app.py

"""
Gradio front-end + smolagents CodeAgent
---------------------------------------
• If you set an OPENAI_API_KEY the agent will call OpenAI (GPT-4o by default).
• Otherwise it falls back to a free Hugging Face chat-completion model
  (defaults to microsoft/Phi-3-mini-4k-instruct which the public Inference
  API exposes for the Chat Completion task).
• You can override the fallback by defining HF_MODEL_ID and, if needed,
  HF_API_TOKEN in the Space → Settings → Secrets.
"""

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

# Path to your MCP tool server
SERVER_PATH = pathlib.Path(__file__).with_name("mcp_server.py")

# Decide which base model to use
OPENAI_KEY   = os.getenv("OPENAI_API_KEY")
HF_MODEL_ID  = os.getenv("HF_MODEL_ID", "microsoft/Phi-3-mini-4k-instruct")

if OPENAI_KEY:                          # --- OpenAI branch -------------
    from smolagents.models import OpenAIChat           # <- works in all versions
    BASE_MODEL = OpenAIChat(                           # gpt-4o by default
        model=os.getenv("OPENAI_MODEL", "gpt-4o-preview"),
        temperature=0.3,
    )
else:                                     # --- Hugging Face branch ----
    BASE_MODEL = InferenceClientModel(               # uses HF Inference API
        model_id=HF_MODEL_ID,
        hf_api_token=os.getenv("HF_API_TOKEN"),      # optional for gated repos
        timeout=90,
    )

# ----------------- callback ---------------------------------------------------
def respond(message: str, history: list):
    """Send user prompt → CodeAgent → SQL tools → natural-language answer."""
    params = StdioServerParameters(command="python", args=[str(SERVER_PATH)])
    with MCPClient(params) as tools:
        agent  = CodeAgent(tools=tools, model=BASE_MODEL)
        answer = agent.run(message)

    history += [
        {"role": "user",      "content": message},
        {"role": "assistant", "content": answer},
    ]
    return history, history

# ----------------- UI ---------------------------------------------------------
with gr.Blocks(title="Enterprise SQL Agent") as demo:
    state   = gr.State([])
    gr.Markdown("## Enterprise SQL Agent — ask questions about your data 🏢➡️📊")

    chat    = gr.Chatbot(type="messages", label="Chat")
    box     = gr.Textbox(
        placeholder="e.g. Who are my inactive Northeast customers?",
        show_label=False,
    )
    box.submit(respond, [box, state], [chat, state])

    with gr.Accordion("Example prompts"):
        gr.Markdown(
            "* Who are my **Northeast** customers with no orders in 6 months?\n"
            "* List customers sorted by **LastOrderDate**.\n"
            "* Draft re-engagement emails for inactive accounts."
        )

    footer = (
        f"_Powered by MCP + smolagents + Gradio • Model: "
        f"{'OpenAI' if OPENAI_KEY else HF_MODEL_ID}_"
    )
    gr.Markdown(footer)

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