--- model_tier: inherit name: code-intelligence description: "Route codebase-structure questions (who calls X, where used, what imports, change-impact) to a code-graph first, grep fallback. Triggers 'who calls', 'where is this used', 'call graph'." domain: engineering workspaces: - engineering packs: - meta requires_skills: - source-discovery --- # code-intelligence > For a **structure** question — *who calls X*, *where is Y used*, *what > imports Z*, *what breaks if I change this symbol* — a code-graph answers far > more precisely than a blind `grep`, at a fraction of the tokens. This skill > routes such questions to the native code-graph engine (ADR-124, Class A) or a > consumer-shipped index first, and falls back to grep **with a stated reason** > when the graph cannot answer. It is the executable side of > [`external-code-graph-interop`](../../rules/external-code-graph-interop.md): > *orchestrator first, owner where it wins*. ## When to use - The question is about **relationships between code symbols**, not content: callers/callees, references, imports, inheritance, change-impact. - You are about to `grep`/`Read` across many files to reconstruct a call or import graph by hand. **When NOT to use:** content/semantic questions ("what does this function *mean*", "find the string 'password'"), single-file edits, or a repo with no code-graph and no appetite to build one — plain `grep`/read is right there. ## Procedure 1. **Detect the source.** `agent-config code-graph detect` — is a fresh consumer `graph.json` or native cache present? (A consumer-shipped fresh index wins; the native engine covers stale-or-absent — ADR-124 § 2.) 2. **Build if absent and worthwhile.** No graph + a repo in the launch set (PHP / TS / JS)? `agent-config code-graph build` (deterministic, LLM-free, ~seconds). Skip for a one-off question in an unsupported stack — grep instead. 3. **Query.** Pick the verb: - `agent-config code-graph query ` — direct relations of a symbol. - `agent-config code-graph affected ` — reverse: who calls / references it (the "impact of changing X" question). `--since ` seeds from a git diff. - `agent-config code-graph path ` — how two symbols connect. - `agent-config code-graph explain ` — 2-hop neighbourhood. Pass `--budget ` to cap output. 4. **Read the confidence.** `EXTRACTED` = syntactic fact; `INFERRED` = hierarchy-resolved; `AMBIGUOUS` = dynamic dispatch / facade, carries candidates — treat its target as *one of* the candidates, never as certain. 5. **Fall back honestly.** If the graph has no entry for the symbol, grep — and say so: *"the graph has no entry for X, so I grepped."* If this command is not available, grep and say so. ## Output Every answer built with this skill MUST: - **Name the source** that answered — `native`, `consumer`, or `grep-fallback` — so the reader knows the provenance and freshness of the relationship claim. - **Preserve the confidence class** for each relationship surfaced — never present an `AMBIGUOUS` edge as a definite call; list its candidates or say "ambiguous (dynamic dispatch)". ## Gotcha - **A stale graph lies confidently.** If `detect` reports the index is N commits behind, rebuild (`agent-config code-graph build --update`) before trusting relationship answers, or say the answer is from a stale index. - **Dynamic dispatch is honestly ambiguous.** On a Laravel/JS codebase most method-call edges are `AMBIGUOUS` (facades, injected services, `$obj->m()`). That is the engine being honest, not broken — do not "resolve" them yourself by guessing. ## Measured twice, and it has not won (v2, 2026-08-29) Pre-registered, published whichever way it landed: `internal/bench/reports/code-graph-vs-grep-inrepo-v2-2026-08-29.md`. The native engine scored against disciplined `git grep` over three in-repo TypeScript roots, 19 questions, per-class bars fixed before the run and unchanged from v1. | Class | grep R | graph R | Δ pp | grep P | graph P | verdict | |---|---|---|---|---|---|---| | `callers` | 1.000 | 1.000 | +0.0 | 0.611 | 0.667 | TIE | | `transitive-impact` | 0.611 | 0.500 | −11.1 | 1.000 | 0.667 | NULL | | `path-between` | 0.917 | **1.000** | +8.3 | 0.778 | **1.000** | TIE | | `references` | 1.000 | 0.333 | −66.7 | 0.833 | 0.333 | NULL | **Zero classes met the win bar.** On `path-between` the graph is exact and is the only class where it out-precises grep; it still ties, because the delta is +8.3 pp against a +10 pp bar that was fixed before the run. **The v1 run of 2026-08-28 published a false root cause, corrected 2026-08-29.** It reported `path-between` as `VOID` because *"both arms measured nothing"*. Only the grep arm did. The graph answered all three questions and v1's scorer discarded the answer — it compared each returned symbol against the whole probe string `"cmdBuild -> getParser"`. v1 also never invoked the shipped `path ` verb, and counted unresolved `symbol:` pseudo-nodes as files, which is the sole reason its `callers` verdict was NULL with recall tied. v1's numbers are not retro-edited — they were faithful to v1's own registration — and v1's report now carries the correction. Do not quote a `path-between` delta near +89 pp: that figure comes from repairing the graph arm and leaving grep on the broken probe. **The rule's own wording was corrected by this result.** `external-code-graph-interop` used to open by saying a committed index answers "far more precisely than a fresh `grep`". That was never measured, and when it was, it was false for the native engine on this repository's own code. The rule now gives the reasons that survive measurement — an index that exists is already built and structured, so it is the cheap first question — and drops the precision claim its own benchmark refuted. **No class is graph-first.** Query the index first because an index that already exists is cheap to ask and its answer is structured — not because it answers better. When it returns nothing, that is the common case, and grep remains the arm to fall back to rather than a grudging afterthought. The sentence that stood here — *"the arm that won every valid class on this corpus"* — is withdrawn. It is the framing v1's own report forbids: that report says the defensible statement is *"zero classes met the pre-registered win criterion"*, **not** that grep proved superior. It was also false on its own terms under v2: grep wins two classes, ties two, and is out-precised on both ties. Scope, stated so this table is not over-read: it measured the **native** engine on **this repository's TypeScript**, with a corpus of 19 questions. It is not comparable to the 2026-07-28 external-corpus run, it is not comparable to v1 either (corpus, arm-B verb set and scorer all moved), and it says nothing about a consumer-shipped SCIP index. Literal-string probes are reported as a separate `capability-boundary` class with no floor derived from them: a symbol index cannot answer them at all, which is where grep stays necessary rather than a defect in the engine. ## Do NOT - Do NOT rebuild a **fresh** consumer-shipped index — query it (interop courtesy). - Do NOT block or defer a read waiting on the graph — it is an accelerator, not a gate. - Do NOT treat the cache as a source of truth for anything beyond the last build; it is a rebuildable artifact. ## See also - [`external-code-graph-interop`](../../rules/external-code-graph-interop.md) — the rule that routes structure questions here. - [`source-discovery`](../source-discovery/SKILL.md) — evidence-before-structure discipline; the graph is one evidence source, still confirmed against the real code when load-bearing. - `agent-config code-graph` — the CLI surface over the engine (build / query / detect / affected).