
There are indications that the reasoning capabilities of Anthropic’s AI model “Claude Opus 5.5” may have declined sharply around November 3, 2026. Developer Shane Melaugh analyzed approximately 1,400 usage records for the AI programming assistant “Claude Code” and found significant changes in the wording used to express the AI’s reasoning and in the way it approached tasks, despite the model name remaining unchanged. is Opus 5.5 nerded?I just had Gemini 4