app/models/OpenAI.py

from app.utils.handle_api import get_api
from langchain_openai import ChatOpenAI


llm = ChatOpenAI(
    # model="gpt-4o-mini", 
    model="gpt-4.1-mini", 
    api_key=get_api(),
    temperature=0.2,
    max_tokens=None
    )