--- name: reusing-code description: Use when you're about to build ANY shape — a component, control, route handler, service class, helper, test scaffold — search recorded snippets FIRST and start from the recorded shape instead of re-solving it. And the FIRST time a shape is built, record it as a snippet so every later instance starts from it. Triggers on "write a util/helper", "I need a function that…", "let me add a component/button/field/route", or having just built the first instance of anything. --- # Reusing code — the pattern library Snippets are the project's **pattern library**, not a dedup net. Each records a named shape — with its language, signature, canonical location (repo · path · symbol), a one-line *"when to reach for it,"* and the code — so every later instance STARTS from the recorded shape: buttons start from the button shape, fields from the field shape, and "special" is a deliberate, named exception rather than drift. A mature project's snippet corpus reads as a map of every shape in it, from the humblest control to the most complex subsystem pattern. Snippets are ordinary embedded notes, so a recorded one also surfaces on its own through recall/auto-inject; this skill is the active reflex around that. ## Before you build any shape — search first - About to build a component, control, route handler, service class, utility, hook, formatter, adapter, or test scaffold? **Search snippets before writing it.** `list_snippets(q="…")` (or a plain `search`) — a matching one may already exist, in this project or another. `list_snippets` searches every project by default; that's deliberate, since a helper you need here was quite possibly written somewhere else. Narrow with `project_id` only when you specifically want this project's own. - **About to edit an existing file? Ask by place, not just by meaning.** `list_snippets(repo="…", path="…")` answers "what canonical helpers are already recorded here?" — `path` matches the exact file or anything beneath it, so `path="frontend/src"` covers the whole tree. Cheaper and sharper than a wording search when you already know where the code is going, and it catches the helper you'd otherwise duplicate a few lines down. `symbol="…"` narrows further, and all three must match the same recorded location. Combine with `q` to ask both at once. - If a snippet fits, pull it in full with `get_snippet(id)` and reuse it — its `location` points at the reference implementation. Adapt, don't re-derive. The pull also does the accounting: the code you then write that references or resembles it is stamped an `instance` of that canon in the shape ledger (classified_by=hook) — reuse from memory leaves no row. - If auto-inject already surfaced a snippet title that looks relevant, that's your cue to `get_snippet` it rather than start from scratch. - **Prior art offered beside a write is not noise — read it.** When Scribe notes that a snippet is already recorded for the file you just wrote or edited, open it before you go any further. Either it's the helper you were about to duplicate — reuse it and drop yours — or it isn't, and the record needs the new location adding. Both are cheaper now than after the duplicate settles in. - **A `Shape ledger at …` line is the ledger speaking, not the record.** It names a duplicate family ("identical body in N other files, no canon"), a repeated name ("defined in N other files") or a canon elsewhere for a name you just wrote — for edits made through Bash (sed, heredocs, scripts) as much as through Write/Edit. Derive the family or reuse the canon *now*; a family that is convention rather than copies is dismissed with `classify_shapes(..., status="exempt", reason_code="convention-plumbing")`, never ignored. - **A `[records this file]` hint is a duty, not a menu.** When the hint says a snippet records the very file you're editing, the record's freshness is now YOUR edit's responsibility: if the edit changes the recorded shape, `update_snippet(id, code=…)` with the new form as part of the same task; if it doesn't, `verify_snippet(id, status="ok", commit_sha=…)` costs one call and re-stamps the record as checked. Scribe never reads the repo — this moment, in the session that has the context, is the only place the record gets kept true. ## The first time a shape is built — record it - Just built the FIRST instance of anything with a shape — a component, a field, a route, a service pattern, a scaffold? Record it with `create_snippet` while it's fresh. Do **not** stop to judge whether it will recur: the builder of the first instance can never know, and a missed record is invisible until it resurfaces as an uninformed duplicate. Over-recording is safe — dead weight shows up in the usage counters and can be pruned; under-recording has no signal at all. The record is cheap — these fields: - **name** — what it's called, e.g. `useDebouncedRef`. - **code** — the implementation. - **when_to_use** — one sharp line on when to reach for it. This becomes part of the title, so it's what a later recall menu shows — make it earn the pull. - **language**, **signature**, and **location** (`repo` / `path` / `symbol`) so the recorded copy points back at the canonical source. - **project_id** / **system_ids** to associate it with the work it belongs to. - Record the *reference* implementation, not every call site — one good entry per reusable thing. If it already exists, `update_snippet` it instead of recording a second copy (the create gate will flag a near-duplicate anyway). ## A shared snippet is a suggestion, not a standard Scribe is multi-user, so a search can return snippets other people own. Those come back marked `shared: true` with an `owner`. - Read one as **that person's suggestion**, not as the way things are done here. Judge the code on its merits before reaching for it. - Say whose it is when you propose it — "there's a snippet from *alex* that does this" — so the operator can weigh the source, not just the code. - Don't treat it as the house pattern, and don't build on it at scale, without the operator agreeing to adopt it. - Snippets shared directly with the operator only appear when you search for them, never in a plain `list_snippets` — so anything ambient is genuinely theirs. ## Keep the record honest A recorded snippet is offered as prior art on every matching turn, so a wrong one costs more than a missing one. - Details gone stale — a renamed symbol, a moved file, a signature that's changed? Fix it with `update_snippet`. Passing an **empty string** clears a field, so a wrong signature or location can be removed, not just written over. - Recorded something that turned out not to be reusable, or that no longer exists? Retire it with `delete_snippet` — it goes to the trash and can be restored. Don't leave it competing for attention. ## Found the same thing in several places — unify it When you notice the same reusable thing recorded (or written) as several one-offs, don't leave the duplicates competing in recall — **merge them**. `merge_snippets(canonical_id, [other_ids])` keeps one canonical record, folds in the others' call sites as locations, and retires the duplicates to the trash. The result is a single entry that shows every place the thing is used — which is exactly the signal that it was worth consolidating. This is the cure the create gate only hints at when it blocks a near-duplicate. ## Consumer maps are rows, never prose Every enumerated relationship between code and canon belongs in the shape ledger, not in a sentence. When you establish that call sites route through a canonical helper — during an audit, a verify pass, or a consolidation — record each consuming definition with `classify_shapes(project_id, [{path, symbol, status: "instance", snippet_id}])`. A deliberate departure is a `"variant"` (reason required — the why IS the record); a judged one-off is `"exempt"` (reason required). Prose in a verification detail cannot be sorted, queried, or diffed; rows are what make "what uses this?" answerable forever. `list_shapes(project_id, status="unclassified")` is the standing todo — and N same-shaped occurrences matching no canon means derive one first (consolidate, `create_snippet`, then classify the rest against it), never N loose classifications. ## Why this pays off A one-off written a second time is the cost this avoids — and at project scale, the cost is an application whose buttons, fields, and services each exist in four diverging shapes. Recording every shape once — with a location and a crisp "when to use" — means every later session starts from the pattern library instead of re-deriving it. Search before building; record every shape at first build.