diff --git a/tools/ui/src/app.d.ts b/tools/ui/src/app.d.ts
index b9484d9503..814fcf5231 100644
--- a/tools/ui/src/app.d.ts
+++ b/tools/ui/src/app.d.ts
@@ -143,10 +143,8 @@ declare global {
idxThemeStyle?: number;
idxCodeBlock?: number;
- // File System Access API - missing from older DOM lib versions.
- // Used by ChatFormWorkingDirectory's native folder picker. Feature availability
- // is gated at runtime via `typeof window.showDirectoryPicker === 'function'`.
- showDirectoryPicker: (options?: {
+ // File System Access API - not in the DOM lib and unavailable in some browsers
+ showDirectoryPicker?: (options?: {
id?: string;
mode?: 'read' | 'readwrite';
startIn?: FileSystemHandle | string;
diff --git a/tools/ui/src/lib/components/app/chat/ChatMessages/ChatMessage/ChatMessageAssistant/ChatMessageAssistant.svelte b/tools/ui/src/lib/components/app/chat/ChatMessages/ChatMessage/ChatMessageAssistant/ChatMessageAssistant.svelte
index 199d75fcec..ec1214d180 100644
--- a/tools/ui/src/lib/components/app/chat/ChatMessages/ChatMessage/ChatMessageAssistant/ChatMessageAssistant.svelte
+++ b/tools/ui/src/lib/components/app/chat/ChatMessages/ChatMessage/ChatMessageAssistant/ChatMessageAssistant.svelte
@@ -183,8 +183,8 @@