diff --git a/.changeset/6349-batch9-app-shell.md b/.changeset/6349-batch9-app-shell.md
new file mode 100644
index 0000000000..2fa68861f5
--- /dev/null
+++ b/.changeset/6349-batch9-app-shell.md
@@ -0,0 +1,11 @@
+---
+'@object-ui/app-shell': minor
+---
+
+The props of this package's minimal `AppShell` container are declared and exported as `MinimalAppShellProps` instead of `AppShellProps` (objectui#6349, batch 9). `@object-ui/layout` publishes a different `AppShellProps`: the props of its sidebar `AppShell`, the shell the console composes, which takes `navbar`, `defaultOpen`, `branding` and `rightRail` where this container takes `header` and `footer`. One exported name stood for two props types across the two packages, and layout keeps it.
+
+**Type change, breaking for some consumers.** `AppShellProps` is no longer exported from `@object-ui/app-shell`. Replace `import type { AppShellProps } from '@object-ui/app-shell'` with `MinimalAppShellProps`; the members (`sidebar`, `header`, `footer`, `children`, `className`) are unchanged. The old import fails to compile with TS2305 ("has no exported member 'AppShellProps'"). The `AppShell` component keeps its name.
+
+`MetadataTypeStatus` and `UserDataAdapter` are no longer declared a second time in this package. `MetadataTypeStatus` is re-exported from `@object-ui/react`, which declares the same four statuses (`'idle' | 'loading' | 'ready' | 'error'`) for `MetadataContextValue.getTypeStatus`. `UserDataAdapter` is re-exported from `@object-ui/data-objectstack`, whose `createObjectStackUserStateAdapter` builds exactly the adapter `UserStateAdaptersProvider` injects. Both declarations had the same members as this package's copies, so this package's entry still exports both names with the same shapes, and those imports do not change.
+
+No runtime behaviour changes.
diff --git a/.changeset/6349-batch9-data-objectstack.md b/.changeset/6349-batch9-data-objectstack.md
new file mode 100644
index 0000000000..4aec8d9ffc
--- /dev/null
+++ b/.changeset/6349-batch9-data-objectstack.md
@@ -0,0 +1,7 @@
+---
+'@object-ui/data-objectstack': patch
+---
+
+Doc comments only. `UserDataAdapter` now carries the contract notes `@object-ui/app-shell` kept on its own copy of the interface: implementations must be safe to call concurrently and should never throw, so the hosting provider can degrade to localStorage when the backend fails. `@object-ui/app-shell` now re-exports this declaration instead of declaring a second one (objectui#6349, batch 9). The type and its members are unchanged.
+
+No runtime behaviour changes.
diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index 673cfcd69e..cfc4a04e2d 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -160,7 +160,7 @@ Third-Party App
 
 ```tsx
 import { AppShell } from '@object-ui/app-shell';
-import type { AppShellProps } from '@object-ui/app-shell';
+import type { MinimalAppShellProps } from '@object-ui/app-shell';
 import { ObjectView } from '@object-ui/plugin-view';
 import { DataSourceProvider, useDataSource } from '@object-ui/providers';
 import type { DataSourceProviderProps } from '@object-ui/providers';
@@ -172,7 +172,7 @@ import type { DataSourceProviderProps } from '@object-ui/providers';
 // records where the value goes rather than checking it), and `MySidebar` is
 // your own component, returning whatever `AppShell` accepts for `sidebar`.
 declare const myAPI: DataSourceProviderProps['dataSource'];
-declare function MySidebar(): AppShellProps['sidebar'];
+declare function MySidebar(): MinimalAppShellProps['sidebar'];
 
 function MyConsole() {
   return (
@@ -207,10 +207,10 @@ asked to run on the server, where neither exists.
 'use client';
 
 import { AppShell } from '@object-ui/app-shell';
-import type { AppShellProps } from '@object-ui/app-shell';
+import type { MinimalAppShellProps } from '@object-ui/app-shell';
 import { ThemeProvider } from '@object-ui/providers';
 
-export default function RootLayout({ children }: { children: AppShellProps['children'] }) {
+export default function RootLayout({ children }: { children: MinimalAppShellProps['children'] }) {
   return (
     <ThemeProvider>
       <AppShell>{children}</AppShell>
diff --git a/packages/app-shell/src/components/AppShell.tsx b/packages/app-shell/src/components/AppShell.tsx
index 33fef1a02d..b39cd01952 100644
--- a/packages/app-shell/src/components/AppShell.tsx
+++ b/packages/app-shell/src/components/AppShell.tsx
@@ -1,5 +1,5 @@
 import type { ReactNode } from 'react';
-import type { AppShellProps } from '../types.js';
+import type { MinimalAppShellProps } from '../types.js';
 
 /**
  * AppShell - Minimal layout container
@@ -13,7 +13,7 @@ export function AppShell({
   footer,
   children,
   className = '',
-}: AppShellProps): ReactNode {
+}: MinimalAppShellProps): ReactNode {
   return (
     <div className={`app-shell flex h-screen flex-col ${className}`}>
       {header && <div className="app-shell-header">{header}</div>}
diff --git a/packages/app-shell/src/context/UserStateAdapters.tsx b/packages/app-shell/src/context/UserStateAdapters.tsx
index 42c0270568..cc18e5be2d 100644
--- a/packages/app-shell/src/context/UserStateAdapters.tsx
+++ b/packages/app-shell/src/context/UserStateAdapters.tsx
@@ -23,24 +23,18 @@ import {
   useState,
   type ReactNode,
 } from 'react';
+import type { UserDataAdapter } from '@object-ui/data-objectstack';
 
 // ---------------------------------------------------------------------------
 // Adapter contract
 // ---------------------------------------------------------------------------
 
-/**
- * Generic persistence adapter for a user-scoped list.
- *
- * Implementations must be safe to call concurrently and should *never*
- * throw — failures should be swallowed so the hosting provider can degrade
- * to localStorage-only mode without crashing the UI.
- */
-export interface UserDataAdapter<T> {
-  /** Load the persisted list for the current user. Resolve to [] when absent. */
-  load(): Promise<T[]>;
-  /** Persist the full list (debounced upstream). Errors are silently ignored. */
-  save(items: T[]): Promise<void>;
-}
+// `UserDataAdapter` is `@object-ui/data-objectstack`'s, the one authority:
+// `createObjectStackUserStateAdapter` returns exactly the contract this
+// registry injects, so this module re-exports it rather than declaring a
+// second copy. Its contract notes (never throw; degrade to localStorage) live
+// on that declaration (objectui#6349, batch 9).
+export type { UserDataAdapter };
 
 export type UserStateKind = 'favorites' | 'recent' | 'flowPaletteRecents';
 
diff --git a/packages/app-shell/src/index.ts b/packages/app-shell/src/index.ts
index 2046ec1788..8a6f3be1bf 100644
--- a/packages/app-shell/src/index.ts
+++ b/packages/app-shell/src/index.ts
@@ -52,7 +52,7 @@ export { useRecentItemLabel } from './hooks/useRecentItemLabel.js';
 
 // Types
 export type {
-  AppShellProps,
+  MinimalAppShellProps,
 } from './types.js';
 
 export type {
diff --git a/packages/app-shell/src/providers/MetadataProvider.tsx b/packages/app-shell/src/providers/MetadataProvider.tsx
index 40143ceda4..370553ac34 100644
--- a/packages/app-shell/src/providers/MetadataProvider.tsx
+++ b/packages/app-shell/src/providers/MetadataProvider.tsx
@@ -11,12 +11,16 @@ import { ActiveOrganizationStorage, TokenStorage, useAuth } from '@object-ui/aut
 import { type ObjectStackAdapter } from '@object-ui/data-objectstack';
 import { normalizeSchemaReferenceKeys } from '@object-ui/core';
 import { resolveInlineMode } from '@object-ui/plugin-form';
-import { MetadataCtx, useMetadata, type MetadataContextValue, type MetadataCacheState } from '@object-ui/react';
+import { MetadataCtx, useMetadata, type MetadataContextValue, type MetadataCacheState, type MetadataTypeStatus } from '@object-ui/react';
 import { usePreviewDrafts } from '../preview/PreviewModeContext.js';
 import { createConsoleMetadataClient } from '../views/metadata-admin/metadataClientFactory.js';
 import { subscribeCanvasInvalidate, subscribeMetadataRefresh } from '../assistant/assistantBus.js';
 
-export type { MetadataCacheState, MetadataContextValue };
+// `MetadataTypeStatus` is `@object-ui/react`'s, the one authority: the status
+// `MetadataContextValue.getTypeStatus` returns is the same four words this
+// provider's cache entries carry, so this module re-exports it rather than
+// declaring a second copy (objectui#6349, batch 9).
+export type { MetadataCacheState, MetadataContextValue, MetadataTypeStatus };
 export { useMetadataItem } from '@object-ui/react';
 export { useMetadata };
 
@@ -24,8 +28,6 @@ export { useMetadata };
 // Types
 // ---------------------------------------------------------------------------
 
-export type MetadataTypeStatus = 'idle' | 'loading' | 'ready' | 'error';
-
 interface TypeCacheEntry {
   status: MetadataTypeStatus;
   items: any[];
diff --git a/packages/app-shell/src/types.ts b/packages/app-shell/src/types.ts
index a0d356f1b4..84a01514f9 100644
--- a/packages/app-shell/src/types.ts
+++ b/packages/app-shell/src/types.ts
@@ -14,7 +14,17 @@ export interface DataSource {
   [key: string]: any; // Allow additional methods
 }
 
-export interface AppShellProps {
+/**
+ * Props of this package's minimal `AppShell` container: header, body and
+ * footer slots, with no routing.
+ *
+ * Not `AppShellProps`: `@object-ui/layout` publishes that name for the props of
+ * its own sidebar `AppShell`, the shell the console's `ConsoleLayout` composes,
+ * which takes `navbar`, `defaultOpen`, `branding` and `rightRail` where this
+ * one takes `header` and `footer`. One exported name stood for both until this
+ * declaration was renamed (objectui#6349, batch 9).
+ */
+export interface MinimalAppShellProps {
   /** Sidebar component (optional) */
   sidebar?: ReactNode;
   /** Header component (optional) */
diff --git a/packages/data-objectstack/src/userState.ts b/packages/data-objectstack/src/userState.ts
index a5697c52c6..fbdffaaf18 100644
--- a/packages/data-objectstack/src/userState.ts
+++ b/packages/data-objectstack/src/userState.ts
@@ -68,8 +68,21 @@ export interface ObjectStackUserStateAdapterOptions {
   onError?: (where: 'load' | 'save', error: unknown) => void;
 }
 
+/**
+ * Generic persistence adapter for a user-scoped list.
+ *
+ * Implementations must be safe to call concurrently and should *never*
+ * throw — failures should be swallowed so the hosting provider can degrade
+ * to localStorage-only mode without crashing the UI.
+ *
+ * This is the one declaration of the name: `@object-ui/app-shell`'s
+ * `UserStateAdaptersProvider` injects adapters of this type and re-exports it
+ * (objectui#6349, batch 9).
+ */
 export interface UserDataAdapter<T> {
+  /** Load the persisted list for the current user. Resolve to [] when absent. */
   load(): Promise<T[]>;
+  /** Persist the full list (debounced upstream). Errors are silently ignored. */
   save(items: T[]): Promise<void>;
 }
 
diff --git a/packages/layout/src/__tests__/app-shell-docs-nav-example.test.ts b/packages/layout/src/__tests__/app-shell-docs-nav-example.test.ts
index a4319cbedf..57baa492af 100644
--- a/packages/layout/src/__tests__/app-shell-docs-nav-example.test.ts
+++ b/packages/layout/src/__tests__/app-shell-docs-nav-example.test.ts
@@ -93,8 +93,8 @@ const SIDEBAR_NAV_SRC = readFileSync(
 /**
  * The page documents `@object-ui/layout`'s AppShell — every example on it
  * imports from `@object-ui/layout` — so this is the source of truth for its
- * props. `packages/app-shell` exports a same-named `AppShellProps` for a
- * different component; that one is not what this page teaches.
+ * props. `packages/app-shell` exports `MinimalAppShellProps` for a different,
+ * same-named `AppShell` component; that one is not what this page teaches.
  */
 const APP_SHELL_SRC = readFileSync(
   join(REPO_ROOT, 'packages', 'layout', 'src', 'AppShell.tsx'),
diff --git a/packages/layout/src/__tests__/guide-layout-app-shell-doc.test.ts b/packages/layout/src/__tests__/guide-layout-app-shell-doc.test.ts
index 6484e7476c..0ddef3c415 100644
--- a/packages/layout/src/__tests__/guide-layout-app-shell-doc.test.ts
+++ b/packages/layout/src/__tests__/guide-layout-app-shell-doc.test.ts
@@ -100,10 +100,12 @@
  * (objectui#4793 / #4808); pinning the whole docs tree to source is
  * objectui#3786's problem, not this one.
  *
- * Note also that `@object-ui/app-shell` exports a DIFFERENT `AppShellProps`
- * (`packages/app-shell/src/types.ts`) which really does declare `header` — that
- * is a separate component, and reading this one's key list off this one's source
- * is what keeps the two from being conflated again.
+ * Note also that `@object-ui/app-shell` exports a DIFFERENT props type for its
+ * own `AppShell`, `MinimalAppShellProps` (`packages/app-shell/src/types.ts`),
+ * which really does declare `header` — that is a separate component, and
+ * reading this one's key list off this one's source is what keeps the two from
+ * being conflated again. Until objectui#6349 (batch 9) it was also spelled
+ * `AppShellProps`.
  */
 
 import { describe, it, expect } from 'vitest';
diff --git a/packages/layout/src/__tests__/readme-app-shell-example.test.ts b/packages/layout/src/__tests__/readme-app-shell-example.test.ts
index a69c53affc..da26ea9654 100644
--- a/packages/layout/src/__tests__/readme-app-shell-example.test.ts
+++ b/packages/layout/src/__tests__/readme-app-shell-example.test.ts
@@ -66,10 +66,12 @@
  * `app-shell-docs-nav-example.test.ts`'s surface (objectui#4793), and pinning
  * the whole docs tree to source is objectui#3786's problem, not this one.
  *
- * Note also that `@object-ui/app-shell` exports a DIFFERENT `AppShellProps`
- * (`packages/app-shell/src/types.ts`) which really does declare `header` — that
- * is a separate component, and reading this one's key list off this one's source
- * is what keeps the two from being conflated again.
+ * Note also that `@object-ui/app-shell` exports a DIFFERENT props type for its
+ * own `AppShell`, `MinimalAppShellProps` (`packages/app-shell/src/types.ts`),
+ * which really does declare `header` — that is a separate component, and
+ * reading this one's key list off this one's source is what keeps the two from
+ * being conflated again. Until objectui#6349 (batch 9) it was also spelled
+ * `AppShellProps`.
  */
 
 import { describe, it, expect } from 'vitest';
@@ -264,9 +266,9 @@ describe("the README's AppShell examples pass only props AppShellProps declares
       [
         'An `<AppShell>` example in packages/layout/README.md is passing `header` again.',
         'That prop does not exist on this component (objectui#4817). Note that',
-        '`@object-ui/app-shell` exports a different `AppShellProps` which DOES declare',
-        '`header` — this README documents `@object-ui/layout`\'s, whose top-bar slot is',
-        '`navbar`.',
+        '`@object-ui/app-shell`\'s own `AppShell` takes `MinimalAppShellProps`, which DOES',
+        'declare `header` — this README documents `@object-ui/layout`\'s, whose top-bar',
+        'slot is `navbar`.',
       ].join('\n'),
     ).toBe(false);
   });
diff --git a/scripts/__tests__/one-authority-per-exported-name-6273.test.ts b/scripts/__tests__/one-authority-per-exported-name-6273.test.ts
index fc43aeb340..77ed18b839 100644
--- a/scripts/__tests__/one-authority-per-exported-name-6273.test.ts
+++ b/scripts/__tests__/one-authority-per-exported-name-6273.test.ts
@@ -376,7 +376,17 @@ const KNOWN_COLLISIONS: ReadonlyMap<string, readonly string[]> = new Map([
   // (`field`, `type`). RENAME branch: the general name stays on
   // `@object-ui/types`, and the grid's declaration now spells
   // `GroupAggregationConfig` (objectui#6349, batch 7).
-  ['AppShellProps', ['packages/app-shell/src/types.ts', 'packages/layout/src/AppShell.tsx']],
+  // `AppShellProps` sat here, colliding between `packages/app-shell/src/types.ts`
+  // and `packages/layout/src/AppShell.tsx`. Two components, not one drifted
+  // shape: app-shell's is the props of its minimal `AppShell` container
+  // (`header` and `footer` slots, no routing) and layout's the props of the
+  // sidebar shell the console's `ConsoleLayout` composes (`navbar`,
+  // `defaultOpen`, `branding`, `rightRail`). app-shell depends on layout, but
+  // re-pointing its name at layout's does not compile. RENAME branch: app-shell's
+  // declaration now spells `MinimalAppShellProps`, and the app-shell root
+  // publishes that name instead; layout is the one authority. The two `AppShell`
+  // components keep their names — value names are outside this gate's bound
+  // (objectui#6349, batch 9).
   // `ActionSchema` sat here, colliding between `packages/types/src/crud.ts` and
   // `packages/types/src/ui-action.ts`. Structurally unrelated types — 28 members
   // each, 9 shared, `type` the literal `'action'` there and `ActionType` here — so
@@ -520,7 +530,14 @@ const KNOWN_COLLISIONS: ReadonlyMap<string, readonly string[]> = new Map([
   // `type: 'separator'` legal on one side and a refusal on the other. That is
   // the RENAME branch: app's declaration now spells `AppMenuItem`, the name
   // `src/index.ts` always published it under (objectui#6349).
-  ['MetadataTypeStatus', ['packages/app-shell/src/providers/MetadataProvider.tsx', 'packages/react/src/context/AppShellContext.tsx']],
+  // `MetadataTypeStatus` sat here, colliding between
+  // `packages/app-shell/src/providers/MetadataProvider.tsx` and
+  // `packages/react/src/context/AppShellContext.tsx`. One status, declared
+  // twice with the same four words (`'idle' | 'loading' | 'ready' | 'error'`):
+  // the provider's per-type cache entries carry it and the context's
+  // `getTypeStatus` returns it. app-shell depends on `@object-ui/react`, so
+  // react's is the one authority and `MetadataProvider.tsx` RE-EXPORTS it; the
+  // app-shell root still publishes the name (objectui#6349, batch 9).
   // `NamedActionDef` sat here — two IDENTICAL declarations inside plugin-grid.
   // `resolveLegacyRowActions.ts` is the one authority; `resolveBulkActions.ts`
   // re-exports it (objectui#6349).
@@ -570,7 +587,15 @@ const KNOWN_COLLISIONS: ReadonlyMap<string, readonly string[]> = new Map([
   // `@objectstack/spec` counterpart, so it was RETIRED with its two companions
   // (`UndoRedoEntry`, `UndoRedoConfig`) rather than renamed. The designer's
   // declaration is the one authority (objectui#6349, batch 5).
-  ['UserDataAdapter', ['packages/app-shell/src/context/UserStateAdapters.tsx', 'packages/data-objectstack/src/userState.ts']],
+  // `UserDataAdapter` sat here, colliding between
+  // `packages/app-shell/src/context/UserStateAdapters.tsx` and
+  // `packages/data-objectstack/src/userState.ts`. One contract with identical
+  // members (`load()` and `save(items)`, generic over the item): the adapter
+  // `createObjectStackUserStateAdapter` builds is the adapter app-shell's
+  // registry injects. app-shell depends on `@object-ui/data-objectstack`, so
+  // that declaration is the one authority (it took app-shell's contract notes)
+  // and `UserStateAdapters.tsx` RE-EXPORTS it; the app-shell root still
+  // publishes the name (objectui#6349, batch 9).
   // `ValidationFunction` sat here, colliding between
   // `packages/types/src/data-protocol.ts` and `packages/types/src/field-types.ts`.
   // The two signatures disagree at both ends of the arrow — data-protocol's takes