Anthropic Releases and Temporarily Suspends Claude Fable 5

On June 9, 2026, Anthropic launched Claude Fable 5, a model designed for long-horizon tasks, but it was taken offline shortly after due to a U.S. government export directive. It shares architecture with Claude Mythos 5, supporting extensive token usage. The model includes mandatory data retention requirements, which have affected its deployment with partners like Microsoft. By Andrew Hoblitzell