Louvain only ever found the reasoning chains (the graph is disconnected
by nature — every connected component became its own cluster) and
edge-orphans could never join anything. Clusters are now RELATED TOPICS:
propositions grouped by meaning.
- Embedder (src/server/embeddings.ts): in-process transformers.js v4
running EmbeddingGemma-300M q8 (MTEB 68.4, ~300MB one-time download),
MRL-truncated to 512d, "title: none | text:" prefix on 100% of inputs,
L2-normalized so cosine = dot. Model/dim mismatch voids the ledger
(full re-embed). Injected at the composition root — the agent layer
never imports the server layer (architecture law).
- Ledger (data/graph/embeddings.json): model + dim + vectors + the
persisted cluster partition. Reclustering runs at the END of every
embedding batch (post-merge hook, both front doors) — never per read
(the agglomerative pass is ~1.5s at 338 nodes).
- Clustering (src/core/semantic-clusters.ts): hand-rolled average-linkage
agglomerative over cosine (npm HDBSCAN is an abandoned alpha). Stragglers
stay singletons by default; attachStragglers is the all-in toggle.
Threshold 0.60 swept on the real graph: 26 topics, 74/90 edge-orphans
land in real topics, 10 stragglers.
- Consumers (snapshot, settle, namer, replay) read the persisted
partition — one cluster concept everywhere; core-survival label
matching unchanged (20/26 topics kept labels).
- Louvain retired: detectCommunities + graphology* deps deleted
(graphology-louvain had leaked into the client bundle since the
clusters wave); scripts/bench-graph.ts (dead FA2 bench) removed.
- scripts/embed-graph.ts: backfill/cold-start (338 nodes in 150s
including the one-time model download).
The 'virtual node' realized as a centroid force: two allocation-free
O(n) passes per tick (membership resolved once at sim creation;
Float64Array sums). Measured indistinguishable from force-off at 338
nodes (271ms vs 272ms per 400-tick settle).
- createGraphSimulation: SimOptions.clusterPull + linkStrength +
velocityDecay (physics controls plumbing); degree-scaled link
stiffness so linkStrength=1 is exactly d3's default
- settleGraphLayout split into layout-settle.ts (it computes the
Louvain partition for the pull); layout.ts stays browser-barrel-pure
- barrel no longer re-exports clusters.ts: graphology + louvain are
fully out of the client bundle (verified against built chunks)
- replay passes the per-batch partition; CLUSTER_PULL_STRENGTH=0.15
tuned by sweep: cluster spread 63->36 world units, centroid
separation and total span unchanged (no blob merge, no collapse)
amosblomqvist