SAE Management
The SAEs panel is the unified home for every sparse autoencoder in your workspace, regardless of where it came from:
- Trained — SAEs produced by miStudio training jobs
- HuggingFace — pre-trained SAEs downloaded from the Hub (including Gemma Scope)
- Local — SAE files imported from disk

Each card shows the SAE's base model, layer, hook type, dimensions (d_model → n_features), architecture, and source. From here you can launch feature extraction, open steering, export to Neuronpedia, or delete.
Downloading Pre-Trained SAEs
Enter a HuggingFace repository ID and preview the available SAE files before downloading:

- Multi-select downloads: select several SAEs from one repository and download them in a single operation
- Grouped preview: files are organized by directory structure so multi-layer repos stay navigable
- Compatibility check: dimensions are validated against the base model before extraction
Gemma Scope
Google's Gemma Scope repositories follow a layer_N/width_16k/average_l0_XX/ layout. miStudio parses this structure automatically — pick the layer, width, and L0 variant you want, and the SAE is stored locally in SAELens community format.
Importing SAEs
A run that was stopped early has no SAE to import until it is finalized. Click Finalize on the training, then import as usual — see Training Lifecycle & Checkpoints.
Two import paths complement HF downloads:
- Import from training — register the SAE(s) a completed miStudio training produced. Multi-layer/multi-hook trainings expose all of their SAEs for import; already-imported ones appear disabled in the picker so you can't double-import. The hook type is auto-detected from each SAE's
cfg.json. - Import from file — point at an SAE directory already on disk.
Formats and Conversion
miStudio reads and writes two formats and converts between them automatically during download/import:
| Format | Layout | Used by |
|---|---|---|
| SAELens community standard | cfg.json + sae_weights.safetensors | Gemma Scope, most published SAEs |
| miStudio native | config.json + model.safetensors (+ training metadata) | miStudio training output |
Format detection is automatic — you never select a format manually.
Extracting Features from an SAE
Every SAE card has an Extract Features action that launches the SAE→features pipeline described in Feature Extraction. Extraction progress streams to the card, and in-flight extractions can be cancelled. A batch extract action processes several SAEs sequentially.
Delete Semantics
Deleting an SAE offers two behaviors:
| Option | What happens | Reversible? |
|---|---|---|
| Delete with files (default) | Hard delete — removes the SAE record, its weight files, and cascades to all features extracted from it | No |
| Keep files | Soft delete — the record is marked deleted but weights stay on disk | Yes (re-import) |
The default hard delete removes every extracted feature, label, and activation example derived from the SAE. If you've invested labeling effort, export to Neuronpedia first or use the soft-delete option.
Uploading to HuggingFace
Trained SAEs can be pushed back to the Hub for sharing. Uploads use a layer_XX/width_{n}k/ directory convention compatible with the Gemma Scope layout, so your published SAEs are browsable with the same tooling. Configure your HF token in Settings → API Keys first.