# Anthropic Claude Fable 5.1

Anthropic Claude Fable 5.1 is available in the Business API catalog.

- Model ID: `anthropic/claude-fable-5.1`
- Provider: Anthropic
- Modality: text → text
- Type: null
- Status: stable
- Delivery: sync
- Output format: json

## Authentication

Send your API key in the `X-API-Key` header.

The same key reads the org balance at `GET https://api.dev.pika.art/billing/balance`, which is free to call and confirms the request can be paid for before you submit it.

## Endpoint

```
POST https://api.dev.pika.art/anthropic/v1/messages
```

Required headers:

- `anthropic-version: 2023-06-01`

## Request

```json
{
  "model": "anthropic/claude-fable-5.1",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": "Hello, who are you?"
    }
  ]
}
```

## Response

```json
{
  "id": "msg_...",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "I'm Claude, an AI assistant made by Anthropic."
    }
  ],
  "usage": {
    "input_tokens": 12,
    "output_tokens": 24
  }
}
```