DeepSeek API

Use the DeepSeek API via direct curl calls to access powerful AI language models for chat, reasoning, and code generation.

Official docs: https://api-docs.deepseek.com/

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When to Use

Use this skill when you need to:

• Chat completions with DeepSeek-V3.2 model
• Deep reasoning tasks using the reasoning model
• Code generation and completion (FIM - Fill-in-the-Middle)
• OpenAI-compatible API as a cost-effective alternative

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Prerequisites

1. Sign up at DeepSeek Platform and create an account
2. Go to API Keys and generate a new API key
3. Top up your balance (no free tier, but very affordable pricing)

export DEEPSEEK_API_KEY="your-api-key"

Pricing (per 1M tokens)

Type	Price
Input (cache hit)	$0.028
Input (cache miss)	$0.28
Output	$0.42

Rate Limits

DeepSeek does not enforce strict rate limits. They will try to serve every request. During high traffic, connections are maintained with keep-alive signals.

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How to Use

All examples below assume you have DEEPSEEK_API_KEY set.

The base URL for the DeepSeek API is:

• https://api.deepseek.com (recommended)
• https://api.deepseek.com/v1 (OpenAI-compatible)

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1. Basic Chat Completion

Send a simple chat message:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "system",
      "content": "You are a helpful assistant."
    },
    {
      "role": "user",
      "content": "Hello, who are you?"
    }
  ]
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json

Available models:

• deepseek-chat: DeepSeek-V3.2 non-thinking mode (128K context, 8K max output)
• deepseek-reasoner: DeepSeek-V3.2 thinking mode (128K context, 64K max output)

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2. Chat with Temperature Control

Adjust creativity/randomness with temperature:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "user",
      "content": "Write a short poem about coding."
    }
  ],
  "temperature": 0.7,
  "max_tokens": 200
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json | jq -r '.choices[0].message.content'

Parameters:

• temperature (0-2, default 1): Higher = more creative, lower = more deterministic
• top_p (0-1, default 1): Nucleus sampling threshold
• max_tokens: Maximum tokens to generate

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3. Streaming Response

Get real-time token-by-token output:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "user",
      "content": "Explain quantum computing in simple terms."
    }
  ],
  "stream": true
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json

Streaming returns Server-Sent Events (SSE) with delta chunks, ending with data: [DONE].

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4. Deep Reasoning (Thinking Mode)

Use the reasoner model for complex reasoning tasks:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-reasoner",
  "messages": [
    {
      "role": "user",
      "content": "What is 15 * 17? Show your work."
    }
  ]
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json | jq -r '.choices[0].message.content'

The reasoner model excels at math, logic, and multi-step problems.

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5. JSON Output Mode

Force the model to return valid JSON:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "system",
      "content": "You are a JSON generator. Always respond with valid JSON."
    },
    {
      "role": "user",
      "content": "List 3 programming languages with their main use cases."
    }
  ],
  "response_format": {
    "type": "json_object"
  }
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json | jq -r '.choices[0].message.content'

---

6. Multi-turn Conversation

Continue a conversation with message history:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "user",
      "content": "My name is Alice."
    },
    {
      "role": "assistant",
      "content": "Nice to meet you, Alice."
    },
    {
      "role": "user",
      "content": "What is my name?"
    }
  ]
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json | jq -r '.choices[0].message.content'

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7. Code Completion (FIM)

Use Fill-in-the-Middle for code completion (beta endpoint):

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "prompt": "def add(a, b):\n ",
  "max_tokens": 20
}

Then run:

curl -s "https://api.deepseek.com/beta/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json | jq -r '.choices[0].text'

FIM is useful for:

• Code completion in editors
• Filling gaps in documents
• Context-aware text generation

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8. Function Calling (Tools)

Define functions the model can call:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "user",
      "content": "What is the weather in Tokyo?"
    }
  ],
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "get_weather",
        "description": "Get the current weather for a location",
        "parameters": {
          "type": "object",
          "properties": {
            "location": {
              "type": "string",
              "description": "The city name"
            }
          },
          "required": ["location"]
        }
      }
    }
  ]
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json

The model will return a tool_calls array when it wants to use a function.

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9. Check Token Usage

Extract usage information from response:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json | jq '.usage'

Response includes:

• prompt_tokens: Input token count
• completion_tokens: Output token count
• total_tokens: Sum of both

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OpenAI SDK Compatibility

DeepSeek is fully compatible with OpenAI SDKs. Just change the base URL:

Python:

from openai import OpenAI
client = OpenAI(api_key="your-deepseek-key", base_url="https://api.deepseek.com")

Node.js:

import OpenAI from 'openai';
const client = new OpenAI({ apiKey: 'your-deepseek-key', baseURL: 'https://api.deepseek.com' });

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Tips: Complex JSON Payloads

For complex requests with nested JSON (like function calling), use a temp file to avoid shell escaping issues:

Write to /tmp/deepseek_request.json:

{
  "model": "deepseek-chat",
  "messages": [{"role": "user", "content": "What is the weather in Tokyo?"}],
  "tools": [{
    "type": "function",
    "function": {
      "name": "get_weather",
      "description": "Get current weather",
      "parameters": {
        "type": "object",
        "properties": {"location": {"type": "string"}},
        "required": ["location"]
      }
    }
  }]
}

Then run:

curl -s "https://api.deepseek.com/chat/completions" -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $DEEPSEEK_API_KEY" -d @/tmp/deepseek_request.json

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Guidelines

1. Choose the right model: Use deepseek-chat for general tasks, deepseek-reasoner for complex reasoning
2. Use caching: Repeated prompts with same prefix benefit from cache pricing ($0.028 vs $0.28)
3. Set max_tokens: Prevent runaway generation by setting appropriate limits
4. Use streaming for long responses: Better UX for real-time applications
5. JSON mode requires system prompt: When using response_format, include JSON instructions in system message
6. FIM uses beta endpoint: Code completion endpoint is at api.deepseek.com/beta
7. Complex JSON: Use temp files with -d @filename to avoid shell quoting issues