app.py

# ─────────────────────────────  app.py  ─────────────────────────────────────
# NOTE: just push this one file to your HF Space repo. The bootstrap section
#       installs the needed packages inside the container at first launch.

# ╭──────────────────────── 0. Bootstrap helper ─────────────────────────────╮
import importlib, subprocess, sys, os, datetime
from typing import List

def ensure(pkg: str, ver: str | None = None):
    """Import a package or pip-install it into the current env, then import."""
    try:
        return importlib.import_module(pkg)
    except ModuleNotFoundError:
        target = f"{pkg}=={ver}" if ver else pkg
        print(f"[bootstrap] installing {target} …", flush=True)
        subprocess.check_call([sys.executable, "-m", "pip", "install", target])
        return importlib.import_module(pkg)

# minimal deps: pytz + *monolithic* langchain (0.1.x) + openai
pytz       = ensure("pytz")
langchain  = ensure("langchain", "0.1.16")   # stable, includes tool decorator
openai_pkg = ensure("openai")                # backend used by ChatOpenAI

# ╰───────────────────────────────────────────────────────────────────────────╯


# ╭──────────────────────── 1. Imports after install ────────────────────────╮
from langchain.tools import tool, Tool
from langchain.chat_models import ChatOpenAI
from langchain.agents import create_openai_functions_agent, AgentExecutor
# ╰───────────────────────────────────────────────────────────────────────────╯


# ╭──────────────────────── 2. Tool definitions ─────────────────────────────╮
@tool
def my_custom_tool(arg1: str, arg2: int) -> str:
    """A placeholder tool you can extend later.
    Args:
        arg1: any string
        arg2: any integer
    """
    return f"Received arg1='{arg1}', arg2={arg2}. Build your magic here!"

@tool
def get_current_time_in_timezone(timezone: str) -> str:
    """Return the current local time in the given IANA timezone."""
    try:
        tz = pytz.timezone(timezone)
        return datetime.datetime.now(tz).strftime("%Y-%m-%d %H:%M:%S")
    except Exception as e:
        return f"Error: {e}"
# ╰───────────────────────────────────────────────────────────────────────────╯


# ╭──────────────────────── 3. Build agent once ─────────────────────────────╮
tools: List[Tool] = [
    Tool.from_function(my_custom_tool,                  name="my_custom_tool"),
    Tool.from_function(get_current_time_in_timezone,    name="get_current_time_in_timezone"),
]

llm   = ChatOpenAI(                    # uses env var OPENAI_API_KEY
    model       = "gpt-3.5-turbo",
    temperature = 0,
)

agent = create_openai_functions_agent(llm, tools)
agent_executor = AgentExecutor(agent=agent, tools=tools, verbose=False)
# ╰───────────────────────────────────────────────────────────────────────────╯


# ╭──────────────────────── 4. CLI test loop (optional) ─────────────────────╮
if __name__ == "__main__":
    if not os.getenv("OPENAI_API_KEY"):
        print("⚠️  Please set OPENAI_API_KEY as an env-var (HF Space → Secrets).")
    print("🔮 Agent ready. Type a question or 'q' to quit.")
    while True:
        user = input("🗣  ")
        if user.lower().strip() in {"q", "quit", "exit"}:
            break
        result = agent_executor.invoke({"input": user})
        print("🤖", result["output"])
# ╰───────────────────────────────────────────────────────────────────────────╯