V1ChatCompletionsRequest(对话接口 POST /v1/chat/completions)

{
    "model": "gpt-4o",
    "messages": [
        {
            "role": "system",
            "content": "你是一个有帮助的助手。"
        },
        {
            "role": "user",
            "content": "你好"
        }
    ]
}