ChatDeepSeek integration

Integrate with the ChatDeepSeek chat model using LangChain JavaScript.

This will help you getting started with DeepSeek chat models. For detailed documentation of all ChatDeepSeek features and configurations head to the API reference.

Overview

Integration details

Class	Package	Serializable	PY support	Downloads	Version
ChatDeepSeek	@langchain/deepseek	beta	✅

Model features

See the links in the table headers below for guides on how to use specific features.

Tool calling	Structured output	Image input	Audio input	Video input	Token-level streaming	Token usage	Logprobs
✅	✅	❌	❌	❌	✅	✅	✅

Note that as of 1/27/25, tool calling and structured output are not currently supported for deepseek-reasoner.

Setup

To access DeepSeek models you’ll need to create a DeepSeek account, get an API key, and install the @langchain/deepseek integration package.

You can also access the DeepSeek API through providers like Together AI or Ollama.

Credentials

Head to https://deepseek.com/ to sign up to DeepSeek and generate an API key. Once you’ve done this set the DEEPSEEK_API_KEY environment variable:

export DEEPSEEK_API_KEY="your-api-key"

If you want to get automated tracing of your model calls you can also set your LangSmith API key by uncommenting below:

# export LANGSMITH_TRACING="true"
# export LANGSMITH_API_KEY="your-api-key"

Installation

The LangChain ChatDeepSeek integration lives in the @langchain/deepseek package:

npm

npm install @langchain/deepseek @langchain/core

yarn add @langchain/deepseek @langchain/core

pnpm add @langchain/deepseek @langchain/core

Instantiation

Now we can instantiate our model object and generate chat completions:

import { ChatDeepSeek } from "@langchain/deepseek";

const llm = new ChatDeepSeek({
  model: "deepseek-reasoner",
  temperature: 0,
  // other params...
})

const aiMsg = await llm.invoke([
  [
    "system",
    "You are a helpful assistant that translates English to French. Translate the user sentence.",
  ],
  ["human", "I love programming."],
])
aiMsg

AIMessage {
  "id": "e2874482-68a7-4552-8154-b6a245bab429",
  "content": "J'adore la programmation.",
  "additional_kwargs": {
    "reasoning_content": "..."
  },
  "response_metadata": {
    "tokenUsage": {
      "promptTokens": 23,
      "completionTokens": 7,
      "totalTokens": 30
    },
    "finish_reason": "stop",
    "model_name": "deepseek-reasoner",
    "usage": {
      "prompt_tokens": 23,
      "completion_tokens": 7,
      "total_tokens": 30,
      "prompt_tokens_details": {
        "cached_tokens": 0
      },
      "prompt_cache_hit_tokens": 0,
      "prompt_cache_miss_tokens": 23
    },
    "system_fingerprint": "fp_3a5770e1b4"
  },
  "tool_calls": [],
  "invalid_tool_calls": [],
  "usage_metadata": {
    "output_tokens": 7,
    "input_tokens": 23,
    "total_tokens": 30,
    "input_token_details": {
      "cache_read": 0
    },
    "output_token_details": {}
  }
}

console.log(aiMsg.content)

J'adore la programmation.

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API reference

For detailed documentation of all ChatDeepSeek features and configurations head to the API reference: https://api.js.langchain.com/classes/_langchain_deepseek.ChatDeepSeek.html

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