Three days. Claude Fable 5 — Anthropic's most capable model ever shipped to the public, posting 95% on SWE-bench Verified — was live for exactly 72 hours before the US government issued an export control directive on June 12 that forced Anthropic to pull it globally. For everyone. Including US users. Including Anthropic employees who hold foreign passports.
Here is what Fable 5 actually is, what the government directive says, what Anthropic says about it, and what developers building on Claude should do while this gets resolved.
What Claude Fable 5 Is
Anthropic launched Claude Fable 5 on June 9, 2026, alongside Claude Mythos 5, its restricted sibling for government-adjacent cybersecurity work. Fable 5 is the first publicly available model in Anthropic's new "Mythos-class" tier — a category above the previous frontier that Claude Opus 4.8 (released May 28) occupied.
The benchmark gap is not close. Fable 5 posted 95.0% on SWE-bench Verified and 80.3% on SWE-bench Pro. The next best competitor on SWE-bench Pro is GPT-5.5, sitting at 58.6%. That is a 21.7-point gap — roughly twice the margin by which Claude Opus 4.8 led its generation. Across all eight coding benchmarks Anthropic published at launch, Fable 5 led with an average margin of 11.8 points:
