diff --git a/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/ChatMessagesContainer.tsx b/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/ChatMessagesContainer.tsx
index 620c108388..f2c0d9e442 100644
--- a/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/ChatMessagesContainer.tsx
+++ b/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/ChatMessagesContainer.tsx
@@ -51,6 +51,7 @@ function renderSegments(
   messageID: string,
   onRetry?: () => void,
   isLastMessage?: boolean,
+  isMessageStreaming?: boolean,
 ): React.ReactNode[] {
   return segments.map((seg, segIdx) => {
     if (seg.kind === "collapsed-group") {
@@ -64,6 +65,7 @@ function renderSegments(
         partIndex={seg.index}
         onRetry={onRetry}
         isLastMessage={isLastMessage}
+        isMessageStreaming={isMessageStreaming}
       />
     );
   });
@@ -375,6 +377,7 @@ export function ChatMessagesContainer({
                       message.id,
                       isLastAssistant ? onRetry : undefined,
                       isLastAssistant,
+                      isCurrentlyStreaming,
                     )
                   : message.parts.map((part, i) => (
                       <MessagePartRenderer
@@ -384,6 +387,7 @@ export function ChatMessagesContainer({
                         partIndex={i}
                         onRetry={isLastAssistant ? onRetry : undefined}
                         isLastMessage={isLastAssistant}
+                        isMessageStreaming={isCurrentlyStreaming}
                       />
                     ))}
                 {isLastInTurn && !isCurrentlyStreaming && (
diff --git a/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/components/MessagePartRenderer.tsx b/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/components/MessagePartRenderer.tsx
index b86f73d86b..a4dbfb04be 100644
--- a/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/components/MessagePartRenderer.tsx
+++ b/autogpt_platform/frontend/src/app/(platform)/copilot/components/ChatMessagesContainer/components/MessagePartRenderer.tsx
@@ -95,6 +95,7 @@ interface Props {
   partIndex: number;
   onRetry?: () => void;
   isLastMessage?: boolean;
+  isMessageStreaming?: boolean;
 }
 
 export function MessagePartRenderer({
@@ -103,6 +104,7 @@ export function MessagePartRenderer({
   partIndex,
   onRetry,
   isLastMessage,
+  isMessageStreaming,
 }: Props) {
   const key = `${messageID}-${partIndex}`;
 
@@ -176,6 +178,7 @@ export function MessagePartRenderer({
           key={key}
           part={part as ToolUIPart}
           isLastMessage={isLastMessage}
+          isMessageStreaming={isMessageStreaming}
         />
       );
     case "tool-create_agent":
diff --git a/autogpt_platform/frontend/src/app/(platform)/copilot/tools/DecomposeGoal/DecomposeGoal.tsx b/autogpt_platform/frontend/src/app/(platform)/copilot/tools/DecomposeGoal/DecomposeGoal.tsx
index 53992d9e13..33b7e5939c 100644
--- a/autogpt_platform/frontend/src/app/(platform)/copilot/tools/DecomposeGoal/DecomposeGoal.tsx
+++ b/autogpt_platform/frontend/src/app/(platform)/copilot/tools/DecomposeGoal/DecomposeGoal.tsx
@@ -68,9 +68,17 @@ interface EditableStep {
 interface Props {
   part: ToolUIPart;
   isLastMessage?: boolean;
+  // True while the parent assistant message is still streaming. We disable
+  // Approve/Modify in this window because the chat session is locked to
+  // the in-flight turn — sending a new user message would fail.
+  isMessageStreaming?: boolean;
 }
 
-export function DecomposeGoalTool({ part, isLastMessage }: Props) {
+export function DecomposeGoalTool({
+  part,
+  isLastMessage,
+  isMessageStreaming,
+}: Props) {
   const text = getAnimationText(part);
   const { onSend } = useCopilotChatActions();
 
@@ -88,6 +96,12 @@ export function DecomposeGoalTool({ part, isLastMessage }: Props) {
     isDecompositionOutput(output) &&
     output.requires_approval;
 
+  // The Approve/Modify buttons are visible (so the user knows what's
+  // coming) but click-disabled while the assistant is still streaming
+  // its summary text after the tool call. The countdown ring keeps
+  // ticking so it stays in sync with the server-side timer.
+  const actionsEnabled = showActions && !isMessageStreaming;
+
   // Authoritative countdown comes from the backend tool response so the
   // server-side fallback timer and the client are guaranteed to agree.
   const countdownSeconds =
@@ -181,14 +195,16 @@ export function DecomposeGoalTool({ part, isLastMessage }: Props) {
     return () => clearInterval(interval);
   }, [showActions, timerActive, part.toolCallId]);
 
-  // Auto-approve when countdown reaches 0 (only if timer is still active and actions visible).
-  // showActions prevents firing after isLastMessage changes (race condition guard).
+  // Auto-approve when countdown reaches 0 — but only after the assistant
+  // has finished streaming its summary text. Firing during streaming would
+  // hit the same locked-session failure as a manual click. If the timer
+  // hits 0 mid-stream, this effect re-runs when actionsEnabled flips true.
   // approve() is stable via approvedRef — safe to omit from deps.
   useEffect(() => {
-    if (secondsLeft === 0 && timerActive && showActions) {
+    if (secondsLeft === 0 && timerActive && actionsEnabled) {
       approve();
     }
-  }, [secondsLeft, timerActive, showActions]); // approve reads refs only — safe to omit
+  }, [secondsLeft, timerActive, actionsEnabled]); // approve reads refs only — safe to omit
 
   const progress = secondsLeft / countdownSeconds;
   const dashOffset = CIRCUMFERENCE * (1 - progress);
@@ -292,7 +308,11 @@ export function DecomposeGoalTool({ part, isLastMessage }: Props) {
             {showActions && (
               <div className="flex items-center gap-2 pt-1">
                 {isEditing ? (
-                  <Button variant="primary" onClick={approve}>
+                  <Button
+                    variant="primary"
+                    onClick={approve}
+                    disabled={!actionsEnabled}
+                  >
                     <span className="inline-flex items-center gap-1.5">
                       <CheckIcon size={14} weight="bold" />
                       Approve
@@ -301,7 +321,12 @@ export function DecomposeGoalTool({ part, isLastMessage }: Props) {
                 ) : (
                   <>
                     {/* Primary CTA — encourages user to run the agent */}
-                    <Button variant="primary" size="small" onClick={approve}>
+                    <Button
+                      variant="primary"
+                      size="small"
+                      onClick={approve}
+                      disabled={!actionsEnabled}
+                    >
                       <span className="group/label inline-flex items-center gap-2">
                         <span className="inline-flex items-center gap-1.5 group-hover/label:hidden">
                           Starting in
@@ -344,7 +369,12 @@ export function DecomposeGoalTool({ part, isLastMessage }: Props) {
                         </span>
                       </span>
                     </Button>
-                    <Button variant="ghost" size="small" onClick={handleModify}>
+                    <Button
+                      variant="ghost"
+                      size="small"
+                      onClick={handleModify}
+                      disabled={!actionsEnabled}
+                    >
                       <span className="inline-flex items-center gap-1.5">
                         <PencilSimpleIcon size={14} weight="bold" />
                         Modify