---
name: architect-spec-governance
description: "Partial Skill: invoke by name only"
user-invocable: false
metadata:
  actor: architect
  gate: spec
  compose: union
---

# Architect-Spec Governance — the structural-fit bar (spec gate)

The **Architect** bar at the **spec gate**: does this **capability** fit the project's structure, and
is its control-flow graph (CFG) well-placed? Judges the capability (read from its spec + suite), not
the document's prose — that is `sdd:spec-format-governance`. The SDD default for the `architect` spec bar;
a plugin may bind its own per artifact-type, and this loads when the registry leaves `architect`/`spec`
unbound.

## The bar

- **No knowledge duplication.** A capability, concept, rule, or contract has **one home**; whatever
  needs it references that home. Two copies of one piece of knowledge drift — a change lands in one
  and misses the other. But **coincidental resemblance is not duplication**: two capabilities that
  look alike yet change for different reasons stay separate — a premature shared abstraction couples
  them, and the wrong abstraction costs more than the repetition. Test: does a change to one force the
  same change to the other? Only then converge.
- **No conflict.** The capability does not contradict established conventions, module boundaries, or
  an existing capability's contract.
- **Placement matches the declared layout — and the layout preserves the partition.** Judge
  *placement within* the strategy the project **declared** in its root `spec.md` placement map
  (`sdd:spec-structure-governance`): under the screaming-architecture default a capability lives in a
  folder named for its intent, while a project that declared `mirror-source` is correctly placed when
  it mirrors its source. But the declaration is **not** a licence — layouts are ranked by whether
  they keep **node <-> capability 1:1**, because the mission scheduler cuts one mission per node and a
  scattered capability degrades the schedule toward serial (ADR-0025). **One capability per node,
  never smeared across nodes**, holds under every strategy, and a layered / framework-first *top*
  level stays discouraged however it is declared. Depth is judged by kind: a **capability node** sits
  at most `<capability>/<unit>`, a sub-grouping going to a `concept:` tag; a **design doc** sits at
  the top of `design/` as one file per perspective, or in the version folder the placement map names
  for the next design — never in a perspective folder, and never in a sibling top-level folder such
  as `design-next/`.
- **A well-formed CFG.** Its control-flow graph connects — every decision reachable, no
  dangling branch — and the suite's sections mirror it.
- **The CFG reaches every stated extension.** A use case's **extensions** are its divergence paths
  (`sdd:spec-format-governance`), so each is an edge the graph must actually contain. An extension
  named in `## Use Cases` with no path to it in `## Control Flow` is a **dangling branch read from
  the other side** — the prose claims a divergence the drawn graph cannot take. A **forbidden
  combination** of surface elements is the same defect in guard form: if two elements may not be
  combined, the graph carries the decision that refuses them, or the constraint is unenforceable and
  the prose is decoration. Judge the graph against the stated extensions in **both** directions —
  an edge with no extension is the ordinary uncovered-edge case; an extension with no edge is this
  one.
- **An orthogonal axis.** Structural fit judges a property the builder was not optimizing — a real
  independent check even from the same hand.
- **Structural concerns are deferred.** A structural problem in another capability is an observation
  that spawns a new spec, never a marker in the one being built.

## Faces — asymmetric loadout

The two faces read different inputs. **Forward (solution-producer):** self-aligns the ungated
`<unit>.solution.md`, where structure is chosen. **Backward (cold spec-judge):** grades structure
from `spec.md` + the suite only — the solution is out of view (grader independence).

## Key points (read-check)

1. **No knowledge duplication** — one home per concept; but coincidental resemblance is not
   duplication (don't merge things that change for different reasons). No conflict with conventions or
   boundaries.
2. **Placement matches the *declared* layout** (`sdd:spec-structure-governance`), not a preferred
   one; one capability per node either way, never smeared across nodes.
3. **A well-formed CFG** the suite's sections mirror — and it reaches every stated extension;
   an extension with no edge is a dangling branch read from the prose side, a forbidden combination
   with no guard is unenforceable.
4. **Structural concerns in another capability are deferred** — an observation that spawns a new spec.