diff --git a/src/api/chat.ts b/src/api/chat.ts
index c3f5686..66eb5dc 100644
--- a/src/api/chat.ts
+++ b/src/api/chat.ts
@@ -58,6 +58,8 @@ export const ChatAPI = {
         imageUrls
       })
       .then((r) => r.data),
+  switchBranch: (agentId: string, userMsgId: string, branchId: string) =>
+    api.post(`/agents/${agentId}/messages/${userMsgId}/branches/${branchId}/switch`).then((r) => r.data),
   clear: (roomId: string) =>
     api.delete(`/rooms/${roomId}/messages`).then((r) => r.data)
 };
diff --git a/src/pages/chat/components/ChatInput.tsx b/src/pages/chat/components/ChatInput.tsx
index 0c15144..f90bd26 100644
--- a/src/pages/chat/components/ChatInput.tsx
+++ b/src/pages/chat/components/ChatInput.tsx
@@ -11,7 +11,7 @@ export default function ChatInput(props: {
   setInput: (v: string) => void;
   sending: boolean;
   attachments: ChatAttachment[];
-  setAttachments: (updater: (prev: ChatAttachment[]) => ChatAttachment[]) => ChatAttachment[];
+  setAttachments: (updater: (prev: ChatAttachment[]) => ChatAttachment[]) => void;
   imageUrls: string[];
   setImageUrls: (updater: (prev: string[]) => string[]) => void;
   onSend: () => void;