Anthropic publishes Claude system prompts documentation

Anthropic released documentation for Claude's system prompts, which provide context like current date and behavioral guidance for Claude.ai and mobile apps. According to Anthropic's platform documentation, system prompts are periodically updated to improve responses and do not apply to the Claude API, with each Claude 4.6 generation model ID representing a single fixed snapshot. The release was immediately overshadowed by user backlash against Anthropic's concurrent watermarking feature announcement.