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-flash(1) deepseek-v4-pro(2)

(1) Use deepseek-flash as the model name. The legacy names deepseek-v4-flash and deepseek-v4-flash-vision-exp are still accepted, but the corresponding models have been retired, their requests are served by the DeepSeek-V4.1-Flash model and billed at the Flash price.

(2) After extensive testing, V4.1 Flash has comprehensively surpassed V4 Pro in performance, cost, speed, and total time, so we plan to retire V4 Pro in an orderly manner. From 12:00 Beijing Time on September 14, 2026, and until V4.1 Pro is released in the future, requests to deepseek-v4-pro will all be routed to V4.1 Flash and billed at the V4.1 Flash price.

Integrate with Agent Tools

DeepSeek Harness is now in developer preview for agent harness developers worldwide. See the DeepSeek Harness Guide for details.

The DeepSeek API is supported by many popular AI agent and coding assistant tools. If you use tools like Claude Code, GitHub Copilot, or OpenCode, you can use DeepSeek as the backend model directly — no code required.

See the Agent Integrations Guide for details.

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-flash",
        "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-flash",
    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-flash",
    thinking: {"type": "enabled"},
    reasoning_effort: "high",
    stream: false,
  });

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

main();