How to beginner · 3 min read

How to use DeepSeek Coder

Q: How to use DeepSeek Coder

Use the DeepSeek API via its OpenAI-compatible endpoint by setting your API key and calling client.chat.completions.create with the deepseek-chat model. This enables AI-assisted coding tasks with a GPT-4-class model specialized for coding.

Quick answer

Use the DeepSeek API via its OpenAI-compatible endpoint by setting your API key and calling client.chat.completions.create with the deepseek-chat model. This enables AI-assisted coding tasks with a GPT-4-class model specialized for coding.

PREREQUISITES

Python 3.8+
DeepSeek API key
pip install openai>=1.0

Setup

Install the openai Python package and set your DeepSeek API key as an environment variable.

Install package: pip install openai
Set environment variable: export DEEPSEEK_API_KEY='your_api_key' (Linux/macOS) or setx DEEPSEEK_API_KEY "your_api_key" (Windows)

bash

pip install openai

Step by step

Use the OpenAI SDK with the DeepSeek API base URL and deepseek-chat model to generate code completions.

python

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["DEEPSEEK_API_KEY"], base_url="https://api.deepseek.com")

response = client.chat.completions.create(
    model="deepseek-chat",
    messages=[{"role": "user", "content": "Write a Python function to reverse a string."}]
)

print(response.choices[0].message.content)

output

def reverse_string(s):
    return s[::-1]

Common variations

You can use async calls, stream responses, or switch to the deepseek-reasoner model for advanced reasoning tasks.

python

import asyncio
from openai import OpenAI

async def async_example():
    client = OpenAI(api_key=os.environ["DEEPSEEK_API_KEY"], base_url="https://api.deepseek.com")
    stream = await client.chat.completions.acreate(
        model="deepseek-chat",
        messages=[{"role": "user", "content": "Generate a Python class for a linked list."}],
        stream=True
    )
    async for chunk in stream:
        print(chunk.choices[0].delta.content or '', end='')

asyncio.run(async_example())

output

class LinkedList:
    def __init__(self):
        self.head = None
    # ...

Troubleshooting

If you get authentication errors, verify your DEEPSEEK_API_KEY environment variable is set correctly. For network issues, check your internet connection and DeepSeek service status.

✅

Key Takeaways

Use the OpenAI SDK with base_url="https://api.deepseek.com" to access DeepSeek models.
The deepseek-chat model is optimized for coding tasks and supports chat completions.
Async and streaming calls improve responsiveness for large code generation.
Keep your API key secure and set it via environment variables.
Check DeepSeek status and network if you encounter errors.

Verified 2026-04 · deepseek-chat, deepseek-reasoner

Verify ↗