Neuron Explorer for Qwen3.5-4B: See every neuron at work, make targeted edits

Steering-first neuron explorer for Qwen3.5-4B. Every MLP neuron in a layer is pushed up and down on a few prompts, every rollout is kept, and the explorer lays the results out over a 3D view of the model.

uv sync uv run python explorer/server.py # http://localhost:8791

Reads sweep runs from runs/ and per-layer stats from stats/, both produced by the sweep below; the caches in explorer/cache/ ship with the repo. Loads Qwen3.5-4B locally (MPS, CUDA or CPU) for live steered chat, lens, connections and live inference over your own text.

Runs on a CUDA 13 GPU pod with the steering fork of vLLM (RhizoNymph/vllm).

bash sweep/setup_pod.sh # fork, deps, model; writes /workspace/env.sh python sweep/neuron_stats.py --layers 22 --tokens 2000000 --out stats/q35-4b python sweep/steer_sweep.py --stats stats/q35-4b_L22.npz --design main_rel --dose-unit rel
--neurons all --random-controls 256 --run q35-4b-L22 sweep/run_depth.sh "4 9 13 17" 384 64 # random-subset sweep across several layers

main_rel doses are fractions of the median residual norm leaving the layer: {who, snake, orange} × {−0.7, +0.5, +0.8} and {free} × {+3}, plus one unsteered baseline per prompt.

research_log.md holds the findings and reasoning; NOTES.md the source notes.