core[patch]: fix no current event loop for sql history in async mode (#22933)

- **Description:** When use
RunnableWithMessageHistory/SQLChatMessageHistory in async mode, we'll
get the following error:
```
Error in RootListenersTracer.on_chain_end callback: RuntimeError("There is no current event loop in thread 'asyncio_3'.")
```
which throwed by
ddfbca38df/libs/community/langchain_community/chat_message_histories/sql.py (L259).
and no message history will be add to database.

In this patch, a new _aexit_history function which will'be called in
async mode is added, and in turn aadd_messages will be called.

In this patch, we use `afunc` attribute of a Runnable to check if the
end listener should be run in async mode or not.

  - **Issue:** #22021, #22022 
  - **Dependencies:** N/A

libs/community/langchain_community/chat_message_histories/sql.py

@@ -1,4 +1,3 @@
-import asyncio
 import contextlib
 import json
 import logging
@@ -252,13 +251,7 @@ class SQLChatMessageHistory(BaseChatMessageHistory):
             await session.commit()
 
     def add_messages(self, messages: Sequence[BaseMessage]) -> None:
-        # The method RunnableWithMessageHistory._exit_history() call
+        # Add all messages in one transaction
-        #  add_message method by mistake and not aadd_message.
-        # See https://github.com/langchain-ai/langchain/issues/22021
-        if self.async_mode:
-            loop = asyncio.get_event_loop()
-            loop.run_until_complete(self.aadd_messages(messages))
-        else:
         with self._make_sync_session() as session:
             for message in messages:
                 session.add(self.converter.to_sql_model(message, self.session_id))

libs/core/langchain_core/runnables/history.py

@@ -16,6 +16,7 @@ from typing import (
 from langchain_core.chat_history import BaseChatMessageHistory
 from langchain_core.load.load import load
 from langchain_core.pydantic_v1 import BaseModel
+from langchain_core.runnables import RunnableBranch
 from langchain_core.runnables.base import Runnable, RunnableBindingBase, RunnableLambda
 from langchain_core.runnables.passthrough import RunnablePassthrough
 from langchain_core.runnables.utils import (
@@ -306,8 +307,17 @@ class RunnableWithMessageHistory(RunnableBindingBase):
             history_chain = RunnablePassthrough.assign(
                 **{messages_key: history_chain}
             ).with_config(run_name="insert_history")
-        bound = (
+        bound: Runnable = (
-            history_chain | runnable.with_listeners(on_end=self._exit_history)
+            history_chain
+            | RunnableBranch(
+                (
+                    RunnableLambda(
+                        self._is_not_async, afunc=self._is_async
+                    ).with_config(run_name="RunnableWithMessageHistoryInAsyncMode"),
+                    runnable.with_alisteners(on_end=self._aexit_history),
+                ),
+                runnable.with_listeners(on_end=self._exit_history),
+            )
         ).with_config(run_name="RunnableWithMessageHistory")
 
         if history_factory_config:
@@ -367,6 +377,12 @@ class RunnableWithMessageHistory(RunnableBindingBase):
         else:
             return super_schema
 
+    def _is_not_async(self, *args: Sequence[Any], **kwargs: Dict[str, Any]) -> bool:
+        return False
+
+    async def _is_async(self, *args: Sequence[Any], **kwargs: Dict[str, Any]) -> bool:
+        return True
+
     def _get_input_messages(
         self, input_val: Union[str, BaseMessage, Sequence[BaseMessage], dict]
     ) -> List[BaseMessage]:
@@ -483,6 +499,23 @@ class RunnableWithMessageHistory(RunnableBindingBase):
         output_messages = self._get_output_messages(output_val)
         hist.add_messages(input_messages + output_messages)
 
+    async def _aexit_history(self, run: Run, config: RunnableConfig) -> None:
+        hist: BaseChatMessageHistory = config["configurable"]["message_history"]
+
+        # Get the input messages
+        inputs = load(run.inputs)
+        input_messages = self._get_input_messages(inputs)
+        # If historic messages were prepended to the input messages, remove them to
+        # avoid adding duplicate messages to history.
+        if not self.history_messages_key:
+            historic_messages = config["configurable"]["message_history"].messages
+            input_messages = input_messages[len(historic_messages) :]
+
+        # Get the output messages
+        output_val = load(run.outputs)
+        output_messages = self._get_output_messages(output_val)
+        await hist.aadd_messages(input_messages + output_messages)
+
     def _merge_configs(self, *configs: Optional[RunnableConfig]) -> RunnableConfig:
         config = super()._merge_configs(*configs)
         expected_keys = [field_spec.id for field_spec in self.history_factory_config]

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

@@ -62,6 +62,31 @@ def test_input_messages() -> None:
     }
 
 
+async def test_input_messages_async() -> None:
+    runnable = RunnableLambda(
+        lambda messages: "you said: "
+        + "\n".join(str(m.content) for m in messages if isinstance(m, HumanMessage))
+    )
+    store: Dict = {}
+    get_session_history = _get_get_session_history(store=store)
+    with_history = RunnableWithMessageHistory(runnable, get_session_history)
+    config: RunnableConfig = {"configurable": {"session_id": "1_async"}}
+    output = await with_history.ainvoke([HumanMessage(content="hello")], config)
+    assert output == "you said: hello"
+    output = await with_history.ainvoke([HumanMessage(content="good bye")], config)
+    assert output == "you said: hello\ngood bye"
+    assert store == {
+        "1_async": ChatMessageHistory(
+            messages=[
+                HumanMessage(content="hello"),
+                AIMessage(content="you said: hello"),
+                HumanMessage(content="good bye"),
+                AIMessage(content="you said: hello\ngood bye"),
+            ]
+        )
+    }
+
+
 def test_input_dict() -> None:
     runnable = RunnableLambda(
         lambda input: "you said: "
@@ -82,6 +107,28 @@ def test_input_dict() -> None:
     assert output == "you said: hello\ngood bye"
 
 
+async def test_input_dict_async() -> None:
+    runnable = RunnableLambda(
+        lambda input: "you said: "
+        + "\n".join(
+            str(m.content) for m in input["messages"] if isinstance(m, HumanMessage)
+        )
+    )
+    get_session_history = _get_get_session_history()
+    with_history = RunnableWithMessageHistory(
+        runnable, get_session_history, input_messages_key="messages"
+    )
+    config: RunnableConfig = {"configurable": {"session_id": "2_async"}}
+    output = await with_history.ainvoke(
+        {"messages": [HumanMessage(content="hello")]}, config
+    )
+    assert output == "you said: hello"
+    output = await with_history.ainvoke(
+        {"messages": [HumanMessage(content="good bye")]}, config
+    )
+    assert output == "you said: hello\ngood bye"
+
+
 def test_input_dict_with_history_key() -> None:
     runnable = RunnableLambda(
         lambda input: "you said: "
@@ -104,6 +151,28 @@ def test_input_dict_with_history_key() -> None:
     assert output == "you said: hello\ngood bye"
 
 
+async def test_input_dict_with_history_key_async() -> None:
+    runnable = RunnableLambda(
+        lambda input: "you said: "
+        + "\n".join(
+            [str(m.content) for m in input["history"] if isinstance(m, HumanMessage)]
+            + [input["input"]]
+        )
+    )
+    get_session_history = _get_get_session_history()
+    with_history = RunnableWithMessageHistory(
+        runnable,
+        get_session_history,
+        input_messages_key="input",
+        history_messages_key="history",
+    )
+    config: RunnableConfig = {"configurable": {"session_id": "3_async"}}
+    output = await with_history.ainvoke({"input": "hello"}, config)
+    assert output == "you said: hello"
+    output = await with_history.ainvoke({"input": "good bye"}, config)
+    assert output == "you said: hello\ngood bye"
+
+
 def test_output_message() -> None:
     runnable = RunnableLambda(
         lambda input: AIMessage(
@@ -132,7 +201,34 @@ def test_output_message() -> None:
     assert output == AIMessage(content="you said: hello\ngood bye")
 
 
-def test_input_messages_output_message() -> None:
+async def test_output_message_async() -> None:
+    runnable = RunnableLambda(
+        lambda input: AIMessage(
+            content="you said: "
+            + "\n".join(
+                [
+                    str(m.content)
+                    for m in input["history"]
+                    if isinstance(m, HumanMessage)
+                ]
+                + [input["input"]]
+            )
+        )
+    )
+    get_session_history = _get_get_session_history()
+    with_history = RunnableWithMessageHistory(
+        runnable,
+        get_session_history,
+        input_messages_key="input",
+        history_messages_key="history",
+    )
+    config: RunnableConfig = {"configurable": {"session_id": "4_async"}}
+    output = await with_history.ainvoke({"input": "hello"}, config)
+    assert output == AIMessage(content="you said: hello")
+    output = await with_history.ainvoke({"input": "good bye"}, config)
+    assert output == AIMessage(content="you said: hello\ngood bye")
+
+
 class LengthChatModel(BaseChatModel):
     """A fake chat model that returns the length of the messages passed in."""
 
@@ -145,28 +241,42 @@ def test_input_messages_output_message() -> None:
     ) -> ChatResult:
         """Top Level call"""
         return ChatResult(
-                generations=[
+            generations=[ChatGeneration(message=AIMessage(content=str(len(messages))))]
-                    ChatGeneration(message=AIMessage(content=str(len(messages))))
-                ]
         )
 
     @property
     def _llm_type(self) -> str:
         return "length-fake-chat-model"
 
+
+def test_input_messages_output_message() -> None:
     runnable = LengthChatModel()
     get_session_history = _get_get_session_history()
     with_history = RunnableWithMessageHistory(
         runnable,
         get_session_history,
     )
-    config: RunnableConfig = {"configurable": {"session_id": "4"}}
+    config: RunnableConfig = {"configurable": {"session_id": "5"}}
     output = with_history.invoke([HumanMessage(content="hi")], config)
     assert output.content == "1"
     output = with_history.invoke([HumanMessage(content="hi")], config)
     assert output.content == "3"
 
 
+async def test_input_messages_output_message_async() -> None:
+    runnable = LengthChatModel()
+    get_session_history = _get_get_session_history()
+    with_history = RunnableWithMessageHistory(
+        runnable,
+        get_session_history,
+    )
+    config: RunnableConfig = {"configurable": {"session_id": "5_async"}}
+    output = await with_history.ainvoke([HumanMessage(content="hi")], config)
+    assert output.content == "1"
+    output = await with_history.ainvoke([HumanMessage(content="hi")], config)
+    assert output.content == "3"
+
+
 def test_output_messages() -> None:
     runnable = RunnableLambda(
         lambda input: [
@@ -190,13 +300,43 @@ def test_output_messages() -> None:
         input_messages_key="input",
         history_messages_key="history",
     )
-    config: RunnableConfig = {"configurable": {"session_id": "5"}}
+    config: RunnableConfig = {"configurable": {"session_id": "6"}}
     output = with_history.invoke({"input": "hello"}, config)
     assert output == [AIMessage(content="you said: hello")]
     output = with_history.invoke({"input": "good bye"}, config)
     assert output == [AIMessage(content="you said: hello\ngood bye")]
 
 
+async def test_output_messages_async() -> None:
+    runnable = RunnableLambda(
+        lambda input: [
+            AIMessage(
+                content="you said: "
+                + "\n".join(
+                    [
+                        str(m.content)
+                        for m in input["history"]
+                        if isinstance(m, HumanMessage)
+                    ]
+                    + [input["input"]]
+                )
+            )
+        ]
+    )
+    get_session_history = _get_get_session_history()
+    with_history = RunnableWithMessageHistory(
+        runnable,  # type: ignore
+        get_session_history,
+        input_messages_key="input",
+        history_messages_key="history",
+    )
+    config: RunnableConfig = {"configurable": {"session_id": "6_async"}}
+    output = await with_history.ainvoke({"input": "hello"}, config)
+    assert output == [AIMessage(content="you said: hello")]
+    output = await with_history.ainvoke({"input": "good bye"}, config)
+    assert output == [AIMessage(content="you said: hello\ngood bye")]
+
+
 def test_output_dict() -> None:
     runnable = RunnableLambda(
         lambda input: {
@@ -223,13 +363,46 @@ def test_output_dict() -> None:
         history_messages_key="history",
         output_messages_key="output",
     )
-    config: RunnableConfig = {"configurable": {"session_id": "6"}}
+    config: RunnableConfig = {"configurable": {"session_id": "7"}}
     output = with_history.invoke({"input": "hello"}, config)
     assert output == {"output": [AIMessage(content="you said: hello")]}
     output = with_history.invoke({"input": "good bye"}, config)
     assert output == {"output": [AIMessage(content="you said: hello\ngood bye")]}
 
 
+async def test_output_dict_async() -> None:
+    runnable = RunnableLambda(
+        lambda input: {
+            "output": [
+                AIMessage(
+                    content="you said: "
+                    + "\n".join(
+                        [
+                            str(m.content)
+                            for m in input["history"]
+                            if isinstance(m, HumanMessage)
+                        ]
+                        + [input["input"]]
+                    )
+                )
+            ]
+        }
+    )
+    get_session_history = _get_get_session_history()
+    with_history = RunnableWithMessageHistory(
+        runnable,
+        get_session_history,
+        input_messages_key="input",
+        history_messages_key="history",
+        output_messages_key="output",
+    )
+    config: RunnableConfig = {"configurable": {"session_id": "7_async"}}
+    output = await with_history.ainvoke({"input": "hello"}, config)
+    assert output == {"output": [AIMessage(content="you said: hello")]}
+    output = await with_history.ainvoke({"input": "good bye"}, config)
+    assert output == {"output": [AIMessage(content="you said: hello\ngood bye")]}
+
+
 def test_get_input_schema_input_dict() -> None:
     class RunnableWithChatHistoryInput(BaseModel):
         input: Union[str, BaseMessage, Sequence[BaseMessage]]
@@ -404,3 +577,114 @@ def test_using_custom_config_specs() -> None:
             ]
         ),
     }
+
+
+async def test_using_custom_config_specs_async() -> None:
+    """Test that we can configure which keys should be passed to the session factory."""
+
+    def _fake_llm(input: Dict[str, Any]) -> List[BaseMessage]:
+        messages = input["messages"]
+        return [
+            AIMessage(
+                content="you said: "
+                + "\n".join(
+                    str(m.content) for m in messages if isinstance(m, HumanMessage)
+                )
+            )
+        ]
+
+    runnable = RunnableLambda(_fake_llm)
+    store = {}
+
+    def get_session_history(user_id: str, conversation_id: str) -> ChatMessageHistory:
+        if (user_id, conversation_id) not in store:
+            store[(user_id, conversation_id)] = ChatMessageHistory()
+        return store[(user_id, conversation_id)]
+
+    with_message_history = RunnableWithMessageHistory(
+        runnable,  # type: ignore
+        get_session_history=get_session_history,
+        input_messages_key="messages",
+        history_messages_key="history",
+        history_factory_config=[
+            ConfigurableFieldSpec(
+                id="user_id",
+                annotation=str,
+                name="User ID",
+                description="Unique identifier for the user.",
+                default="",
+                is_shared=True,
+            ),
+            ConfigurableFieldSpec(
+                id="conversation_id",
+                annotation=str,
+                name="Conversation ID",
+                description="Unique identifier for the conversation.",
+                default=None,
+                is_shared=True,
+            ),
+        ],
+    )
+    result = await with_message_history.ainvoke(
+        {
+            "messages": [HumanMessage(content="hello")],
+        },
+        {"configurable": {"user_id": "user1_async", "conversation_id": "1_async"}},
+    )
+    assert result == [
+        AIMessage(content="you said: hello"),
+    ]
+    assert store == {
+        ("user1_async", "1_async"): ChatMessageHistory(
+            messages=[
+                HumanMessage(content="hello"),
+                AIMessage(content="you said: hello"),
+            ]
+        )
+    }
+
+    result = await with_message_history.ainvoke(
+        {
+            "messages": [HumanMessage(content="goodbye")],
+        },
+        {"configurable": {"user_id": "user1_async", "conversation_id": "1_async"}},
+    )
+    assert result == [
+        AIMessage(content="you said: goodbye"),
+    ]
+    assert store == {
+        ("user1_async", "1_async"): ChatMessageHistory(
+            messages=[
+                HumanMessage(content="hello"),
+                AIMessage(content="you said: hello"),
+                HumanMessage(content="goodbye"),
+                AIMessage(content="you said: goodbye"),
+            ]
+        )
+    }
+
+    result = await with_message_history.ainvoke(
+        {
+            "messages": [HumanMessage(content="meow")],
+        },
+        {"configurable": {"user_id": "user2_async", "conversation_id": "1_async"}},
+    )
+    assert result == [
+        AIMessage(content="you said: meow"),
+    ]
+    assert store == {
+        ("user1_async", "1_async"): ChatMessageHistory(
+            messages=[
+                HumanMessage(content="hello"),
+                AIMessage(content="you said: hello"),
+                HumanMessage(content="goodbye"),
+                AIMessage(content="you said: goodbye"),
+            ]
+        ),
+        ("user2_async", "1_async"): ChatMessageHistory(
+            messages=[
+                HumanMessage(content="meow"),
+                AIMessage(content="you said: meow"),
+            ]
+        ),
+    }