@@ -0,0 +1,18 @@
+---
+'@objectstack/spec': minor
+---
+
+spec(ui): a navigation group that says nothing opens — `GroupNavItem.expanded` defaults to `true`
+
+Clause-②: yes
+Metadata-protocol: semantic
+
+<!-- adr-0087: registered ui-nav-group-expanded-default-open -->
+
+**BREAKING** — a declared default moves, shipped as `minor` under the launch-window convention. The author who relied on the documented default (`false`, "a group starts collapsed unless the author opens it") for a group meant to stay out of the daily user's sight — an advanced, developer or diagnostics section — now sees it open on first view wherever the app is parsed (`defineStack`, `defineApp`, a compiled `objectstack.json`). The remedy is one key on that group: `expanded: false`.
+
+- **Before.** `GroupNavItemSchema.expanded` defaulted to `false`. An app parsed through `defineStack` or `defineApp` (and so every compiled `objectstack.json`) carried a written `expanded: false` on every group whose author said nothing. The console honours a written `false` as an explicit close, so those groups started collapsed. An app registered without a parse (the platform's Setup and Account apps) arrived without the key, and the console opened its groups. The protocol and the console disagreed about what a silent group means.
+- **Now.** The default is `true`. A group that says nothing parses to `expanded: true` and opens on first view, the same answer the console already gave a group without the key. A group holding the current route still opens whatever it declares.
+- **To keep a group closed**, write `expanded: false`. Setup's Advanced group and Account's Developer group already do, and they still collapse. Every authored `expanded` parses exactly as before, and a non-boolean is still refused.
+- **Compiled artifacts.** A document that serialised an earlier parse (an `os compile` artifact) carries the old written `false`, and its groups stay closed. Recompile it, or delete the key.
+- **Upgrade path.** The ADR-0087 D3 semantic entry `ui-nav-group-expanded-default-open` carries the change to `os migrate meta` and the upgrade guide. The default change is declared in the build's default-change ledger. No key is added or removed.
@@ -286,7 +286,7 @@ Documentation entry on the app menu (ADR-0046). Targets a `book` and/or a `doc`
 | **requiresObject** | `string` | optional | Hide/disable this entry unless the named object is registered in the runtime |
 | **requiresService** | `string` | optional | Hide/disable this entry unless the named kernel service is registered |
 | **type** | `'group'` | ✅ |  |
-| **expanded** | `boolean` | optional (default: `false`) | Default expansion state in sidebar |
+| **expanded** | `boolean` | optional (default: `true`) | Whether the group starts open in the sidebar. Omitted, it opens; write `false` to keep it closed until the user opens it. A group holding the current route opens whatever it declares. |
 | **children** | `({ id: string; label?: string \| Record<string, string>; icon?: string; order?: number; … } \| { type: 'separator'; id?: string; order?: number } \| … +8 more)[]` | ✅ | Child navigation items |
 
 ### Nested Shape: `App.areas[number]`
@@ -475,7 +475,7 @@ Documentation entry on the app menu (ADR-0046). Targets a `book` and/or a `doc`
 | **requiresObject** | `string` | optional | Hide/disable this entry unless the named object is registered in the runtime |
 | **requiresService** | `string` | optional | Hide/disable this entry unless the named kernel service is registered |
 | **type** | `'group'` | ✅ |  |
-| **expanded** | `boolean` | optional (default: `false`) | Default expansion state in sidebar |
+| **expanded** | `boolean` | optional (default: `true`) | Whether the group starts open in the sidebar. Omitted, it opens; write `false` to keep it closed until the user opens it. A group holding the current route opens whatever it declares. |
 
 ### Nested Shape: `GroupNavItem.dataSource`
 
@@ -680,7 +680,7 @@ Documentation entry on the app menu (ADR-0046). Targets a `book` and/or a `doc`
 | **requiresObject** | `string` | optional | Hide/disable this entry unless the named object is registered in the runtime |
 | **requiresService** | `string` | optional | Hide/disable this entry unless the named kernel service is registered |
 | **type** | `'group'` | ✅ |  |
-| **expanded** | `boolean` | optional (default: `false`) | Default expansion state in sidebar |
+| **expanded** | `boolean` | optional (default: `true`) | Whether the group starts open in the sidebar. Omitted, it opens; write `false` to keep it closed until the user opens it. A group holding the current route opens whatever it declares. |
 | **children** | `({ id: string; label?: string \| Record<string, string>; icon?: string; order?: number; … } \| { type: 'separator'; id?: string; order?: number } \| … +8 more)[]` | ✅ | Child navigation items |
 
 
@@ -879,7 +879,7 @@ Documentation entry on the app menu (ADR-0046). Targets a `book` and/or a `doc`
 | **requiresObject** | `string` | optional | Hide/disable this entry unless the named object is registered in the runtime |
 | **requiresService** | `string` | optional | Hide/disable this entry unless the named kernel service is registered |
 | **type** | `'group'` | ✅ |  |
-| **expanded** | `boolean` | optional (default: `false`) | Default expansion state in sidebar |
+| **expanded** | `boolean` | optional (default: `true`) | Whether the group starts open in the sidebar. Omitted, it opens; write `false` to keep it closed until the user opens it. A group holding the current route opens whatever it declares. |
 | **children** | `({ id: string; label?: string \| Record<string, string>; icon?: string; order?: number; … } \| { type: 'separator'; id?: string; order?: number } \| … +8 more)[]` | ✅ | Child navigation items |
 
 
@@ -1200,7 +1200,7 @@ Documentation entry on the app menu (ADR-0046). Targets a `book` and/or a `doc`
 | **requiresObject** | `string` | optional | Hide/disable this entry unless the named object is registered in the runtime |
 | **requiresService** | `string` | optional | Hide/disable this entry unless the named kernel service is registered |
 | **type** | `'group'` | ✅ |  |
-| **expanded** | `boolean` | optional (default: `false`) | Default expansion state in sidebar |
+| **expanded** | `boolean` | optional (default: `true`) | Whether the group starts open in the sidebar. Omitted, it opens; write `false` to keep it closed until the user opens it. A group holding the current route opens whatever it declares. |
 | **children** | `[NavigationItem](#navigationitem)[]` | ✅ | Child navigation items |
 
 ### Nested Shape: `NavigationItem[type='group'].dataSource`
 
@@ -143,7 +143,9 @@ Links to an external URL:
 
 ### Group Navigation
 
-Groups items into collapsible sections with children:
+Groups items into collapsible sections with children. A group opens on first view unless it
+declares `expanded: false`, which keeps it closed until the user opens it; a group that holds the
+current route opens whatever it declares.
 
 ```typescript
 {
 
@@ -47,7 +47,7 @@
     "ui/GalleryConfig:cardSize = \"medium\"",
     "ui/GalleryConfig:coverFit = \"cover\"",
     "ui/GlobalFilter:scope = \"dashboard\"",
-    "ui/GroupNavItem:expanded = false",
+    "ui/GroupNavItem:expanded = true",
     "ui/GroupingField:collapsed = false",
     "ui/GroupingField:order = \"asc\"",
     "ui/HttpRequest:method = \"GET\"",
 
@@ -667,5 +667,19 @@ export const DEFAULT_CHANGES_BY_MAJOR: Readonly<Record<number, readonly Declared
         + 'sections would re-create exactly the reading the ruling removed, and every declared value '
         + 'keeps its meaning.',
     },
+    {
+      key: 'ui/GroupNavItem:expanded',
+      from: 'false',
+      to: 'true',
+      reason:
+        'A RULED default change (maintainer ruling record 6431302164, letter A): a navigation group '
+        + 'that says nothing opens. The console already opened a group that arrived without the key; '
+        + 'what moves is the PARSED value. An app parsed through `defineStack` / `defineApp` used to '
+        + 'carry a written `expanded: false` on every silent group, which the console honoured as an '
+        + 'explicit close, and now carries `true`, so those groups open on first view. To keep a group '
+        + 'closed until the user opens it, write `expanded: false`. The `semantic` entry '
+        + '`ui-nav-group-expanded-default-open` carries the change to `os migrate meta` and the '
+        + 'upgrade guide.',
+    },
   ],
 };
@@ -0,0 +1,53 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+import type { SemanticMigration } from '../../types.js';
+
+// The declared default of `GroupNavItemSchema.expanded` moved from `false` to
+// `true` (maintainer ruling 6431302164 on objectstack#26370, letter A). The
+// product behaviour was ruled twice before the protocol followed it:
+// objectui#13336 (letter A — a group that does not say `expanded: false`
+// opens, and the "8 or more children collapse" rule is gone) and
+// hotcrm#2194 (letter B). The console's NavigationRenderer already opens an
+// undeclared group, so the protocol now states what the console does. A
+// default move reaches every silent document with no parse error and nothing
+// in the author's diff, so the upgrade path carries it as a TODO: only the
+// deployment can say which group that never declared the key was relying on
+// starting closed. The same class as `list-view-edit-inline-default-on` and
+// `view-pagination-page-size-default-50`: no key is removed, so there is no
+// tombstone and no RETIRED_KEYS_BY_MAJOR row, and no D2 conversion exists.
+// The citations live here, not in the printed guidance, which carries no
+// tracker number.
+export const entry: SemanticMigration = {
+  id: 'ui-nav-group-expanded-default-open',
+  // No backticks in `surface` — build-upgrade-guide.ts renders it inside a code
+  // span AND a table cell.
+  surface: 'ui.GroupNavItem.expanded — an OMITTED expanded on an app navigation group',
+  replacement: 'nothing, to take the platform default: the group opens on first view. To keep a '
+    + 'group closed until the user opens it — an advanced or developer section the daily user '
+    + 'should not see first — write it: `expanded: false`',
+  reason:
+    'A RULED behaviour change on a default, so there is nothing to rewrite and nothing to '
+    + 'refuse: the maintainer ruled that a navigation group which says nothing opens, and the '
+    + 'declared default of `GroupNavItemSchema.expanded` moved from `false` to `true`. The console '
+    + 'already behaved this way for a group that arrived without the key — its length does not '
+    + 'decide, and a group holding the current route opens whatever it declares — so the protocol '
+    + 'now states the behaviour instead of contradicting it. What changes is the parsed and served '
+    + 'shape: a group parsed through the app schema (`defineStack`, `defineApp`) used to carry a '
+    + 'written `expanded: false` that the console honoured as an explicit close, and now carries '
+    + '`expanded: true`. A group registered without a parse still arrives without the key and still '
+    + 'opens. Not losslessly convertible because the question is intent, not text: a mechanical pass '
+    + 'that wrote `expanded: false` into every silent group would preserve the old posture and defeat '
+    + 'the ruling, and one that wrote `true` would add nothing the default does not already do. Only '
+    + 'the deployment knows which silent groups were meant to start closed. The accept set is '
+    + 'unchanged — a boolean — and every authored `expanded` parses exactly as before. A document that '
+    + 'serialised an earlier parse (an `os compile` artifact) carries a written `false` and its groups '
+    + 'stay closed; recompile it, or delete the key.',
+  acceptanceCriteria:
+    'A group navigation item that omits `expanded` parses to `expanded: true`, and an app whose '
+    + 'navigation holds such a group parses with `navigation[].expanded` true; an authored '
+    + '`expanded: false` still parses to `false` and an authored `true` to `true`; a non-boolean is '
+    + 'still refused. In the console, a group that declares nothing is open on first view, and a '
+    + 'group that declares `expanded: false` is closed unless it holds the current route. Every '
+    + 'group that must start closed declares `expanded: false` and shows its children only after the '
+    + 'user opens it.',
+};
@@ -79,7 +79,7 @@ export const objectWithoutChildren: NavigationItem = {
 
 /**
  * `expanded` is REQUIRED on the output side: `GroupNavItemSchema` declares it
- * `.default(false)`, so a parsed group always carries it. If this suppression
+ * `.default(true)`, so a parsed group always carries it. If this suppression
  * goes unused the default was dropped from the schema — and every consumer
  * reading `item.expanded` off a parsed app silently started getting
  * `undefined`.
 
@@ -208,10 +208,52 @@ describe('GroupNavItemSchema', () => {
       type: 'group' as const,
     };
 
+    const result = GroupNavItemSchema.parse(navItem);
+    // ADR-0087 D3 `ui-nav-group-expanded-default-open`: a group that says nothing opens.
+    expect(result.expanded).toBe(true);
+  });
+
+  it('keeps an authored expanded: false closed', () => {
+    const navItem = {
+      id: 'nav_advanced',
+      label: 'Advanced',
+      type: 'group' as const,
+      expanded: false,
+    };
+
     const result = GroupNavItemSchema.parse(navItem);
     expect(result.expanded).toBe(false);
   });
 
+  it('refuses a non-boolean expanded', () => {
+    const result = GroupNavItemSchema.safeParse({
+      id: 'nav_sales',
+      label: 'Sales',
+      type: 'group' as const,
+      expanded: 'yes',
+    });
+    expect(result.success).toBe(false);
+    expect(result.error?.issues.map((i) => i.path.join('.'))).toContain('expanded');
+  });
+
+  it('opens a silent group nested in a parsed app', () => {
+    const app = AppSchema.parse({
+      name: 'nav_probe',
+      label: 'Nav Probe',
+      navigation: [
+        {
+          id: 'grp_outer',
+          type: 'group',
+          label: 'Outer',
+          children: [{ id: 'grp_inner', type: 'group', label: 'Inner', expanded: false, children: [] }],
+        },
+      ],
+    });
+    const outer = app.navigation?.[0] as { expanded?: boolean; children?: Array<{ expanded?: boolean }> };
+    expect(outer.expanded).toBe(true);
+    expect(outer.children?.[0]?.expanded).toBe(false);
+  });
+
   it('should accept group with expanded state', () => {
     const navItem = {
       id: 'nav_admin',
 
@@ -808,7 +808,12 @@ export const DocNavItemSchema = lazySchema(() => strictObject(navItemSurface('do
 export const GroupNavItemSchema = lazySchema(() => strictObject(navItemSurface('group'), {
   ...BaseNavItemSchema.shape,
   type: z.literal('group'),
-  expanded: z.boolean().default(false).describe('Default expansion state in sidebar'),
+  // ADR-0087 D3 `ui-nav-group-expanded-default-open`: a group that says
+  // nothing opens; `expanded: false` is how an author keeps one closed.
+  expanded: z.boolean().default(true).describe(
+    'Whether the group starts open in the sidebar. Omitted, it opens; write `false` to keep it closed '
+    + 'until the user opens it. A group holding the current route opens whatever it declares.',
+  ),
   // children property is added in the recursive definition below
 }));
Original file line number	Diff line number	Diff line change
`@@ -143,7 +143,9 @@ Links to an external URL:`
`143`	`143`
`144`	`144`	`### Group Navigation`
`145`	`145`
`146`		`-Groups items into collapsible sections with children:`
	`146`	`+Groups items into collapsible sections with children. A group opens on first view unless it`
	`147`	+declares `expanded: false`, which keeps it closed until the user opens it; a group that holds the
	`148`	`+current route opens whatever it declares.`
`147`	`149`
`148`	`150`	```typescript
`149`	`151`	`{`