# 多轮对话

本指南将介绍如何使用 DeepSeek `/chat/completions` API 进行多轮对话。

DeepSeek `/chat/completions` API 是一个“无状态” API，即服务端不记录用户请求的上下文，用户在每次请求时，**需将之前所有对话历史拼接好后**，传递给对话 API。

下面的代码以 Python 语言，展示了如何进行上下文拼接，以实现多轮对话。

```python
from openai import OpenAI
client = OpenAI(api_key="<DeepSeek API Key>", base_url="https://api.deepseek.com")

# Round 1
messages = [{"role": "user", "content": "What's the highest mountain in the world?"}]
response = client.chat.completions.create(
    model="deepseek-chat",
    messages=messages
)

messages.append(response.choices[0].message)
print(f"Messages Round 1: {messages}")

# Round 2
messages.append({"role": "user", "content": "What is the second?"})
response = client.chat.completions.create(
    model="deepseek-chat",
    messages=messages
)

messages.append(response.choices[0].message)
print(f"Messages Round 2: {messages}")
```



------

在**第一轮**请求时，传递给 API 的 `messages` 为：

```json
[
    {"role": "user", "content": "What's the highest mountain in the world?"}
]
```



在**第二轮**请求时：

1. 要将第一轮中模型的输出添加到 `messages` 末尾
2. 将新的提问添加到 `messages` 末尾

最终传递给 API 的 `messages` 为：

```json
[
    {"role": "user", "content": "What's the highest mountain in the world?"},
    {"role": "assistant", "content": "The highest mountain in the world is Mount Everest."},
    {"role": "user", "content": "What is the second?"}
]
```