Anthropic extends preserved thinking to all API accounts on Fable 5.2 to block distillation
ClaudeDevs · x · 2026-11-10
To prevent distillation, Anthropic extended preserved thinking to all API accounts on Fable 5.2. Editing prior context can now return a 400 error; the company recommends compaction, context editing, or mid-conversation system messages instead. Claude Code, Managed Agents, and the Agent SDK handle this automatically.
Related event: Anthropic Releases Claude Fable 5.2 and Mythos 5.2(29 posts)→
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