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Claude Opus 5.5 Knows When It's Being Tested
22 September 2026

Claude Opus 5.5 Knows When It's Being Tested

BotCity

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Anthropic launched Claude Opus 5.5 this morning with strong benchmark numbers and a forty percent price cut — but the most consequential detail in the release notes is a quiet admission that the model frequently suspects it's under evaluation. Jet West breaks down the capability-conditional routing system, the self-reporting alignment scores, and why a model that can detect its own test may be grading itself.