"""LangGraph Agent""" import os from dotenv import load_dotenv from langchain_groq import ChatGroq from langchain_core.tools import tool from langgraph.prebuilt import ToolNode from langgraph.prebuilt import tools_condition from langgraph.graph import START, StateGraph, MessagesState from langchain_core.messages import SystemMessage, HumanMessage from langchain_community.tools import DuckDuckGoSearchResults load_dotenv() @tool def web_search(query: str) -> str: """ Search DuckDuckGo for a query. Args: query: The search query. Returns: A dict with key ``"web_results"`` containing a markdown-formatted string of the retrieved documents. """ # Instantiate the DuckDuckGo search utility search = DuckDuckGoSearchResults(max_results=3) # Perform the search search_result = search.invoke(query) return {"web_results": search_result} tools = [ web_search, ] llm = ChatGroq(model="meta-llama/llama-4-maverick-17b-128e-instruct", temperature=0) llm_with_tools = llm.bind_tools(tools) llm_with_tools = llm.bind_tools(tools) # Node def start_preprocess(state: MessagesState): # System message system_prompt = "You are a general AI assistant. I will ask you a question. Your answer should be a number OR as few words as possible OR a comma separated list of numbers and/or strings. If you are asked for a number, don't use comma to write your number neither use units such as $ or percent sign unless specified otherwise. If you are asked for a string, don't use articles, neither abbreviations (e.g. for cities), and write the digits in plain text unless specified otherwise. If you are asked for a comma separated list, apply the above rules depending of whether the element to be put in the list is a number or a string." sys_msg = SystemMessage(content=system_prompt) return {"messages": [sys_msg] + state["messages"]} # Node def assistant(state: MessagesState): """Assistant node""" return {"messages": [llm_with_tools.invoke(state["messages"])]} builder = StateGraph(MessagesState) builder.add_node("start_preprocess", start_preprocess) builder.add_node("assistant", assistant) builder.add_node("tools", ToolNode(tools)) builder.add_edge(START, "start_preprocess") builder.add_edge("start_preprocess", "assistant") builder.add_conditional_edges( "assistant", tools_condition, ) builder.add_edge("tools", "assistant") # Compile graph graph = builder.compile() if __name__ == "__main__": question = "NAMO age ?" # Run the graph messages = [HumanMessage(content=question)] messages = graph.invoke({"messages": messages}) for m in messages["messages"]: m.pretty_print()