@@ -0,0 +1,69 @@
+---
+"@objectstack/spec": minor
+---
+
+feat(spec)!: `object-grid` and `object-calendar` constrain the `sort` VALUE to the `SortItem` array — one sort orthography platform-wide reaches the last two unconstrained doors (#16553; objectui#8221, decision batch #77 option B)
+
+<!-- adr-0087: registered object-block-sort-item-array -->
+
+**BREAKING** accept-set change at two doors — `ComponentPropsMap['object-grid'].sort`
+and `ComponentPropsMap['object-calendar'].sort` — shipped as `minor` under the
+repo's launch-window convention for breaking changes; the migration prescription
+is registered under protocol major 18 as `object-block-sort-item-array`.
+
+One `sort` spelling platform-wide, the array (objectui#8221, decision batch #77,
+2026-09-07, maintainer verbatim 「其他同意」, option B; the consumer half is
+objectui PR #8758, which drops the legacy string arm from
+`convertSortToQueryParams`). Item 4 of that ruling is this release's subject:
+「`ComponentPropsMap` for `object-calendar` and `object-grid` constrains the
+`sort` value to the array shape (today it accepts anything), so the spec, the
+registrations and the helper agree; that is a pull-back to the declared contract,
+ordinary tier」.
+
+Until this release both doors declared `z.unknown()` — no orthography at all.
+Measured on `@objectstack/spec` 17.2.0 and re-measured on this tree before the
+change: an array, the legacy string clause and a bare NUMBER all returned
+`success: true`, while `bogusProp` was refused by name on the same call. So key
+checking was live and only the VALUE was unheld, and an author following
+objectui's own registrations (`plugin-grid/src/index.tsx:222` has published
+`type: 'array'` all along) and an author following the legacy string each got a
+silent success receipt for a different shape — while objectui's html tier
+answered `type-mismatch` on the second one. Both doors now declare
+`z.array(SortItemSchema)`, the array `ElementDataSourceSchema.sort`,
+`ListPageSchema.sort` and `element:record_picker`'s flat `sort` shorthand already
+carry: one shared schema, not a third copy.
+
+Sequenced measurement-first, as this family has to be. At the objectui pin this
+repo builds against (`53ded82b`) the string is still lowered —
+`ObjectGrid.tsx:1844-1851` carries an explicit `typeof === 'string'` arm onto
+`$orderby` beside the array arm, and `ObjectCalendar.tsx:431` hands `schema.sort`
+to `convertSortToQueryParams`, whose string arm is still present at
+`sort-query.ts:66-70`. This declaration therefore lands ahead of the pinned
+consumer, which the ruling permits explicitly — either order, since the
+registrations already declare the array — and the next pin bump carries the
+retirement in.
+
+**Migration** (`object-block-sort-item-array`): `sort: 'created_at desc'` becomes
+`sort: [{ field: 'created_at', order: 'desc' }]`; a bare field name
+`sort: 'created_at'` meant ascending and becomes
+`sort: [{ field: 'created_at', order: 'asc' }]` — `order` is required in
+`SortItemSchema`, so it is written out rather than omitted; a comma-separated
+clause becomes one array entry per key, in the same order. The string is refused
+at `sort` (`invalid_type`, expected array), as is a bare number; a misspelled or
+absent direction is refused at `sort.0.order`. Metadata AT REST is not rewritten
+and this disposition adds no D2 conversion — a stored page carrying a string
+`sort` keeps loading and still renders at the pinned `.objectui-sha`; what
+changes is that RE-SAVING it is refused at the `sort` door.
+
+**Not moved by this release.** `record:related_list.sort` keeps its declared
+string arm: that string is the `'field'` / `'-field'` dialect read by
+`RelatedList.normalizeSortSpec`, it never reaches `convertSortToQueryParams`, and
+retiring it was not ruled — objectui#8221's own implementing round narrowed it,
+established the dialect and reverted the narrowing byte-identically.
+`object-grid.defaultSort` is a different key, already retired by #11805. Zero
+authored `sort` values on either block exist in this repo (the two showcase pages
+that author `object-grid` declare none), so nothing in-tree was converted.
+
+Type aliases are unchanged: `SortItemSchema`'s input equals its infer, so neither
+block's parsed state moves for this key, and both already take the
+`…PropsParsed` route for `filter` (ADR-0122).
@@ -312,7 +312,7 @@ Sort field and direction pair
 | **calendar** | `any` | optional | Calendar field config: `{ startDateField, endDateField?, titleField?, colorField?, allDayField? }` |
 | **defaultView** | `Enum<'month' \| 'week' \| 'day'>` | optional | Initial view mode |
 | **filter** | `{ field: string; operator: Enum<'equals' \| 'not_equals' \| 'contains' \| 'not_contains' \| 'icontains' \| …>; value?: string \| number \| boolean \| null \| (string \| number)[] }[]` | optional | Base query filter — the ViewFilterRule array form `[{ field, operator, value }, ...]`, the one filter orthography every `filter` door in this map shares. The MongoDB-style record form is refused — see migration `element-data-source-and-object-block-filter-rule-array` |
-| **sort** | `any` | optional | Sort for the fetched events |
+| **sort** | `{ field: string; order: Enum<'asc' \| 'desc'> }[]` | optional | Row order for the fetched events — the SortItem array form `[{ field, order }, ...]`, the one sort orthography every declared `sort` door on this platform shares; lowered to the wire `$orderby`. The legacy string clause (`name desc`) is refused — see migration `object-block-sort-item-array` |
 | **data** | `any[]` | optional | Pre-fetched records — skips the internal fetch |
 | **staticData** | `any[]` | optional | Static inline records |
 | **locale** | `string` | optional | Locale override for the calendar chrome |
@@ -328,6 +328,15 @@ View filter rule
 | **operator** | `Enum<'equals' \| 'not_equals' \| 'contains' \| 'not_contains' \| 'icontains' \| …>` | ✅ | Filter operator |
 | **value** | `string \| number \| boolean \| null \| (string \| number)[]` | optional | Filter value. The accepted SHAPE depends on the operator: `in` / `not_in` take an array (any length, including []), `between` takes exactly [min, max], every other operator takes a scalar. The unary operators (is_empty / is_not_empty / is_null / is_not_null) take their direction from the operator name and ignore this key. |
 
+### Nested Shape: `ObjectCalendarProps.sort[number]`
+
+Sort field and direction pair
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **field** | `string` | ✅ | Field name to sort by |
+| **order** | `Enum<'asc' \| 'desc'>` | ✅ | Sort direction |
+
 
 ---
 
@@ -393,7 +402,7 @@ View filter rule
 | **fields** | `any[]` | optional | Field list fallback used when `columns` is absent |
 | **filter** | `{ field: string; operator: Enum<'equals' \| 'not_equals' \| 'contains' \| 'not_contains' \| 'icontains' \| …>; value?: string \| number \| boolean \| null \| (string \| number)[] }[]` | optional | Base query filter — the ViewFilterRule array form `[{ field, operator, value }, ...]`, the one filter orthography every `filter` door in this map shares; lowered to the wire `$filter`. THE key, singular — not the plural misspelling. The MongoDB-style record form is refused — see migration `element-data-source-and-object-block-filter-rule-array` |
 | **defaultFilters** | `any` | optional | Legacy base-filter fallback, read only when `filter` is absent. Prefer `filter` |
-| **sort** | `any` | optional | Initial sort (array of `{ field, order }`) |
+| **sort** | `{ field: string; order: Enum<'asc' \| 'desc'> }[]` | optional | Initial row order — the SortItem array form `[{ field, order }, ...]`, the one sort orthography every declared `sort` door on this platform shares; lowered to the wire `$orderby`. The legacy string clause (`name desc`) is refused — see migration `object-block-sort-item-array` |
 | **defaultSort** | `never` | optional | [REMOVED] `object-grid` property `defaultSort` was removed in @objectstack/spec 17 (ADR-0049) — it was the legacy second spelling of `sort`: a single `{ field, order }` pair read only when `sort` was absent, so one intent had two spellings and a grid authoring both silently ignored this one. Rename the key to `sort` and wrap the value in an array (`defaultSort: { field, order }` becomes `sort: [{ field, order }]`); the pair itself is unchanged. Run `os migrate meta --from 17` to list the mechanical edits for existing sources; apply them by hand. |
 | **pagination** | `any` | optional | Pagination config (`{ pageSize, pageSizeOptions, … }`); its presence enables paging |
 | **pageSize** | `number` | optional | Flat page-size shorthand; `pagination.pageSize` wins when both are set |
@@ -434,6 +443,15 @@ View filter rule
 | **operator** | `Enum<'equals' \| 'not_equals' \| 'contains' \| 'not_contains' \| 'icontains' \| …>` | ✅ | Filter operator |
 | **value** | `string \| number \| boolean \| null \| (string \| number)[]` | optional | Filter value. The accepted SHAPE depends on the operator: `in` / `not_in` take an array (any length, including []), `between` takes exactly [min, max], every other operator takes a scalar. The unary operators (is_empty / is_not_empty / is_null / is_not_null) take their direction from the operator name and ignore this key. |
 
+### Nested Shape: `ObjectGridProps.sort[number]`
+
+Sort field and direction pair
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **field** | `string` | ✅ | Field name to sort by |
+| **order** | `Enum<'asc' \| 'desc'>` | ✅ | Sort direction |
+
 ### Nested Shape: `ObjectGridProps.data[provider='object']`
 
 | Property | Type | Required | Description |
 
@@ -0,0 +1,74 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+import type { SemanticMigration } from '../../types.js';
+
+export const entry: SemanticMigration = {
+  id: 'object-block-sort-item-array',
+  surface:
+    'The `sort` prop of `object-grid` and `object-calendar` in `ComponentPropsMap` '
+    + '(the FORM: the accept-anything `z.unknown()` at both block doors, vs the '
+    + '`SortItem` array `[{ field, order }, ...]`)',
+  replacement:
+    '`z.array(SortItemSchema)` at both doors — the array `ElementDataSourceSchema.sort`, '
+    + '`ListPageSchema.sort` and `element:record_picker`\'s flat `sort` shorthand already '
+    + 'carry. The legacy OData-ish clause `sort: \'created_at desc\'` becomes '
+    + '`sort: [{ field: \'created_at\', order: \'desc\' }]`; a bare field name '
+    + '`sort: \'created_at\'` meant ascending and becomes '
+    + '`sort: [{ field: \'created_at\', order: \'asc\' }]` — `order` is required in '
+    + '`SortItemSchema`, so it is written out rather than omitted. A comma-separated '
+    + 'clause becomes one array entry per key, in the same order. `record:related_list` '
+    + 'is NOT moved by this entry: its string is the `\'field\'` / `\'-field\'` dialect '
+    + 'read by `RelatedList.normalizeSortSpec`, which never reaches '
+    + '`convertSortToQueryParams`, and retiring it was not ruled. '
+    + '`object-grid.defaultSort` is a different key, retired separately by the '
+    + '`ui__ObjectGridProps__defaultSort` entry.',
+  reason:
+    'One `sort` spelling platform-wide, the array (objectui#8221, decision batch #77, '
+    + '2026-09-07, maintainer verbatim 「其他同意」, option B; the consumer half is '
+    + 'objectui PR #8758, which drops the string arm from `convertSortToQueryParams`). '
+    + 'Item 4 of that ruling is this entry\'s subject: 「`ComponentPropsMap` for '
+    + '`object-calendar` and `object-grid` constrains the `sort` value to the array shape '
+    + '(today it accepts anything), so the spec, the registrations and the helper agree; '
+    + 'that is a pull-back to the declared contract, ordinary tier」. The `z.unknown()` at '
+    + 'both doors was a read-point record (#7751), the same vintage as the `filter` doors '
+    + 'the `element-data-source-and-object-block-filter-rule-array` entry moved, and not an '
+    + 'exception to the ruling: measured on `@objectstack/spec` 17.2.0 an array, a string '
+    + 'and a bare NUMBER all returned `success: true` while `bogusProp` was refused by name '
+    + 'on the same call, so key checking was live and only the VALUE was unheld. Meanwhile '
+    + 'objectui\'s own html tier has published `type: \'array\'` for the grid all along '
+    + '(`plugin-grid/src/index.tsx:222`) and answered `type-mismatch` on the string — a '
+    + 'spelling `@object-ui/core` implemented, the docs taught and the validator refused, '
+    + 'which is what made this a ruling rather than a mechanical widening. '
+    + 'Sequenced measurement-first: at the objectui pin this repo builds against '
+    + '(`53ded82b`) the string is still lowered — `ObjectGrid.tsx:1844-1851` carries an '
+    + 'explicit `typeof === \'string\'` arm onto `$orderby`, and `ObjectCalendar.tsx:431` '
+    + 'hands `schema.sort` to `convertSortToQueryParams`, whose string arm is still present '
+    + 'at `sort-query.ts:66-70`. So this declaration lands AHEAD of the pinned consumer, '
+    + 'which the ruling permits explicitly (either order; the registrations already declare '
+    + 'the array). The in-repo sweep found ZERO authored `sort` on either block — the two '
+    + 'showcase pages that author `object-grid` (`command-center.page.ts`, '
+    + '`my-work.page.ts`) declare none — with the same grep shape finding 40+ string `sort` '
+    + 'values at OTHER doors (view definitions, ObjectQL `query.sort`) as the control that '
+    + 'the sweep fires; so this entry carries the prescription for authors outside the repo. '
+    + '⚠️ Metadata AT REST is deliberately NOT rewritten and this disposition adds no D2 '
+    + 'conversion: `os migrate meta --stored` replays D2 conversions only, and the read path '
+    + 'does not re-validate stored rows (`applyConversionsToStoredItem` replays the chain '
+    + 'without validating, by its own contract), so a stored page carrying a string `sort` '
+    + 'keeps loading and is still rendered by objectui at the pinned `.objectui-sha`. What '
+    + 'changes is that RE-SAVING it is refused at the `sort` door, on its next save and not '
+    + 'before. ADR-0049, ADR-0087.',
+  acceptanceCriteria:
+    '`ComponentPropsMap[\'object-grid\' | \'object-calendar\'].safeParse({ objectName, '
+    + 'sort: [{ field: \'created_at\', order: \'desc\' }] })` succeeds and the parsed `sort` '
+    + 'is that same array, equal value-for-value to '
+    + '`ElementDataSourceSchema.parse({ object, sort: <that array> }).sort`. The legacy '
+    + 'string clause is refused at the `sort` path on both doors (`invalid_type`, expected '
+    + 'array), and so is a bare number; a misspelled or ABSENT direction is refused at '
+    + '`sort.0.order` (`invalid_value` — `order` is a required enum, so both take one '
+    + 'verdict) and a missing field at `sort.0.field` (`invalid_type`). An undeclared key '
+    + 'is still refused BY NAME on the same call (`unrecognized_keys` naming it), the '
+    + 'control that makes those refusals verdicts rather than a schema reporting nothing. '
+    + 'No `sort` door in `ComponentPropsMap` accepts a string except `record:related_list`, '
+    + 'which is the one deliberate exception. At runtime each block orders exactly as the '
+    + 'array orders — the same `$orderby` the string lowered to.',
+};