@@ -0,0 +1,16 @@
+---
+'@objectstack/spec': minor
+'@objectstack/lint': minor
+'@objectstack/cli': minor
+---
+
+feat(spec): a `page:tabs` item label gains a translation key, `pages.<page>.components.<tabsId>.items.<value>.label`
+
+Clause-②: yes (widening)
+
+- **Before.** `pages.<page>.components` is keyed by component id, and a `page:tabs` item is not a component and carries no id, so a tab label had no key. `items` was refused as an unknown key, and `translatePage` never read `items[].label`. A localized page kept its tab strip in the authoring language.
+- **Now.** `pages.<page>.components.<tabsId>.items.<value>.label` is a declared key. It is addressed by the tabs component's own `id` and the item's `value` (the stable `?tab=` token), and `translatePage` overlays it onto that item's `label`, across the locale chain. The entry is closed: `title`, `name` and `text` are renames onto `label`. An item without a `value` has no key, because its renderer token is index-derived and an array index is never a bundle key. Author a `value` on the item, or keep localizing that label with an inline locale map.
+- **`walkAddressedPageComponents`.** A visitor's edit to a panel's own keys (its `label`) now stands when the visitor keeps the panel list's authored shape. Panel children are still descended from the authored document.
+- **`objectstack validate`.** `@objectstack/lint`'s translation-reference check accepts the key over a declared `page:tabs` item `value`. It refuses it as `translation-target-unknown` over an unknown value (with "Did you mean"), over a component of another type (a `page:accordion` is pointed at the inline locale map, since its panels have no stable key), and under a component id the page does not declare.
+- **`os i18n extract` / coverage.** The extractor writes a slot for every valued tab item, and the coverage check demands it. An inline locale map on the item label is counted as authored, as before.
+- **Unchanged.** Every existing `pages` key, and an inline locale map on a tab label that the bundle does not key.
@@ -80,6 +80,7 @@ export default defineStack({
 | Dataset dimension and measure labels | `datasets.<name>.dimensions.<dimension>.label` / `datasets.<name>.measures.<measure>.label` |
 | Page labels and `page:header` copy | `pages.<name>.label` / `description` / `title` / `subtitle` — on a `kind: 'slotted'` page the header under `slots.header` is the page's header |
 | Page component copy, by component id | `pages.<name>.components.<id>.title` / `description` / `label` / `placeholder` / `emptyText` — reached under `regions[].components[]` and `slots.<slot>`, through `properties.children` and a `page:tabs` / `page:accordion` panel's `items[].children` |
+| Page tab labels (`page:tabs` items) | `pages.<name>.components.<tabsId>.items.<value>.label` — keyed by the tabs component's `id` and the item's `value`; an item without a `value` has no key (localize it with an inline locale map), and `page:accordion` panels have none |
 | Screen-flow wizards (flow label, screen headings and body text, screen field copy) | `flows.<flow>.label` / `flows.<flow>.screens.<node_id>.title` / `.description` / `.fields.<field>.label` / `.placeholder` / `.inlineHelpText` — a screen field's help text is `inlineHelpText`, the key the field itself declares, not `help`; see the boundary note below |
 | Global actions, messages | `globalActions`, `messages` |
 | Settings UI shell copy (the source badge on a settings row) | `settingsCommon.sourceLabels.<layer>` — the per-namespace settings copy under `settings` is **platform-only**: an app bundle carrying it is refused by name, and the platform's own strings are translated in `@objectstack/service-settings`'s bundle |
 
@@ -19,4 +19,4 @@ hand-patch a number here** — fix the code or the verdict and regenerate.
 
 | Dir | Sites |
 |---|---|
-| `system/` | 376 |
+| `system/` | 377 |
@@ -103,6 +103,7 @@
  *   pages.<page>.label / .description
  *   pages.<page>.title / .subtitle   (from the page's `page:header` component)
  *   pages.<page>.components.<id>.<key>  (per-component copy, #6080)
+ *   pages.<page>.components.<tabsId>.items.<value>.label  (a `page:tabs` item label)
  *   flows.<flow>.label
  *   flows.<flow>.screens.<node_id>.title                       (#7646 / #11287)
  *   flows.<flow>.screens.<node_id>.description                 (#22507)
@@ -137,7 +138,9 @@ import {
   FLOW_SCREEN_COPY_KEYS,
   FLOW_SCREEN_FIELD_COPY_KEYS,
   FLOW_TERMINAL_MESSAGE_KEYS,
+  PAGE_TABS_COMPONENT_TYPE,
   globalFilterKey,
+  pageTabItemKey,
   walkAddressedPageComponents,
 } from '@objectstack/spec/system';
 import { FLOW_REGION_SLOTS_BY_TYPE, flowScreenFieldOptionKey } from '@objectstack/spec/automation';
@@ -1169,6 +1172,22 @@ function emitPageComponentCopy(out: ExpectedEntry[], page: any, name: string): v
         // records nothing (#14749).
         pushEntry(out, ['pages', name, 'components', id as string, key], value, 'page');
       }
+      // A `page:tabs` component's tab labels, keyed by each item's `value`
+      // under the tabs component's id — the key `translatePage` reads. An
+      // item without a `value` gets no slot: its renderer token is
+      // index-derived, and an array index is never a bundle key (#14749).
+      if (component.type === PAGE_TABS_COMPONENT_TYPE && Array.isArray(props.items)) {
+        for (const item of props.items as unknown[]) {
+          const value = pageTabItemKey(item);
+          if (value === undefined) continue;
+          pushEntry(
+            out,
+            ['pages', name, 'components', id as string, 'items', value, 'label'],
+            (item as Record<string, unknown>).label,
+            'page',
+          );
+        }
+      }
     }
     return component;
   });
 
@@ -0,0 +1,111 @@
+// Copyright (c) 2026 ObjectStack contributors. Apache-2.0 license.
+//
+// A `page:tabs` item's `label` had no translation key. `pages.<page>.components`
+// is keyed by component id, a tab item is not a component and carries no id,
+// and `translatePage` never read `items[].label`, so a localized page kept its
+// tab strip in the authoring language (measured on HotCRM's
+// `sales_home_page`: three English tabs under a translated header).
+//
+// The key is `pages.<page>.components.<tabsId>.items.<value>.label`: the tabs
+// component's own id, then the item's `value`, the stable `?tab=` token the
+// renderer already reads. Unlike a key with no reader, `translatePage` reads
+// this one, so the extractor offers the slot and coverage demands it. An item
+// without a `value` gets no key: its renderer token is index-derived, and an
+// array index is never a bundle key (the identity-first direction of the
+// #14749 ruling).
+
+import { describe, it, expect } from 'vitest';
+import { collectExpectedEntries, extractTranslations } from '../src/utils/i18n-extract';
+import { computeI18nCoverage } from '../src/utils/i18n-coverage';
+import { TranslationDataSchema, translatePage } from '@objectstack/spec/system';
+
+const homePage = () => ({
+  name: 'sales_home_page',
+  label: 'Sales Home',
+  regions: [{
+    name: 'main',
+    components: [{
+      type: 'page:tabs',
+      id: 'home_tabs',
+      properties: {
+        items: [
+          { label: 'My Leads', value: 'my_leads', children: [{ type: 'record:related_list', id: 'home_my_leads', properties: { title: 'Leads' } }] },
+          { label: { en: 'My Open Deals', 'zh-CN': '我的商机' }, value: 'my_deals', children: [] },
+          // No `value`: no key, whatever its label says.
+          { label: 'My Open Tasks', children: [] },
+        ] as any[],
+      },
+    }],
+  }],
+});
+
+/** Every `…components.<id>.items.*` path the walker emits, as dot-paths. */
+const itemEntries = (config: any) =>
+  collectExpectedEntries(config).filter((e) => e.path[0] === 'pages' && e.path[4] === 'items');
+
+describe('the extractor scaffolds a key for every valued tab item', () => {
+  it('emits `pages.<page>.components.<tabsId>.items.<value>.label`, and nothing for an item without a `value`', () => {
+    expect(itemEntries({ pages: [homePage()] }).map((e) => e.path.join('.'))).toEqual([
+      'pages.sales_home_page.components.home_tabs.items.my_leads.label',
+      'pages.sales_home_page.components.home_tabs.items.my_deals.label',
+    ]);
+  });
+
+  it('seeds a plain label, and records an inline locale map as authored with no seed', () => {
+    const [leads, deals] = itemEntries({ pages: [homePage()] });
+    expect(leads.sourceValue).toBe('My Leads');
+    expect(deals.sourceValue).toBeUndefined();
+    expect(deals.inlineLocales).toEqual({ en: 'My Open Deals', 'zh-CN': '我的商机' });
+  });
+
+  it('CONTROL: the panel children keep their component keys', () => {
+    const paths = collectExpectedEntries({ pages: [homePage()] }).map((e) => e.path.join('.'));
+    expect(paths).toContain('pages.sales_home_page.components.home_my_leads.title');
+  });
+
+  it('emits nothing for `items` on a component that is not `page:tabs`', () => {
+    const page = homePage();
+    (page.regions[0].components[0] as any).type = 'page:accordion';
+    expect(itemEntries({ pages: [page] })).toEqual([]);
+  });
+
+  it('emits nothing for a tabs component with no id', () => {
+    const page = homePage();
+    delete (page.regions[0].components[0] as any).id;
+    expect(itemEntries({ pages: [page] })).toEqual([]);
+  });
+});
+
+describe('the emitted key is the key the schema declares and the resolver reads', () => {
+  it('`TranslationDataSchema` accepts a bundle written at the extracted path, and `translatePage` applies it', () => {
+    const out = extractTranslations({ pages: [homePage()] }, { locales: ['zh-CN'] });
+    const zh = out.bundles['zh-CN'] as any;
+    expect(zh?.pages?.sales_home_page?.components?.home_tabs?.items?.my_leads).toBeDefined();
+
+    const data = { pages: { sales_home_page: { components: { home_tabs: { items: { my_leads: { label: '我的线索' } } } } } } };
+    expect(TranslationDataSchema.safeParse(data).success).toBe(true);
+    const translated: any = translatePage(homePage(), { 'zh-CN': data } as any, { locale: 'zh-CN' });
+    expect(translated.regions[0].components[0].properties.items[0].label).toBe('我的线索');
+  });
+});
+
+describe('coverage', () => {
+  const config = (items: Record<string, unknown>) => ({
+    pages: [homePage()],
+    i18n: { supportedLocales: ['en', 'zh-CN'] },
+    translations: [{ 'zh-CN': { pages: { sales_home_page: { components: { home_tabs: { items } } } } } }],
+  });
+
+  const itemIssues = (report: { issues: Array<{ key: string }> }) =>
+    report.issues.filter((i) => i.key.includes('.items.')).map((i) => i.key);
+
+  it('reports an untranslated tab label', () => {
+    expect(itemIssues(computeI18nCoverage(config({})))).toEqual([
+      'pages.sales_home_page.components.home_tabs.items.my_leads.label',
+    ]);
+  });
+
+  it('stays quiet once the pack keys it — and about the inline-map item that covers its locale', () => {
+    expect(itemIssues(computeI18nCoverage(config({ my_leads: { label: '我的线索' } })))).toEqual([]);
+  });
+});
@@ -2347,6 +2347,113 @@ describe('validateTranslationReferences — flow approval steps (`approvals.<nod
   });
 });
 
+describe('validateTranslationReferences — `page:tabs` item labels (`components.<tabsId>.items.<value>.label`)', () => {
+  /**
+   * HotCRM's measured shape: a home page whose `page:tabs` holds the three
+   * tabs, beside an accordion and a related list, so each verdict below is
+   * judged against the same metadata as the clean run and differs only in
+   * the bundle.
+   */
+  const homeStack = {
+    pages: [
+      {
+        name: 'sales_home_page',
+        label: 'Sales Home',
+        regions: [{
+          name: 'main',
+          components: [
+            {
+              type: 'page:tabs',
+              id: 'home_tabs',
+              properties: {
+                items: [
+                  { label: 'My Leads', value: 'my_leads', children: [{ type: 'record:related_list', id: 'home_my_leads', properties: { title: 'Leads' } }] },
+                  { label: 'My Open Deals', value: 'my_deals', children: [] },
+                  { label: 'My Open Tasks', children: [] },
+                ],
+              },
+            },
+            { type: 'page:accordion', id: 'faq', properties: { items: [{ label: 'Pricing', children: [] }] } },
+          ],
+        }],
+      },
+    ],
+  };
+  const bundle = (pages: unknown) => ({ ...homeStack, translations: [{ 'zh-CN': { pages } }] });
+  const tabs = (items: unknown, extra: Record<string, unknown> = {}) =>
+    bundle({ sales_home_page: { components: { home_tabs: { items }, ...extra } } });
+
+  it('reports nothing for the label of a valued tab item', () => {
+    expect(validateTranslationReferences(tabs({ my_leads: { label: '我的线索' }, my_deals: { label: '我的商机' } }))).toEqual([]);
+  });
+
+  it('controls: the component keys of the same page still resolve beside it, judged by nothing new', () => {
+    expect(
+      validateTranslationReferences(
+        tabs({ my_leads: { label: '我的线索' } }, { home_my_leads: { title: '线索' }, faq: { label: '常见问题' } }),
+      ),
+    ).toEqual([]);
+  });
+
+  it('refuses an item key over an UNKNOWN value, with the nearest tab value offered', () => {
+    const findings = validateTranslationReferences(tabs({ my_lead: { label: 'x' } }));
+    expect(findings).toHaveLength(1);
+    expect(findings[0].rule).toBe(TRANSLATION_TARGET_UNKNOWN);
+    expect(findings[0].severity).toBe('error');
+    expect(findings[0].path).toBe('translations[0]["zh-CN"].pages.sales_home_page.components.home_tabs.items.my_lead');
+    expect(findings[0].message).toBe(
+      'Translations are keyed to tab "my_lead", which `page:tabs` "home_tabs" on page "sales_home_page" gives ' +
+        'no item as its `value`, so the tab keeps its source-locale label. Did you mean "my_leads"?',
+    );
+    expect(findings[0].hint).toBe(
+      "Tab-item translations are keyed by the item's `value`; give the item a `value` if it has none.",
+    );
+  });
+
+  it('refuses an item key over an index token, which no key ever reaches', () => {
+    const findings = validateTranslationReferences(tabs({ 'tab-2': { label: 'x' } }));
+    expect(findings).toHaveLength(1);
+    expect(findings[0].path).toBe('translations[0]["zh-CN"].pages.sales_home_page.components.home_tabs.items.tab-2');
+  });
+
+  it('refuses `items` on a `page:accordion`, pointing at the inline locale map', () => {
+    const findings = validateTranslationReferences(bundle({ sales_home_page: { components: { faq: { items: { pricing: { label: 'x' } } } } } }));
+    expect(findings).toHaveLength(1);
+    expect(findings[0].path).toBe('translations[0]["zh-CN"].pages.sales_home_page.components.faq.items');
+    expect(findings[0].message).toBe(
+      'Translations carry tab items for "faq", which page "sales_home_page" declares as a `page:accordion`, ' +
+        'whose panels have no stable key, so nothing resolves them.',
+    );
+    expect(findings[0].hint).toBe('Localize an accordion panel label in place, as an inline locale map on `items[].label`.');
+  });
+
+  it('refuses `items` on a component of another type, by name', () => {
+    const findings = validateTranslationReferences(
+      bundle({ sales_home_page: { components: { home_my_leads: { items: { leads: { label: 'x' } } } } } }),
+    );
+    expect(findings).toHaveLength(1);
+    expect(findings[0].message).toBe(
+      'Translations carry tab items for "home_my_leads", which page "sales_home_page" declares as a ' +
+        '`record:related_list`, not a `page:tabs`, so nothing resolves them.',
+    );
+    expect(findings[0].hint).toBe('Tab-item translations go under the `id` of a `page:tabs` component.');
+  });
+
+  it('refuses `items` under a component id the page does not declare', () => {
+    const findings = validateTranslationReferences(bundle({ sales_home_page: { components: { home_tab: { items: { my_leads: { label: 'x' } } } } } }));
+    expect(findings).toHaveLength(1);
+    expect(findings[0].path).toBe('translations[0]["zh-CN"].pages.sales_home_page.components.home_tab.items');
+    expect(findings[0].message).toBe(
+      'Translations carry tab items for "home_tab", a component id page "sales_home_page" does not declare, ' +
+        'so nothing resolves them. Did you mean "home_tabs"?',
+    );
+  });
+
+  it('control: a page this stack does not declare is not judged by this check', () => {
+    expect(validateTranslationReferences(bundle({ other_page: { components: { t: { items: { a: { label: 'x' } } } } } }))).toEqual([]);
+  });
+});
+
 describe('validateTranslationReferences — flow toasts and screen-field options (#22507)', () => {
   /**
    * hotclm's measured shape, trimmed: a screen flow that authors a completion
@@ -4035,6 +4142,10 @@ describe('[#22161] one-line verdicts — translation-target-unknown, translation
     '`resultDialog.fields` does not declare',
     'declares no `fields` (it renders the whole response as JSON)',
     'Translations are keyed to picklist "',
+    'gives no item as its `value`',
+    'whose panels have no stable key',
+    'not a `page:tabs`, so nothing resolves them',
+    'a component id page "',
   ];
   const OPTION_ARMS = [
     'which declares no `options` at all (field type',
@@ -4186,6 +4297,9 @@ describe('[#22161] one-line fixes — translation-target-unknown', () => {
     'Move the `resultDialog` translations under the action',
     "Match the key to a declared field's literal `path`",
     "Match the key to a picklist's `name`",
+    "Tab-item translations are keyed by the item's `value`",
+    'Localize an accordion panel label in place',
+    'Tab-item translations go under the `id` of a `page:tabs` component',
   ];
 
   it('every `fix:` line the cases above fired is one line of at most 200 characters', () => {