diff --git a/web/src/lib/components/layout/LeftSidebar.svelte b/web/src/lib/components/layout/LeftSidebar.svelte
index c53eae3..41801f1 100644
--- a/web/src/lib/components/layout/LeftSidebar.svelte
+++ b/web/src/lib/components/layout/LeftSidebar.svelte
@@ -43,7 +43,13 @@
 		type Section,
 		type TagCategory
 	} from '$lib/stores/filters.svelte';
-	import { isAuthenticated, session, userBasePath } from '$lib/stores/session.svelte';
+	import {
+		isAuthenticated,
+		session,
+		userBasePath,
+		toOriginalsPath,
+		toUserPath
+	} from '$lib/stores/session.svelte';
 	import { openMove } from '$lib/stores/moveDialog.svelte';
 	import { indexer } from '$lib/stores/indexer.svelte';
 	import FolderTree, { buildTree } from './FolderTree.svelte';
@@ -285,10 +291,15 @@
 	}
 
 	const createFolderMut = createMutation(() => ({
-		mutationFn: (relPath: string) => createFolder(relPath),
+		// The sidebar deals in user-relative paths (BasePath stripped); the
+		// sidecar operates on originals-relative paths. Translate on the way
+		// out (toOriginalsPath) and back for display (toUserPath), exactly like
+		// the move flow — otherwise a BasePath user's folder ops resolve to the
+		// wrong directory and the sidecar returns "invalid path".
+		mutationFn: (relPath: string) => createFolder(toOriginalsPath(relPath)),
 		onSuccess: (r) => {
 			qc.invalidateQueries({ queryKey: ['folders'] });
-			toast.success(`Folder created: ${r.path}`);
+			toast.success(`Folder created: ${toUserPath(r.path)}`);
 		},
 		onError: (err) =>
 			toast.error(err instanceof Error ? err.message : 'Could not create folder')
@@ -296,31 +307,36 @@
 
 	const renameFolderMut = createMutation(() => ({
 		mutationFn: (args: { rel: string; newName: string }) =>
-			renameFolder(args.rel, args.newName),
+			renameFolder(toOriginalsPath(args.rel), args.newName),
 		onSuccess: (r) => {
 			qc.invalidateQueries({ queryKey: ['folders'] });
 			qc.invalidateQueries({ queryKey: ['photos'] });
+			// Handler returns originals-relative paths; map back to the UI's
+			// user-relative space before comparing/navigating.
+			const oldUi = toUserPath(r.oldPath);
+			const newUi = toUserPath(r.newPath);
 			// If the active folder filter was on this folder, follow the rename.
-			if (filters.folderPath === r.oldPath) {
-				setFolderPath(r.newPath);
-				const params = new URLSearchParams({ folder: r.newPath });
+			if (filters.folderPath === oldUi) {
+				setFolderPath(newUi);
+				const params = new URLSearchParams({ folder: newUi });
 				void goto(`/?${params.toString()}`, { keepFocus: true, noScroll: true });
 			}
-			toast.success(`Renamed: ${r.oldPath} → ${r.newPath}`);
+			toast.success(`Renamed: ${oldUi} → ${newUi}`);
 		},
 		onError: (err) =>
 			toast.error(err instanceof Error ? err.message : 'Rename failed')
 	}));
 
 	const deleteFolderMut = createMutation(() => ({
-		mutationFn: (rel: string) => deleteFolder(rel),
+		mutationFn: (rel: string) => deleteFolder(toOriginalsPath(rel)),
 		onSuccess: (r) => {
 			qc.invalidateQueries({ queryKey: ['folders'] });
-			if (filters.folderPath && filters.folderPath.startsWith(r.path)) {
+			const ui = toUserPath(r.path);
+			if (filters.folderPath && filters.folderPath.startsWith(ui)) {
 				setFolderPath(null);
 				void goto('/', { keepFocus: true, noScroll: true });
 			}
-			toast.success(`Folder deleted: ${r.path}`);
+			toast.success(`Folder deleted: ${ui}`);
 		},
 		onError: (err) =>
 			toast.error(err instanceof Error ? err.message : 'Delete failed')