Update app.py

app.py

@@ -20,7 +20,7 @@ from typing_extensions import TypedDict, Annotated
 # Updated imports for LangChain
 from langchain.embeddings.openai import OpenAIEmbeddings
 from langchain.vectorstores import Chroma
-from langchain.schema import HumanMessage, AIMessage
+from langchain.schema import HumanMessage, AIMessage, ToolMessage
 from langchain.text_splitter import RecursiveCharacterTextSplitter
 from langchain.tools.retriever import create_retriever_tool
 
@@ -80,9 +80,8 @@ development_tool = create_retriever_tool(
 tools = [research_tool, development_tool]
 
 # --- Agent and Workflow Functions ---
-# Note: We are using only AIMessage and HumanMessage for our message types.
 class AgentState(TypedDict):
-    messages: Annotated[Sequence[AIMessage | HumanMessage], add_messages]
+    messages: Annotated[Sequence[AIMessage | HumanMessage | ToolMessage], add_messages]
 
 def agent(state: AgentState):
     logger.info("Agent invoked")