# 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.

Human version: https://kymaapi.com/models/claude-fable-5.1
Live JSON: `GET https://kymaapi.com/v1/models` (no auth required)

## Facts

- **Model ID**: `claude-fable-5.1`: pass this as `model` in the request body
- **Creator**: Anthropic
- **Released**: 2026-09-01
- **Context window**: 1M tokens
- **Max output**: 128K tokens per response, a hard ceiling, not a default
- **Price**: $13.50 in / $67.50 out per 1M
- **Capabilities**: tools, vision, reasoning

## Call it

```bash
curl https://kymaapi.com/v1/chat/completions \
  -H "Authorization: Bearer $KYMA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-fable-5.1", "messages": [{"role": "user", "content": "Hello"}]}'
```

## See also

- All models: https://kymaapi.com/models.md
- Pricing: https://kymaapi.com/pricing.md
- Other models by Anthropic: https://kymaapi.com/models?q=Anthropic