add memory feature

frontend/pages/tool_agent.py

@@ -6,8 +6,11 @@
 from langchain.agents import AgentExecutor, create_tool_calling_agent
 from langchain.memory import ConversationBufferWindowMemory
 from langchain_community.callbacks import StreamlitCallbackHandler
+from langchain_community.chat_message_histories import ChatMessageHistory
+from langchain_core.chat_history import BaseChatMessageHistory
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
 from langchain_core.runnables import RunnableConfig
+from langchain_core.runnables.history import RunnableWithMessageHistory
 from langchain_openai import AzureChatOpenAI
 from tools.fetch_contoso_rules import fetch_contoso_rules
 from tools.search_ddg import search_ddg
@@ -48,6 +51,21 @@
 ユーザーが日本語で質問した場合は、日本語で回答してください。ユーザーがスペイン語で質問した場合は、スペイン語で回答してください。
 """
 
+store = {}
+
+
+def wrap_with_history(runnable):
+    def get_session_history(session_id: str) -> BaseChatMessageHistory:
+        if session_id not in store:
+            store[session_id] = ChatMessageHistory()
+        return store[session_id]
+
+    return RunnableWithMessageHistory(
+        runnable,
+        get_session_history,
+        history_messages_key="chat_history",
+    )
+
 
 def init_page():
     st.set_page_config(page_title="Web Browsing Agent", page_icon="🤗")
@@ -96,7 +114,9 @@ def create_agent():
 def main():
     init_page()
     init_messages()
-    web_browsing_agent = create_agent()
+    session_id = "example_session"
+
+    web_browsing_agent = wrap_with_history(create_agent())
 
     for msg in st.session_state["memory"].chat_memory.messages:
         st.chat_message(msg.type).write(msg.content)
@@ -108,9 +128,19 @@ def main():
             st_cb = StreamlitCallbackHandler(st.container(), expand_new_thoughts=True)
             response = web_browsing_agent.invoke(
                 {"input": prompt},
-                config=RunnableConfig({"callbacks": [st_cb]}),
+                config=RunnableConfig(
+                    {
+                        "callbacks": [
+                            st_cb,
+                        ],
+                        "configurable": {
+                            "session_id": session_id,
+                        },
+                    }
+                ),
             )
             st.write(response["output"])
+            print(f"\chat_history:\n{store[session_id]}")
 
 
 if __name__ == "__main__":