What problem does it solve?
This Skill helps you train and analyze Sparse Autoencoders to decompose dense neural network activations into sparse, interpretable features.
Core Features & Use Cases
- Pre-trained SAE loading and activation analysis: Identify which sparse features activate for specific inputs, measure sparsity, and validate reconstruction quality against original activations.
- Custom SAE training workflow: Configure and train SAEs with sparsity-promoting loss (MSE reconstruction plus L1 feature penalty), including practical hyperparameters for controlling dead features and interpretability.
- Feature-level interpretation and steering: Attribute model logits to individual SAE features and optionally steer generation by adding feature directions to the residual stream.
Use it for feature discovery, superposition/sparsity studies, monosemantic representation research, and mechanistic interpretability experiments on transformer activations.
Quick Start
Use the sparse-autoencoder-training skill to train and evaluate an SAE for a chosen transformer hook point using SAELens, then inspect top-activating features and reconstruction error.