From 6f2ffa8fed8f5b84074624013450d4cb61809612 Mon Sep 17 00:00:00 2001
From: James Hush <james@daily.co>
Date: Mon, 19 Jan 2026 11:07:56 +0800
Subject: [PATCH] fix: add type annotations to event_handler decorator

Add proper generic type annotations to the event_handler decorator
so that static type checkers (pyright, mypy) understand the decorated
function is returned and used, eliminating false reportUnusedFunction
warnings.

Changes:
- Import TypeVar and Callable from typing
- Define F TypeVar bound to Callable[..., Any]
- Add Callable[[F], F] return type to event_handler method
- Add F type annotations to inner decorator function
---
 src/pipecat/utils/base_object.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/pipecat/utils/base_object.py b/src/pipecat/utils/base_object.py
index f6e4c47de..e8c4b13ad 100644
--- a/src/pipecat/utils/base_object.py
+++ b/src/pipecat/utils/base_object.py
@@ -16,12 +16,15 @@ import inspect
 import traceback
 from abc import ABC
 from dataclasses import dataclass
-from typing import Any, Dict, List, Optional
+from typing import Any, Callable, Dict, List, Optional, Set, Tuple, TypeVar
 
 from loguru import logger
 
 from pipecat.utils.utils import obj_count, obj_id
 
+# TypeVar for preserving function signatures in decorators
+F = TypeVar("F", bound=Callable[..., Any])
+
 
 @dataclass
 class EventHandler:
@@ -99,7 +102,7 @@ class BaseObject(ABC):
             logger.debug(f"{self}: waiting on event handlers to finish {list(event_names)}...")
             await asyncio.wait(tasks)
 
-    def event_handler(self, event_name: str):
+    def event_handler(self, event_name: str) -> Callable[[F], F]:
         """Decorator for registering event handlers.
 
         Args:
@@ -109,7 +112,7 @@ class BaseObject(ABC):
             The decorator function that registers the handler.
         """
 
-        def decorator(handler):
+        def decorator(handler: F) -> F:
             self.add_event_handler(event_name, handler)
             return handler