diff --git a/site/src/api/queries/chats.ts b/site/src/api/queries/chats.ts
index 8cac0be230..24b930ff53 100644
--- a/site/src/api/queries/chats.ts
+++ b/site/src/api/queries/chats.ts
@@ -143,12 +143,6 @@ export const infiniteChats = (opts?: { q?: string; archived?: boolean }) => {
 	} satisfies UseInfiniteQueryOptions<TypesGen.Chat[]>;
 };
 
-export const chats = () => ({
-	queryKey: chatsKey,
-	queryFn: () => API.getChats(),
-	refetchOnWindowFocus: true as const,
-});
-
 export const chat = (chatId: string) => ({
 	queryKey: chatKey(chatId),
 	queryFn: () => API.getChat(chatId),
diff --git a/site/src/pages/AgentsPage/AgentDetail.tsx b/site/src/pages/AgentsPage/AgentDetail.tsx
index a4a49bd1c4..75bc585e0e 100644
--- a/site/src/pages/AgentsPage/AgentDetail.tsx
+++ b/site/src/pages/AgentsPage/AgentDetail.tsx
@@ -3,7 +3,6 @@ import { isApiError } from "api/errors";
 import {
 	chat,
 	chatMessagesForInfiniteScroll,
-	chats,
 	createChatMessage,
 	deleteChatQueuedMessage,
 	editChatMessage,
@@ -294,7 +293,11 @@ const AgentDetail: FC = () => {
 		...chatMessagesForInfiniteScroll(agentId ?? ""),
 		enabled: Boolean(agentId),
 	});
-	const chatsQuery = useQuery(chats());
+	const parentChatID = getParentChatID(chatQuery.data);
+	const parentChatQuery = useQuery({
+		...chat(parentChatID ?? ""),
+		enabled: Boolean(parentChatID),
+	});
 	const workspaceId = chatQuery.data?.workspace_id;
 	const workspaceQuery = useQuery({
 		...workspaceById(workspaceId ?? ""),
@@ -706,10 +709,7 @@ const AgentDetail: FC = () => {
 		</title>
 	);
 
-	const parentChatID = getParentChatID(chatQuery.data);
-	const parentChat = parentChatID
-		? chatsQuery.data?.find((chat) => chat.id === parentChatID)
-		: undefined;
+	const parentChat = parentChatQuery.data;
 	const workspaceRoute = workspace
 		? `/@${workspace.owner_name}/${workspace.name}`
 		: null;
diff --git a/site/src/pages/AgentsPage/AgentsPage.tsx b/site/src/pages/AgentsPage/AgentsPage.tsx
index 3a3886df66..9f5243275f 100644
--- a/site/src/pages/AgentsPage/AgentsPage.tsx
+++ b/site/src/pages/AgentsPage/AgentsPage.tsx
@@ -54,6 +54,7 @@ import { useAgentsPWA } from "./useAgentsPWA";
 
 const lastModelConfigIDStorageKey = "agents.last-model-config-id";
 const nilUUID = "00000000-0000-0000-0000-000000000000";
+const EMPTY_MODEL_CONFIGS: TypesGen.ChatModelConfig[] = [];
 
 // Type guard for SSE events from the chat list watch endpoint.
 function isChatListSSEEvent(
@@ -249,7 +250,10 @@ const AgentsPage: FC = () => {
 			return next;
 		});
 	}, []);
-	const chatList = chatsQuery.data?.pages.flat() ?? [];
+	const chatList = useMemo(
+		() => chatsQuery.data?.pages.flat() ?? [],
+		[chatsQuery.data],
+	);
 	const isArchiving =
 		archiveAgentMutation.isPending || archiveAndDeleteMutation.isPending;
 	const archivingChatId =
@@ -386,14 +390,15 @@ const AgentsPage: FC = () => {
 					const chatEvent = sse.data;
 					const updatedChat = chatEvent.chat;
 
-					// Read the previous status from the query cache, which
-					// is synchronously updated by both the per-chat WebSocket
-					// (via updateSidebarChat) and this handler. This avoids
-					// the async-lag of a useEffect-based status map.
-					const currentChats = readInfiniteChatsCache(queryClient);
-					const prevStatus = currentChats?.find(
+					// Read the previous status from the infinite chat list
+					// cache before we write the update below. The per-chat
+					// query cache (chatKey) only exists for chats the user
+					// has opened, so reading from the list cache ensures
+					// prevStatus is available for background agents too.
+					const prevStatus = readInfiniteChatsCache(queryClient)?.find(
 						(c) => c.id === updatedChat.id,
-					)?.status; // Only play the chime for top-level chats, not sub-agents.
+					)?.status;
+					// Only play the chime for top-level chats, not sub-agents.
 					if (!updatedChat.parent_chat_id) {
 						maybePlayChime(
 							prevStatus,
@@ -522,7 +527,7 @@ const AgentsPage: FC = () => {
 				agentId={agentId}
 				chatList={chatList}
 				catalogModelOptions={catalogModelOptions}
-				modelConfigs={chatModelConfigsQuery.data ?? []}
+				modelConfigs={chatModelConfigsQuery.data ?? EMPTY_MODEL_CONFIGS}
 				logoUrl={appearance.logo_url}
 				handleNewAgent={handleNewAgent}
 				isCreating={createMutation.isPending}