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CHANGELOG.md

@@ -10,9 +10,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Added automatic hangup logic to the Twilio serializer. This feature hangs up
-  the Twilio call when an `EndFrame` is received. It is enabled by default and
+  the Twilio call when an `EndFrame` or `CancelFrame` is received. It is
-  is configurable via the `auto_hang_up` `InputParam`. To use this feature, set
+  enabled by default and is configurable via the `auto_hang_up` `InputParam`.
-  up the following env vars: `TWILIO_ACCOUNT_SID` and `TWILIO_AUTH_TOKEN`.
 
 - Added `SmartTurnMetricsData`, which contains end-of-turn prediction metrics,
   to the `MetricsFrame`. Using `MetricsFrame`, you can now retrieve prediction
@@ -85,6 +84,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed an issue where LLM input parameters were not working and applied correctly in `GoogleVertexLLMService`, causing
   unexpected behavior during inference.
 
+### Other
+
+- Updated the `twilio-chatbot` example to use the auto-hangup feature.
+
 ## [0.0.63] - 2025-04-11
 
 ### Added

dot-env.template

@@ -97,3 +97,7 @@ PIPER_BASE_URL=...
 # Smart turn
 LOCAL_SMART_TURN_MODEL_PATH=
 REMOTE_SMART_TURN_URL=
+
+# Twilio
+TWILIO_ACCOUNT_SID=
+TWILIO_AUTH_TOKEN=

examples/twilio-chatbot/bot.py

@@ -54,7 +54,14 @@ async def save_audio(server_name: str, audio: bytes, sample_rate: int, num_chann
         logger.info("No audio data to save")
 
 
-async def run_bot(websocket_client: WebSocket, stream_sid: str, testing: bool):
+async def run_bot(websocket_client: WebSocket, stream_sid: str, call_sid: str, testing: bool):
+    serializer = TwilioFrameSerializer(
+        stream_sid=stream_sid,
+        call_sid=call_sid,
+        account_sid=os.getenv("TWILIO_ACCOUNT_SID", ""),
+        auth_token=os.getenv("TWILIO_AUTH_TOKEN", ""),
+    )
+
     transport = FastAPIWebsocketTransport(
         websocket=websocket_client,
         params=FastAPIWebsocketParams(
@@ -64,7 +71,7 @@ async def run_bot(websocket_client: WebSocket, stream_sid: str, testing: bool):
             vad_enabled=True,
             vad_analyzer=SileroVADAnalyzer(),
             vad_audio_passthrough=True,
-            serializer=TwilioFrameSerializer(stream_sid),
+            serializer=serializer,
         ),
     )
 

examples/twilio-chatbot/requirements.txt

@@ -1,4 +1,5 @@
-pipecat-ai[cartesia,openai,silero,deepgram,twilio]
+pipecat-ai[cartesia,openai,silero,deepgram]
+fastapi
 uvicorn
 python-dotenv
 loguru

examples/twilio-chatbot/server.py

@@ -38,8 +38,9 @@ async def websocket_endpoint(websocket: WebSocket):
     call_data = json.loads(await start_data.__anext__())
     print(call_data, flush=True)
     stream_sid = call_data["start"]["streamSid"]
+    call_sid = call_data["start"]["callSid"]
     print("WebSocket connection accepted")
-    await run_bot(websocket, stream_sid, app.state.testing)
+    await run_bot(websocket, stream_sid, call_sid, app.state.testing)
 
 
 if __name__ == "__main__":

pyproject.toml

@@ -86,7 +86,6 @@ simli = [ "simli-ai~=0.1.10"]
 soundfile = [ "soundfile~=0.13.0" ]
 tavus=[]
 together = []
-twilio = [ "fastapi~=0.115.6", "twilio~=9.5.2"]
 ultravox = [ "transformers~=4.48.0", "vllm~=0.7.3" ]
 webrtc = [ "aiortc~=1.11.0", "opencv-python~=4.11.0.86" ]
 websocket = [ "websockets~=13.1", "fastapi~=0.115.6" ]

src/pipecat/serializers/twilio.py

@@ -4,10 +4,8 @@
 # SPDX-License-Identifier: BSD 2-Clause License
 #
 
-import asyncio
 import base64
 import json
-import os
 from typing import Optional
 
 from loguru import logger
@@ -16,6 +14,7 @@ from pydantic import BaseModel
 from pipecat.audio.utils import create_default_resampler, pcm_to_ulaw, ulaw_to_pcm
 from pipecat.frames.frames import (
     AudioRawFrame,
+    CancelFrame,
     EndFrame,
     Frame,
     InputAudioRawFrame,
@@ -36,9 +35,15 @@ class TwilioFrameSerializer(FrameSerializer):
     media streams protocol. It supports audio conversion, DTMF events, and automatic
     call termination.
 
+    When auto_hang_up is enabled (default), the serializer will automatically terminate
+    the Twilio call when an EndFrame or CancelFrame is processed, but requires Twilio
+    credentials to be provided.
+
     Attributes:
         _stream_sid: The Twilio Media Stream SID.
         _call_sid: The associated Twilio Call SID.
+        _account_sid: Twilio account SID for API access.
+        _auth_token: Twilio authentication token for API access.
         _params: Configuration parameters.
         _twilio_sample_rate: Sample rate used by Twilio (typically 8kHz).
         _sample_rate: Input sample rate for the pipeline.
@@ -58,16 +63,27 @@ class TwilioFrameSerializer(FrameSerializer):
         sample_rate: Optional[int] = None
         auto_hang_up: bool = True
 
-    def __init__(self, stream_sid: str, call_sid: str, params: InputParams = InputParams()):
+    def __init__(
+        self,
+        stream_sid: str,
+        call_sid: str,
+        account_sid: Optional[str] = None,
+        auth_token: Optional[str] = None,
+        params: InputParams = InputParams(),
+    ):
         """Initialize the TwilioFrameSerializer.
 
         Args:
             stream_sid: The Twilio Media Stream SID.
             call_sid: The associated Twilio Call SID.
+            account_sid: Twilio account SID.
+            auth_token: Twilio auth token.
             params: Configuration parameters.
         """
         self._stream_sid = stream_sid
         self._call_sid = call_sid
+        self._account_sid = account_sid
+        self._auth_token = auth_token
         self._params = params
 
         self._twilio_sample_rate = self._params.twilio_sample_rate
@@ -104,8 +120,8 @@ class TwilioFrameSerializer(FrameSerializer):
         Returns:
             Serialized data as string or bytes, or None if the frame isn't handled.
         """
-        if self._params.auto_hang_up and isinstance(frame, (EndFrame)):
+        if self._params.auto_hang_up and isinstance(frame, (EndFrame, CancelFrame)):
-            asyncio.create_task(self._hang_up_call())
+            await self._hang_up_call()
             return None
         elif isinstance(frame, StartInterruptionFrame):
             answer = {"event": "clear", "streamSid": self._stream_sid}
@@ -132,26 +148,41 @@ class TwilioFrameSerializer(FrameSerializer):
         return None
 
     async def _hang_up_call(self):
-        """Hang up the Twilio call using the REST API."""
+        """Hang up the Twilio call using Twilio's REST API."""
         try:
-            from twilio.rest import Client
+            import aiohttp
 
-            account_sid = os.getenv("TWILIO_ACCOUNT_SID")
+            account_sid = self._account_sid
-            auth_token = os.getenv("TWILIO_AUTH_TOKEN")
+            auth_token = self._auth_token
 
             if not account_sid or not auth_token:
                 logger.warning(
-                    "Missing Twilio credentials (TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN), cannot hang up call"
+                    "Cannot hang up Twilio call: account_sid and auth_token must be provided"
                 )
                 return
 
-            # Create Twilio client and hang up the call using the correct CallSid
+            # Twilio API endpoint for updating calls
-            client = Client(account_sid, auth_token)
+            endpoint = f"https://api.twilio.com/2010-04-01/Accounts/{account_sid}/Calls/{self._call_sid}.json"
-            client.calls(self._call_sid).update(status="completed")
+
+            # Create basic auth from account_sid and auth_token
+            auth = aiohttp.BasicAuth(account_sid, auth_token)
+
+            # Parameters to set the call status to "completed" (hang up)
+            params = {"Status": "completed"}
+
+            # Make the POST request to update the call
+            async with aiohttp.ClientSession() as session:
+                async with session.post(endpoint, auth=auth, data=params) as response:
+                    if response.status == 200:
+                        logger.info(f"Successfully terminated Twilio call {self._call_sid}")
+                    else:
+                        # Get the error details for better debugging
+                        error_text = await response.text()
+                        logger.error(
+                            f"Failed to terminate Twilio call {self._call_sid}: "
+                            f"Status {response.status}, Response: {error_text}"
+                        )
 
-            logger.info(f"Successfully terminated Twilio call {self._call_sid}")
-        except ImportError:
-            logger.warning("Twilio Python SDK not installed. Install with: pip install twilio")
         except Exception as e:
             logger.exception(f"Failed to hang up Twilio call: {e}")
 

src/pipecat/transports/network/fastapi_websocket.py

@@ -212,6 +212,7 @@ class FastAPIWebsocketOutputTransport(BaseOutputTransport):
 
     async def cancel(self, frame: CancelFrame):
         await super().cancel(frame)
+        await self._write_frame(frame)
         await self._client.disconnect()
 
     async def cleanup(self):

src/pipecat/transports/network/websocket_server.py

@@ -196,6 +196,10 @@ class WebsocketServerOutputTransport(BaseOutputTransport):
         await self._params.serializer.setup(frame)
         self._send_interval = (self._audio_chunk_size / self.sample_rate) / 2
 
+    async def stop(self, frame: EndFrame):
+        await super().stop(frame)
+        await self._write_frame(frame)
+
     async def cleanup(self):
         await super().cleanup()
         await self._transport.cleanup()
@@ -206,8 +210,6 @@ class WebsocketServerOutputTransport(BaseOutputTransport):
         if isinstance(frame, StartInterruptionFrame):
             await self._write_frame(frame)
             self._next_send_time = 0
-        elif isinstance(frame, EndFrame):
-            await self._write_frame(frame)
 
     async def send_message(self, frame: TransportMessageFrame | TransportMessageUrgentFrame):
         await self._write_frame(frame)