Allow any kind of history for Langchain agents (#45)

examples/tool_calling_with_memory.py

@@ -18,7 +18,7 @@ def main():
     researcher = ReActToolCallingAgent(
         tools=tools,
         verbose=True,
-        with_history=True,
+        chat_history=True,
         # llm=init_llm(
         #     llm_framework=LLMFramework.LANGCHAIN,
         #     llm_family=LLMFamily.ANTHROPIC,

motleycrew/agents/langchain/langchain.py

@@ -4,14 +4,13 @@
 
 from langchain.agents import AgentExecutor
 from langchain_core.runnables import RunnableConfig
-from langchain_core.runnables.history import RunnableWithMessageHistory
-from langchain_core.chat_history import BaseChatMessageHistory, InMemoryChatMessageHistory
+from langchain_core.runnables.history import RunnableWithMessageHistory, GetSessionHistoryCallable
+from langchain_core.chat_history import InMemoryChatMessageHistory
 from langchain_core.language_models import BaseLanguageModel
 from langchain_core.prompts.chat import ChatPromptTemplate
 
 
 from motleycrew.agents.parent import MotleyAgentParent
-from motleycrew.agents.abstract_parent import MotleyAgentAbstractParent
 
 from motleycrew.tools import MotleyTool
 from motleycrew.tracking import add_default_callbacks_to_langchain_config
@@ -29,8 +28,7 @@ def __init__(
         agent_factory: MotleyAgentFactory | None = None,
         tools: Sequence[MotleySupportedTool] | None = None,
         verbose: bool = False,
-        with_history: bool = False,
-        chat_history: BaseChatMessageHistory | None = None,
+        chat_history: bool | GetSessionHistoryCallable = True,
     ):
         """Description
 
@@ -40,6 +38,10 @@ def __init__(
             agent_factory (:obj:`MotleyAgentFactory`, optional):
             tools (:obj:`Sequence[MotleySupportedTool]`, optional):
             verbose (bool):
+            chat_history (:obj:`bool`, :obj:`GetSessionHistoryCallable`):
+            Whether to use chat history or not. If `True`, uses `InMemoryChatMessageHistory`.
+            If a callable is passed, it is used to get the chat history by session_id.
+            See Langchain `RunnableWithMessageHistory` get_session_history param for more details.
         """
         super().__init__(
             description=description,
@@ -49,21 +51,24 @@ def __init__(
             verbose=verbose,
         )
 
-        self.with_history = with_history
-        self.chat_history = chat_history or InMemoryChatMessageHistory()
+        if chat_history is True:
+            chat_history = InMemoryChatMessageHistory()
+            self.get_session_history_callable = lambda _: chat_history
+        else:
+            self.get_session_history_callable = chat_history
 
     def materialize(self):
         """Materialize the agent and wrap it in RunnableWithMessageHistory if needed."""
         if self.is_materialized:
             return
 
         super().materialize()
-        if self.with_history:
+        if self.get_session_history_callable:
             if isinstance(self._agent, RunnableWithMessageHistory):
                 return
             self._agent = RunnableWithMessageHistory(
                 runnable=self._agent,
-                get_session_history=lambda _: self.chat_history,
+                get_session_history=self.get_session_history_callable,
                 input_messages_key="input",
                 history_messages_key="chat_history",
             )
@@ -88,7 +93,7 @@ def invoke(
         prompt = self.compose_prompt(task_dict, task_dict.get("prompt"))
 
         config = add_default_callbacks_to_langchain_config(config)
-        if self.with_history:
+        if self.get_session_history_callable:
             config["configurable"] = config.get("configurable") or {}
             config["configurable"]["session_id"] = (
                 config["configurable"].get("session_id") or "default"
@@ -110,7 +115,7 @@ def from_function(
         tools: Sequence[MotleySupportedTool] | None = None,
         prompt: ChatPromptTemplate | Sequence[ChatPromptTemplate] | None = None,
         require_tools: bool = False,
-        with_history: bool = False,
+        chat_history: bool | GetSessionHistoryCallable = True,
         verbose: bool = False,
     ) -> "LangchainMotleyAgent":
         """Description
@@ -123,6 +128,10 @@ def from_function(
             tools (:obj:`Sequence[MotleySupportedTool]`, optional):
             prompt (:obj:`ChatPromptTemplate`, :obj:`Sequence[ChatPromptTemplate]`, optional):
             require_tools (bool):
+            chat_history (:obj:`bool`, :obj:`GetSessionHistoryCallable`):
+            Whether to use chat history or not. If `True`, uses `InMemoryChatMessageHistory`.
+            If a callable is passed, it is used to get the chat history by session_id.
+            See Langchain `RunnableWithMessageHistory` get_session_history param for more details.
             verbose (bool):
 
         Returns:
@@ -149,7 +158,7 @@ def agent_factory(tools: dict[str, MotleyTool]):
             name=name,
             agent_factory=agent_factory,
             tools=tools,
-            with_history=with_history,
+            chat_history=chat_history,
             verbose=verbose,
         )
 

motleycrew/agents/langchain/tool_calling_react.py

@@ -1,9 +1,10 @@
 from typing import Sequence, List, Union
 
-from langchain_core.messages import BaseMessage, HumanMessage, ChatMessage
+from langchain_core.messages import BaseMessage, HumanMessage, ToolMessage
 from langchain_core.language_models import BaseChatModel
 from langchain_core.prompts.chat import ChatPromptTemplate
 from langchain_core.runnables import Runnable, RunnablePassthrough, RunnableLambda
+from langchain_core.runnables.history import GetSessionHistoryCallable
 from langchain_core.tools import BaseTool
 from langchain_core.agents import AgentFinish, AgentActionMessageLog
 from langchain_core.prompts import MessagesPlaceholder
@@ -147,7 +148,11 @@ def merge_consecutive_messages(messages: Sequence[BaseMessage]) -> List[BaseMess
     """
     merged_messages = []
     for message in messages:
-        if not merged_messages or type(merged_messages[-1]) != type(message):
+        if (
+            not merged_messages
+            or type(merged_messages[-1]) != type(message)
+            or isinstance(message, ToolMessage)
+        ):
             merged_messages.append(message)
         else:
             merged_messages[-1].content = merge_content(
@@ -223,8 +228,8 @@ def __new__(
         description: str | None = None,
         name: str | None = None,
         prompt: ChatPromptTemplate | Sequence[ChatPromptTemplate] | None = None,
-        with_history: bool = False,
         llm: BaseChatModel | None = None,
+        chat_history: bool | GetSessionHistoryCallable = True,
         verbose: bool = False,
     ):
         """Description
@@ -233,7 +238,11 @@ def __new__(
             tools (Sequence[MotleySupportedTool]):
             description (:obj:`str`, optional):
             name (:obj:`str`, optional):
-            prompt (:obj:ChatPromptTemplate`, :obj:`Sequence[ChatPromptTemplate]', optional):
+            prompt (:obj:ChatPromptTemplate`, :obj:`Sequence[ChatPromptTemplate]`, optional):
+            chat_history (:obj:`bool`, :obj:`GetSessionHistoryCallable`):
+            Whether to use chat history or not. If `True`, uses `InMemoryChatMessageHistory`.
+            If a callable is passed, it is used to get the chat history by session_id.
+            See Langchain `RunnableWithMessageHistory` get_session_history param for more details.
             llm (:obj:`BaseLanguageModel`, optional):
             verbose (:obj:`bool`, optional):
         """
@@ -245,6 +254,6 @@ def __new__(
             prompt=prompt,
             function=create_tool_calling_react_agent,
             require_tools=True,
-            with_history=with_history,
+            chat_history=chat_history,
             verbose=verbose,
         )