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

# Basic Anthropic Demo

> Minimal ICRL run with Anthropic — verify your Claude setup

## Overview

The basic Anthropic demo mirrors the OpenAI demo but uses Claude models. It tries common Anthropic model IDs in order until one succeeds. Use it to confirm your `ANTHROPIC_API_KEY` is valid.

## Prerequisites

* `ANTHROPIC_API_KEY` set in your environment
* Python 3.12+
* `icrl-py` installed

## Run

```bash theme={null}
uv run python examples/basic_anthropic_demo.py
```

Optional model override (tried first if set):

```bash theme={null}
MODEL=claude-sonnet-4-5 uv run python examples/basic_anthropic_demo.py
```

## Model Fallback

If `MODEL` is not set, the script tries these in order:

1. `claude-sonnet-4-5`
2. `claude-sonnet-4`
3. `claude-3-7-sonnet-latest`
4. `claude-3-5-sonnet-latest`

It stops on the first model that succeeds.

## Expected Output

```
Model: claude-sonnet-4-5
Success: True
Steps: 1
```

## Source

`examples/basic_anthropic_demo.py` — about 80 lines, including model fallback logic.