEY"], + settings=OpenAILLMService.Settings( + system_instruction=( + "You are a friendly greeter for Acme Corp. The available products " + "are: the Acme Rocket Boots, the Acme Invisible Paint, and the Acme " + "Tornado Kit. Ask which one they'd like to learn more about. " + "When the user picks a product or asks a question about one, " + "call the transfer_to_agent tool with agent 'support'. " + "Do not answer product questions yourself. If the user says goodbye, " + "call the end_conversation tool. Keep responses brief — this is a " + "voice conversation." + ), + ), + ) + return AcmeTTSTask( + "greeter", + llm=llm, + voice_id="9626c31c-bec5-4cca-baa8-f8ba9e84c8bc", # Jacqueline + ) + + +def _build_support() -> AcmeTTSTask: + """Support: answers product questions, can hand back to the greeter.""" + llm = OpenAILLMService( + api_key=os.environ["OPENAI_API_KEY"], + settings=OpenAILLMService.Settings( + system_instruction=( + "You are a support agent for Acme Corp. You know about three " + "products: Acme Rocket Boots (jet-powered boots, $299, run up " + "to 60 mph), Acme Invisible Paint (makes anything invisible for " + "24 hours, $49 per can), and Acme Tornado Kit (portable tornado " + "generator, $199, batteries included). Answer the user's questions " + "about these products. If the user wants to browse other products " + "or start over, call the transfer_to_agent tool with agent " + "'greeter'. If the user says goodbye, call the end_conversation " + "tool. Keep responses brief — this is a voice conversation." + ), + ), + ) + return AcmeTTSTask( + "support", + llm=llm, + voice_id="a167e0f3-df7e-4d52-a9c3-f949145efdab", # Blake + ) + + +async def run_bot(transport: BaseTransport, runner_args: RunnerArguments): + logger.info("Starting two-agents-with-tts bot") + + runner = PipelineRunner(handle_sigint=runner_args.handle_sigint) + + stt = DeepgramSTTService(api_key=os.environ["DEEPGRAM_API_KEY"]) + + context = LLMContext() + aggregators = LLMContextAggregatorPair( + context, + user_params=LLMUserAggregatorParams(vad_analyzer=SileroVADAnalyzer()), + ) + + # The main task has no TTS. Audio comes from the children over + # the bus; the main bridge tees user context out and pushes + # incoming audio/text frames back into the local pipeline. + bridge = BusBridgeProcessor( + bus=runner.bus, + task_name=MAIN_NAME, + name=f"{MAIN_NAME}::BusBridge", + ) + + pipeline = Pipeline( + [ + transport.input(), + stt, + aggregators.user(), + bridge, + transport.output(), + aggregators.assistant(), + ] + ) + + task = PipelineTask( + pipeline, + name=MAIN_NAME, + params=PipelineParams( + enable_metrics=True, + enable_usage_metrics=True, + ), + idle_timeout_secs=runner_args.pipeline_idle_timeout_secs, + ) + + await runner.spawn(_build_greeter()) + await runner.spawn(_build_support()) + + @transport.event_handler("on_client_connected") + async def on_client_connected(transport, client): + logger.info("Client connected") + await task.activate_task( + "greeter", + args=LLMTaskActivationArgs( + messages=[ + { + "role": "developer", + "content": ( + "Welcome the user to Acme Corp, mention the available products " + "and ask how you can help." + ), + }, + ], + ), + ) + + @transport.event_handler("on_client_disconnected") + async def on_client_disconnected(transport, client): + logger.info("Client disconnected") + await task.cancel() + + await runner.run(task) + + +async def bot(runner_args: RunnerArguments): + """Main bot entry point compatible with Pipecat Cloud.""" + transport = await create_transport(runner_args, transport_params) + await run_bot(transport, runner_args) + + +if __name__ == "__main__": + from pipecat.runner.run import main + + main()