diff --git a/site/src/pages/AgentsPage/AgentChatInput.tsx b/site/src/pages/AgentsPage/AgentChatInput.tsx
index b07e99f677..81b74d60ce 100644
--- a/site/src/pages/AgentsPage/AgentChatInput.tsx
+++ b/site/src/pages/AgentsPage/AgentChatInput.tsx
@@ -324,25 +324,35 @@ export const AgentChatInput = memo<AgentChatInputProps>(
 				isEditingHistoryMessage && editingHistoryMessageID !== null
 					? editingHistoryMessageID
 					: undefined;
+			// Capture the raw input before clearing so we can restore
+			// it if the request fails.
+			const capturedInput = input;
+
+			// Clear the input and editing state immediately so the
+			// user can start typing their next message without waiting
+			// for the network round-trip.
+			setInput("");
+			onInputChange?.("");
+			if (queueEditID !== null) {
+				setEditingQueuedMessageID(null);
+				setDraftBeforeQueueEdit(null);
+			}
+			if (isEditingHistoryMessage) {
+				setIsEditingHistoryMessage(false);
+				setEditingHistoryMessageID(null);
+				setDraftBeforeHistoryEdit(null);
+				onEditCleared?.();
+			}
+
 			try {
-				await onSend(input, editedMessageID);
+				await onSend(capturedInput, editedMessageID);
 				if (queueEditID !== null && onDeleteQueuedMessage) {
 					await onDeleteQueuedMessage(queueEditID);
 				}
-				setInput("");
-				onInputChange?.("");
-				if (queueEditID !== null) {
-					setEditingQueuedMessageID(null);
-					setDraftBeforeQueueEdit(null);
-				}
-				if (isEditingHistoryMessage) {
-					setIsEditingHistoryMessage(false);
-					setEditingHistoryMessageID(null);
-					setDraftBeforeHistoryEdit(null);
-					onEditCleared?.();
-				}
 			} catch {
-				// Keep input on failure so the user can retry.
+				// Restore the input so the user can retry.
+				setInput(capturedInput);
+				onInputChange?.(capturedInput);
 			} finally {
 				// Re-focus the textarea so the user can keep typing.
 				textareaRef.current?.focus();
diff --git a/site/src/pages/AgentsPage/AgentDetail.tsx b/site/src/pages/AgentsPage/AgentDetail.tsx
index 116ed2ae17..3dc0bad79a 100644
--- a/site/src/pages/AgentsPage/AgentDetail.tsx
+++ b/site/src/pages/AgentsPage/AgentDetail.tsx
@@ -614,7 +614,31 @@ const AgentDetail: FC = () => {
 		if (scrollContainerRef.current) {
 			scrollContainerRef.current.scrollTop = 0;
 		}
-		await sendMutation.mutateAsync(request);
+
+		// Inject an optimistic user message so the bubble appears in
+		// the timeline immediately, without waiting for the server.
+		const previousMessages = getOrderedMessagesFromStore(store);
+		const previousChatStatus = store.getSnapshot().chatStatus;
+		const optimisticMessage: TypesGen.ChatMessage = {
+			id: -Date.now(),
+			chat_id: agentId,
+			created_at: new Date().toISOString(),
+			role: "user",
+			content: toOptimisticMessageParts(content),
+		};
+		store.upsertDurableMessage(optimisticMessage);
+		store.clearStreamState();
+		store.setChatStatus("pending");
+
+		try {
+			await sendMutation.mutateAsync(request);
+		} catch (error) {
+			// Roll back the optimistic message so the timeline
+			// returns to its previous state.
+			store.replaceMessages(previousMessages);
+			store.setChatStatus(previousChatStatus);
+			throw error;
+		}
 		if (typeof window !== "undefined") {
 			if (selectedModelConfigID) {
 				localStorage.setItem(