selected the llm to use

agent.py

@@ -6,6 +6,19 @@ from youtube_transcript_api import YouTubeTranscriptApi
 from PIL import Image
 import pytesseract
 import pandas as pd
+from dotenv import load_dotenv
+
+from langgraph.graph import StateGraph, START, END
+from langgraph.prebuilt import ToolNode, tools_condition
+from langchain_openai import ChatOpenAI
+from langchain_core.messages import HumanMessage, SystemMessage
+from typing import TypedDict, Dict, Any, Optional, List
+
+load_dotenv()
+
+## ----- API KEYS  ----- ##
+
+openai_api_key = os.getenv("OPENAI_API_KEY")
 
 ## ----- TOOLS DEFINITION ----- ##
 
@@ -229,4 +242,23 @@ tools = [
     Tool.from_function(func=execute_python_code, name="Python Code Executor", description="Run and return output from a Python script."),
     # Excel parsing
     Tool.from_function(func=total_sales_from_excel, name="Excel Sales Parser", description="Compute total food sales from Excel file."),
-]
+]
+
+
+## ----- LLM MODEL ----- ##
+
+llm = ChatOpenAI(model="gpt-4o", temperature=0)
+llm_with_tools = llm.bind_tools(tools)
+
+## ----- SYSTEM PROMPT ----- ##
+
+with open("system_prompt.txt", "r", encoding="utf-8") as f:
+    system_prompt = f.read()
+print(system_prompt)
+
+# System message
+sys_msg = SystemMessage(content=system_prompt)
+
+## ----- GRAPH AGENT PIPELINE ----- ##
+
+