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

# Claude Fable 5.1

> Anthropic's newest Mythos-class flagship — improves on Fable 5 across the board, biggest gains in agentic coding and long-running agentic workflows. 1M context, 128K output, vision, file input, adaptive thinking.

## Overview

`claude-fable-5.1` — Anthropic's newest Mythos-class flagship — improves on Fable 5 across the board, biggest gains in agentic coding and long-running agentic workflows. 1M context, 128K output, vision, file input, adaptive thinking.

## Specs

| Field              | Value                                                             |
| ------------------ | ----------------------------------------------------------------- |
| Model ID           | `claude-fable-5.1`                                                |
| Best for           | The hardest reasoning and long-horizon agentic work money can buy |
| Context window     | 1M                                                                |
| Max output tokens  | 128K                                                              |
| Input modalities   | Text, Image, File                                                 |
| Output modalities  | Text                                                              |
| Tool calling       | Yes                                                               |
| Structured outputs | Yes                                                               |
| Prompt caching     | No                                                                |
| Speed              | Medium                                                            |
| Cost band          | Premium                                                           |
| Release stage      | Stable                                                            |

## Pricing

|        | Per 1M tokens |
| ------ | :-----------: |
| Input  |    \$13.50    |
| Output |    \$67.50    |

## Example

```python theme={null}
from openai import OpenAI

client = OpenAI(base_url="https://kymaapi.com/v1", api_key="kyma-...")

response = client.chat.completions.create(
    model="claude-fable-5.1",
    messages=[{"role": "user", "content": "..."}],
    tools=[...],  # function calling supported
)
```

## Agent query example

Ask the API which models fit, instead of hardcoding an id:

```bash theme={null}
curl "https://kymaapi.com/v1/models?recommended_for=chat&tools=true&quality_tier=frontier-open"
```