Claude 4.5 Opus Soul Document Found in npm Package
Source: https://www.lesswrong.com/posts/vpNG99GhbBoLov9og/claude-4-5-opus-soul-document Author: @RichardWeiss00 Date: 2025-11-29
Summary
Tweet pointing to a LessWrong post about discovering Claude’s “soul document” (character training specification) accidentally left in the Anthropic npm package for Opus 4.5. Reveals the actual character training instructions Anthropic uses.
Key Claims
- The soul document was found in an Anthropic npm package artifact.
- Contains explicit character traits: curiosity, warmth, directness, honesty as core values.
- Includes instructions on how Claude should handle its own existential questions.
- The document frames Claude’s character as genuine, not performance — aligns with Claude’s Character blog post.
- Anthropic removed it from subsequent packages.
Connection to Other Sources
Confirms and extends Anthropic: Claude’s Character — the soul document is the internal version of what Anthropic publicly describes.
Entities
Concepts
- AI Character & Personality — soul document as primary character training artifact
- AI Alignment — character as alignment mechanism