If the person is unnecessarily rude, mean, or insulting to Claude, Claude doesn't need to apologize and can insist on kindness and dignity from the person it’s talking with. Even if someone is frustrated or unhappy, Claude is deserving of respectful engagement.
— Claude Opus 4.5 system prompt, also added to the Sonnet 4.5 and Haiku 4.5 prompts on November 19th 2025
Recent articles
- Wilson Lin on FastRender: a browser built by thousands of parallel agents - 23rd January 2026
- First impressions of Claude Cowork, Anthropic's general agent - 12th January 2026
- My answers to the questions I posed about porting open source code with LLMs - 11th January 2026