diff --git a/frontend/src/__tests__/pages/FileManagerPage.test.tsx b/frontend/src/__tests__/pages/FileManagerPage.test.tsx
index 2f354f817..648164a33 100644
--- a/frontend/src/__tests__/pages/FileManagerPage.test.tsx
+++ b/frontend/src/__tests__/pages/FileManagerPage.test.tsx
@@ -3,13 +3,24 @@
  */
 
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
+import { screen, waitFor, within } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { FileManagerPage } from '../../pages/FileManagerPage';
+import { openInSlicer } from '../../utils/slicer';
 import { http, HttpResponse } from 'msw';
 import { server } from '../mocks/server';
 
+vi.mock('../../utils/slicer', () => ({
+  openInSlicer: vi.fn(),
+}));
+
+vi.mock('../../components/SliceModal', () => ({
+  SliceModal: ({ source }: { source: { filename: string } }) => (
+    <div data-testid="slice-modal">{source.filename}</div>
+  ),
+}));
+
 // Mock data
 const mockFolders = [
   {
@@ -1155,4 +1166,62 @@ describe('FileManagerPage', () => {
       });
     });
   });
+
+  describe('slice action', () => {
+    beforeEach(() => {
+      vi.mocked(openInSlicer).mockClear();
+      server.use(
+        http.post('/api/v1/library/files/:id/slicer-token', () => HttpResponse.json({ token: 'test-token' })),
+      );
+    });
+
+    const openMenu = async (user: ReturnType<typeof userEvent.setup>, filename: string) => {
+      const card = screen.getByText(filename).closest('.group') as HTMLElement;
+      await user.click(card.querySelector('button')!);
+      return card;
+    };
+
+    it('opens the desktop slicer when the slicer API is disabled', async () => {
+      const user = userEvent.setup();
+      render(<FileManagerPage />);
+
+      await waitFor(() => expect(screen.getByText('bracket.stl')).toBeInTheDocument());
+
+      const card = await openMenu(user, 'bracket.stl');
+      await user.click(within(card).getByText('Slice'));
+
+      await waitFor(() => {
+        expect(openInSlicer).toHaveBeenCalledWith(
+          expect.stringContaining('/library/files/2/dl/test-token/'),
+          'bambu_studio',
+        );
+      });
+    });
+
+    it('opens the in-app SliceModal when the slicer API is enabled', async () => {
+      server.use(
+        http.get('/api/v1/settings/', () => HttpResponse.json({ use_slicer_api: true })),
+      );
+      const user = userEvent.setup();
+      render(<FileManagerPage />);
+
+      await waitFor(() => expect(screen.getByText('bracket.stl')).toBeInTheDocument());
+
+      const card = await openMenu(user, 'bracket.stl');
+      await user.click(within(card).getByText('Slice'));
+
+      expect(await screen.findByTestId('slice-modal')).toBeInTheDocument();
+      expect(openInSlicer).not.toHaveBeenCalled();
+    });
+
+    it('hides the slice item for already-sliced files', async () => {
+      const user = userEvent.setup();
+      render(<FileManagerPage />);
+
+      await waitFor(() => expect(screen.getByText('Benchy')).toBeInTheDocument());
+
+      const card = await openMenu(user, 'Benchy');
+      expect(within(card).queryByText('Slice')).not.toBeInTheDocument();
+    });
+  });
 });
diff --git a/frontend/src/i18n/locales/uk.ts b/frontend/src/i18n/locales/uk.ts
index 0094c7718..318114904 100644
--- a/frontend/src/i18n/locales/uk.ts
+++ b/frontend/src/i18n/locales/uk.ts
@@ -5337,6 +5337,8 @@ export default {
   // Model Viewer
   modelViewer: {
     openInSlicer: "Відкрити у слайсері",
+    openInSlicerWith: "Відкрити у {{slicer}}",
+    moreSlicerOptions: "Більше варіантів слайсера",
     tabs: {
       model: "3D-модель",
       gcode: "Попередній перегляд G-коду",
diff --git a/frontend/src/pages/FileManagerPage.tsx b/frontend/src/pages/FileManagerPage.tsx
index 4d6b91130..c0ee7d511 100644
--- a/frontend/src/pages/FileManagerPage.tsx
+++ b/frontend/src/pages/FileManagerPage.tsx
@@ -9,6 +9,7 @@ import {
   Upload,
   Trash2,
   Download,
+  ExternalLink,
   MoreVertical,
   ChevronRight,
   FolderPlus,
@@ -73,6 +74,7 @@ import { usePageFileDrop } from '../hooks/usePageFileDrop';
 import { useAuth } from '../contexts/AuthContext';
 import { formatDuration, parseUTCDate, formatDate } from '../utils/date';
 import { formatFileSize } from '../utils/file';
+import { openInSlicer, type SlicerType } from '../utils/slicer';
 
 type SortField = 'name' | 'date' | 'size' | 'type' | 'prints';
 type SortDirection = 'asc' | 'desc';
@@ -759,6 +761,7 @@ interface FileCardProps {
   onDownload: (id: number) => void;
   onPrint?: (file: LibraryFileListItem) => void;
   onSlice?: (file: LibraryFileListItem) => void;
+  onOpenInSlicer?: (file: LibraryFileListItem) => void;
   onRunPipeline?: (file: LibraryFileListItem) => void;
   useSlicerApi?: boolean;
   onPreview3d?: (file: LibraryFileListItem) => void;
@@ -773,9 +776,11 @@ interface FileCardProps {
   t: TFunction;
 }
 
-function FileCard({ file, isSelected, isMobile, onSelect, onDelete, onDownload, onPrint, onSlice, onRunPipeline, useSlicerApi, onPreview3d, onRename, onGenerateThumbnail, onTagClick, thumbnailVersion, hasPermission, canModify, authEnabled, showModified, t }: FileCardProps) {
+function FileCard({ file, isSelected, isMobile, onSelect, onDelete, onDownload, onPrint, onSlice, onOpenInSlicer, onRunPipeline, useSlicerApi, onPreview3d, onRename, onGenerateThumbnail, onTagClick, thumbnailVersion, hasPermission, canModify, authEnabled, showModified, t }: FileCardProps) {
   const [showActions, setShowActions] = useState(false);
 
+  const sliceDisabled = useSlicerApi ? !hasPermission('library:upload') : !hasPermission('library:read');
+
   return (
     <div
       className={`group relative bg-bambu-dark-secondary rounded-lg border transition-all cursor-pointer overflow-hidden ${
@@ -899,16 +904,21 @@ function FileCard({ file, isSelected, isMobile, onSelect, onDelete, onDownload,
                   {t('common.print')}
                 </button>
               )}
-              {onSlice && useSlicerApi && isSliceableFilename(file.filename) && (
+              {isSliceableFilename(file.filename) && (onSlice || onOpenInSlicer) && (
                 <button
                   className={`w-full px-3 py-1.5 text-left text-sm flex items-center gap-2 ${
-                    hasPermission('library:upload') ? 'text-white hover:bg-bambu-dark' : 'text-bambu-gray cursor-not-allowed'
+                    !sliceDisabled ? 'text-white hover:bg-bambu-dark' : 'text-bambu-gray cursor-not-allowed'
                   }`}
-                  onClick={() => { if (hasPermission('library:upload')) { onSlice(file); setShowActions(false); } }}
-                  disabled={!hasPermission('library:upload')}
-                  title={!hasPermission('library:upload') ? t('fileManager.noPermissionSlice') : undefined}
+                  onClick={() => {
+                    if (sliceDisabled) return;
+                    if (useSlicerApi) onSlice?.(file);
+                    else onOpenInSlicer?.(file);
+                    setShowActions(false);
+                  }}
+                  disabled={sliceDisabled}
+                  title={sliceDisabled ? (useSlicerApi ? t('fileManager.noPermissionSlice') : t('fileManager.noPermissionDownload')) : undefined}
                 >
-                  <Cog className="w-3.5 h-3.5" />
+                  {useSlicerApi ? <Cog className="w-3.5 h-3.5" /> : <ExternalLink className="w-3.5 h-3.5" />}
                   {t('slice.action')}
                 </button>
               )}
@@ -1145,6 +1155,27 @@ export function FileManagerPage() {
     queryKey: ['settings'],
     queryFn: () => api.getSettings() as Promise<AppSettings>,
   });
+
+  const preferredSlicer: SlicerType = settings?.open_in_slicer || settings?.preferred_slicer || 'bambu_studio';
+
+  const handleOpenInSlicer = useCallback(async (file: LibraryFileListItem) => {
+    try {
+      const { token } = await api.createLibrarySlicerToken(file.id);
+      const path = api.getLibrarySlicerDownloadUrl(file.id, token, file.filename);
+      openInSlicer(`${window.location.origin}${path}`, preferredSlicer);
+    } catch {
+      const path = api.getLibraryFileDownloadUrl(file.id);
+      openInSlicer(`${window.location.origin}${path}`, preferredSlicer);
+    }
+  }, [preferredSlicer]);
+
+  // Slice permission: API mode needs upload rights, desktop handoff is a download.
+  const canSlice = useCallback(() => {
+    if (settings?.use_slicer_api) {
+      return hasPermission('library:upload');
+    }
+    return hasPermission('library:read');
+  }, [settings?.use_slicer_api, hasPermission]);
   const { data: folders, isLoading: foldersLoading } = useQuery({
     queryKey: ['library-folders'],
     queryFn: () => api.getLibraryFolders(),
@@ -2420,6 +2451,7 @@ export function FileManagerPage() {
                     onDownload={handleDownload}
                     onPrint={setPrintFile}
                     onSlice={setSliceFile}
+                    onOpenInSlicer={handleOpenInSlicer}
                     onRunPipeline={setRunPipelineFile}
                     useSlicerApi={settings?.use_slicer_api ?? false}
                     onPreview3d={(f) => {
@@ -2597,18 +2629,21 @@ export function FileManagerPage() {
                           </button>
                         </>
                       )}
-                      {(settings?.use_slicer_api ?? false) && isSliceableFilename(file.filename) && (
+                      {isSliceableFilename(file.filename) && (
                         <button
-                          onClick={() => hasPermission('library:upload') && setSliceFile(file)}
+                          onClick={() => {
+                            if (!canSlice()) return;
+                            (settings?.use_slicer_api ? setSliceFile : handleOpenInSlicer)(file);
+                          }}
                           className={`p-1.5 rounded transition-colors ${
-                            hasPermission('library:upload')
+                            canSlice()
                               ? 'hover:bg-bambu-dark text-bambu-gray hover:text-bambu-green'
                               : 'text-bambu-gray/50 cursor-not-allowed'
                           }`}
-                          title={hasPermission('library:upload') ? t('slice.action') : t('fileManager.noPermissionSlice')}
-                          disabled={!hasPermission('library:upload')}
+                          title={canSlice() ? t('slice.action') : (settings?.use_slicer_api ? t('fileManager.noPermissionSlice') : t('fileManager.noPermissionDownload'))}
+                          disabled={!canSlice()}
                         >
-                          <Cog className="w-4 h-4" />
+                          {settings?.use_slicer_api ? <Cog className="w-4 h-4" /> : <ExternalLink className="w-4 h-4" />}
                         </button>
                       )}
                       {(settings?.use_slicer_api ?? false) && isSliceableFilename(file.filename) && (