Your First API Call

The DeepSeek API uses an API format compatible with OpenAI/Anthropic. By modifying the configuration, you can use the OpenAI/Anthropic SDK or softwares compatible with the OpenAI/Anthropic API to access the DeepSeek API.

PARAM	VALUE
base_url (OpenAI)	https://api.deepseek.com
base_url (Anthropic)	https://api.deepseek.com/anthropic
api_key	apply for an API key
model*	deepseek-v4-flash deepseek-v4-pro deepseek-chat (to be deprecated on 2026/07/24) deepseek-reasoner (to be deprecated on 2026/07/24)

* The model names deepseek-chat and deepseek-reasoner will be deprecated on 2026/07/24. For compatibility, they correspond to the non-thinking mode and thinking mode of deepseek-v4-flash, respectively.

Invoke The Chat API

Once you have obtained an API key, you can access the DeepSeek model using the following example scripts in the OpenAI API format. This is a non-stream example, you can set the stream parameter to true to get stream response.

For examples using the Anthropic API format, please refer to Anthropic API.

curl

curl https://api.deepseek.com/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer ${DEEPSEEK_API_KEY}" \
  -d '{
        "model": "deepseek-v4-pro",
        "messages": [
          {"role": "system", "content": "You are a helpful assistant."},
          {"role": "user", "content": "Hello!"}
        ],
        "thinking": {"type": "enabled"},
        "reasoning_effort": "high",
        "stream": false
      }'

python

# Please install OpenAI SDK first: `pip3 install openai`
import os
from openai import OpenAI

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

response = client.chat.completions.create(
    model="deepseek-v4-pro",
    messages=[
        {"role": "system", "content": "You are a helpful assistant"},
        {"role": "user", "content": "Hello"},
    ],
    stream=False,
    reasoning_effort="high",
    extra_body={"thinking": {"type": "enabled"}}
)

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

nodejs

// Please install OpenAI SDK first: `npm install openai`

import OpenAI from "openai";

const openai = new OpenAI({
        baseURL: 'https://api.deepseek.com',
        apiKey: process.env.DEEPSEEK_API_KEY,
});

async function main() {
  const completion = await openai.chat.completions.create({
    messages: [{ role: "system", content: "You are a helpful assistant." }],
    model: "deepseek-v4-pro",
    thinking: {"type": "enabled"},
    reasoning_effort: "high",
    stream: false,
  });

  console.log(completion.choices[0].message.content);
}

main();