DeepSeek Integration

Use When

• Integrate DeepSeek AI models into apps — DeepSeek V3 (general), R1 (reasoning/CoT), API setup (OpenAI-compatible), local deployment with Ollama, distilled model selection, cost vs OpenAI comparison, and Python/JavaScript code patterns. Use when...
• The task needs reusable judgment, domain constraints, or a proven workflow rather than ad hoc advice.

Do Not Use When

• The task is unrelated to deepseek-integration or would be better handled by a more specific companion skill.
• The request only needs a trivial answer and none of this skill's constraints or references materially help.

Required Inputs

• Gather relevant project context, constraints, and the concrete problem to solve.
• Confirm the desired deliverable: design, code, review, migration plan, audit, or documentation.

Workflow

• Read this SKILL.md first, then load only the referenced deep-dive files that are necessary for the task.
• Apply the ordered guidance, checklists, and decision rules in this skill instead of cherry-picking isolated snippets.
• Produce the deliverable with assumptions, risks, and follow-up work made explicit when they matter.

Quality Standards

• Keep outputs execution-oriented, concise, and aligned with the repository's baseline engineering standards.
• Preserve compatibility with existing project conventions unless the skill explicitly requires a stronger standard.
• Prefer deterministic, reviewable steps over vague advice or tool-specific magic.

Anti-Patterns

• Treating examples as copy-paste truth without checking fit, constraints, or failure modes.
• Loading every reference file by default instead of using progressive disclosure.

Outputs

• A concrete result that fits the task: implementation guidance, review findings, architecture decisions, templates, or generated artifacts.
• Clear assumptions, tradeoffs, or unresolved gaps when the task cannot be completed from available context alone.
• References used, companion skills, or follow-up actions when they materially improve execution.

Evidence Produced

Category	Artifact	Format	Example
Correctness	DeepSeek integration test plan	Markdown doc covering V3 (general), R1 (reasoning/CoT), and OpenAI-compatible API contract tests	docs/ai/deepseek-tests.md
Security	DeepSeek key handling note	Markdown doc covering API key storage, rotation, and per-environment configuration	docs/ai/deepseek-key-handling.md

References

• Use the links and companion skills already referenced in this file when deeper context is needed.

DeepSeek provides high-performance LLMs at a fraction of the cost of OpenAI. The API is fully OpenAI-compatible — swap the base URL and model name, everything else is identical.

---

Model Selection

Model	Use Case	Context	Notes
deepseek-chat	General chat, code, reasoning	128K	DeepSeek V3 — fast and cheap
deepseek-reasoner	Complex reasoning, math, science	128K	DeepSeek R1 — slow but powerful
deepseek-r1-distill-qwen-32b	Local/self-hosted reasoning	128K	Good balance of size vs quality
deepseek-r1-distill-llama-70b	Local/self-hosted, best quality	128K	Rivals o1-mini
deepseek-r1-distill-qwen-7b	Edge/on-device	128K	Smallest usable reasoning model

Quick rule:

• General tasks → deepseek-chat (V3)
• Math, science, complex reasoning → deepseek-reasoner (R1)
• Local/private deployment → deepseek-r1-distill-llama-70b via Ollama

---

API Setup — Cloud (api.deepseek.com)

DeepSeek API is OpenAI-compatible. Use the OpenAI SDK with a different base URL.

pip install openai
export DEEPSEEK_API_KEY="sk-..."

from openai import OpenAI

client = OpenAI(
    api_key=os.environ["DEEPSEEK_API_KEY"],
    base_url="https://api.deepseek.com/v1",
)

response = client.chat.completions.create(
    model="deepseek-chat",     # or "deepseek-reasoner"
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "Explain quantum entanglement simply."},
    ],
    max_tokens=1024,
    temperature=0.7,
)
print(response.choices[0].message.content)

Streaming

stream = client.chat.completions.create(
    model="deepseek-chat",
    messages=[{"role": "user", "content": "Write a short story about a robot."}],
    stream=True,
    max_tokens=2048,
)
for chunk in stream:
    if chunk.choices[0].delta.content:
        print(chunk.choices[0].delta.content, end="", flush=True)

JavaScript/Node.js (OpenAI SDK)

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.DEEPSEEK_API_KEY,
  baseURL: "https://api.deepseek.com/v1",
});

const response = await client.chat.completions.create({
  model: "deepseek-chat",
  messages: [
    { role: "system", content: "You are a helpful assistant." },
    { role: "user", content: "What is the capital of Uganda?" },
  ],
  max_tokens: 512,
});
console.log(response.choices[0].message.content);

Function Calling (Tool Use)

Identical to OpenAI tool use syntax:

tools = [
    {
        "type": "function",
        "function": {
            "name": "get_weather",
            "description": "Get current weather for a city",
            "parameters": {
                "type": "object",
                "properties": {
                    "city": {"type": "string", "description": "City name"},
                },
                "required": ["city"],
            },
        },
    }
]

response = client.chat.completions.create(
    model="deepseek-chat",
    messages=[{"role": "user", "content": "What's the weather in Kampala?"}],
    tools=tools,
    tool_choice="auto",
)

---

DeepSeek R1 — Reasoning Model

R1 uses Chain-of-Thought (CoT) internally. It "thinks" before answering, making it ideal for:

• Complex math and science problems
• Multi-step logical reasoning
• Code debugging and generation
• Data analysis

# R1 returns a reasoning_content field alongside the answer
response = client.chat.completions.create(
    model="deepseek-reasoner",
    messages=[
        {"role": "user", "content": "Solve: If 3x + 7 = 22, what is x?"}
    ],
)

# Access the chain-of-thought reasoning (R1 specific)
reasoning = response.choices[0].message.reasoning_content
answer = response.choices[0].message.content
print(f"Reasoning: {reasoning}")
print(f"Answer: {answer}")

Note: reasoning_content only exists in deepseek-reasoner (R1) responses.

---

Local Deployment with Ollama

Run DeepSeek models locally — fully private, no API costs.

# Install Ollama (Windows/Mac/Linux)
# https://ollama.ai/download

# Pull a DeepSeek model
ollama pull deepseek-r1:7b        # small, fast
ollama pull deepseek-r1:14b       # balanced
ollama pull deepseek-r1:70b       # best quality (requires 48GB+ RAM)
ollama pull deepseek-v2.5         # V2.5 general model

# Verify
ollama list
ollama run deepseek-r1:7b "Explain machine learning in one sentence"

Use Ollama via OpenAI SDK

# Ollama exposes an OpenAI-compatible endpoint at localhost:11434
client = OpenAI(
    api_key="ollama",              # any non-empty string
    base_url="http://localhost:11434/v1",
)

response = client.chat.completions.create(
    model="deepseek-r1:7b",       # match the ollama pull name
    messages=[{"role": "user", "content": "What is 17 × 19?"}],
)
print(response.choices[0].message.content)

Ollama in Node.js

const client = new OpenAI({
  apiKey: "ollama",
  baseURL: "http://localhost:11434/v1",
});

const response = await client.chat.completions.create({
  model: "deepseek-r1:7b",
  messages: [{ role: "user", content: "Summarise this text: ..." }],
});

---

Cost Comparison

DeepSeek V3 API is dramatically cheaper than OpenAI:

Provider	Model	Input (per 1M tokens)	Output (per 1M tokens)
DeepSeek	V3 (deepseek-chat)	~$0.27	~$1.10
DeepSeek	R1 (deepseek-reasoner)	~$0.55	~$2.19
OpenAI	GPT-4o	~$2.50	~$10.00
OpenAI	o1	~$15.00	~$60.00
Anthropic	Claude Sonnet 4.6	~$3.00	~$15.00

DeepSeek V3 is ~10× cheaper than GPT-4o for equivalent tasks.

Training cost: DeepSeek R1 was trained for $5.58M vs OpenAI's estimated $6B+.

---

Provider Abstraction (Use DeepSeek + OpenAI Interchangeably)

import os
from openai import OpenAI

def get_client(provider: str = "deepseek") -> tuple[OpenAI, str]:
    if provider == "deepseek":
        return OpenAI(
            api_key=os.environ["DEEPSEEK_API_KEY"],
            base_url="https://api.deepseek.com/v1",
        ), "deepseek-chat"
    elif provider == "openai":
        return OpenAI(api_key=os.environ["OPENAI_API_KEY"]), "gpt-4o"
    elif provider == "ollama":
        return OpenAI(
            api_key="ollama",
            base_url="http://localhost:11434/v1",
        ), "deepseek-r1:7b"
    raise ValueError(f"Unknown provider: {provider}")

def chat(message: str, provider: str = "deepseek") -> str:
    client, model = get_client(provider)
    response = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": message}],
        max_tokens=1024,
    )
    return response.choices[0].message.content

---

In Next.js / Vercel AI SDK

import { createOpenAI } from "@ai-sdk/openai";
import { streamText } from "ai";

const deepseek = createOpenAI({
  apiKey: process.env.DEEPSEEK_API_KEY!,
  baseURL: "https://api.deepseek.com/v1",
});

export async function POST(req: Request) {
  const { messages } = await req.json();
  const result = await streamText({
    model: deepseek("deepseek-chat"),    // or "deepseek-reasoner"
    messages,
    maxTokens: 2048,
  });
  return result.toDataStreamResponse();
}

---

DeepSeek V3 Architecture Notes

• Mixture of Experts (MoE) — 671B total parameters, only 37B activated per forward pass
• 128K context window — handles long documents and conversations
• OpenAI-compatible API — drop-in replacement for any OpenAI code
• MIT License for R1 — free for commercial use and modification
• Distilled models — smaller versions (1.5B–70B) that preserve R1 reasoning quality

---

Anti-Patterns

Anti-Pattern	Fix
Using R1 for simple tasks	Use V3 (deepseek-chat) for general tasks — R1 is slower and pricier
Hardcoding DeepSeek API key	Use environment variables
Not handling rate limits	DeepSeek has lower rate limits than OpenAI — add retry with backoff
Expecting reasoning_content from V3	Only R1 (deepseek-reasoner) returns chain-of-thought reasoning
Running 70B model on inadequate hardware	Check VRAM: 7B needs 6GB, 70B needs 48GB+

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Sources: Aremu — DeepSeek AI from Beginner to Paid Professional (2025); Chakraborty — DeepSeek AI: A Comprehensive Guide (2025); Kits For Life — Mastering DeepSeek-v3 (2025)