| name | detect-impl-gaps |
| description | Detect spec→impl gaps mechanically via the Spec Reader and emit the current gap-id set as JSON. Required thin-transport surface per livespec/SPECIFICATION/contracts.md. Pure read-and-emit pass-through — never mutates the work-items store, never prompts the user. Invoke as `/livespec-orchestrator-beads-fabro:detect-impl-gaps [--spec-target <path>] [--project-root <path>] [--json] [--since-version <vN>]`. |
| allowed-tools | Bash |
detect-impl-gaps
Thin-transport pass-through. All behavior lives in
.claude-plugin/scripts/livespec_orchestrator_beads_fabro/commands/detect_impl_gaps.py.
Invocation
python3 "${CLAUDE_PLUGIN_ROOT}/scripts/bin/detect_impl_gaps.py" "$@"
Supported flags:
--spec-target <path> — path to the spec tree (default:
SPECIFICATION/ under --project-root).--project-root <path> — project root (default: current working
directory).--json — emit {"gap_ids": [...]} JSON instead of
human-readable lines.--since-version <vN> (optional, default unset) — restrict the
scan to spec files whose content differs between the historical
version <vN> and the live spec. Accepts either v<N> (e.g.
v082) or a bare positive integer (e.g. 82). For each such
file, only MUST / SHOULD clauses present in the LIVE version are
surfaced — clauses removed by the diff are not gaps (they were
spec content that no longer exists). When omitted, the skill
scans every file in the live spec (pre-flag behavior, unchanged).
Validation of --since-version:
- The value MUST resolve to a positive integer. Non-integer or
non-positive input exits
2 with a usage error written to
stderr.
- The version directory
<spec-root>/history/v<padded-N>/ MUST
exist. Missing version exits 3 with a
SpecVersionNotFoundError message naming the expected path.
- When
<vN> equals the live spec's latest cut version AND the
live tree matches that snapshot byte-for-byte, the diff is empty
and the skill emits an empty gap-id set.
When to use
- Doctor's
gap-tracking-one-to-one and no-stale-gap-tied
invariants subprocess detect-impl-gaps --json to enumerate the
current gap-id set against the work-items JSONL store.
- The heavyweight
capture-impl-gaps sibling invokes
detect-impl-gaps --json as its detection step before walking
the user through per-gap consent.
- The heavyweight
implement skill invokes detect-impl-gaps --json at gap-tied closure verification to confirm the
gap_id is no longer present in the returned set.
Properties
- Non-mutating. No JSONL writes, no spec modifications, no
user prompts.
- Pure function of spec state. Same spec text yields the same
gap-id set; gap-id derivation hashes
<spec-file>\x1f<heading-path>\x1f<rule-text>.
- Excludes
proposed_changes/ via the Spec Reader's exclusion
contract — only ratified canonical content surfaces.
- No LLM in the detection path. Pattern-matching of
MUST / MUST NOT / SHOULD / SHOULD NOT keywords (uppercase only)
outside fenced code blocks is deterministic.
