Anthropic announced that its latest anti‑distillation measures have dramatically lowered the amount of model reasoning data that attackers can harvest. The company reports a 10‑to‑100‑fold drop in extracted tokens after adding preserved thinking, a two‑stage classifier and stricter account limits. These changes affect Claude Opus 5.5, Claude Sonnet 5.5, Claude Fable 5.1 and similar models. Legitimate developers may need to tweak integrations, and Anthropic now charges for requests blocked by the new safeguards.
Why it matters
Developers using Claude will see fewer disruptions from illicit copying attempts, but must adapt to new integration steps and potential charges for blocked calls.
