Anthropic Publishes Updated Claude Consumer App System Prompts, Adds Song Lyric Restriction
Anthropic has published the system prompts for its Claude consumer applications, including Claude.ai and mobile apps, and reorganized them into an index page with per-model pages. The updated prompts include a new instruction strongly discouraging the reproduction of song lyrics, as well as restrictions on drawing copyrighted characters or logos. The prompts are available in Markdown format, facilitating easy diffing of changes.
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Simon Willison
Anthropic publish the system prompts for their Claude consumer applications ( Claude.ai and the Claude mobile apps - sadly not for Claude Cowork or Claude Code). I love that they do this, and that they share not just the current prompts but historic changes to their prompts as well. They used to keep all of the prompts on a single page, but when I checked today I noticed they had re-arranged those prompts into an index page and then a page per model - here's the page for Haiku 4.5 for example, which has the original prompt from October 15th 2025 and an updated prompt from January 18th 2026. A neat thing about Anthropic's platform.claude.com/docs site is that it's designed to be usable by LLMs. You can add .md to any page to get back the content as Markdown - here's the system prompt index page and the Markdown prompts for Fable 5.1 . TL;DR: this makes it really easy to diff the prompts. Don't reproduce song lyrics Don't draw copyrighted characters or logos Tweaks to Claude's answering
