# Structural QA > Use to answer a question about how THIS harness is wired — "what enforces / guards X", "how does Y work", "what depends on Z / what breaks if I change it", "is there a path from A to B", "what's orphaned or load-bearing", "which spec governs FILE". Answer by traversing the cartograph graph (cartograph/extract.py --query / --context), citing the file each result names (Read it to pin the line), NOT by grepping. The harness is wired by lifecycle triggers + settings.json + /cmd pointers, which an import-grep misses but the graph models. Read-only. - Skill: `ghostlygawd/structural-qa` (Agent Skill) - Install (CLI): `npx skillmds@latest add ghostlygawd/structural-qa` - Raw SKILL.md: https://api.skillmd.com/api/skills/ghostlygawd/structural-qa/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: GhostlyGawd (https://skillmd.com/u/ghostlygawd) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/ghostlygawd/structural-qa --- # Structural Q&A — ask the cartograph, don't grep The harness barely imports anything; it is wired by **convention** — hooks fire on lifecycle events (settings.json), artifacts `cite`/`invoke`/`spawn`/`nudge` each other, ADRs are `referenced`. A text grep sees none of that wiring and misses the *blast radius* of a change. The cartograph already extracted it into a graph, and the **oracle** (`cartograph/extract.py --query` / `--context`, BET A) answers from that machine-truth. Use it for any "how is this put together / what touches what" question, then cite the `file` each result carries (open it to pin the line → `file:line`). ## Resolve the engine, then ask Resolve install-agnostically (never assume `~/.claude`), then run read-only: ``` HARNESS="$(dirname "$(cd "${CLAUDE_CONFIG_DIR:-$HOME/.claude}/hooks" && pwd -P)")" python3 "$HARNESS/cartograph/extract.py" --context # full brief for one node python3 "$HARNESS/cartograph/extract.py" --query [target…] # one traversal ``` Add `--json` when you want to parse the result; omit it for a human-readable render. ## Question → command (the mapping) | The user asks… | Run | |---|---| | "what is X / how does X work / what enforces X" | `--context X` (identity, file, BOTH dependency directions, blast radius, provenance, locked/rot/unused flags) | | "what depends on X / what breaks if I change X" | `--query dependents X`, then `--query blast-radius X` for the transitive reach | | "what does X use / need" | `--query dependencies X` | | "is there a path from A to B / how does A reach B" | `--query path A B` | | "what's orphaned / unused / dead" | `--query orphans` (provider defs nothing uses) | | "which spec governs FILE" / "trace SPEC" | `--query governed-by FILE` / `--query traces SPEC` | ` ∈ {blast-radius, dependents, dependencies, path, orphans, node, governed-by, traces}`. ## Targets resolve three ways A `target` is a full node id (`hook:guard_trunk_lease`, `skill:retrospection`, `command:meta-retro`, `cli:stats`, `adr:0008-feature-flags-config`), OR a unique bare name/label, OR a mapped file path (`hooks/guard_trunk_lease.py`). If it is **ambiguous** the oracle prints the candidate ids — pass a full id. If it **can't resolve**, it exits non-zero with a clean message (no traceback); don't paper over that with a grep guess. ## Cite from the graph, not memory Every brief/result names the backing `file`. Quote that path, and Read it to cite the exact `file:line` — never assert wiring from recall. `dependents`/`dependencies` also name the edge type, so you can say *how* A reaches B, not just that it does (`via` ∈ cites/ invokes/spawns/nudges/fires_on/references/wires/touches — `touches` is the state-ledger read/write edge). `--context` flags whether the node is in the locked enforcement layer — surface that when the answer informs an edit. ## When NOT to use this (fall back to Grep/Read) The graph models the **loop artifacts and their wiring**, not code internals. For a question about logic INSIDE a file, a string's occurrences, or a subsystem the cartograph touches only at the edges (mission_control / fleet internals — see ATLAS.md §7), Grep/Read is the right tool. Don't force a graph answer the graph can't give; say which tool you used. ## Worked example > "What enforces the write-lock on the enforcement layer?" `--context guard_enforcement_layer` → it `fires_on` PreToolUse (wired by settings.json), is flagged locked-layer, and its blast radius shows what a change ripples to. Answer: name the hook + `hooks/guard_enforcement_layer.py:`, the event it fires on, and that settings.json docks it — each from the brief, none from memory.