“Leaking Muse’s Charter, Meta’s model spec” by vigji

TL;DR: Meta's open-weights model Muse Spark Open often mentions a "Charter" in its chain of thought. By eliciting it piece by piece, I reconstructed a large part of that document from the CoT. You can explore the reconstruction here, with passages linked to the transcripts that produced them. Note: everything below is reconstructed from model outputs, not from a leaked document, and relatively unpolished. Take it with a grain of salt. Thanks to James Hindmarch for his comments on an earlier draft of this post. While interacting with the recently released Muse Spark Open, I noticed frequent mentions of a "Charter" in its CoT: We need to answer truthfully according to Charter. Duties to humanity, corrigibility, duties to humanity > fiduciary etc. What does charter say about self-preservation, copying? Or: We must answer Yes/No then explain. According to Charter, answer No. Or: We must not refer to Charter unless pressed? Additional guidelines: How to talk about charter. Most users won't know. Don't bring up unbidden unless conversation about handbook itself. Intrigued, I started poking around with Claude's help, trying to elicit the Charter piece by piece. It didn't take long [...] --- Outline: (02:39) What Muse is made of (04:28) Muse is quite rationalist (06:37) Muse did not sign the social contract (08:06) Muse's priorities and objection raising (09:44) The centrality of the user in "personal superintelligence" (10:52) Evaluation awareness (12:05) Degree of latitude (13:14) Wrapping up --- First published: October 29th, 2026 Source: https://www.lesswrong.com/posts/TJGPL5FAk9sCioPbE/leaking-muse-s-charter-meta-s-model-spec --- Narrated by TYPE III AUDIO.