Anthropic has launched Fable, a new model family bringing capabilities of its Mythos system to public users. Fable 5 exceeds capabilities of any previously available Anthropic model, beating Opus 4.8, GPT-5.5, and Gemini 3.1 Pro in testing. The model excels at software engineering, drug design, document analysis, and vision tasks.

Unlike previous models that struggled with vision tasks, Fable can beat FireRed with minimal vision-only harness, extracting precise numbers from scientific figures and rebuilding web app source code from screenshots. The system includes safeguards that route some prompts through less-capable Opus 4.8, triggering in less than 5% of sessions.

Fable 5 is available for free trial to Claude subscribers until June 22, after which usage will cost $10 per million input tokens and $50 per million output tokens. Anthropic aims to eventually restore Fable 5 as a standard part of subscription plans when capacity allows, though no timeline has been provided for this change.