from typing import TypedDict, Annotated
from langgraph.graph.message import add_messages
class AgentState(TypedDict, total=False):
    messages: Annotated[list, add_messages]
    # Fields that the agent node can set to request a tool
    web_search_query: str
    ocr_path: str
    excel_path: str
    excel_sheet_name: str
    # Fields to hold the tool outputs
    web_search_result: str
    ocr_result: str
    excel_result: str
    # A “final_answer” field that the last agent node will fill
    final_answer: str# (Keep Constants as is)