Replication of Chris Hay's "I Decoupled Attention from Weights — Gemma 4 26B" YouTube demo,
using the cross-platform cronos3k/larql fork
and the chrishayuk/gemma-3-4b-it-vindex.
What this is: mechanistic interpretability via LQL (Lazarus Query Language). You are NOT running the LLM for text generation. You are querying the model's FFN weight structure as a graph — inspecting which features activate, comparing concept representations across layers, and optionally editing knowledge directly in the vindex.
# 1. Build the LARQL binary (cross-platform fork, Linux/macOS/Windows)
bash setup_env.sh
# 2. Download the Gemma 3 4B vindex (~4-5 GB)
bash fetch_vindex.sh
# 3. Launch the interactive LQL REPL
python lql_repl.py
# 4. Or run the YouTube demo queries non-interactively
python lql_repl.py --script demo_queries.lql-- Which features fire most strongly at layers 20-23 for this prompt?
WALK "The capital of France is" TOP 10;
-- Compare concept representations side-by-side at the same layer
PROBE "France is" vs "Germany is" vs "Japan is" AT LAYER 22;
-- Predict what the model thinks comes next
INFER "The capital of France is" TOP 5;
-- Edit the model's knowledge directly (not a fine-tune — writes to the graph)
INSERT INTO EDGES (entity, relation, target)
VALUES ("Atlantis", "capital-of", "Poseidon");.
├── setup_env.sh # Rust toolchain + clone cronos3k/larql + cargo build --release
├── fetch_vindex.sh # HuggingFace CLI download of gemma-3-4b-it-vindex
├── lql_repl.py # Interactive REPL + --script mode for batch query files
├── demo_queries.lql # The exact query sequence from Chris Hay's YouTube demo
└── data/
└── gemma3-4b.vindex/ # Populated by fetch_vindex.sh
LQL queries do sparse KNN lookups, not full autoregressive generation.
A DigitalOcean Basic 8 GB / 4 vCPU droplet (~$0.07/hr on-demand) is sufficient.
SSH in from Codespaces, run bash setup_env.sh, done.
- Original LARQL + LQL language: chrishayuk/larql
- Cross-platform fork (Linux/CUDA builds): cronos3k/larql
- HuggingFace Space (zero-install browser demo): https://huggingface.co/spaces/cronos3k/LARQL-Explorer