@@ -0,0 +1,20 @@
+---
+'@object-ui/i18n': patch
+'@object-ui/app-shell': patch
+---
+
+perf(i18n, app-shell)!: the marketplace pages' strings leave the eager language packs for a lazy `marketplace` namespace
+
+Clause-②: yes (narrowing)
+Metadata-protocol: none
+
+<!-- adr-0087: not-required (runtime-interface-only ui/packages/i18n/src/locales/en.ts#TranslationKeys) the key type of the console's own translation catalogue: no Zod schema, no spec declaration and no stored metadata reads it, so the compiler is the channel that reaches every caller -->
+
+The console loads one language pack eagerly, `en`, and its chunk had grown to 59,951 of the 60,000 gzipped bytes its ceiling allows. About 3 KB of it was the `marketplace.*` group, read only by the two marketplace pages, which are lazy routes. That group now lives in `@object-ui/i18n/namespaces/marketplace`: ten catalogues, one per built-in language, each its own chunk, fetched when a marketplace page opens. The console's `en` chunk reads 57,010 bytes.
+
+- **The pages wait for their text.** App-shell's marketplace catalogue and package pages render their load skeleton until the catalogue for the console's language (and `en`, the fallback) has arrived, and again after a language switch, so a visitor never sees English in a translated console or a raw key. A catalogue that cannot be fetched shows the console's own "Something went wrong" with Try again, which fetches it again.
+- **`useMarketplaceNamespace()`** (from the new subpath) is the hook behind that frame: it answers `loading`, `ready` or `failed` with a `retry()`, merges the catalogues into the page's i18next instance without overwriting a host's own `resources`, and uses a catalogue already made resident by `registerBuiltInLocales()` without fetching it.
+- **What stays in the packs.** Studio's packages page, outside the marketplace route, draws marketplace installs with the same components: their keys (`marketplace.installedAdditiveNote`, `marketplace.notLoaded.*`, `marketplace.action.uninstall`, `marketplace.action.uninstalling`, `marketplace.action.details`, `marketplace.uninstall.confirm`, `marketplace.uninstall.confirmNotLoaded`, `marketplace.uninstall.successInList`, `marketplace.uninstall.successNotLoaded`, `marketplace.install.dependencyMissing.*` and `marketplace.install.protocolCheckSkipped.*`) stay in every pack.
+- **Every string still in every language.** No text changed. `@object-ui/i18n/locales` (the all-ten door) hands out each language complete, its pack merged with its namespace catalogue, so key parity and `registerBuiltInLocales()` still cover the moved keys.
+
+**BREAKING** (`@object-ui/i18n`, TypeScript and the pack modules): the package entry's `en`, the exported `TranslationKeys` (`typeof en`) and the pack modules `@object-ui/i18n/locales/<code>` no longer hold the moved `marketplace.*` keys. A `t()` call that names one still compiles, since its key is a `string`. A component outside app-shell's marketplace pages that reads one of those keys calls `useMarketplaceNamespace()` and renders it once the answer is `ready`; code that reads the catalogue objects directly reads them from `@object-ui/i18n/locales`, whose ten languages are complete.
@@ -1235,6 +1235,46 @@ export default defineConfig({
             { name: 'i18n-ns-studio-en', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]studio[\\/]en\.ts$/, priority: 84 },
             { name: 'i18n-ns-studio-zh', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]studio[\\/]zh\.ts$/, priority: 84 },
             //
+            // The `marketplace` namespace (objectstack#30588): the pack group the
+            // two marketplace pages read, moved out of the ten packs so the
+            // eager `i18n-locale-en` chunk stops carrying it. All ten catalogues
+            // are `import()`ed by `packages/i18n/src/namespaces/marketplace/index.ts`
+            // when a marketplace page mounts, none is resident, so one group per
+            // catalogue for the rule above. The loader module gets a group too:
+            // without one it would fall to `i18n-runtime` below and be eager,
+            // while its only reader is the marketplace pages' frame.
+            //
+            // ⛔ Both the loader's group and the frame's (`marketplace-namespace-gate`,
+            // app-shell's `MarketplaceNamespaceGate.tsx`, the one module that
+            // imports the loader) take `includeDependenciesRecursively: false`,
+            // and the frame needs its group at all, for two measured reasons
+            // (console build of objectstack#30588, eager closure read from
+            // `eager-closure.json`):
+            //   - with rolldown's default the loader's group followed its imports
+            //     and took `locales/registry.ts` out of `i18n-runtime` and the
+            //     dynamic-import preload helper out of `framework`; both are
+            //     eager, so the group became an eager 2,374 B gz chunk;
+            //   - without a group of its own the frame, shared by the two lazy
+            //     marketplace pages, landed in the chunk those pages share with
+            //     the eager Studio packages page (`MarketplaceRowActions.tsx` and
+            //     the refusal readers), which is EAGER by that co-tenancy, and
+            //     pulled the loader into the eager closure with it (+1,281 B gz).
+            // With both, the loader, the frame and the ten catalogues are lazy,
+            // the shared chunk is the one the base build emits, and the only
+            // change to the eager closure is `i18n-locale-en`'s.
+            { name: 'i18n-ns-marketplace', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]index\.ts$/, priority: 84, includeDependenciesRecursively: false },
+            { name: 'i18n-ns-marketplace-en', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]en\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-zh', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]zh\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-ja', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]ja\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-ko', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]ko\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-de', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]de\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-fr', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]fr\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-es', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]es\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-pt', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]pt\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-ru', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]ru\.ts$/, priority: 84 },
+            { name: 'i18n-ns-marketplace-ar', test: /[\\/]packages[\\/]i18n[\\/]src[\\/]namespaces[\\/]marketplace[\\/]ar\.ts$/, priority: 84 },
+            { name: 'marketplace-namespace-gate', test: /[\\/]packages[\\/]app-shell[\\/]src[\\/]console[\\/]marketplace[\\/](?:MarketplaceNamespaceGate\.tsx|marketplaceFrameHolding\.ts)$/, priority: 84, includeDependenciesRecursively: false },
+            //
             // ⛔ `i18n-runtime` takes `includeDependenciesRecursively: false`
             // for the reason `data-adapter` below does (objectui#9345, read out
             // there in full): it outranks `framework` (83 over 80), and since
 
@@ -0,0 +1,75 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * The marketplace pages' frame for their own strings (objectstack#30588).
+ *
+ * The `marketplace.*` keys these pages read are not in the console's eager
+ * language pack: they are `@object-ui/i18n`'s lazy `marketplace` namespace,
+ * fetched when a page here mounts (the namespace module's header says why).
+ * This frame renders the page only once the namespace answers `ready` for the
+ * instance's language, so a visitor sees the copy-free load skeleton the pages
+ * already use (`MarketplaceResolving`), never an English sentence in a
+ * translated console nor a raw key. A language switch while a page is open
+ * shows the skeleton again until that language's catalogue has arrived.
+ *
+ * That swap unmounts the page body while the visitor stays on the page, so an
+ * unmount cleanup that means "the visitor left" (`SampleDataLeaveBanner`)
+ * asks `useMarketplaceFrameHolding()` (`marketplaceFrameHolding.ts`) first.
+ *
+ * A catalogue that cannot be fetched is said once, in the console's own error
+ * words (resident pack keys, which need no fetch), with a Try again that asks
+ * for it again — never a skeleton that waits forever, and never a retry loop.
+ *
+ * ⛔ Every component in this directory that reads a `marketplace.*` key renders
+ * under this frame (the two pages wrap their bodies in it), or is one of the
+ * files Studio's packages page also renders — `MarketplaceRowActions.tsx`,
+ * `dependencyMissing.ts`, `protocolCheckSkipped.ts` — whose keys stayed in
+ * the packs for that reason and need no frame.
+ * `__tests__/marketplaceNamespaceBoundary.test.ts` holds both halves.
+ */
+
+import { useCallback, useLayoutEffect, useRef, type ReactNode } from 'react';
+import { RotateCcw } from 'lucide-react';
+import { Button, Empty, EmptyTitle } from '@object-ui/components';
+import { useObjectTranslation } from '@object-ui/i18n';
+import { useMarketplaceNamespace } from '@object-ui/i18n/namespaces/marketplace';
+import { MarketplaceResolving } from './MarketplaceResolving.js';
+import { MarketplaceFrameHolding } from './marketplaceFrameHolding.js';
+
+export function MarketplaceNamespaceGate({ children }: { children: ReactNode }) {
+  const namespace = useMarketplaceNamespace();
+  const holding = useRef(false);
+  useLayoutEffect(() => {
+    holding.current = namespace.status !== 'ready';
+  });
+  const isHolding = useCallback(() => holding.current, []);
+  return (
+    <MarketplaceFrameHolding.Provider value={isHolding}>
+      {namespace.status === 'ready' ? (
+        children
+      ) : namespace.status === 'failed' ? (
+        <MarketplaceNamespaceFailed onRetry={namespace.retry} />
+      ) : (
+        <MarketplaceResolving />
+      )}
+    </MarketplaceFrameHolding.Provider>
+  );
+}
+
+function MarketplaceNamespaceFailed({ onRetry }: { onRetry: () => void }) {
+  const { t } = useObjectTranslation();
+  return (
+    <div
+      className="mx-auto flex w-full max-w-6xl items-center justify-center p-8"
+      data-testid="marketplace-namespace-failed"
+    >
+      <Empty>
+        <EmptyTitle>{t('console.errors.somethingWentWrong')}</EmptyTitle>
+        <Button variant="outline" size="sm" onClick={onRetry} className="mt-4 gap-2">
+          <RotateCcw className="h-4 w-4" />
+          {t('console.errors.tryAgain')}
+        </Button>
+      </Empty>
+    </div>
+  );
+}
@@ -112,6 +112,7 @@ import { SuggestedBindingsPanel, type SuggestedBindingsStrings } from '../../com
 import { ConnectorCredentialsStep } from './ConnectorCredentialsStep.js';
 import type { SuggestedBinding } from '../../services/suggestedBindingsApi.js';
 import { errorCodeIs } from '@object-ui/types';
+import { MarketplaceNamespaceGate } from './MarketplaceNamespaceGate.js';
 
 /**
  * Whether a cloud install lands in the environment this console renders, read
@@ -163,7 +164,19 @@ function versionEntryId(version: string): string {
   return `marketplace-version-${version}`;
 }
 
+/**
+ * The page under the frame that fetches its strings first — the
+ * `marketplace` namespace (`MarketplaceNamespaceGate.tsx` says why).
+ */
 export function MarketplacePackagePage() {
+  return (
+    <MarketplaceNamespaceGate>
+      <MarketplacePackagePageBody />
+    </MarketplaceNamespaceGate>
+  );
+}
+
+function MarketplacePackagePageBody() {
   const navigate = useNavigate();
   const { packageId, appName } = useParams<{ packageId?: string; appName?: string }>();
   const { isAdmin, isResolved } = useWorkspaceAdminStatus();
 
@@ -56,6 +56,7 @@ import { useProtocolCheckSkippedText } from './protocolCheckSkipped.js';
 import { ProtocolCheckSkippedNote } from './ProtocolCheckSkippedNote.js';
 import { ConnectorCredentialsStep } from './ConnectorCredentialsStep.js';
 import { packagesHref } from '../../views/metadata-admin/packageSource.js';
+import { MarketplaceNamespaceGate } from './MarketplaceNamespaceGate.js';
 
 /**
  * The card grid's track (objectui#12616): a card is never narrower than 240px,
@@ -306,7 +307,19 @@ type OrgDeployState =
   | { phase: 'served'; manifestId: string; version: string | undefined; name: string; app: ServedApp | null }
   | { phase: 'timeout'; manifestId: string; version: string | undefined; name: string };
 
+/**
+ * The page under the frame that fetches its strings first — the
+ * `marketplace` namespace (`MarketplaceNamespaceGate.tsx` says why).
+ */
 export function MarketplacePage() {
+  return (
+    <MarketplaceNamespaceGate>
+      <MarketplacePageBody />
+    </MarketplaceNamespaceGate>
+  );
+}
+
+function MarketplacePageBody() {
   const navigate = useNavigate();
   const { appName } = useParams();
   const { isAdmin, isResolved } = useWorkspaceAdminStatus();
 
@@ -16,19 +16,24 @@
  * It is raised only for a package this session recorded loading sample data
  * into (`sampleDataNotice.ts`), and only while a notification provider is
  * mounted: the page renders this component under that guard, since
- * `useNotifications()` throws outside one.
+ * `useNotifications()` throws outside one. A language switch that sends the
+ * page's frame back to its load skeleton unmounts this component too, with
+ * the installer still on the page: that is not a leave, so no banner is
+ * raised (`useMarketplaceFrameHolding`).
  */
 
 import { useEffect, useRef } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { useNotifications } from '@object-ui/react';
 import { useObjectTranslation } from '@object-ui/i18n';
 import { attachBanner, requestClearConfirm, sampleDataNotice, withdrawBanner } from './sampleDataNotice.js';
+import { useMarketplaceFrameHolding } from './marketplaceFrameHolding.js';
 
 export function SampleDataLeaveBanner({ manifestId }: { manifestId: string | null }) {
   const { notify, dismiss } = useNotifications();
   const { t } = useObjectTranslation();
   const navigate = useNavigate();
+  const isFrameHolding = useMarketplaceFrameHolding();
   // The cleanup below runs once the page is gone, so it reads the functions
   // of the last render rather than those of the render that set it up.
   const latest = useRef({ notify, dismiss, t, navigate });
@@ -41,6 +46,8 @@ export function SampleDataLeaveBanner({ manifestId }: { manifestId: string | nul
     // Back on the package page: its install note speaks for the sample data.
     withdrawBanner(manifestId);
     return () => {
+      // The frame took the page back for a language's strings: still here.
+      if (isFrameHolding?.()) return;
       const notice = sampleDataNotice(manifestId);
       if (!notice) return;
       const { notify: raise, dismiss: drop, t: tr, navigate: go } = latest.current;
@@ -60,7 +67,7 @@ export function SampleDataLeaveBanner({ manifestId }: { manifestId: string | nul
       });
       attachBanner(notice.manifestId, () => drop(id));
     };
-  }, [manifestId]);
+  }, [manifestId, isFrameHolding]);
 
   return null;
 }