@@ -0,0 +1,18 @@
+---
+"@objectstack/metadata-protocol": patch
+---
+
+fix(metadata-protocol): a page saved without `type` is stored and served with the `type` default that `PageSchema` declares (#20101)
+
+Clause-②: no
+
+`PageSchema` declares `type: PageTypeSchema.default('record')`, so a page authored without `type` is a record page. `saveMetaItem` parsed the body with that default and then stored the body as authored, and the `/meta` reads serve stored rows without parsing them. A record page authored without `type` was therefore served with no `type` at all. A renderer that picks an object's record page by `type === 'record'` never picked it.
+
+The declared default now reaches the served body at two points:
+
+- **Save.** When the schema gate accepts a page that omits `type`, the stored body gets the declared default, on draft and publish saves alike. A page with an explicit `type` is stored unchanged. Because the stored row and the served document are the same bytes, a client that re-saves the page it just read writes nothing: the checksum and the version stay the same.
+- **Read.** A page row stored before this change is served with the declared default. This covers the list and single `/meta/page` reads, the cached read, draft reads and the `?preview=draft` list, the layered read, boot hydration into the registry, and the `searchAll` page sweep, whose hit now carries `pageType: 'record'` for such a page. The row itself is not rewritten, and `os migrate meta --stored` reports it canonical.
+
+The value is read from the registered `page` schema, never written out a second time. Only an absent `type` is filled: an explicit value, of any page type, is served as stored.
+
+What moves for a client: the served body of such a page gains `type: 'record'`, a key `PageSchema` already declares. The set of accepted bodies is unchanged. The ETag of the cached single read for such a page changes once, because the served content changed. Saving that page again after reading it stores `type` once. From then on a read-then-save round-trip writes nothing.
@@ -513,3 +513,81 @@ describe('draft preview diagnostics do not judge the injected `_draft` badge (#7
         });
     });
 });
+
+/**
+ * [#20101] The WRITE half of the served page-type default, pinned against the
+ * #4326 invariant this file exists for.
+ *
+ * `PageSchema` declares `type: PageTypeSchema.default('record')`. The save gate
+ * parsed with that default and then stored the authored body verbatim, so a
+ * page authored without `type` was stored without it, served without it, and
+ * never picked as the object's record page. The read seam now fills the
+ * declared default for such rows (`protocol.stored-conversions.test.ts` pins
+ * that half). The write half is what keeps THIS file's invariant: if the read
+ * seam were the only fix, the served document would carry a key its row did
+ * not, and the first GET → PUT of every such page would write a one-key change
+ * and a history row that nobody authored.
+ *
+ * The expected value is read from the registered schema, the same source the
+ * implementation reads, never spelled as a second literal.
+ */
+describe('[#20101] a page saved without `type` stores and serves the declared default', () => {
+    const DECLARED = (getMetadataTypeSchema('page') as any).shape.type.parse(undefined);
+    const typelessPage = (name: string) => ({ name, label: 'Invoice', object: 'crm_invoice' });
+    const rowOf = (rows: Map<string, Row>, name: string, state = 'active') =>
+        Array.from(rows.values()).find((r) => r.name === name && r.state === state)!;
+
+    it('precondition: the declared default is `record`', () => {
+        expect(DECLARED).toBe('record');
+    });
+
+    it('publish and draft saves store it, and the list and the single read serve it', async () => {
+        const { engine, rows } = makeStubEngine();
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        await protocol.saveMetaItem({ type: 'page', name: 'invoice_record', item: typelessPage('invoice_record') });
+        await protocol.saveMetaItem({
+            type: 'page', name: 'invoice_record_next', item: typelessPage('invoice_record_next'), mode: 'draft',
+        });
+
+        expect(JSON.parse(rowOf(rows, 'invoice_record').metadata)).toEqual({ ...typelessPage('invoice_record'), type: DECLARED });
+        expect(JSON.parse(rowOf(rows, 'invoice_record_next', 'draft').metadata).type).toBe(DECLARED);
+
+        const listed = (await protocol.getMetaItems({ type: 'page' })).items as any[];
+        expect(listed.find((i) => i.name === 'invoice_record')?.type).toBe(DECLARED);
+        const single: any = await protocol.getMetaItem({ type: 'page', name: 'invoice_record' });
+        expect(single.item.type).toBe(DECLARED);
+        const draft: any = await protocol.getMetaItem({ type: 'page', name: 'invoice_record_next', state: 'draft' });
+        expect(draft.item.type).toBe(DECLARED);
+    });
+
+    it('an explicit non-record `type` is stored and served unchanged', async () => {
+        const { engine, rows } = makeStubEngine();
+        const protocol = new ObjectStackProtocolImplementation(engine);
+        const appPage = { name: 'launchpad', label: 'Launchpad', type: 'app' };
+
+        await protocol.saveMetaItem({ type: 'page', name: 'launchpad', item: appPage });
+
+        expect(JSON.parse(rowOf(rows, 'launchpad').metadata)).toEqual(appPage);
+        const single: any = await protocol.getMetaItem({ type: 'page', name: 'launchpad' });
+        expect(single.item.type).toBe('app');
+    });
+
+    it('GET → PUT of the served page is byte-identical: same stored body, same checksum, same version', async () => {
+        const { engine, rows } = makeStubEngine();
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        await protocol.saveMetaItem({ type: 'page', name: 'invoice_record', item: typelessPage('invoice_record') });
+        const before = { ...rowOf(rows, 'invoice_record') };
+
+        const served: any = (await protocol.getMetaItem({ type: 'page', name: 'invoice_record' })).item;
+        expect(served.type).toBe(DECLARED); // precondition — the served body carries the default
+        await protocol.saveMetaItem({ type: 'page', name: 'invoice_record', item: served });
+
+        const after = rowOf(rows, 'invoice_record');
+        expect(after.metadata).toBe(before.metadata);
+        expect(after.checksum).toBe(before.checksum);
+        // The repository's identical-body short-circuit: no write happened at all.
+        expect(after.version).toBe(before.version);
+    });
+});
@@ -33,6 +33,7 @@
 
 import { describe, it, expect, vi } from 'vitest';
 import { SearchAllPageHitSchema, SearchAllResponseSchema } from '@objectstack/spec/api';
+import { PageSchema } from '@objectstack/spec/ui';
 import { ObjectStackProtocolImplementation } from './protocol.js';
 
 const text = (name: string) => ({ name, type: 'text' });
@@ -133,6 +134,22 @@ describe('[#13216] searchAll sweeps published pages into `pages`', () => {
         expect(body.error?.issues ?? []).toEqual([]);
     });
 
+    it("[#20101] a stored page with no `type` is hit with `pageType` = PageSchema's declared default", async () => {
+        // The sweep reads the SERVED set, so it inherits the read seam's fill:
+        // a page authored without `type` is a record page, and the hit says so
+        // instead of omitting `pageType`. The value is read from the schema.
+        const declared = (PageSchema as unknown as { shape: { type: { parse(v: unknown): unknown } } })
+            .shape.type.parse(undefined);
+        const { p } = makeProtocol({
+            storedRows: [storedPage({ body: { name: 'invoice_record', label: 'Invoice record', object: 'invoice' } })],
+        });
+
+        const result = await p.searchAll({ q: 'invoice' });
+
+        expect(declared).toBe('record');
+        expect(result.pages).toEqual([{ kind: 'page', name: 'invoice_record', title: 'Invoice record', pageType: declared }]);
+    });
+
     it('a DRAFT row of the same shape does not surface — the sweep reads the published state only', async () => {
         const body = {
             name: 'pending_dashboard',
 
@@ -24,6 +24,7 @@ import { describe, expect, it } from 'vitest';
 // of this package's (file, verb) pairs sat in the gate's DEBT ledger until
 // #5619 sank the two predicates into a package both sides already depend on.
 import { assertEngineDeleteDispatch, assertEngineUpdateDispatch, assertEngineFindOnePredicate } from '@objectstack/metadata-core';
+import { PageSchema } from '@objectstack/spec/ui';
 import { ObjectStackProtocolImplementation } from './protocol.js';
 
 interface Row {
@@ -255,3 +256,86 @@ describe('loadMetaFromDb — boot hydration converts, diagnoses, never drops (#3
         expect(registered.some((r) => r.kind === 'object' && r.body?.name === 'corrupt_thing')).toBe(true);
     });
 });
+
+// ── [#20101] a declared DEFAULT is part of the canonical served shape ─────────
+//
+// `PageSchema` declares `type: PageTypeSchema.default('record')`: a page
+// authored without `type` IS a record page. Every row a save wrote before
+// #20101 is stored without the key (the save path persisted the authored body
+// verbatim), and a consumer that selects an object's record page by
+// `type === 'record'` never picked one. The rehydration seam now serves the
+// declared default — and ONLY serves it: the row at rest is not rewritten, and
+// the stored-migration pass finds nothing to do (no stored-row rewrite is part
+// of this fix).
+//
+// The expected value is READ from the schema, like the implementation reads
+// it, so a pin here cannot quietly become a second spelling of the default.
+const DECLARED_PAGE_TYPE = (PageSchema as unknown as { shape: { type: { parse(v: unknown): unknown } } })
+    .shape.type.parse(undefined);
+
+const typelessPageBody = { name: 'invoice_record', label: 'Invoice', object: 'crm_invoice' };
+const typelessPageRow = { type: 'page', name: 'invoice_record', metadata: typelessPageBody };
+const appPageRow = { type: 'page', name: 'launchpad', metadata: { name: 'launchpad', label: 'Launchpad', type: 'app' } };
+const typelessDraftRow = {
+    type: 'page', name: 'invoice_record_next', state: 'draft',
+    metadata: { name: 'invoice_record_next', label: 'Invoice (next)', object: 'crm_invoice' },
+};
+
+describe('[#20101] a stored page row without `type` is served with PageSchema\'s declared default', () => {
+    it('precondition: the declared default the pins below read is `record`', () => {
+        expect(DECLARED_PAGE_TYPE).toBe('record');
+    });
+
+    it('the list and the single read serve the declared default; an explicit non-record type is untouched', async () => {
+        const { engine } = makeStubEngine([typelessPageRow, appPageRow]);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        const listed = (await protocol.getMetaItems({ type: 'page' })).items as any[];
+        expect(listed.find((i) => i.name === 'invoice_record')?.type).toBe(DECLARED_PAGE_TYPE);
+        expect(listed.find((i) => i.name === 'launchpad')?.type).toBe('app');
+
+        const single: any = await protocol.getMetaItem({ type: 'page', name: 'invoice_record' });
+        expect(single.item.type).toBe(DECLARED_PAGE_TYPE);
+        expect(single.item._diagnostics?.valid).toBe(true);
+        const control: any = await protocol.getMetaItem({ type: 'page', name: 'launchpad' });
+        expect(control.item.type).toBe('app');
+    });
+
+    it('the draft reads serve it too — the pinned `?state=draft` read and the list preview', async () => {
+        const { engine } = makeStubEngine([typelessDraftRow]);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+
+        const draft: any = await protocol.getMetaItem({ type: 'page', name: 'invoice_record_next', state: 'draft' });
+        expect(draft.item.type).toBe(DECLARED_PAGE_TYPE);
+        const preview = (await protocol.getMetaItems({ type: 'page', previewDrafts: true })).items as any[];
+        expect(preview.find((i) => i.name === 'invoice_record_next')?.type).toBe(DECLARED_PAGE_TYPE);
+    });
+
+    it('boot hydration registers the defaulted body', async () => {
+        const { engine, registered } = makeStubEngine([typelessPageRow]);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+        const res = await protocol.loadMetaFromDb();
+        expect(res).toEqual({ loaded: 1, errors: 0, invalid: 0, storeUnavailable: false });
+        const page = registered.find((r) => r.kind === 'item' && r.type === 'page')!;
+        expect(page.body.type).toBe(DECLARED_PAGE_TYPE);
+    });
+
+    it('the row at rest is NOT rewritten: its bytes survive the reads, and the migration pass reports it canonical', async () => {
+        const { engine, rows } = makeStubEngine([typelessPageRow, typelessDraftRow]);
+        const protocol = new ObjectStackProtocolImplementation(engine);
+        const before = rows.map((r) => r.metadata);
+
+        await protocol.getMetaItems({ type: 'page', previewDrafts: true });
+        await protocol.getMetaItem({ type: 'page', name: 'invoice_record' });
+        expect(rows.map((r) => r.metadata)).toEqual(before);
+        expect(JSON.parse(rows[0]!.metadata)).toEqual(typelessPageBody);
+
+        // The fill is a READ-side fact, not an ADR-0087 conversion: it emits no
+        // notice, so `os migrate meta --stored` has no row to rewrite.
+        const preview = await protocol.migrateStoredMetadata({ types: ['page'] });
+        expect(preview).toMatchObject({ scanned: 2, canonical: 2, pending: 0, failed: 0, rows: [] });
+        const applied = await protocol.migrateStoredMetadata({ types: ['page'], apply: true });
+        expect(applied).toMatchObject({ scanned: 2, canonical: 2, rewritten: 0, failed: 0, rows: [] });
+        expect(rows.map((r) => r.metadata)).toEqual(before);
+    });
+});
@@ -693,7 +693,9 @@ const HAND_CRAFTED_SCHEMAS: Record<string, Record<string, unknown>> = {
  *     (e.g. `isPinned`, `isDefault`, `sortOrder`) survive the round-trip.
  *     The one exception is filter `operator` spellings, which are grafted back
  *     from `parsed.data` so a save stops minting new legacy-alias rows — see
- *     {@link graftNormalizedOperators}.
+ *     {@link graftNormalizedOperators}. [#20101] A page that omits `type` is
+ *     stored with the default `PageSchema` declares for it — see
+ *     {@link withDeclaredPageTypeDefault}.
  *   - Types without a registered schema (the wiring-layer types
  *     `function`/`service`/`router`, and any plugin types that have not
  *     yet called `registerMetadataTypeSchema()`) fall through unvalidated.
@@ -1324,6 +1326,54 @@ export function graftFoldedFormSections(authored: unknown, parsed: unknown): unk
     return rest.sections !== undefined ? rest : { ...rest, sections: groups };
 }
 
+/**
+ * [#20101] Give a page body that omits `type` the default `PageSchema`
+ * declares for it, and change nothing else.
+ *
+ * `PageSchema` declares `type: PageTypeSchema.default('record')`, so a page
+ * authored without `type` IS a record page. The save gate parses with that
+ * default and then persists the authored body verbatim (ADR-0005
+ * §"Validation", {@link resolveOverlaySchema}), and every read serves a stored
+ * row without parsing it. A record page written the natural way, with the
+ * defaulted key left out, therefore reached every reader of the served body
+ * with no `type` at all. A consumer that picks an object's record page by
+ * `type === 'record'` never picked it. The parse applied the declared default
+ * and nothing the server sends carried it.
+ *
+ * One function, applied at both seams:
+ *  - the WRITE (`saveMetaItem`, once the schema gate has accepted the body),
+ *    so a new row stores the key and a GET → PUT round-trip of the served
+ *    document stays byte-identical (#4326's invariant). A fix on the read
+ *    side alone breaks that round-trip: the first re-save of every such page
+ *    would write a one-key change and a history row that nobody authored;
+ *  - the READ ({@link ObjectStackProtocolImplementation.convertStoredItem},
+ *    the rehydration seam every stored row passes through), so a row stored
+ *    before this fix is served with the default and never rewritten. The row
+ *    at rest keeps its bytes and there is no migration.
+ *
+ * The value is READ from the registered `page` schema, the one the save gate
+ * validates with, and is never spelled here. A literal would be a second,
+ * silent spelling of the default: the consumer-side `?? 'record'` this
+ * replaces, moved up one layer.
+ *
+ * ⛔ The scope is `type` on `page` and nothing wider. It is not a general
+ * "fill every declared default" pass. Other stored types declare top-level
+ * defaults in the same position, and each of those is its own decision.
+ *
+ * Only an ABSENT key is filled (zod applies a default to `undefined`, not to
+ * `null`), and an explicit value is left as it is. Returns the input itself
+ * when nothing is filled.
+ */
+function withDeclaredPageTypeDefault(type: string, item: unknown): unknown {
+    if ((PLURAL_TO_SINGULAR[type] ?? type) !== 'page') return item;
+    if (!item || typeof item !== 'object' || Array.isArray(item)) return item;
+    if ((item as Record<string, unknown>).type !== undefined) return item;
+    const pageSchema = getMetadataTypeSchema('page') as { shape?: Record<string, z.ZodTypeAny> } | undefined;
+    const declared = pageSchema?.shape?.type?.safeParse(undefined);
+    if (!declared?.success || declared.data === undefined) return item;
+    return { ...(item as Record<string, unknown>), type: declared.data };
+}
+
 /**
  * #2555 — compute the identity fields (`viewKind`, `object`, `label`) a view
  * overlay is missing but the registry entry it shadows carries. The overlay's
@@ -4678,10 +4728,17 @@ export class ObjectStackProtocolImplementation implements
      * executor registry (`reservedNodeTypes`), which this layer does not
      * have. Flows canonicalize at `AutomationEngine.registerFlow` — the
      * execution seam — with the same full-chain policy.
+     *
+     * [#20101] …and a page that omits `type` is read with the default
+     * `PageSchema` declares ({@link withDeclaredPageTypeDefault}). That fill is
+     * applied HERE and not in {@link convertStoredItemDetailed}: it is not an
+     * ADR-0087 conversion and emits no notice, so the stored-migration pass
+     * (the Detailed caller) has nothing to rewrite, and the row at rest keeps
+     * its bytes.
      */
     private convertStoredItem(type: string, data: unknown): unknown {
         const singular = PLURAL_TO_SINGULAR[type] ?? type;
-        return this.convertStoredItemDetailed(type, data, (n) => {
+        const converted = this.convertStoredItemDetailed(type, data, (n) => {
             const name = (data as { name?: unknown } | null | undefined)?.name;
             const key = `${n.conversionId}|${singular}|${String(name ?? '')}`;
             if (this.storedConversionWarned.has(key)) return;
@@ -4692,6 +4749,7 @@ export class ObjectStackProtocolImplementation implements
                 `"os migrate meta --stored --apply") to persist the canonical shape.`,
             );
         }).item;
+        return withDeclaredPageTypeDefault(singular, converted);
     }
 
     /**
@@ -16120,6 +16178,13 @@ export class ObjectStackProtocolImplementation implements
                     graftFoldedFormSections(request.item, parsed.data),
                     parsed.data,
                 );
+                // [#20101] …and a page's declared `type` default, the one
+                // default that a reader of the served body selects on. It is
+                // stored so that the served document and the stored row are
+                // the same bytes, and a GET → PUT round-trip is a no-op. The
+                // read seam fills the same default for rows stored before this
+                // fix. See {@link withDeclaredPageTypeDefault}.
+                request.item = withDeclaredPageTypeDefault(request.type, request.item);
             }
         }