app.py

# Python's OS interface for accessing environment variables
import os
# Intropesction utilities, you can auto-wrap it as a tool later.
import inspect
# HTTP client, Make REST calls for endpoints
import requests
# Parses CSV/Excel files
import pandas as pd 
# Gradio - Provides the web format front-end you see in the Space-text boxes, logs, "Run Agent" button etc.
import gradio as gr
# smolagent - minimalist agent framework for LLMs with tools
# CodeAgent - Orchestrate ReAct loop, logs each step
# Tool - a base class and a decorator (@tool)
# InferenceClientModel - Wrapper for HF's Serverless Inference API so you dont need to stand up your own TGI/LLM endpoint
from smolagents import CodeAgent, DuckDuckGoSearchTool, Tool, InferenceClientModel
# Programmatic huggingface-cli login, so the app can: pull private models, call paid-tier inference, push artefacts
from huggingface_hub import login
# Quick helper to pull LangChain's built-in tools so you can blend them with smolagent tools if you wish.
from langchain.agents import load_tools


# Configuration constant
# Unit-4 scoring micro-services where your agent submits answers and receivess a JSON score.
# --- Constants
DEFAULT_API_URL = "https://agents-course-unit4-scoring.hf.space"

# --- Basic Agent Definition ---
# ---- THIS IS WHERE YOU CAN BUILD WHAT YOU WANT ----
class BasicAgent:
    def __init__(self):
        # Pull a HF access token from the Space's secrets or your local shell. You can download private models, call paid-tier Inference endpoints, push artefacts
        hf_token = os.getenv("HUGGINGFACE_HUB_TOKEN") or os.getenv("HF_TOKEN")
        # IF IT WORKS LOGIN INTO HF HUB VIA THIS TOKEN
        if hf_token:
            login(token=hf_token)
        else:
            try:
                login()
            except Exception as e:
                raise Exception(
                    # helpful, course-style message
                    "Authentication failed. Please enter:\n"
                    "1. Run 'huggingface-cli login' in your terminal, or\n"
                    "2. Set HUGGINGFACE_HUB_TOKEN environment variable with your token, or\n"
                    "3. Get a token from https://huggingface.co/settings/tokens"
                ) from e
    
    # Warps the servesless inference endpoint for the chosen model
    # Initialize the model
    # InferenceClientModel handles throttling, batching, and streaming under the hood
    self.model = InferenceClientModel("Qwen/Qwen2.5-Code-32B-Instruct")
    
    # Add a first tool
    # Initialize the search tool
    # DuckDuckGoSearchTool - Gives the agent web-search super-powers it can pull fresh facts during its reasoning loop.
    self.search_tool = DuckDuckGoSearchTool()

    # smolagents's flagship class - 
    # Code Agent follows a ReAct-style loop, literally write Python code, executes it in a sandbox, inspects the result, then decides its next step
    self.agent = CodeAgent(
        model=self.model,
        tools=[self.search_tool],
        # drops in a small standard library (Python REPL, JSON loader etc.) so you can solve many tasks without defining anything else.
        add_base_tools=True # - python_repl, browser, math etc.
    )

    # Send a single "bootstrap" run whose only job is lock in behaviour rules:
    self.response = self.agent.run(
        """
        You are a general AI assistant.
        I will ask you a question. Report your thoughts, and finish your answer with the following template: [FINAL ANSWER].
        YOUR FINAL 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, do not use comma to write your number neither use units such as $ or percent sign unless specified otherwise. 
        If you are asked for a string, do not 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. 
        You have access to the following tools:
        Tool Name: search_tool, description:  lets you search and browse the internet for accessing the most updated information out there.
        If you require more tools to get a correct answer, create your own tools to utilize.    
        """)