yatsu-proactive

The proactive loop that keeps the loss signal fresh AND covered — the core contract tells every agent to measure what it changed, and the Stop gate, scoped to that agent's own changed nodes, nudges once on a stale score or an uncovered frontend node. Both reuse spex yatsu scan --changed.

raw source

A loss signal is only useful while it is FRESH and COVERED: a node's reading goes stale the moment its code moves, and a frontend node with no yatsu.md has no signal at all. Both rot silently when measuring is on-demand. Make the system keep its own scores honest — tell every agent to measure what it changed, and surface the gap in the flow. But surface only the agent's OWN gaps: nagging it about a score that went stale in a node it never opened is noise it rightly ignores (three workers in a row asked "is this mine?").

expanded spec

Two surfaces, one engine — yatsu-core's spex yatsu scan --changed, scoped to the nodes the current branch touched (vs its fork-point from the main branch), reporting three gap classes: yatsu-drift / yatsu-missing (a node with a yatsu.md whose score is stale / unmeasured) and yatsu-uncovered (a frontend node carrying no yatsu.md).

The core contract (core, folded into every launched agent) carries the rule: changed a node with a yatsu.md? re-measure it. Made an obvious frontend change to a node with none? give it one. That makes measuring part of finishing, not a chore left for later.

The Stop gate (the stop-gate hook) adds the nudge. When a session stops CLEAN-DONE (its work committed and a done/awaiting declaration made — the moment a change lands), the gate runs scan --changed and, if a gap touches what the agent changed, emits a pointer through the hook's additionalContext: re-measure a stale score, or give an uncovered frontend node a scenario. It is not a gate — a gap is a heads-up, not a wall, and it never alters the commit/declare gates' stop verdict, riding their allow paths only.

It fires once. The additionalContext itself forces one continuation, so the gate guards the nudge on stop_hook_active — re-emitting on that forced re-stop is exactly what looped 31 turns and tripped the Stop-hook block cap. Nudge on the first natural stop; stay silent on the continuation; let the agent stop.

Out of scope: scan's own engine, freshness derivation, and the changed-node / frontend-surface classification (yatsu-core); this node is only the two proactive surfaces that consume it.