# Claude Fable 5: AI model fact sheet

- **Provider:** anthropic
- **Released:** 2026-06-09
- **Context window:** 1,000,000 tokens
- **API pricing:** $10.00 / 1M input, $50.00 / 1M output
- **OpenRouter ID:** anthropic/claude-fable-5
- **Capabilities:** conversation, reasoning, code-generation, analysis, agentic-tool-use, tool-use, planning

Claude Fable 5 is Anthropic's first publicly available Mythos-class model, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, offers reasoning support, and has a 1M-token context window. Designed for long-running, complex, and asynchronous tasks that previously required frequent human check-ins, it is particularly strong at end-to-end work that would otherwise take a person hours, days, or weeks, taking on problems that are long-running, ambiguous, or highly multi-step. It executes well-scoped tasks with few mistakes, automatically self-correcting through verification loops, and ships with robust safeguards that fall back to Claude Opus 4.8 on a small fraction of high-risk queries.

Source: real side-by-side outputs, pricing and specs at https://rival.tips/models/claude-fable-5