Claude's new system prompt really doesn't want to reproduce song lyrics
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…
Opening of the original on Simon Willison
Summary
Anthropic now publishes system prompts for its Claude consumer applications, including historical changes. This allows users to track prompt evolution, such as recent updates to the Haiku 4.5 model. The company makes these prompts accessible as Markdown, simplifying comparisons. A notable instruction in the updated prompts is to avoid reproducing song lyrics.
Why it matters
Why it matters: Anthropic's transparency in publishing system prompts offers insight into AI safety and content moderation strategies. This practice, unlike many competitors, allows developers and researchers to study how models are guided. The specific instruction against reproducing song lyrics highlights a focus on copyright and intellectual property. This approach affects consumer-facing AI products and sets a precedent for how companies might manage AI behavior and user expectations regarding creative content.
Related: Google: Claude's new system prompt really doesn't want to reproduce song lyrics · Anthropic: Developing Enterprise Frontier Safeguards with our customers · Microsoft: Responsible AI in 2026: How we are adapting for what’s ahead · Meta: Get the full story behind the light · xAI: Nobody Is Saying Why OpenAI and Anthropic Had Outages Today
Rated low: routine. Worth knowing, not worth rearranging your day for.
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Questions people ask
- What system prompts does Anthropic publish?
- Anthropic publishes system prompts for its Claude consumer applications, including Claude.ai and mobile apps. They also share historical changes to these prompts.
- How can I access the system prompts?
- You can access the system prompts on Anthropic's platform.claude.com/docs site. Adding .md to a page URL retrieves the content as Markdown, making it easy to compare different versions.
- What is a new restriction in Claude's system prompts?
- Recent updates to Claude's system prompts include a directive not to reproduce song lyrics and to avoid drawing copyrighted characters or logos.
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Page generated Sep 3, 2026. Summaries are Subvolts' own; the story belongs to Simon Willison.