What problem does it solve?
Sparse Autoencoders (SAEs) help decompose dense neural network activations into sparse, more interpretable features, making mechanistic interpretability and feature discovery feasible instead of guesswork.
Core Features & Use Cases
- Train and evaluate SAEs with SAELens: set up training configurations, run training loops, and track interpretability-focused metrics like L0, CE recovery, dead features, and reconstruction quality.
- Load pre-trained SAEs and analyze features: encode activations into sparse features, inspect top-activating features per token/position, and quantify reconstruction performance.
- Use features for interpretability workflows: perform feature attribution, steering with SAE directions, and causal feature ablation to test which features matter for specific predictions.
Quick Start
Train a custom Sparse Autoencoder on GPT-2 activations by instructing the AI to follow the Skill’s “Workflow 2: Training a Custom SAE” steps and fill in your chosen model hook point, dataset path, and SAE hyperparameters.