import os
from openai import OpenAI

def call_llm(prompt):    
    client = OpenAI(api_key=os.environ.get("OPENAI_API_KEY", "your-api-key"))
    r = client.chat.completions.create(
        model="gpt-4o-mini",
        messages=[{"role": "user", "content": prompt}]
    )
    return r.choices[0].message.content

# Example usage
if __name__ == "__main__":
    print(call_llm("Tell me a short joke"))