fix(webui): hide actions until turn end

webui/src/components/MessageBubble.tsx

@@ -52,6 +52,8 @@ import type {
 
 interface MessageBubbleProps {
   message: UIMessage;
+  /** The containing agent turn has not received turn_end yet. */
+  isTurnStreaming?: boolean;
   /** Give temporary-chat user turns the dashed private-mode treatment. */
   temporary?: boolean;
   /** When false, hide this message's copy button. Default true. */
@@ -260,6 +262,7 @@ function UserDeliveryStatus({
 /** Render user turns as compact bubbles and assistant turns as document-like prose. */
 export function MessageBubble({
   message,
+  isTurnStreaming = false,
   temporary = false,
   showCopyAction = true,
   cliApps = [],
@@ -381,7 +384,8 @@ export function MessageBubble({
     : "";
   const automationTriggeredLabel = t("message.automationTriggered");
 
-  const showAssistantActions = message.role === "assistant" && !message.isStreaming && !empty;
+  const showAssistantActions =
+    message.role === "assistant" && !message.isStreaming && !isTurnStreaming && !empty;
   const showCopyButton = showCopyAction && showAssistantActions;
   const showForkButton = showAssistantActions && !!onForkFromHere;
   const forkLabel = t("message.forkFromHere");

webui/src/components/thread/ThreadMessages.tsx

@@ -91,6 +91,9 @@ export function ThreadMessages({
     && pendingTurn !== null
     && !pendingTurn.hasVisibleOutput
   ) ? pendingTurn : null;
+  const currentTurnStartIndex = isStreaming
+    ? activeTurnStartIndex(units, activeTurnId)
+    : units.length;
   const unitKeys = useMemo(() => unitKeysForDisplay(units), [units]);
   let nextUserIndex = hiddenUserMessageCount;
 
@@ -140,7 +143,15 @@ export function ThreadMessages({
             userPromptId={userPromptId}
             hasBodyBelow={hasBodyBelow}
             deferOffscreenRender={deferOffscreenRender}
-            isTurnStreaming={liveActivityClusterIndices.has(index)}
+            isTurnStreaming={
+              unit.type === "activity"
+                ? liveActivityClusterIndices.has(index)
+                : isStreaming && (
+                    unit.message.turnId
+                      ? unit.message.turnId === activeTurnId
+                      : index > currentTurnStartIndex
+                  )
+            }
             forkIndex={forkIndex}
             showForkBoundary={index === forkBoundaryAfterUnitIndex}
             forkBoundaryLabel={t("thread.forkedFromHistory")}
@@ -280,6 +291,7 @@ const ThreadDisplayUnit = memo(function ThreadDisplayUnit({
         ) : (
           <MessageBubble
             message={unit.message}
+            isTurnStreaming={isTurnStreaming}
             temporary={temporary}
             cliApps={cliApps}
             mcpPresets={mcpPresets}
@@ -317,6 +329,27 @@ function threadDisplayUnitPropsEqual(
   );
 }
 
+function activeTurnStartIndex(units: DisplayUnit[], activeTurnId: string | null): number {
+  if (activeTurnId) {
+    const index = units.findIndex((unit) => (
+      unit.type === "message"
+      && unit.message.role === "user"
+      && unit.message.deliveryStatus !== "failed"
+      && unit.message.turnId === activeTurnId
+    ));
+    if (index >= 0) return index;
+  }
+  for (let i = units.length - 1; i >= 0; i -= 1) {
+    const unit = units[i];
+    if (
+      unit.type === "message"
+      && unit.message.role === "user"
+      && unit.message.deliveryStatus !== "failed"
+    ) return i;
+  }
+  return -1;
+}
+
 function displayUnitsEqual(previous: DisplayUnit, next: DisplayUnit): boolean {
   if (previous.type !== next.type) return false;
   if (previous.type === "message" && next.type === "message") {

webui/src/components/thread/ThreadShell.tsx

@@ -216,17 +216,18 @@ function isStaleThreadSnapshot(
   return snapshot.every((message, index) => sameMessageShape(current[index], message));
 }
 
-function latestActiveTurnId(messages: UIMessage[]): string | null {
+function latestActiveTurnId(messages: UIMessage[], runStartedAt: number | null): string | null {
   for (let index = messages.length - 1; index >= 0; index -= 1) {
     const message = messages[index];
     if (message.isStreaming && message.turnId) return message.turnId;
   }
+  if (runStartedAt === null) return null;
   for (let index = messages.length - 1; index >= 0; index -= 1) {
     const message = messages[index];
     if (
-      message.role === "user"
-      && message.deliveryStatus !== "failed"
+      message.role !== "user"
       && message.turnId
+      && message.createdAt >= runStartedAt * 1000
     ) return message.turnId;
   }
   return null;
@@ -808,8 +809,8 @@ export function ThreadShell({
   const currentGoalState = messagesReady ? goalState : undefined;
   const turnActive = messagesReady && (isStreaming || currentRunStartedAt !== null);
   const restoredViewportTurnId = useMemo(
-    () => turnActive ? latestActiveTurnId(displayMessages) : null,
-    [displayMessages, turnActive],
+    () => turnActive ? latestActiveTurnId(displayMessages, currentRunStartedAt) : null,
+    [currentRunStartedAt, displayMessages, turnActive],
   );
   const rememberedViewportTurnId = chatId
     ? activeViewportTurnByChatIdRef.current.get(chatId) ?? null
@@ -818,7 +819,10 @@ export function ThreadShell({
     ? client.getRunTurnId(chatId)
     : null;
   const viewportTurnId = messagesReady && turnActive
-    ? canonicalRunTurnId ?? rememberedViewportTurnId ?? restoredViewportTurnId
+    ? canonicalRunTurnId
+      ?? rememberedViewportTurnId
+      ?? historyActiveTurnId
+      ?? restoredViewportTurnId
     : null;
   const activeTurnStartedHere =
     viewportTurnId !== null && viewportTurnId === submittedViewportTurnId;