> ## Documentation Index
> Fetch the complete documentation index at: https://opentouter.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# LangChain

> Using OpenRouter with LangChain

## Using LangChain

LangChain provides a standard interface for working with chat models. You can use OpenRouter with LangChain using the dedicated `ChatOpenRouter` integration packages. For more details on LangChain's model interface, see the [LangChain Models documentation](https://docs.langchain.com/oss/python/langchain/models).

**Resources:**

* [LangChain Python integration](https://docs.langchain.com/oss/python/integrations/chat/openrouter): [langchain-openrouter on PyPI](https://pypi.org/project/langchain-openrouter/)
* [LangChain JavaScript integration](https://docs.langchain.com/oss/javascript/integrations/chat/openrouter): [@langchain/openrouter on npm](https://www.npmjs.com/package/@langchain/openrouter)

<CodeGroup>
  ```typescript title="TypeScript" lines theme={null}
  import { ChatOpenRouter } from "@langchain/openrouter";

  const model = new ChatOpenRouter(
    "anthropic/claude-sonnet-4.6",
    { temperature: 0.8 }
  );

  // Example usage
  const response = await model.invoke([
    { role: "system", content: "You are a helpful assistant." },
    { role: "user", content: "Hello, how are you?" },
  ]);
  ```

  ```python title="Python" lines theme={null}
  from langchain_openrouter import ChatOpenRouter

  model = ChatOpenRouter(
      model="anthropic/claude-sonnet-4.6",
      temperature=0.8,
  )

  # Example usage
  response = model.invoke("What NFL team won the Super Bowl in the year Justin Bieber was born?")
  print(response.content)
  ```
</CodeGroup>

For full documentation — including streaming, tool calling, structured output, reasoning, multimodal inputs, provider routing, and more — see the LangChain integration guides:

* [Python: ChatOpenRouter](https://docs.langchain.com/oss/python/integrations/chat/openrouter)
* [JavaScript: ChatOpenRouter](https://docs.langchain.com/oss/javascript/integrations/chat/openrouter)