Anthropic Releases and Temporarily Suspends Claude Fable 5
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Anthropic's new model suspended by government, major AI industry news.
Anthropic released Claude Fable 5 on June 9, 2026, as the first publicly available model in its Mythos class, but a US government export directive forced it offline within three days. Fable 5 shares the same underlying architecture as the unreleased Mythos 5, featuring a 1M token context window, 128K output tokens, and double the pricing of Claude Opus 4.8 at $10/$50 per million input/output tokens. The model is designed for sustained agentic autonomy with always-on adaptive thinking, task budgets, and mandatory 30-day data retention for safety classifiers, which caused Microsoft to remove it from Copilot's model picker.