---
name: shape-accounting
description: Use when a project's shape accounting needs attention — the pattern_coverage line from enter_project shows unclassified shapes or is missing on a forge-served project, the operator asks about coverage/accounting/canon, or you just proved a code-to-canon relationship (an audit enumerated call sites, a consolidation repointed consumers, a verify pass confirmed a helper's users). Triggers on "coverage", "accounted", "unclassified", "classify shapes", "what uses this", or finishing any consolidation.
---

# Shape accounting — every shape classified against canon

The snippet library records **canon** (small); the shape ledger accounts for
**every extracted definition** in a project's bound repos (total). Each ledger
row carries a status:

- `canonical` — IS a snippet's reference (the coverage sync stamps these
  mechanically; you rarely set it).
- `instance` of snippet N — conforms to recorded canon. Canon in another
  project counts (a family-level button shape fully accounts for a local use).
- `variant` of snippet N — a deliberate, named departure. **Reason required**
  — the why IS the record.
- `exempt` — judged genuinely one-off. **Reason required.** A recorded
  judgment, not silence — it stops the next pass re-litigating it.
- `unclassified` — nobody has judged it yet. **This is the todo list.**

## The loop

1. **Seed / refresh** — the ledger fills from coverage computation. Entering a
   project triggers a background seed automatically; when you need it current
   *now* (before a classification batch, or when the line is missing on a
   forge-served project), call `refresh_pattern_coverage(project_id)` — it
   returns the fresh accounting line. Takes seconds; it moves repo archives.
2. **Read the todo** — `list_shapes(project_id, status="unclassified")`,
   optionally scoped by `path` to the directories the coverage line names as
   largest. `snippet_id=N` reads a consumer map.
3. **Judge in batches** — `classify_shapes(project_id, [{path, symbol,
   status, snippet_id?, reason?}])`. All-or-nothing: a bad item applies
   nothing. Rows, never prose — a consumer list in a note or verification
   detail cannot be sorted, queried, or diffed.

## Rows that arrive on their own

Two feeds keep the ledger current between your batches, so most shapes never
need a hand judgment:

- **The sync** stamps a snippet's own reference location `canonical`
  (`classified_by: mechanical`).
- **The write path** stamps instances as you work: when you `get_snippet` a
  canon and then Write/Edit code that references or resembles it, the
  definitions being written land as `instance` rows (`classified_by: hook`,
  the evidence in `reason`), and the prior-art hook tells you what landed
  ("Shape accounting: recorded at … → instance of #N"). Offered-but-unopened
  snippets stamp nothing — so *pull the canon you are instantiating*; that
  pull is what turns your reuse into accounting. A hook row is evidence, not
  judgment: it never overrides a classification you made, and a
  `classify_shapes` call overrides it.

## The derive-first rule

N same-shaped occurrences matching **no** recorded canon is never N loose
classifications — it is a consolidation candidate: derive one reference from
the dominant form, `create_snippet` it, migrate the outliers, then classify
the rest as instances. Canon is determined from the code; consistency comes
from the derivation, not from asking permission.

## What this buys

Divergence becomes mechanical: when button B appears where button A is canon,
the ledger says *unintended divergence* or *justified variant with its
reason* — nobody re-derives the history. `get_snippet` shows each snippet's
`instances` and `variants`, so "what uses this?" is answered from rows before
any contract change lands on its consumers.