Anthropic says it cut 80 percent of Claude Code's system prompt because Fable 5 models "want a smaller system prompt"

Anthropic drastically reduced Claude Code's system prompt by 80%. New Fable 5 models require fewer instructions and examples, allowing for more imaginative outputs by steering through context rather than strict rules. This shift signals a growing trend towards more capable models that learn implicitly from contextual guidance.

Opening Kapyn…