agent.py

import os
from dotenv import load_dotenv
from langchain_core.messages import SystemMessage, HumanMessage
from langgraph.prebuilt import ToolNode
from langgraph.graph import START, StateGraph, MessagesState
from langgraph.prebuilt import tools_condition
from langchain_openai import AzureChatOpenAI
from tools import multiply, add, subtract, divide, modulus, wiki_search, web_search, arvix_search

load_dotenv()

# load the system prompt from the file
with open("system_prompt.txt", "r", encoding="utf-8") as f:
    system_prompt = f.read()

# System message
sys_msg = SystemMessage(content=system_prompt)

# Build graph function
def build_graph():
    """Build the graph"""
    llm = AzureChatOpenAI(
        api_version=os.getenv("AZURE_OPENAI_API_VERSION"),
        azure_deployment=os.getenv("AZURE_OPENAI_MODEL"),
        temperature=0,
        max_tokens=None,
        timeout=None,
        max_retries=2,
    )

    tools = [
        multiply,
        add,
        subtract,
        divide,
        modulus,
        wiki_search,
        web_search,
        arvix_search,
    ]

    llm_with_tools = llm.bind_tools(tools)


    # Node
    def assistant(state: MessagesState):
        """Assistant node"""
        return {"messages": [llm_with_tools.invoke(state["messages"])]}

    ## The graph
    builder = StateGraph(MessagesState)

    # Define nodes: these do the work
    builder.add_node("assistant", assistant)
    builder.add_node("tools", ToolNode(tools))

    # Define edges: these determine how the control flow moves
    builder.add_edge(START, "assistant")
    builder.add_conditional_edges(
        "assistant",
        # If the latest message requires a tool, route to tools
        # Otherwise, provide a direct response
        tools_condition,
    )
    builder.add_edge("tools", "assistant")

    return builder.compile()

# Test
if __name__ == "__main__":
    # question = "When was a picture of St. Thomas Aquinas first added to the Wikipedia page on the Principle of double effect?"
    # question = "Examine the video at https://www.youtube.com/watch?v=1htKBjuUWec.\n\nWhat does Teal'c say in response to the question \"Isn't that hot?\""
    question = "Who's the current President of France?"
    # Build the graph
    graph = build_graph()
    # Run the graph
    messages = [HumanMessage(content=question)]
    messages = graph.invoke({"messages": messages})
    for m in messages["messages"]:
        m.pretty_print()