Product contract
Control the residual stream, deliberately.
Ster is a native Rust toolkit for reading hidden states, learning representation directions, measuring them, and applying them during generation.
What Ster owns
Ster owns the local representation-engineering loop for open-weight language models. It loads a checkpoint, captures final-token residual states after selected transformer blocks, learns layer-indexed directions, and applies a selected direction before the next block.
The runtime uses Candle directly so tokenization, attention, KV caching, sampling, activation capture, and steering remain in one native process.
Current surface
- Llama-family Safetensors checkpoints from a local directory or Hugging Face Hub.
- CAA, PCA, and logistic-probe direction training.
- Holdout selection across method and layer.
- Pair-ordering accuracy and projection-margin evaluation.
- Additive residual-stream steering during autoregressive generation.
- Versioned JSON pair, activation, steering, and evaluation artifacts.
Boundaries
- Unsupported model architectures fail before weights are loaded; Ster does not guess adapters from tensor names.
- Hosted model routing belongs to Brama.
- Fleet placement and job lifecycle belong to Stado.
- Credentials belong to Skarbiec.
- The retired Python package and wisent command are not compatibility surfaces.