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

# Overview

> [Anthropic](https://www.anthropic.com/) is an AI safety and research company, and is the creator of `Claude`.
> This page covers all integrations between `Anthropic` models and `LangChain`.

## Installation and Setup

To use `Anthropic` models, you need to install a python package:

<CodeGroup>
  ```bash pip theme={null}
  pip install -U langchain-anthropic
  ```

  ```bash uv theme={null}
  uv add langchain-anthropic
  ```
</CodeGroup>

You need to set the `ANTHROPIC_API_KEY` environment variable.
You can get an Anthropic API key [here](https://console.anthropic.com/settings/keys)

## Chat Models

### ChatAnthropic

See a [usage example](/oss/python/integrations/chat/anthropic).

```python theme={null}
from langchain_anthropic import ChatAnthropic

model = ChatAnthropic(model='claude-3-opus-20240229')
```

## LLMs

### \[Legacy] AnthropicLLM

**NOTE**: `AnthropicLLM` only supports legacy `Claude 2` models.
To use the newest `Claude 3` models, please use `ChatAnthropic` instead.

See a [usage example](/oss/python/integrations/llms/anthropic).

```python theme={null}
from langchain_anthropic import AnthropicLLM

model = AnthropicLLM(model='claude-2.1')
```