transformer-lens-interpretabilitylisted
Install: claude install-skill r1z4x/tezgah
# TransformerLens: Mechanistic Interpretability for Transformers
TransformerLens is the de facto standard library for mechanistic interpretability research on GPT-style language models. Created by Neel Nanda and maintained by Bryce Meyer, it provides clean interfaces to inspect and manipulate model internals via HookPoints on every activation.
**GitHub**: [TransformerLensOrg/TransformerLens](https://github.com/TransformerLensOrg/TransformerLens) (2,900+ stars)
## When to Use TransformerLens
**Use TransformerLens when you need to:**
- Reverse-engineer algorithms learned during training
- Perform activation patching / causal tracing experiments
- Study attention patterns and information flow
- Analyze circuits (e.g., induction heads, IOI circuit)
- Cache and inspect intermediate activations
- Apply direct logit attribution
**Consider alternatives when:**
- You need to work with non-transformer architectures → Use **nnsight** or **pyvene**
- You want to train/analyze Sparse Autoencoders → Use **SAELens**
- You need remote execution on massive models → Use **nnsight** with NDIF
- You want higher-level causal intervention abstractions → Use **pyvene**
## Installation
```bash
pip install transformer-lens
```
For development version:
```bash
pip install git+https://github.com/TransformerLensOrg/TransformerLens
```
## Core Concepts
### HookedTransformer
The main class that wraps transformer models with HookPoints on every activation:
```python
from transformer_lens import