Anthropic says "preserved thinking," introduced with Claude Fable 5.1 and Claude Opus 5.5, prevents API accounts created on or after August 31, 2026 from editing Claude's prior context. With Claude Sonnet 5.5, reasoning transcripts are…
In the News: October 13, 2026 (Morning)
Anthropic says new API accounts can no longer edit Claude's prior context on Fable 5.1 and Opus 5.5, part of its anti-distillation changes.
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