About

Apertus Claritas is a platform for collecting and sharing interpretability research on Apertus, Switzerland's open multilingual language model. It brings together researchers, students and independent contributors to document what we are learning: what works, what fails and where understanding remains incomplete.

What makes Apertus Claritas unique is that it offers both an inside view and an open view. Rather than only showcasing polished results, it creates space for exploratory findings, intermediate insights, negative results and technically grounded reflections that help others understand this model more deeply.

Apertus builder summit
ETH Apertus key visual
Alps supercomputer in Ticino

Topics

Topics we cover include but are not limited to the following:

  • Features circuits, latent representations and geometry
  • Sparse autoencoders and transcoders
  • Probing, activation steering and interventions
  • Training dynamics across checkpoints and parameter scales
  • Safety monitoring including hallucinations, anthropomorphic concepts and behavioural drift
  • Agentic interpretability and automated monitoring
  • Tools, datasets and interactive interpretability interfaces

Get to know us

Team· 4
Anna Hedström

Anna Hedström

Core Team

Fatima Zahra Moudakir

Fatima Zahra Moudakir

Developer

Lasse Bærland Strand

Lasse Bærland Strand

Developer

Thilo Spinner

Thilo Spinner

Developer

Advisors· 4
Andreas Krause

Andreas Krause

Advisor

Imanol Schlag

Imanol Schlag

Advisor

Menna El-Assady

Menna El-Assady

Advisor

Oleg Lavrovsky

Oleg Lavrovsky

Advisor

Reviewers· 3
Anna Hedström

Anna Hedström

Reviewer

Julian Minder

Julian Minder

Reviewer

Yannick Metz

Yannick Metz

Reviewer

Contributors· 6
Aleks Stepančič

Aleks Stepančič

Contributor

Arundhati Balasubramaniam

Arundhati Balasubramaniam

Contributor

Matteo Pelossi

Matteo Pelossi

Contributor

Tymoteusz Kwiecinski

Tymoteusz Kwiecinski

Contributor

Yannick Metz

Yannick Metz

Contributor

alexander sternfeld

alexander sternfeld

Contributor

Supporting labs
ivia-labLAS
Hosted within the Swiss AI ecosystem
EPFL AI CenterETH AI CenterCSCS