On June 9, 2026, Anthropic released Fable 5. It matters because of where it comes from: the Mythos class, Anthropic's most capable line of models, which until now was used only internally. Fable 5 is the first Mythos-class model anyone can use.
Here is the simplest way to understand it. Fable 5 has the same underlying capability as Claude Mythos 5, with safety safeguards added so it can be released to the public. You are getting the real thing, packaged for everyday use.
What is it good at? Fable 5 is state-of-the-art in software engineering, knowledge work, vision tasks, and scientific research. In plain terms: building software, doing serious thinking and writing work, understanding images, and working through research problems.
Two capabilities change what you can hand over to Claude.
Long-duration autonomous work. Fable 5 keeps working on a task for a long time without you steering every step, and reasons across millions of tokens of context. Entire projects, not single questions.
Advanced vision. It can extract data from scientific figures and rebuild web apps from screenshots. Show it a chart and it pulls the numbers out.
Who is it for? Anyone whose work involves big, sprawling tasks. You do not need to be technical. If you have ever had a project that felt too large or too messy to hand to an assistant, Fable 5 was built for it.
Fable 5 is the first publicly available model from Anthropic's Mythos class, released June 9, 2026. It has the same underlying capability as Claude Mythos 5, with safety safeguards added for public release. It is state-of-the-art in software engineering, knowledge work, vision, and scientific research, and it is built for long-duration autonomous work across very long context. Next: why long tasks are where it shines.