Bonsai J-Lens

x = position · y = layer (L0 bottom → output top) · z = rank (1 in front) · drag to orbit, scroll to zoom, click a voxel to select
why rather thanor
how to read this
Everything the model writes into this position's residual stream adds up, exactly, to its final logits (the final norm is a single scale, held at its actual value).
Big plot: the race between the chosen token and two rivals. x = how far it leads the first rival, y = the second, in logits. Each layer adds two arrows, tip to tail: its attention/memory write (solid) and its MLP write (dashed); colour = layer. Shading = who is ahead.
Right: the current layer's arrows split into their largest pieces: a head reading one earlier position (orange; ties into the KV tab), or one MLP neuron (blue) with the words its write points to. Grey = everything else.
Strip: both margins over the layers (click to jump).
Direct attribution: each write's own path to the output. A write that later layers read and act on is credited only for its direct part; mid-layer pieces are often small here even when they matter downstream.
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