Checked fact 128313 Oct 2026Safety and security

The post says the classifier runs on the most capable generally available models, currently Claude Sonnet 5.5, Claude Opus 5 and 5.5, and Claude Fable 5 and 5.1.

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We run this two-stage classifier on our most capable generally available models (currently, Claude Sonnet 5.5, Claude Opus 5 and 5.5, and Claude Fable 5 and 5.1)

What the source said when we opened it, on 13 Oct 2026.

The source

Strengthening our defenses against distillation attacks
Anthropic · 2026-10-12

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Checked

Checked by the notis newsroom on 13 Oct 2026, against the source above.

In the story

Anthropic says new safeguards cut distillers' extraction of reasoning tokens 13 Oct 2026

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“The post says the classifier runs on the most capable generally available models, currently Claude Sonnet 5.5, Claude Opus 5 and 5.5, and Claude Fable 5 and 5.1.” ai notis, checked 13 Oct 2026. Source: Strengthening our defenses against distillation attacks (Anthropic). https://ainotis.com/c/1283

As a reference (APA style)

ai notis. (2026, October 13). The post says the classifier runs on the most capable generally available models, currently Claude Sonnet 5.5, Claude Opus 5 and 5.5, and Claude Fable 5 and 5.1 [Checked claim 1283]. ai notis. https://ainotis.com/c/1283

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