Anthropic Releases and Temporarily Suspends Claude Fable 5 (opens in new tab)

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.