src/core/llm.py

# src/llm.py
from langchain_openai import ChatOpenAI
from src.config.config import (
    LLM_MODEL,
    OPENROUTER_BASE_URL,
    OPENROUTER_API_KEY
)

def load_llm():
    if not OPENROUTER_API_KEY:
        raise EnvironmentError("OPENROUTER_API_KEY not set")

    return ChatOpenAI(
        model=LLM_MODEL,
        base_url=OPENROUTER_BASE_URL,
        api_key=OPENROUTER_API_KEY
    )