import os
from langchain.chat_models import ChatOpenAI
from langchain.schema import HumanMessage

# Example of streaming with LangChain
if __name__ == "__main__":
    # Use OpenAI API key from env
    os.environ.setdefault("OPENAI_API_KEY", "sk-...")
    model = ChatOpenAI(temperature=0.7)
    # Stream response
    for chunk in model.stream([HumanMessage(content="Hello, world!" )]):
        print(chunk.content, end="", flush=True)
    print("\n[Done]")