Claude Fable 5 Safeguards: The Opus 4.8 Fallback Explained Fewer than 5% of Claude Fable 5 sessions trigger an Opus 4.8 safety fallback. What activates it, what it costs at scale, and how to manage it in your stack. June 22, 2026 • Kimmo Hakonen Claude Fable 5 AI safety responsible AI EU AI Act enterprise AI