diff --git a/frontend/src/app/DocumentsRoute.tsx b/frontend/src/app/DocumentsRoute.tsx
index ff777f8..3acdb42 100644
--- a/frontend/src/app/DocumentsRoute.tsx
+++ b/frontend/src/app/DocumentsRoute.tsx
@@ -1,4 +1,4 @@
-import React, { useCallback, useEffect, useMemo } from 'react';
+import React, { useCallback, useEffect } from 'react';
 import type { ReactNode, ComponentProps } from 'react';
 import { useNavigate, useParams } from 'react-router-dom';
 import {
@@ -7,7 +7,6 @@ import {
 import { PreviewProvider, usePreviewContext } from '../viewer/PreviewContext';
 import { DocumentOpenProvider } from '../lib/context/DocumentOpenContext';
 import { useWorkspaceSurface } from './useWorkspaceSurface';
-import { DocumentsHeaderBreadcrumb } from '../documents/panel/DocumentsPanelHeader';
 import { SidebarProvider, useSidebarContext } from '../sidebar/SidebarContext';
 import { PanelManagerProvider, usePanelManager } from './PanelManagerContext';
 import Sidebar from '../sidebar/Sidebar';
@@ -30,34 +29,22 @@ const DocumentsInner: React.FC<{
   const { openDetailPanel } = surfaceConfig;
   const sidebarHidden = sidebarCollapsed || sidebarSuppressed;
 
-  const navigate = useNavigate();
-
-  const handleBreadcrumbNavigate = useCallback((crumb: DocumentsHeaderBreadcrumb) => {
-    if (!crumb || !crumb.id) {
-      return;
-    }
-    const target = crumb.id === 'root' ? '/documents' : `/documents/folder/${crumb.id}`;
-    navigate(target);
-  }, [navigate]);
-
   const handleOpenSidepanel = useCallback((docId: string) => {
     if (openDetailPanel) {
       openDetailPanel(docId);
     }
   }, [openDetailPanel]);
 
-  const documentsTablePropsWithNav = useMemo(() => (
-    surfaceConfig.documentsTableProps
-      ? {
-        ...surfaceConfig.documentsTableProps,
-        onBreadcrumbNavigate: handleBreadcrumbNavigate,
-        documents: folderData.documents,
-        subfolders: folderData.subfolders,
-        currentFolderName: folderData.folder?.name,
-        isSearchLoading: folderData.loading,
-      }
-      : null
-  ), [surfaceConfig.documentsTableProps, handleBreadcrumbNavigate, folderData]);
+  const documentsTablePropsWithNav = surfaceConfig.documentsTableProps
+    ? {
+      ...surfaceConfig.documentsTableProps,
+      onBreadcrumbNavigate: surfaceConfig.handleBreadcrumbNavigate,
+      documents: folderData.documents,
+      subfolders: folderData.subfolders,
+      currentFolderName: folderData.folder?.name,
+      isSearchLoading: folderData.loading,
+    }
+    : null;
 
   const { surface } = useWorkspaceSurface({
     sidebarHidden,
diff --git a/frontend/src/app/useDocumentsShell.ts b/frontend/src/app/useDocumentsShell.ts
index 7760cd2..1ffc9f3 100644
--- a/frontend/src/app/useDocumentsShell.ts
+++ b/frontend/src/app/useDocumentsShell.ts
@@ -9,6 +9,7 @@ import type { Identifier } from '../types/identifiers';
 type WorkspaceSurfaceConfig = Omit<UseWorkspaceSurfaceArgs, 'sidebarHidden' | 'onExpandSidebar'> & {
   openDetailPanel?: (documentId: Identifier) => void;
   closeDetailPanel?: () => void;
+  handleBreadcrumbNavigate?: (crumb: any) => void;
 };
 
 interface DocumentsShellView {
@@ -37,6 +38,7 @@ const useDocumentsShell = (): DocumentsShellView => {
       ensureAssetUrl: shell.ensureAssetUrl as WorkspaceSurfaceConfig['ensureAssetUrl'],
       getDocumentAsset: shell.getDocumentAsset as WorkspaceSurfaceConfig['getDocumentAsset'],
       notifyApiError: shell.notifyApiError as WorkspaceSurfaceConfig['notifyApiError'],
+      handleBreadcrumbNavigate: shell.handleBreadcrumbNavigate as WorkspaceSurfaceConfig['handleBreadcrumbNavigate'],
     };
 
     const sidebarWithActions = sidebar
diff --git a/frontend/src/app/workspaceUtils.ts b/frontend/src/app/workspaceUtils.ts
index 55b1adb..f13494e 100644
--- a/frontend/src/app/workspaceUtils.ts
+++ b/frontend/src/app/workspaceUtils.ts
@@ -1,3 +1,4 @@
+import type { FolderTreeNode } from '../lib/api/apiTypes';
 import {
   DEFAULT_FOLDER_NAME,
   DEFAULT_SORT_DIRECTION,
@@ -50,3 +51,14 @@ export const createRootNode = () => ({
   loaded: false,
   hasChildren: false,
 });
+
+export const flattenFolderTree = (data: FolderTreeNode[]): FolderTreeNode[] => {
+  const result: FolderTreeNode[] = [];
+  data.forEach((item) => {
+    result.push(item);
+    if (item.children) {
+      result.push(...flattenFolderTree(item.children));
+    }
+  });
+  return result;
+};
diff --git a/frontend/src/documents/FoldersManager.ts b/frontend/src/documents/FoldersManager.ts
index fdfc1c2..f8215f4 100644
--- a/frontend/src/documents/FoldersManager.ts
+++ b/frontend/src/documents/FoldersManager.ts
@@ -2,17 +2,25 @@ import { shallowEqual } from 'react-redux';
 import type { FolderNodeId } from '../types/identifiers';
 import type { Folder } from '../types/documents';
 
+import type { FolderTreeNode } from '../lib/api/apiTypes';
+import { getFolderTree } from '../lib/api/apiClient';
+import { flattenFolderTree } from '../app/workspaceUtils';
+
 type ManagedFolder = Folder;
 
 type FetchFolder = (id: FolderNodeId) => Promise<unknown>;
 
+
 class FoldersManager<T extends ManagedFolder = ManagedFolder> {
     private byId: Map<FolderNodeId, T>;
     private fetcher?: FetchFolder;
     private inflight: Map<FolderNodeId, Promise<T | null>>;
+    private treePromise: Promise<FolderTreeNode[]> | null = null;
+    private treeSnapshot: FolderTreeNode[] = [];
     private listeners: Set<() => void>;
     private emitScheduled: boolean;
 
+
     constructor(
         fetchFolder?: FetchFolder,
     ) {
@@ -172,6 +180,40 @@ class FoldersManager<T extends ManagedFolder = ManagedFolder> {
     getSnapshot(): Map<FolderNodeId, T> {
         return this.byId;
     }
+
+    getTreeSnapshot(): FolderTreeNode[] {
+        return this.treeSnapshot;
+    }
+
+    async ensureTree(): Promise<FolderTreeNode[]> {
+        if (this.treeSnapshot.length > 0) {
+            return this.treeSnapshot;
+        }
+
+        if (this.treePromise) {
+            return this.treePromise;
+        }
+
+        this.treePromise = (async () => {
+            try {
+                const raw = await getFolderTree();
+                const flattened = flattenFolderTree(raw);
+                this.ingest(flattened);
+                const roots = raw as FolderTreeNode[];
+                this.treeSnapshot = roots;
+                this.emit();
+                return roots;
+            } catch (error) {
+                console.warn('Failed to fetch folder tree', error);
+                return [];
+            } finally {
+                this.treePromise = null;
+            }
+        })();
+
+        return this.treePromise;
+    }
 }
 
+
 export default FoldersManager;
diff --git a/frontend/src/documents/data/useDocumentsWorkspace.ts b/frontend/src/documents/data/useDocumentsWorkspace.ts
index 1414572..22a6898 100644
--- a/frontend/src/documents/data/useDocumentsWorkspace.ts
+++ b/frontend/src/documents/data/useDocumentsWorkspace.ts
@@ -139,6 +139,15 @@ const useDocumentsWorkspace = ({
   const routeFolderId = folderMatch?.params?.folderId || null;
   const routeDocumentId = docMatch?.params?.documentId || null;
   const previewDocumentId = routeDocumentId;
+
+  const handleBreadcrumbNavigate = useCallback((crumb: { id?: Identifier | string } | null) => {
+    if (!crumb || !crumb.id) {
+      return;
+    }
+    const target = crumb.id === 'root' ? '/documents' : `/documents/folder/${crumb.id}`;
+    navigate(target);
+  }, [navigate]);
+
   const {
     status: appStatus,
     token,
@@ -1310,6 +1319,7 @@ const useDocumentsWorkspace = ({
     documentsFilter,
     documentsManager,
     foldersManager,
+    handleBreadcrumbNavigate,
   };
 
   // hook callers handle rendering / routing
diff --git a/frontend/src/documents/data/useFolderData.ts b/frontend/src/documents/data/useFolderData.ts
index 13b6646..4dafc3e 100644
--- a/frontend/src/documents/data/useFolderData.ts
+++ b/frontend/src/documents/data/useFolderData.ts
@@ -14,7 +14,7 @@ interface UseFolderDataResult {
     refresh: () => Promise<void>;
 }
 
-export const useFolderData = (
+const useFolderData = (
     folderId: Identifier | 'root' = 'root',
     documentsManager?: DocumentsManager<Document>,
     foldersManager?: FoldersManager<Folder>
diff --git a/frontend/src/documents/features/folders/useFolderTree.ts b/frontend/src/documents/features/folders/useFolderTree.ts
index 37eaffb..637da86 100644
--- a/frontend/src/documents/features/folders/useFolderTree.ts
+++ b/frontend/src/documents/features/folders/useFolderTree.ts
@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { getFolderTree, listFolderContents } from '../../../lib/api/apiClient';
 import type { Dispatch, MutableRefObject, SetStateAction } from 'react';
-import { createRootNode, DEFAULT_FOLDER_NAME } from '../../../app/workspaceUtils';
+import { createRootNode, DEFAULT_FOLDER_NAME, flattenFolderTree } from '../../../app/workspaceUtils';
 import {
   getEntryId,
   isDocumentEntry,
@@ -76,10 +76,13 @@ const useFolderTree = ({
           const next = new Map(prev);
           const rootChildren: FolderNodeId[] = [];
 
-          data.forEach((item) => {
+          const flatData = flattenFolderTree(data);
+
+          flatData.forEach((item) => {
             const id = item.id as FolderNodeId;
             const parentId = (item.parent_id || 'root') as FolderNodeId;
-            const children = (item.children || []).map((c) => c as FolderNodeId);
+            // item.children is now FolderTreeNode[], so map to IDs
+            const children = (item.children || []).map((c) => c.id as FolderNodeId);
 
             next.set(id, {
               id,
diff --git a/frontend/src/documents/features/selection/SelectionFloatingActions.tsx b/frontend/src/documents/features/selection/SelectionFloatingActions.tsx
index acf0c08..423848e 100644
--- a/frontend/src/documents/features/selection/SelectionFloatingActions.tsx
+++ b/frontend/src/documents/features/selection/SelectionFloatingActions.tsx
@@ -1,6 +1,8 @@
-import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
-import { DEFAULT_FOLDER_NAME } from '../../../constants/workspace';
-import { getFolderTree } from '../../../lib/api/apiClient';
+import React, { useCallback, useEffect, useMemo, useState, useSyncExternalStore } from 'react';
+import { DEFAULT_FOLDER_NAME } from '../../../app/workspaceUtils';
+import { useAppShell } from '../../../lib/context/AppShellContext';
+import FoldersManager from '../../FoldersManager';
+
 import {
   TrashIcon,
   AnalyzeIcon,
@@ -12,10 +14,10 @@ import {
 import SelectionAssignmentMenu, { SelectionAssignmentMenuItem } from './SelectionAssignmentMenu';
 import SelectionFolderMenu from './SelectionFolderMenu';
 import SelectionSummary from './SelectionSummary';
-import { useAppState } from '../../../lib/store/appState';
+
 import { useWorkspaceSelectionContext } from '../../../app/WorkspaceSelectionContext';
 import type { DocumentId } from '../../../types/identifiers';
-import type { FolderTreeNode, FolderTreeResponseItem } from '../../../lib/api/apiTypes';
+import type { FolderTreeNode } from '../../../lib/api/apiTypes';
 
 type NullableDocumentId = DocumentId | null;
 
@@ -217,62 +219,33 @@ const SelectionFloatingActions: React.FC<SelectionFloatingActionsProps> = ({
   onClearSelection = null,
   onMoveDocumentsToFolder,
 }) => {
-  const { token, tenant } = useAppState() as { token?: string; tenant?: { id?: DocumentId; name?: string } | null };
-  const tenantId = tenant?.id ?? null;
+
 
   const documentLookupMap = useMemo(() => (
     documentLookup instanceof Map ? documentLookup : new Map<DocumentId, Document>()
   ), [documentLookup]);
   const tagLookupMap = tagLookupById instanceof Map ? tagLookupById : null;
 
-  const [remoteFolderTree, setRemoteFolderTree] = useState<FolderTreeNode[] | null>(null);
-  const folderTreeFetchRef = useRef<Promise<FolderTreeNode[]> | null>(null);
+  const shell = useAppShell();
+  const foldersManager = shell.foldersManager as FoldersManager;
+
+  const [remoteFolderTree, setRemoteFolderTree] = useState<FolderTreeNode[]>([]);
+
+  // Sync with manager
+  const treeSnapshot = useSyncExternalStore(
+    useCallback(cb => foldersManager.subscribe(cb), [foldersManager]),
+    () => foldersManager.getTreeSnapshot(),
+    () => foldersManager.getTreeSnapshot(),
+  );
 
   useEffect(() => {
-    setRemoteFolderTree(null);
-    folderTreeFetchRef.current = null;
-  }, [tenantId, token]);
+    setRemoteFolderTree(treeSnapshot);
+  }, [treeSnapshot]);
 
-  const requestFolderTree = useCallback(async (): Promise<FolderTreeNode[]> => {
-    if (!token) {
-      setRemoteFolderTree([]);
-      return [];
-    }
+  const requestFolderTree = useCallback(() => {
+    foldersManager.ensureTree();
+  }, [foldersManager]);
 
-    if (Array.isArray(remoteFolderTree)) {
-      return remoteFolderTree;
-    }
-
-    if (folderTreeFetchRef.current) {
-      return folderTreeFetchRef.current;
-    }
-
-    const fetchPromise = (async () => {
-      try {
-        const data = await getFolderTree();
-
-        const traverse = (items: FolderTreeResponseItem[]): FolderTreeNode[] => {
-          return items.map(item => ({
-            ...item,
-            children: item.children ? traverse(item.children) : [],
-          }));
-        };
-
-        const roots = traverse(data);
-        setRemoteFolderTree(roots);
-        return roots;
-      } catch (error) {
-        console.warn('[selection] Failed to load folder tree', error);
-        setRemoteFolderTree([]);
-        return [];
-      } finally {
-        folderTreeFetchRef.current = null;
-      }
-    })();
-
-    folderTreeFetchRef.current = fetchPromise;
-    return fetchPromise;
-  }, [remoteFolderTree, token]);
 
   const handleMoveMenuOpen = useCallback(() => {
     requestFolderTree();
diff --git a/frontend/src/lib/api/apiClient.ts b/frontend/src/lib/api/apiClient.ts
index 9cc76d4..7e922c0 100644
--- a/frontend/src/lib/api/apiClient.ts
+++ b/frontend/src/lib/api/apiClient.ts
@@ -12,7 +12,7 @@ import type {
   TenantSnippet,
   TagResponse,
   CorrespondentResponse,
-  FolderTreeResponseItem,
+  FolderTreeNode,
 } from './apiTypes';
 import type { AxiosError, AxiosInstance, InternalAxiosRequestConfig, AxiosRequestConfig } from 'axios';
 
@@ -79,8 +79,8 @@ export const listDocuments = async (params: Record<string, unknown> = {}): Promi
   return Array.isArray(data) ? data : [];
 };
 
-export const getFolderTree = async (): Promise<FolderTreeResponseItem[]> => {
-  const { data } = await api.get<FolderTreeResponseItem[]>('/folders/tree');
+export const getFolderTree = async (): Promise<FolderTreeNode[]> => {
+  const { data } = await api.get<FolderTreeNode[]>('/folders/tree');
   return Array.isArray(data) ? data : [];
 };
 
diff --git a/frontend/src/lib/api/apiTypes.ts b/frontend/src/lib/api/apiTypes.ts
index c021103..b333726 100644
--- a/frontend/src/lib/api/apiTypes.ts
+++ b/frontend/src/lib/api/apiTypes.ts
@@ -69,10 +69,6 @@ export interface FolderTreeNode extends FolderInfo {
   children?: FolderTreeNode[];
 }
 
-export interface FolderTreeResponseItem extends FolderInfo {
-  children?: string[];
-}
-
 export interface CapabilitySetResponse {
   id: string;
   slug: string;