diff --git a/apps/backend/src/handlers/agent.ts b/apps/backend/src/handlers/agent.ts
index 9959a58a0..e2ad15b80 100644
--- a/apps/backend/src/handlers/agent.ts
+++ b/apps/backend/src/handlers/agent.ts
@@ -15,6 +15,7 @@ import { buildImageUrl } from '../utils/image';
 interface HandleAgentMessageInput extends AgentRequest {
 	userId: string;
 	projectId: string | undefined;
+	isProjectAdmin: boolean;
 }
 
 interface HandleAgentMessageResult {
@@ -25,7 +26,7 @@ interface HandleAgentMessageResult {
 }
 
 export const handleAgentRoute = async (opts: HandleAgentMessageInput): Promise<HandleAgentMessageResult> => {
-	const { userId, message, messageToEditId, model, mentions, projectId, adminMode } = opts;
+	const { userId, message, messageToEditId, model, mentions, projectId, isProjectAdmin } = opts;
 
 	if (!projectId) {
 		throw new HandlerError('BAD_REQUEST', noProjectMessage());
@@ -33,6 +34,11 @@ export const handleAgentRoute = async (opts: HandleAgentMessageInput): Promise<H
 
 	await agentService.assertBudget(projectId, model);
 
+	let adminMode = opts.adminMode ?? false;
+	if (opts.adminMode === undefined && isProjectAdmin && opts.chatId) {
+		adminMode = await chatQueries.wasLastUserMessageAdmin(opts.chatId);
+	}
+
 	const source: MessageSource = adminMode ? 'admin' : 'web';
 	let chatId = opts.chatId;
 	const isNewChat = !chatId;
diff --git a/apps/backend/src/queries/chat.queries.ts b/apps/backend/src/queries/chat.queries.ts
index 7396b7e1f..1941ee4fb 100644
--- a/apps/backend/src/queries/chat.queries.ts
+++ b/apps/backend/src/queries/chat.queries.ts
@@ -305,6 +305,18 @@ export const getChatOwnerId = async (chatId: string): Promise<string | undefined
 	return result?.userId;
 };
 
+export const wasLastUserMessageAdmin = async (chatId: string): Promise<boolean> => {
+	const [row] = await db
+		.select({ source: s.chatMessage.source })
+		.from(s.chatMessage)
+		.where(
+			and(eq(s.chatMessage.chatId, chatId), eq(s.chatMessage.role, 'user'), isNull(s.chatMessage.supersededAt)),
+		)
+		.orderBy(desc(s.chatMessage.createdAt))
+		.limit(1);
+	return row?.source === 'admin';
+};
+
 /** Marks all messages from a given message id onwards as superseeded (won't be used in the conversation anymore). */
 export const supersedeMessagesFrom = async (chatId: string, fromMessageId: string): Promise<void> => {
 	await db.transaction(async (t) => {
diff --git a/apps/backend/src/routes/agent.ts b/apps/backend/src/routes/agent.ts
index 265983ad9..11c96560f 100644
--- a/apps/backend/src/routes/agent.ts
+++ b/apps/backend/src/routes/agent.ts
@@ -31,6 +31,7 @@ export const agentRoutes = async (app: App) => {
 			projectId,
 			...body,
 			adminMode: body.adminMode && isProjectAdmin,
+			isProjectAdmin,
 		});
 
 		posthog.capture(user.id, PostHogEvent.MessageSent, {
diff --git a/apps/frontend/src/hooks/use-agent.ts b/apps/frontend/src/hooks/use-agent.ts
index e58d1f116..a545d02ef 100644
--- a/apps/frontend/src/hooks/use-agent.ts
+++ b/apps/frontend/src/hooks/use-agent.ts
@@ -187,7 +187,7 @@ export const useAgent = ({ disableNavigation = false }: { disableNavigation?: bo
 							model: activeSelectedModelRef.current ?? undefined,
 							mentions: mentions.length > 0 ? mentions : undefined,
 							timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
-							adminMode: adminModeAtSend || undefined,
+							adminMode: adminModeAtSend,
 						},
 					};
 				},
@@ -257,9 +257,9 @@ export const useAgent = ({ disableNavigation = false }: { disableNavigation?: bo
 		}
 	}, [error]); // eslint-disable-line react-hooks/exhaustive-deps
 
-	// Carry admin mode across an admin conversation: enable it for chats whose first or
-	// last user message was sent from admin mode, and disable it for normal chats. A
-	// freshly created chat keeps its current mode so follow-ups stay in admin mode.
+	// Carry admin mode across an admin conversation: on load, start in the mode of the latest
+	// user turn (derived from server data, which carries `source`). Once loaded, a manual toggle
+	// always wins — this effect syncs a chat only once, so it never overrides a later user toggle.
 	const syncedAdminChatRef = useRef<string | undefined>(undefined);
 	useEffect(() => {
 		if (!chatId) {
@@ -271,14 +271,14 @@ export const useAgent = ({ disableNavigation = false }: { disableNavigation?: bo
 			syncedAdminChatRef.current = chatId;
 			return;
 		}
-		if (chat.isLoading || messages.length === 0 || syncedAdminChatRef.current === chatId) {
+		const serverMessages = chat.data?.messages;
+		if (chat.isLoading || !serverMessages || serverMessages.length === 0 || syncedAdminChatRef.current === chatId) {
 			return;
 		}
 		syncedAdminChatRef.current = chatId;
-		const userMessages = messages.filter((m) => m.role === 'user');
-		const conversationIsAdmin = userMessages.at(0)?.source === 'admin' || userMessages.at(-1)?.source === 'admin';
-		setAdminMode(conversationIsAdmin);
-	}, [chatId, chat.isLoading, messages, setAdminMode]);
+		const lastUserMessage = serverMessages.filter((m) => m.role === 'user').at(-1);
+		setAdminMode(lastUserMessage?.source === 'admin');
+	}, [chatId, chat.isLoading, chat.data?.messages, setAdminMode]);
 
 	const stopAgent = useCallback(async () => {
 		if (!chatId) {