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

# Anthropic

> Use Claude models from Anthropic.

## Setup

```bash theme={null}
export ANTHROPIC_API_KEY="sk-ant-..."
```

```bash theme={null}
pip install anthropic
```

## Basic Usage

```python theme={null}
from definable.model.anthropic import Claude
from definable.model.message import Message

model = Claude(id="claude-sonnet-4-20250514")
response = model.invoke(
    messages=[Message(role="user", content="Hello!")],
    assistant_message=Message(role="assistant", content=""),
)
print(response.content)
```

## String Shorthand

```python theme={null}
agent = Agent(model="anthropic/claude-sonnet-4-20250514")
```

## Parameters

<ParamField path="id" type="str" default="claude-sonnet-4-20250514">
  Model identifier. Common values: `claude-sonnet-4-20250514`, `claude-haiku-3-5-20241022`.
</ParamField>

<ParamField path="api_key" type="str">
  Anthropic API key. Defaults to `ANTHROPIC_API_KEY`.
</ParamField>

<ParamField path="temperature" type="float">
  Sampling temperature (0.0 to 1.0).
</ParamField>

<ParamField path="max_tokens" type="int" default="4096">
  Maximum output tokens.
</ParamField>

## Imports

```python theme={null}
from definable.model.anthropic import Claude
```