Anthropic's Claude Opus 5 System Prompt Allegedly Leaked

The system prompt for Anthropic's Claude Opus 5 has reportedly leaked, revealing a massive 200,000-character guideline. The leaked prompt includes a new fablesafeguards block, which critics argue is overly conservative and could hinder basic scientific discussions.

2026-07-25 ~ 2026-07-25 · 2 related posts

• Leaked Claude Opus 5 system prompt appears to span 200,000 characters — mcraddock · 2026-07-25
• Repost claims Anthropic’s Claude Opus 5 system prompt leaked in a 200,000-character dump — Scobleizer · 2026-07-25