OpenAI API 速查

核心 API

from openai import OpenAI
client = OpenAI(api_key="sk-xxxxx")

response = client.chat.completions.create(
    model="gpt-4o",
    messages=[
        {"role": "system", "content": "系统提示"},
        {"role": "user", "content": "用户消息"}
    ],
    temperature=0.7,
    max_tokens=1000,
    stream=True  # 流式
)

Function Calling

tools = [{"type": "function", "function": {"name": "fn", "parameters": {...}}}]
response = client.chat.completions.create(model="gpt-4o", messages=[...], tools=tools)

Structured Output

response_format={"type": "json_schema", "json_schema": {"name": "...", "schema": {...}}}

模型价格

模型	上下文	输入价格
gpt-4o	128K	$2.50/1M
gpt-4o-mini	128K	$0.15/1M
o1	200K	$15/1M

要点

• 简单任务用 gpt-4o-mini，限制 max_tokens 控制成本
• 系统提示放在 messages 开头自动缓存
• 处理 RateLimitError 用指数退避重试