What problem does it solve?
This Skill solves the challenge of making neural network internals interpretable by training and using Sparse Autoencoders (SAEs) to decompose dense activations into sparse, human-understandable features.
Core Features & Use Cases
- Train custom SAEs with configurable sparsity/architecture (e.g., standard, gated, top-k) on activations from a chosen model and layer.
- Load and analyze pre-trained SAEs to study feature activation patterns, reconstruction quality, and metrics like L0 and CE loss recovery.
- Steer or attribute predictions by computing feature contributions to logits and applying feature directions via hooks for controlled generation.
Use case example: You are investigating superposition in a transformer layer and want to identify which sparse features are responsible for a concept (e.g., Paris-related associations), then test whether feature ablations change the model’s probability of the target token.
Quick Start
Use the sparse-autoencoder-training skill to train a sparse autoencoder for GPT-2 small residual stream activations at a chosen hook point and then report reconstruction and sparsity metrics.