app.py

import os
import gradio as gr
import datetime
import pytz
from llama_index.core.agent import ReActAgent
from llama_index.core.tools import FunctionTool
from llama_index.llms.huggingface_api import HuggingFaceInferenceAPI

# 1. SETUP LLM
hf_token = os.getenv("HF_TOKEN")

# Fix: Change task to "conversational" as required by the provider
llm = HuggingFaceInferenceAPI(
    model_name="Qwen/Qwen2.5-7B-Instruct", 
    token=hf_token,
    task="conversational", 
    provider="together",
    is_function_calling_model=False 
)

# 2. DEFINE YOUR TOOLS (Must be defined before the Agent)
def get_tokyo_time() -> str:
    """Returns the current time in Tokyo, Japan."""
    tz = pytz.timezone('Asia/Tokyo')
    return f"The current time in Tokyo is {datetime.datetime.now(tz).strftime('%H:%M:%S')}"

def multiply(a: float, b: float) -> float:
    """Multiplies two numbers (a and b) and returns the result."""
    return a * b

# Wrap them in LlamaIndex Tool objects
tools = [
    FunctionTool.from_defaults(fn=get_tokyo_time),
    FunctionTool.from_defaults(fn=multiply)
]

# 3. THE "STABILITY" PROMPT
RE_ACT_PROMPT = """You are a helpful assistant.
For every query, you MUST follow this sequence:
Thought: <your reasoning>
Action: <tool_name>
Action Input: {"arg1": value}
Observation: <result from tool>
... (repeat if needed)
Thought: I have the final answer.
Answer: <your final response to the user>
"""

# 4. CREATE THE AGENT
# Now 'tools' and 'llm' are both correctly defined and configured
agent = ReActAgent.from_tools(
    tools, 
    llm=llm, 
    verbose=True,
    context=RE_ACT_PROMPT
)

# 5. GRADIO INTERFACE
def chat(message, history):
    try:
        response = agent.chat(message)
        return str(response)
    except Exception as e:
        return f"System Error: {str(e)}"

gr.ChatInterface(chat, title="Unit 2: LlamaIndex Agent (Fixed)").launch()