From 08d47daa906dfae8d64d6fc654a3b481ab68693d Mon Sep 17 00:00:00 2001
From: Caspar Broekhuizen <caspar@langchain.dev>
Date: Tue, 9 Sep 2025 14:03:14 -0700
Subject: [PATCH] fix(langgraph): split task function overloads to resolve mypy
 incompatible type error

---
 libs/langgraph/langgraph/func/__init__.py | 24 ++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/libs/langgraph/langgraph/func/__init__.py b/libs/langgraph/langgraph/func/__init__.py
index fd3245791..e5ae577ec 100644
--- a/libs/langgraph/langgraph/func/__init__.py
+++ b/libs/langgraph/langgraph/func/__init__.py
@@ -100,16 +100,25 @@ def task(
     retry_policy: RetryPolicy | Sequence[RetryPolicy] | None = None,
     cache_policy: CachePolicy[Callable[P, str | bytes]] | None = None,
     **kwargs: Unpack[DeprecatedKwargs],
-) -> Callable[
-    [Callable[P, Awaitable[T]] | Callable[P, T]],
-    _TaskFunction[P, T],
-]: ...
+) -> Callable[[Callable[P, T]], _TaskFunction[P, T]]: ...
 
 
 @overload
 def task(
-    __func_or_none__: Callable[P, Awaitable[T]] | Callable[P, T],
-) -> _TaskFunction[P, T]: ...
+    *,
+    name: str | None = None,
+    retry_policy: RetryPolicy | Sequence[RetryPolicy] | None = None,
+    cache_policy: CachePolicy[Callable[P, str | bytes]] | None = None,
+    **kwargs: Unpack[DeprecatedKwargs],
+) -> Callable[[Callable[P, Awaitable[T]]], _TaskFunction[P, T]]: ...
+
+
+@overload
+def task(__func_or_none__: Callable[P, T]) -> _TaskFunction[P, T]: ...
+
+
+@overload
+def task(__func_or_none__: Callable[P, Awaitable[T]]) -> _TaskFunction[P, T]: ...
 
 
 def task(
@@ -120,7 +129,8 @@ def task(
     cache_policy: CachePolicy[Callable[P, str | bytes]] | None = None,
     **kwargs: Unpack[DeprecatedKwargs],
 ) -> (
-    Callable[[Callable[P, Awaitable[T]] | Callable[P, T]], _TaskFunction[P, T]]
+    Callable[[Callable[P, T]], _TaskFunction[P, T]]
+    | Callable[[Callable[P, Awaitable[T]]], _TaskFunction[P, T]]
     | _TaskFunction[P, T]
 ):
     """Define a LangGraph task using the `task` decorator.