Trace walk: every output traces back to named knowledge

A commander looking at a verdict — "this route is tight on clearance" — needs to ask why. Not "what formula produced the number" but "which analyst's assessment, from which source, via which channel, drove this conclusion?" If the answer is "we don't know" or "it's complicated," the verdict is unjustifiable.

ASSAY's trace store (SPEC-02) is the skeleton that makes every output attributable. It is a directed graph of trace edges, written at compute time by the service performing each computation — never reconstructed after the fact (constitution III). A backward walk from any verdict reaches named knowledge; a forward walk from any knowledge item reaches every verdict it influenced.

Try it: click a node, see what it reaches

Click any node below. Forward walk (click a knowledge item) lights up everything it feeds — the channels it compiles into, the verdicts those channels produce. Backward walk (click a verdict) lights up everything that fed it. The edges are typed: you see how each link connects, not just that it does.

Click a node to walk its closure:

K1 (depth) K2 (capacity) K5 (weather)

↓ compiled_into ↓ compiled_into ↓ compiled_into

FE-DEPTH FE-CAPACITY

↓ scored_from ↓ scored_from

P1-C1 P1-C4 P2-C1 P2-C4

Illustrative widget, fixture data. The graph is a simplified view of Meridian's trace topology. Click K2 to see the forward closure (FE-CAPACITY → P1-C4, P2-C4). Click P1-C1 to see the backward closure (FE-DEPTH ← K1). Frozen as shipped on 2026-07-11.

Illustrative widget, fixture data. The trace chains are simplified views of the shipped TraceStore.walk() running over Meridian knowledge K1/K2. Edge types and node roles match the real graph. A chain that dead-ends where a known object was expected reports complete: false — the system never hides a missing link (G3). Frozen as shipped on 2026-07-11.

Why it is load-bearing

Every invariant above Stage 0 depends on the trace store. G3 (attribution): a verdict without a complete backward chain to named knowledge is a defect, and the store surfaces it. G6 (propagation honesty): the forward walk is how the app knows what to glow and what to leave dark. Staleness (thesis F, Stage 6): the transitive walk is how the analysis loop identifies which verdicts depend on stale knowledge. The trace store is not a debugging tool — it is the mechanism that makes ASSAY's honesty properties mechanically enforceable.

Assessment, not fact — and demonstrator, not product. Every number here renders the Meridian Archipelago, an engineered fiction (ASSAY-DEC-8). Nothing on this page reflects any real operational picture. A thesis in ASSAY is only ever explored, never claimed proven.

Sources & trace

Trace store — src/trace.ts
Trace view (orientation map) — src/traceView.ts
Constitution III — edges written at compute time, never reconstructed
G3 (attribution) — a dead-end chain reports complete: false
Research note — 00-foundations.md