deepseek-api

name	deepseek-api
description	Help build/debug DeepSeek API usage (openai-compatible).

deepseek-api

DeepSeek's HTTP API is OpenAI-Compatible. Use the same patterns; just swap the base URL and key.

When to invoke

• User asks "how do I call DeepSeek", "debug my chat completion call", "stream tool calls from DeepSeek", etc.

Basics

• Base URL: https://api.deepseek.com/v1
• Auth: Authorization: Bearer <DEEPSEEK_API_KEY> (or set via env)
• SDK: any OpenAI-compatible SDK works; e.g. openai npm with baseURL: 'https://api.deepseek.com/v1'.

Models

Model	Alias	Strengths
deepseek-chat	→ deepseek-v4-flash	Fast general chat; tool use
deepseek-reasoner	→ deepseek-v4-pro	Multi-step reasoning; emits reasoning_content

Set via the standard model field.

Streaming

Pass stream: true. SSE chunks come back as data: {...}\n\n. Each chunk has choices[0].delta.content for text deltas, and choices[0].delta.tool_calls[] for partial tool calls.

deepseek-reasoner ALSO emits choices[0].delta.reasoning_content — the thinking trace. UI should render this in a collapsible panel.

Tool calling

Standard OpenAI shape:

const r = await client.chat.completions.create({
  model: 'deepseek-chat',
  messages: [...],
  tools: [{
    type: 'function',
    function: {
      name: 'Read',
      description: '...',
      parameters: { type: 'object', properties: {...}, required: [...] }
    }
  }],
  tool_choice: 'auto',
});

Response includes choices[0].message.tool_calls[] when the model chose to call a tool. Loop: send back role: 'tool' messages with the tool_call_id, get next assistant message, repeat until no tool calls.

Pricing (rough; verify on dashboard)

Tier	Input	Output	Reasoning
deepseek-chat	1¥/M	2¥/M	—
deepseek-reasoner	1¥/M	16¥/M	4¥/M

Common pitfalls

• temperature: 1.0 makes tool calls flaky — drop to 0.3 for tool use.
• Streaming + tool_use — must accumulate tool args across chunks; the args field comes in pieces.
• reasoning_content is not in messages — it's separate; don't try to echo it back as a content block to the model.