ai-agents-agent-creation-need-to-create-a-simple-assistant-agent-using-open-686476f1

THEN Install autogen-agentchat and autogen-ext[openai], then create an AssistantAgent with an OpenAIChatCompletionClient and call agent.run(task).

import asyncio
from autogen_agentchat.agents import AssistantAgent
from autogen_ext.models.openai import OpenAIChatCompletionClient

async def main():
    model_client = OpenAIChatCompletionClient(model="gpt-4.1")
    agent = AssistantAgent("assistant", model_client=model_client)
    print(await agent.run(task="Say 'Hello World!'"))
    await model_client.close()

asyncio.run(main())