app.py

import pathlib
import os
import gradio as gr
from mcp import StdioServerParameters
from smolagents import MCPClient, CodeAgent, InferenceClientModel

# Absolute path to sibling mcp_server.py
SERVER_PATH = pathlib.Path(__file__).with_name("mcp_server.py")

# Lazy‑load a Hugging Face Inference model (defaults to Qwen if no id given)
HF_MODEL_ID = os.getenv("HF_MODEL_ID", "Qwen/Qwen3-0.6B")  # small & free-tier friendly


def respond(message: str, history: list):
    """Route the prompt through an MCP‑enabled CodeAgent and return the answer."""
    params = StdioServerParameters(command="python", args=[str(SERVER_PATH)])

    with MCPClient(params) as tools:
        model = InferenceClientModel(model_id=HF_MODEL_ID)
        agent = CodeAgent(tools=tools, model=model)
        answer = agent.run(message)

    # Update chat in OpenAI‑style messages
    history.append({"role": "user", "content": message})
    history.append({"role": "assistant", "content": answer})
    return history, history


with gr.Blocks(title="Enterprise SQL Agent") as demo:
    chat_state = gr.State([])
    chatbot = gr.Chatbot(type="messages", label="Enterprise SQL Agent")

    textbox = gr.Textbox(
        placeholder="Ask: Who are my inactive Northeast customers?",
        show_label=False,
    )
    textbox.submit(respond, [textbox, chat_state], [chatbot, chat_state])

    gr.Markdown(
        """
        ### Example Prompts
        - Who are my Northeast customers who haven’t ordered in 6 months?
        - List customers sorted by last order date.
        - Find clients from the West with recent orders.

        _Powered by smolagents + MCP + Hugging Face Inference API_
        """
    )

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