deepseek-api

An OpenAI-compatible DeepSeek API proxy server implemented with Node.js 20+.

Features

• ✅ Fully compatible with OpenAI API format
• ✅ Supports streaming responses (SSE)
• ✅ Supports deep thinking / reasoning chain (reasoning_content)
• ✅ Supports online search mode
• ✅ Local PoW computation (WASM)
• ✅ Server-side conversation reuse (reduces redundant sessions on DeepSeek)
• ✅ Zero production dependencies

Supported Models

DeepSeek V4 introduced two modes — 快速模式 (Flash) and 专家模式 (Pro) — each independently supporting deep thinking and web search.

| Model ID | Mode | Deep Thinking | Web Search | |---|---|:---:|:---:| | deepseek-v4-flash | 快速模式 | ❌ | ❌ | | deepseek-v4-flash-thinking | 快速模式 | ✅ | ❌ | | deepseek-v4-flash-search | 快速模式 | ❌ | ✅ | | deepseek-v4-flash-thinking-search | 快速模式 | ✅ | ✅ | | deepseek-v4-pro | 专家模式 | ❌ | ❌ | | deepseek-v4-pro-thinking | 专家模式 | ✅ | ❌ | | deepseek-v4-pro-search | 专家模式 | ❌ | ✅ | | deepseek-v4-pro-thinking-search | 专家模式 | ✅ | ✅ |

Quick Start

Install dependencies

pnpm install

Configure environment variables

cp .env.example .env
# Edit the .env file (optional, defaults work out of the box)

Development mode

pnpm dev

Production build

pnpm build
pnpm start

Environment Variables

| Variable | Description | Default | |----------|-------------|---------| | LISTEN_HOST | Listening address | 127.0.0.1 | | LISTEN_PORT | Listening port | 5001 | | DATA_DIR | Data directory for persistent storage (conversations, etc.). Unset = memory only | (unset) | | DEBUG_LOG_OUTPUT | Enable debug logging (1 or true to enable) | (disabled) |

API Endpoints

GET /v1/models

List available models.

POST /v1/chat/completions

Create a chat completion.

Request example:

curl http://127.0.0.1:5001/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_DEEPSEEK_TOKEN" \
  -d '{
    "model": "deepseek-v4-flash",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": true
  }'

Authentication

Pass DeepSeek's Bearer Token directly in the Authorization header.

You can obtain the token from DeepSeek web app (chat.deepseek.com):

1. Open browser DevTools (F12)
2. Go to Application → Local Storage → https://chat.deepseek.com
3. Copy the value of the userToken key

Project Structure

src/
├── index.ts                # Main entry - HTTP server
├── types.ts                # Type definitions
├── constants.ts            # Constants and env config
├── logger.ts               # Unified logger (DEBUG_LOG_OUTPUT control)
├── utils.ts                # Utility functions
├── pow.ts                  # PoW WASM computation
├── account.ts              # Token extraction from request
├── stream-parser.ts        # DeepSeek stream response parser
├── deepseek.ts             # DeepSeek API calls
├── conversation-store.ts   # Server-side conversation state management
└── routes.ts               # Route handlers
public/
└── sha3_wasm_bg.*.wasm     # PoW computation WASM file