Claude's new system prompt doesn't want to reproduce song lyrics(simonwillison.net)

52 points by Bluestein 1 month ago | 37 comments

Changes in the system prompt between Claude Opus 4.6 and 4.7(simonwillison.net)

337 points by pretext 6 months ago | 186 comments

Simon Willison's blog post comparing Anthropic's published Claude system prompts for Opus 4.6 and Opus 4.7, using a git diff to highlight the changes.

Claude 4 System Card(simonwillison.net)

638 points by pvg 1 year ago | 237 comments

Simon Willison's blog post highlighting notable details from Anthropic's 120-page system card for Claude Opus 4 and Claude Sonnet 4.

Claude 4.5 Opus’ Soul Document(lesswrong.com)

290 points by the-needful 10 months ago | 172 comments

Now add a walrus: Prompt engineering in DALL-E 3(simonwillison.net)

246 points by simonw 3 years ago | 62 comments

Notes on the new Claude analysis JavaScript code execution tool(simonwillison.net)

145 points by bstsb 2 years ago | 42 comments