---
id: 144
title: Spec-Phase Edge-Completeness Probe
group: v1.42.1 Features
---

**Command:** `/gsd-spec-phase`

**Purpose:** Surface the omitted domain-boundary edges that silently invalidate a requirement — touching intervals, empty inputs, rounding ties, grapheme truncation — before they become production defects. Runs as `Step 5.5` of spec-phase, after the ambiguity gate.

**Behavior:** For each SPEC requirement the probe classifies its data/behavior shape, then raises only the *applicable* categories from a closed 8-category taxonomy (boundary, adjacency, empty, encoding, ordering, precision, idempotency, concurrency) via a relevance filter. Each raised category proposes one concrete candidate edge, which the author resolves to exactly one of four states:

| State | Meaning | Downstream effect |
|-------|---------|-------------------|
| `covered` | An acceptance criterion handles the edge | Pass/fail line written into the SPEC Acceptance Criteria block; lifted into `plan-phase` `must_haves.truths` |
| `dismissed` | The edge cannot occur (requires a non-empty reason) | Recorded with its reason; empty dismissals are rejected |
| `backstop` | Intent recorded, needs a held-out/property-based test | Lifted into `must_haves.truths` as a non-inferable check |
| `unresolved` | Deferred | Soft-gates the spec; row stamped `⚠ Edge unresolved — planner must treat as assumption` |

When a requirement's prose matches **no** shape cue, the probe does not silently drop it (#1110): it emits a single `unclassified — review manually` candidate so the zero-cue requirement is surfaced for the author to resolve like any other (specify / dismiss-with-reason / defer) — a manual-review nudge, not a hard block.

**Non-English projects: the probe reads English via `text_en`, the SPEC does not have to (#2773, durable fix #3717).** The shape cues are English word-boundary patterns, so a project running with [`response_language`](CONFIGURATION.md) set would otherwise have *every* requirement match nothing, classify to zero shapes, and land in `unclassified` — the taxonomy silently contributing nothing to exactly the kind of spec it exists to harden. `spec-phase` Step 5.5 therefore populates an optional `text_en` field alongside each requirement's `text` with a faithful **English translation**: `text_en` is engine input, never user-facing output, so it is translated while `text` keeps the requirement's own wording (the SPEC stays in the original language), requirement ids are left untouched, and any acceptance criteria written back from the resolved edges return to `response_language`. Translation makes the classifier *applicable*; it does not make it omniscient. A requirement carrying no shape cue in **any** language still classifies to zero — that is the classifier's recorded recall gap (ADR-857 §98), not a translation failure — and the remedy there is the same one an English project uses: author an explicit `shapes` array on the requirement instead of relying on prose classification.

The resolved edges populate a `## Edge Coverage` section in `SPEC.md`. Unresolved *applicable* edges trigger a soft gate (Resolve / Write-anyway-flagged / Keep-probing) rather than a hard block. Under `--auto`, the probe **never auto-dismisses** — it auto-covers where a defensible criterion exists, otherwise auto-backstops, and logs `[auto] edge coverage: C covered, B backstop, U unresolved`. The one exception is an `unclassified` candidate: `--auto` leaves it **`unresolved`** (surfaced as a flagged assumption), never auto-`backstop` — a missing shape is not evidence an edge exists, so minting a held-out edge obligation would be a false claim.

The load-bearing wire is the `plan-phase` lift: `covered` and `backstop` edges become `must_haves.truths` the verifier can check, so the section is not merely documentation. A `backstop` edge is lifted as a **structured non-inferable marker** (`{ statement, verification: backstop }`, a flat scalar — not a prose note), which the **honest verifier** then consumes (see below) — closing the loop the edge-probe opened.

**Honest verifier — abstention on non-inferable checks (#1154).** A non-inferable (`backstop`) truth is one whose correct behavior is not derivable from the spec alone, so the verifier cannot self-detect the gap and would confidently false-pass it (~100% of the time). At verify time, a `backstop` truth the verifier cannot confirm with **explicit evidence** (a passing wired held-out/property-based test, or a directly-observed behavior) **abstains** → `human_needed` with reason `insufficient_spec` (reported as `unverified — held-out test recommended`), **never a silent `passed`**. This is the verify-time, truth-axis mirror of the prohibition judgment-tier disposition (ADR-550 D4): exogenous (driven by the `backstop` tag, never a self-judged "abstain if unsure"), routing-not-diagnosis (the held-out test carries the omitted rule), and capable-tier dependent (reliable on `sonnet`+; the budget `haiku` tier degrades toward current behavior). An inferable truth is never abstained (the over-abstention guard). Reference: [Honest Verifier](../gsd-core/references/honest-verifier.md).

**Requirements:**
- REQ-EDGE-01: The edge pass MUST run after the ambiguity gate and emit a `## Edge Coverage` SPEC section.
- REQ-EDGE-02: The relevance filter MUST raise only applicable categories; each raised edge resolves to exactly one of covered/dismissed/backstop/unresolved.
- REQ-EDGE-03: A `dismissed` resolution MUST require a non-empty reason.
- REQ-EDGE-04: An unresolved applicable edge MUST trigger the soft gate; write-anyway stamps the row as a planner assumption.
- REQ-EDGE-05: `--auto` MUST never auto-dismiss — auto-cover or auto-backstop only.
- REQ-EDGE-06: `plan-phase` MUST lift `covered` criteria and `backstop` notes into `must_haves.truths`.
- REQ-EDGE-07: A requirement whose prose matches no shape cue MUST surface an `unclassified — review manually` candidate (never silently dropped); `--auto` MUST leave it `unresolved`, never auto-`backstop`.
- REQ-EDGE-08: `plan-phase` MUST lift a `backstop` edge into `must_haves.truths` as a structured flat-scalar marker (`{ statement, verification: backstop }`), never a prose parenthetical.
- REQ-HONEST-01: At verify time a `backstop` truth that cannot be confirmed with explicit evidence MUST abstain → `human_needed` (reason `insufficient_spec`), never `passed`; an inferable truth MUST never be abstained (over-abstention guard); abstention MUST be exogenous (driven by the `backstop` tag, not self-judgment).

**Reference:** [Edge Probe](../gsd-core/references/edge-probe.md)