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.
Coverage timeline
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
Related stories
Anthropic to embed invisible watermarks in Claude text, C2PA metadata in files
Anthropic announced it will embed invisible watermarks in text generated by Claude models and add C2PA metadata to supported file types, to comply with the EU AI Act's transparency requirements. The watermarking, based on Google DeepMind's SynthID-Text approach, will apply globally to all models released after August 2, 2026, and will be extended to older models by December 2. The move has drawn criticism for potential impact on writing quality, and an open-source project claiming to remove the watermarks has gained 11k GitHub stars in five days.
11 reports · 6 sources818 points · 727 comments
Anthropic to enable Claude Code auto mode by default in 5 days
Anthropic announced that in five days, all Claude Code instances will default to auto mode, which uses a classifier to approve tool calls automatically. The extra token cost per tool call will not be charged to users, and cloud platforms like Amazon, Google, and Microsoft have one month to switch to default auto mode as well. Anthropic cited low human rejection rates (3% for permission requests) and a controlled experiment showing auto mode blocked 89% of dangerous commands versus 13.6% for humans.
2 reports · 2 sources
Anthropic reportedly A/B tests reduced effort levels in Claude Code
Anthropic is reportedly A/B testing reduced effort levels in Claude Code, its coding tool, according to a Hacker News report. The change would alter the tool's behavior, potentially affecting how much work it performs on tasks. Details on the scope or rollout of the test were not provided.
1 reports · 1 sources214 points · 190 comments
Anthropic's Claude Code drafts feedback reports for user review
Anthropic's Claude Code v2.1.238 or later can automatically draft feedback reports when tools fail, requests cannot be completed, or errors are identified. Drafts are saved locally at ~/.claude/feedback/drafts/ and are not sent to Anthropic until the user explicitly approves. Users can review, edit, or disable the feature via /config.
News updates every hour. Subscribe in your RSS reader to get new stories automatically.
Subscribe