core[patch]: fix chat history circular import (#23182)

libs/core/langchain_core/chat_history.py

@@ -26,7 +26,6 @@ from langchain_core.messages import (
     get_buffer_string,
 )
 from langchain_core.pydantic_v1 import BaseModel, Field
-from langchain_core.runnables import run_in_executor
 
 
 class BaseChatMessageHistory(ABC):
@@ -102,6 +101,8 @@ class BaseChatMessageHistory(ABC):
         In general, fetching messages may involve IO to the underlying
         persistence layer.
         """
+        from langchain_core.runnables.config import run_in_executor
+
         return await run_in_executor(None, lambda: self.messages)
 
     def add_user_message(self, message: Union[HumanMessage, str]) -> None:
@@ -172,6 +173,8 @@ class BaseChatMessageHistory(ABC):
         Args:
             messages: A list of BaseMessage objects to store.
         """
+        from langchain_core.runnables.config import run_in_executor
+
         await run_in_executor(None, self.add_messages, messages)
 
     @abstractmethod
@@ -180,6 +183,8 @@ class BaseChatMessageHistory(ABC):
 
     async def aclear(self) -> None:
         """Remove all messages from the store"""
+        from langchain_core.runnables.config import run_in_executor
+
         await run_in_executor(None, self.clear)
 
     def __str__(self) -> str:

libs/core/langchain_core/runnables/__init__.py

@@ -36,6 +36,7 @@ from langchain_core.runnables.config import (
     run_in_executor,
 )
 from langchain_core.runnables.fallbacks import RunnableWithFallbacks
+from langchain_core.runnables.history import RunnableWithMessageHistory
 from langchain_core.runnables.passthrough import (
     RunnableAssign,
     RunnablePassthrough,
@@ -78,6 +79,7 @@ __all__ = [
     "RunnablePick",
     "RunnableSequence",
     "RunnableWithFallbacks",
+    "RunnableWithMessageHistory",
     "get_config_list",
     "aadd",
     "add",

libs/core/tests/unit_tests/runnables/test_imports.py

@@ -26,6 +26,7 @@ EXPECTED_ALL = [
     "RunnablePick",
     "RunnableSequence",
     "RunnableWithFallbacks",
+    "RunnableWithMessageHistory",
     "get_config_list",
     "aadd",
     "add",