app.py

from sqlalchemy import create_engine
from langchain_community.utilities import SQLDatabase
from langchain_community.agent_toolkits.sql.toolkit import SQLDatabaseToolkit

from langchain.chat_models import init_chat_model

from dotenv import load_dotenv
load_dotenv()

db_path = "art.db"
engine = create_engine(f'sqlite:///{db_path}')

db = SQLDatabase(engine)

#llm = init_chat_model("llama3-8b-8192", model_provider="groq")
llm = init_chat_model("meta-llama/llama-4-scout-17b-16e-instruct", model_provider="groq")
#llm = init_chat_model("gpt-4o-mini", model_provider="openai")

toolkit = SQLDatabaseToolkit(db=db, llm=llm)


from langchain import hub
from langgraph.prebuilt import create_react_agent

# Pull prompt (or define your own)
prompt_template = hub.pull("langchain-ai/sql-agent-system-prompt")
system_message = prompt_template.format(dialect="SQLite", top_k=5)

# Create agent
agent_executor = create_react_agent(
    llm, toolkit.get_tools(), prompt=system_message
)


import gradio as gr

def interact_with_agent(message, history):
    history_langchain_format = {"messages": [("system", "You are a helpful assistant that excel in  data exploration.")]}
    for msg in history:
        if msg['role'] == "user":
            history_langchain_format["messages"].append(("user", msg['content']))
        elif msg['role'] == "assistant":
            history_langchain_format["messages"].append(("assistant", msg['content']))
    history_langchain_format["messages"].append(("user", message))

    response = agent_executor.invoke(history_langchain_format, stream_mode="values")
    return response["messages"][-1].content

demo = gr.ChatInterface(
    interact_with_agent,
    type="messages",
    examples=["What is the title of the oldest art  in the database?",],
    #save_history=True
)

if __name__ == "__main__":
    demo.launch()