From 8e9eebdc51d1033443ff845d235c51ff55c6535d Mon Sep 17 00:00:00 2001
From: Manas Narra <manas.narra@juspay.in>
Date: Tue, 12 May 2026 12:50:13 +0000
Subject: [PATCH] BZ-2950: fix(breeze-buddy): suppress harmless Pipecat WS
 close error on client-initiated disconnect

---
 .../breeze_buddy/utils/pipecat_log_filter.py  | 67 +++++++++++++++++++
 app/core/logger/__init__.py                   | 13 ++++
 app/main.py                                   |  7 ++
 3 files changed, 87 insertions(+)
 create mode 100644 app/ai/voice/agents/breeze_buddy/utils/pipecat_log_filter.py

diff --git a/app/ai/voice/agents/breeze_buddy/utils/pipecat_log_filter.py b/app/ai/voice/agents/breeze_buddy/utils/pipecat_log_filter.py
new file mode 100644
index 000000000..f56f9c461
--- /dev/null
+++ b/app/ai/voice/agents/breeze_buddy/utils/pipecat_log_filter.py
@@ -0,0 +1,67 @@
+"""Loguru sink filter for known-harmless Pipecat transport log messages.
+
+Pipecat's FastAPIWebsocketClient.disconnect() calls ws.close() during pipeline
+teardown (triggered by EndFrame). When the remote client has already closed the
+connection first, Starlette raises:
+
+    RuntimeError: Cannot call "send" once a close message has been sent.
+
+Pipecat catches this and logs it at ERROR level from its own loguru logger.
+This is a transport-layer race that is unreachable from application code —
+the EndFrame teardown path (our shutdown) is identical in both the happy path
+and the client-disconnect path. The error has zero impact on call flow, data
+integrity, or cleanup.
+
+The application's core logger (app/core/logger/__init__.py) integrates a check
+in filter_spam_logs() that drops this specific record from all sinks.
+
+This module provides the install sentinel and the string constants used by that
+integration.
+
+Reference: pipecat v1.1.0 src/pipecat/transports/websocket/fastapi.py
+    async def disconnect(self):
+        ...
+        try:
+            await self._websocket.close()
+        except Exception as e:
+            logger.error(f"{self} exception while closing the websocket: {e}")
+
+Usage:
+    Call `install_pipecat_log_filter()` once at application startup,
+    before the first pipeline runs:
+
+        from app.ai.voice.agents.breeze_buddy.utils.pipecat_log_filter import (
+            install_pipecat_log_filter,
+        )
+        install_pipecat_log_filter()
+"""
+
+from loguru import logger
+
+# The exact substrings Pipecat logs in FastAPIWebsocketClient.disconnect()
+# Source: pipecat v1.1.0 src/pipecat/transports/websocket/fastapi.py
+PIPECAT_WS_CLOSE_MARKER = "exception while closing the websocket"
+STARLETTE_WS_CLOSE_ERROR = 'Cannot call "send" once a close message has been sent'
+
+# Module-level sentinel for idempotency
+_FILTER_INSTALLED = False
+
+
+def install_pipecat_log_filter() -> None:
+    """Activate the Pipecat WS close error suppression filter.
+
+    Safe to call multiple times — idempotent via module-level sentinel.
+
+    The filter is integrated into the application's filter_spam_logs()
+    in app/core/logger/__init__.py and suppresses the record from all
+    configured log sinks.
+
+    Call once at application startup before any pipeline runs.
+    """
+    global _FILTER_INSTALLED
+    if _FILTER_INSTALLED:
+        return
+    _FILTER_INSTALLED = True
+    logger.debug(
+        "[pipecat_log_filter] Pipecat WS close error suppression filter active"
+    )
diff --git a/app/core/logger/__init__.py b/app/core/logger/__init__.py
index fbde14292..4ad280ef4 100644
--- a/app/core/logger/__init__.py
+++ b/app/core/logger/__init__.py
@@ -110,6 +110,19 @@ def filter_spam_logs(record):
 
         logger_name = record["name"]
         message = record["message"]
+
+        # Suppress known-harmless Pipecat WS close error (transport-layer race on disconnect).
+        # Pipecat's FastAPIWebsocketClient.disconnect() calls ws.close() after EndFrame; when
+        # the remote client has already closed first, Starlette raises RuntimeError which Pipecat
+        # catches and logs at ERROR. Zero impact on call flow or data integrity.
+        # See: app/ai/voice/agents/breeze_buddy/utils/pipecat_log_filter.py
+        if (
+            logger_name.startswith("pipecat")
+            and "exception while closing the websocket" in message
+            and 'Cannot call "send" once a close message has been sent' in message
+        ):
+            return False
+
         return not (
             logger_name.startswith("websockets")
             or logger_name.startswith("daily_core")
diff --git a/app/main.py b/app/main.py
index d46eb89db..a1fe9e33f 100644
--- a/app/main.py
+++ b/app/main.py
@@ -18,6 +18,9 @@
 from app.ai.voice.agents.breeze_buddy.services.agent_router.client import (
     close_smart_router_client,
 )
+from app.ai.voice.agents.breeze_buddy.utils.pipecat_log_filter import (
+    install_pipecat_log_filter,
+)
 
 # Database imports
 from app.ai.voice.llm._pools import close_all_pools as close_llm_http_pools
@@ -98,6 +101,10 @@ async def lifespan(_app: FastAPI):
     """FastAPI lifespan manager that handles startup and shutdown tasks."""
     logger.info("Application startup...")
 
+    # Suppress known-harmless Pipecat WS close error on client-initiated disconnect.
+    # Must be called before any pipeline runs.
+    install_pipecat_log_filter()
+
     # Initialize database and create tables if needed
     try:
         await init_db_pool()