Files
pipecat/examples/realtime/realtime-aws-nova-sonic.py
Osman Ipek f1b16a672a feat(nova-sonic): add proactive session continuation for conversations >8min
Nova Sonic sessions have an AWS-imposed ~8-minute time limit. This adds
transparent session continuation that rotates sessions in the background
before the limit is reached, preserving conversation context with no
user-perceptible interruption.

Implementation follows the AWS reference architecture:
- Monitor loop detects when session age exceeds threshold
- On assistant AUDIO contentStart: start buffering user audio, create next
  session (sessionStart + promptStart + system instruction)
- Track SPECULATIVE/FINAL text counts as completion signal
- On completion signal: send conversation history + audioInputStart +
  buffered audio to next session, then promote immediately
- Close old session in background (non-blocking)
- Dead session detection: recreate next session if idle >30s

Key design decisions:
- Session continuation enabled by default (fundamental for long conversations)
- Conversation history tracked in real-time via _sc_conversation_history
  (independent of pipeline context aggregator which updates asynchronously)
- Completion signal check in _handle_content_end_event (after history update)
  to ensure latest text is included in handoff
- Rolling audio buffer (default 3s) captures user audio during transition
- transition_threshold_seconds capped at 420s (7min) for safety margin
- Unified event methods (_send_text_event, _send_client_event, etc.) accept
  optional stream/prompt_name params, eliminating duplicate SC methods

Also adds:
- SessionContinuationParams config (enabled, threshold, buffer, timeout)
2026-04-24 14:55:55 -07:00

232 lines
8.4 KiB
Python

#
# Copyright (c) 2024-2026, Daily
#
# SPDX-License-Identifier: BSD 2-Clause License
#
import asyncio
import os
import random
from datetime import datetime
from dotenv import load_dotenv
from loguru import logger
from pipecat.adapters.schemas.function_schema import FunctionSchema
from pipecat.adapters.schemas.tools_schema import ToolsSchema
from pipecat.audio.vad.silero import SileroVADAnalyzer
from pipecat.frames.frames import LLMRunFrame
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 (
AssistantTurnStoppedMessage,
LLMContextAggregatorPair,
LLMUserAggregatorParams,
UserTurnStoppedMessage,
)
from pipecat.runner.types import RunnerArguments
from pipecat.runner.utils import create_transport
from pipecat.services.aws.nova_sonic.llm import AWSNovaSonicLLMService
from pipecat.services.aws.nova_sonic.session_continuation import SessionContinuationParams
from pipecat.services.llm_service import FunctionCallParams
from pipecat.transports.base_transport import BaseTransport, TransportParams
from pipecat.transports.daily.transport import DailyParams
from pipecat.transports.websocket.fastapi import FastAPIWebsocketParams
# Load environment variables
load_dotenv(override=True)
async def fetch_weather_from_api(params: FunctionCallParams):
temperature = (
random.randint(60, 85)
if params.arguments["format"] == "fahrenheit"
else random.randint(15, 30)
)
# Simulate a long network delay.
# You can continue chatting while waiting for this to complete.
# With Nova 2 Sonic (the default model), the assistant will respond
# appropriately once the function call is complete.
await asyncio.sleep(5)
await params.result_callback(
{
"conditions": "nice",
"temperature": temperature,
"location": params.arguments["location"],
"format": params.arguments["format"],
"timestamp": datetime.now().strftime("%Y%m%d_%H%M%S"),
}
)
weather_function = FunctionSchema(
name="get_current_weather",
description="Get the current weather",
properties={
"location": {
"type": "string",
"description": "The city and state, e.g. San Francisco, CA",
},
"format": {
"type": "string",
"enum": ["celsius", "fahrenheit"],
"description": "The temperature unit to use. Infer this from the users location.",
},
},
required=["location", "format"],
)
# Create tools schema
tools = ToolsSchema(standard_tools=[weather_function])
# We use lambdas to defer transport parameter creation until the transport
# type is selected at runtime.
transport_params = {
"daily": lambda: DailyParams(
audio_in_enabled=True,
audio_out_enabled=True,
),
"twilio": lambda: FastAPIWebsocketParams(
audio_in_enabled=True,
audio_out_enabled=True,
),
"webrtc": lambda: TransportParams(
audio_in_enabled=True,
audio_out_enabled=True,
),
}
async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
logger.info(f"Starting bot")
# Specify initial system instruction.
system_instruction = (
"You are a friendly assistant. The user and you will engage in a spoken dialog exchanging "
"the transcripts of a natural real-time conversation. Keep your responses short, generally "
"two or three sentences for chatty scenarios."
# HACK: if using the older Nova Sonic (pre-2) model, note that you need to inject a special
# bit of text into this instruction to allow the first assistant response to be
# programmatically triggered (which happens in the on_client_connected handler)
# f"{AWSNovaSonicLLMService.AWAIT_TRIGGER_ASSISTANT_RESPONSE_INSTRUCTION}"
)
# Create the AWS Nova Sonic LLM service
llm = AWSNovaSonicLLMService(
secret_access_key=os.environ["AWS_SECRET_ACCESS_KEY"],
access_key_id=os.environ["AWS_ACCESS_KEY_ID"],
# as of 2025-12-09, these are the supported regions:
# - Nova 2 Sonic (the default model):
# - us-east-1
# - us-west-2
# - ap-northeast-1
# - Nova Sonic (the older model):
# - us-east-1
# - ap-northeast-1
region=os.environ["AWS_REGION"],
session_token=os.getenv("AWS_SESSION_TOKEN"),
settings=AWSNovaSonicLLMService.Settings(
voice="tiffany",
system_instruction=system_instruction,
),
# Session continuation is enabled by default, allowing seamless
# conversations longer than the AWS ~8-minute session limit.
# The service rotates sessions in the background with no
# user-perceptible interruption. You can tune the threshold or
# disable it with: session_continuation=SessionContinuationParams(enabled=False)
session_continuation=SessionContinuationParams(
# When to start preparing the next session (default: 360 = 6 min).
# Lower this (e.g. 20) to see a handoff happen quickly during testing.
transition_threshold_seconds=360,
),
# you could choose to pass tools here rather than via context
# tools=tools
)
# Register function for function calls
# you can either register a single function for all function calls, or specific functions
# llm.register_function(None, fetch_weather_from_api)
llm.register_function(
"get_current_weather", fetch_weather_from_api, cancel_on_interruption=False
)
# Set up context and context management.
context = LLMContext(tools=tools)
user_aggregator, assistant_aggregator = LLMContextAggregatorPair(
context,
user_params=LLMUserAggregatorParams(vad_analyzer=SileroVADAnalyzer()),
)
# Build the pipeline
pipeline = Pipeline(
[
transport.input(),
user_aggregator,
llm,
transport.output(),
assistant_aggregator,
]
)
# Configure the pipeline task
task = PipelineTask(
pipeline,
params=PipelineParams(
enable_metrics=True,
enable_usage_metrics=True,
),
idle_timeout_secs=runner_args.pipeline_idle_timeout_secs,
)
# Handle client connection event
@transport.event_handler("on_client_connected")
async def on_client_connected(transport, client):
logger.info(f"Client connected")
# Kick off the conversation.
context.add_message(
{"role": "developer", "content": "Please introduce yourself to the user."}
)
await task.queue_frames([LLMRunFrame()])
# HACK: if using the older Nova Sonic (pre-2) model, you need this special way of
# triggering the first assistant response. Note that this trigger requires a special
# corresponding bit of text in the system instruction.
# await llm.trigger_assistant_response()
# Handle client disconnection events
@transport.event_handler("on_client_disconnected")
async def on_client_disconnected(transport, client):
logger.info(f"Client disconnected")
await task.cancel()
@user_aggregator.event_handler("on_user_turn_stopped")
async def on_user_turn_stopped(aggregator, strategy, message: UserTurnStoppedMessage):
timestamp = f"[{message.timestamp}] " if message.timestamp else ""
line = f"{timestamp}user: {message.content}"
logger.info(f"Transcript: {line}")
@assistant_aggregator.event_handler("on_assistant_turn_stopped")
async def on_assistant_turn_stopped(aggregator, message: AssistantTurnStoppedMessage):
timestamp = f"[{message.timestamp}] " if message.timestamp else ""
line = f"{timestamp}assistant: {message.content}"
logger.info(f"Transcript: {line}")
# Run the pipeline
runner = PipelineRunner(handle_sigint=runner_args.handle_sigint)
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()