diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/ActiveSubtasksList.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/ActiveSubtasksList.tsx
index e289e408..f52a9b92 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/ActiveSubtasksList.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/ActiveSubtasksList.tsx
@@ -119,7 +119,7 @@ function ActiveSubtasksListContent({ taskEntryKey }: ActiveSubtasksListProps) {
 
   return (
     <div className="overflow-hidden border-b border-background">
-      <TodoListPrimitive>
+      <TodoListPrimitive className="mx-auto w-full max-w-4xl">
         <TodoListSection onOpenChange={setIsOpen} open={isOpen}>
           <TodoListSectionTrigger>
             <TodoListSectionLabel
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/DraftPromptBanner.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/DraftPromptBanner.tsx
index 7a8bef2c..0fb5b6e1 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/DraftPromptBanner.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/DraftPromptBanner.tsx
@@ -7,53 +7,55 @@ import { Button, CornerDownLeftIcon, InfoTooltip } from '@/components/system';
 interface DraftPromptBannerProps {
   draftPrompt: string;
   onClick?: () => void;
+  embedded?: boolean;
 }
 
 export function DraftPromptBanner({
   draftPrompt,
   onClick,
+  embedded = false,
 }: DraftPromptBannerProps) {
   const interactive = !!onClick;
 
-  return (
-    <div className="border-t">
-      <div className="2xl:max-w-5xl mx-auto w-full px-4 pb-5 pt-4">
-        <div
-          className={`flex gap-3 items-start ${interactive ? 'cursor-pointer hover:opacity-50' : ''}`}
-          role={interactive ? 'button' : undefined}
-          tabIndex={interactive ? 0 : undefined}
-          onClick={onClick}
-          onKeyDown={
-            interactive
-              ? (e) => {
-                  if (e.key === 'Enter' || e.key === ' ') {
-                    onClick();
-                  }
+  const banner = (
+    <div className="mx-auto w-full max-w-4xl px-4 pb-5 pt-4">
+      <div
+        className={`flex gap-3 items-start ${interactive ? 'cursor-pointer hover:opacity-50' : ''}`}
+        role={interactive ? 'button' : undefined}
+        tabIndex={interactive ? 0 : undefined}
+        onClick={onClick}
+        onKeyDown={
+          interactive
+            ? (e) => {
+                if (e.key === 'Enter' || e.key === ' ') {
+                  onClick();
                 }
-              : undefined
-          }
-        >
-          <div className="resize-none font-mono rounded-xl text-sm text-muted-foreground opacity-70 pointer-events-none">
-            {draftPrompt}
-          </div>
-          {interactive && (
-            <InfoTooltip
-              iconClassName="mt-1 size-3.5 shrink-0"
-              content={`${PRODUCT_NAME} is asleep. Wake it up to keep chatting`}
-            />
-          )}
-          <Button
-            size="icon"
-            variant="default"
-            className="ml-auto"
-            disabled
-            aria-label="Submit"
-            tabIndex={-1}
-          >
-            <CornerDownLeftIcon className="size-4" />
-          </Button>
+              }
+            : undefined
+        }
+      >
+        <div className="resize-none font-mono rounded-xl text-sm text-muted-foreground opacity-70 pointer-events-none">
+          {draftPrompt}
         </div>
+        {interactive && (
+          <InfoTooltip
+            iconClassName="mt-1 size-3.5 shrink-0"
+            content={`${PRODUCT_NAME} is asleep. Wake it up to keep chatting`}
+          />
+        )}
+        <Button
+          size="icon"
+          variant="default"
+          className="ml-auto"
+          disabled
+          aria-label="Submit"
+          tabIndex={-1}
+        >
+          <CornerDownLeftIcon className="size-4" />
+        </Button>
       </div>
     </div>
   );
+
+  return embedded ? banner : <div className="border-t">{banner}</div>;
 }
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/HistoricalContent.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/HistoricalContent.tsx
index 9726cfd6..073c1fcd 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/HistoricalContent.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/HistoricalContent.tsx
@@ -79,7 +79,7 @@ export function HistoricalContent({ session, footer }: HistoricalContentProps) {
       <PreviewPaneProvider>
         <ClosePreviewOnSleepEffect asleep={isAsleep} />
         <div className="flex h-full min-h-0 min-w-0 flex-1">
-          <FramedSurface surfaceClassName="flex flex-col bg-transparent">
+          <FramedSurface surfaceClassName="flex flex-col bg-transparent @container">
             <PreviewPaneLayout session={session}>
               <ArtifactLinkProvider session={session}>
                 <PreviewCommand
@@ -94,16 +94,18 @@ export function HistoricalContent({ session, footer }: HistoricalContentProps) {
                     footer={messagesFooter}
                   />
                   {shouldShowWakeTaskInput && taskRun ? (
-                    <WakeTaskInput
-                      taskRun={taskRun}
-                      initialPrompt={draftPrompt ?? ''}
-                    />
-                  ) : (
-                    isResuming &&
-                    draftPrompt && (
-                      <DraftPromptBanner draftPrompt={draftPrompt} />
-                    )
-                  )}
+                    <HistoricalInputTray>
+                      <WakeTaskInput
+                        taskRun={taskRun}
+                        initialPrompt={draftPrompt ?? ''}
+                        embedded
+                      />
+                    </HistoricalInputTray>
+                  ) : isResuming && draftPrompt ? (
+                    <HistoricalInputTray>
+                      <DraftPromptBanner draftPrompt={draftPrompt} embedded />
+                    </HistoricalInputTray>
+                  ) : null}
                 </div>
               </ArtifactLinkProvider>
             </PreviewPaneLayout>
@@ -115,6 +117,14 @@ export function HistoricalContent({ session, footer }: HistoricalContentProps) {
   );
 }
 
+function HistoricalInputTray({ children }: { children: ReactNode }) {
+  return (
+    <div className="mx-auto w-full overflow-clip rounded-t-md bg-card @[56rem]:rounded-t-lg transition-colors border-2 border-background rounded-b-3xl">
+      {children}
+    </div>
+  );
+}
+
 function ClosePreviewOnSleepEffect({ asleep }: { asleep: boolean }) {
   useClosePreviewOnSleep(asleep);
   return null;
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/LiveContent.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/LiveContent.tsx
index 6c3b85e9..b77e6faa 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/LiveContent.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/LiveContent.tsx
@@ -259,20 +259,16 @@ function LiveContentInner({
                   }
                 />
                 <div className="mx-auto w-full overflow-clip rounded-t-md bg-card @[56rem]:rounded-t-lg transition-colors border-2 border-background rounded-b-3xl">
-                  <div className="max-w-4xl mx-auto">
-                    <PendingUserInputRequestStateProvider
-                      taskId={session.taskId}
-                    >
-                      <TaskInputStack
-                        session={session}
-                        promptInputRef={promptInputRef}
-                        onFileSearchOpen={handleFileSearchOpen}
-                        onCommandSearchOpen={handleCommandSearchOpen}
-                        onBootStatusChange={onBootStatusChange}
-                        scrollToBottom={scrollToBottom}
-                      />
-                    </PendingUserInputRequestStateProvider>
-                  </div>
+                  <PendingUserInputRequestStateProvider taskId={session.taskId}>
+                    <TaskInputStack
+                      session={session}
+                      promptInputRef={promptInputRef}
+                      onFileSearchOpen={handleFileSearchOpen}
+                      onCommandSearchOpen={handleCommandSearchOpen}
+                      onBootStatusChange={onBootStatusChange}
+                      scrollToBottom={scrollToBottom}
+                    />
+                  </PendingUserInputRequestStateProvider>
                 </div>
               </div>
             </ArtifactLinkProvider>
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/Messages.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/Messages.client.test.tsx
index 33a66b54..7e49c9d8 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/Messages.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/Messages.client.test.tsx
@@ -88,6 +88,20 @@ vi.mock('./messages/index', () => ({
 vi.mock('./messages/acp', () => ({
   AcpMessageItem: ({ msg }: { msg: { id: string } }) => <div>{msg.id}</div>,
   AcpGroupedToolMessage: () => null,
+  AcpActivityGroupMessage: ({
+    group,
+    children,
+  }: {
+    group: { ts: number; endTs: number };
+    children: ReactNode;
+  }) => (
+    <div>
+      <button type="button">
+        Worked for {Math.round((group.endTs - group.ts) / 1000)}s
+      </button>
+      <div>{children}</div>
+    </div>
+  ),
   AcpTextMessage: ({ msg }: { msg: { text?: string } }) => (
     <div>{msg.text}</div>
   ),
@@ -482,4 +496,208 @@ describe('Messages', () => {
       }),
     );
   });
+
+  it('collapses eligible background activity between text messages', () => {
+    mockBuildAcpRenderBlocks.mockReturnValue([
+      {
+        kind: 'message',
+        msg: {
+          id: 'assistant-text-1',
+          ts: 1_000,
+          role: 'assistant',
+          kind: 'text',
+          partial: false,
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'reasoning-1',
+          ts: 2_000,
+          role: 'assistant',
+          kind: 'reasoning',
+          partial: false,
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'assistant-text-2',
+          ts: 19_000,
+          role: 'assistant',
+          kind: 'text',
+          partial: false,
+        },
+      },
+    ] as never);
+
+    render(
+      <Messages
+        session={
+          {
+            taskId: 'task-1',
+            prompt: null,
+            taskRun: null,
+            artifacts: [],
+          } as never
+        }
+      />,
+    );
+
+    expect(screen.getByText('Worked for 17s')).toBeInTheDocument();
+    expect(screen.getByText('reasoning-1')).toBeInTheDocument();
+  });
+
+  it('uses the rendered session prompt as the left boundary for initial activity', () => {
+    mockBuildAcpRenderBlocks.mockReturnValue([
+      {
+        kind: 'message',
+        msg: {
+          id: 'reasoning-1',
+          ts: 2_000,
+          role: 'assistant',
+          kind: 'reasoning',
+          partial: false,
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'assistant-text-1',
+          ts: 9_000,
+          role: 'assistant',
+          kind: 'text',
+          partial: false,
+        },
+      },
+    ] as never);
+
+    render(
+      <Messages
+        session={
+          {
+            taskId: 'task-1',
+            prompt: {
+              text: 'Initial prompt',
+              visibleInTranscript: true,
+            },
+            taskRun: null,
+            artifacts: [],
+          } as never
+        }
+      />,
+    );
+
+    expect(screen.getByText('Initial prompt')).toBeInTheDocument();
+    expect(screen.getByText('Worked for 7s')).toBeInTheDocument();
+    expect(screen.getByText('reasoning-1')).toBeInTheDocument();
+  });
+
+  it('collapses initial eligible activity even when there is no visible starting text message', () => {
+    mockBuildAcpRenderBlocks.mockReturnValue([
+      {
+        kind: 'message',
+        msg: {
+          id: 'reasoning-1',
+          ts: 2_000,
+          role: 'assistant',
+          kind: 'reasoning',
+          partial: false,
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'assistant-text-1',
+          ts: 12_000,
+          role: 'assistant',
+          kind: 'text',
+          partial: false,
+        },
+      },
+    ] as never);
+
+    render(
+      <Messages
+        session={
+          {
+            taskId: 'task-1',
+            prompt: null,
+            taskRun: null,
+            artifacts: [],
+          } as never
+        }
+      />,
+    );
+
+    expect(screen.getByText('Worked for 10s')).toBeInTheDocument();
+    expect(screen.getByText('reasoning-1')).toBeInTheDocument();
+  });
+
+  it('keeps todo section markers visible while collapsing following activity', () => {
+    mockBuildAcpRenderBlocks.mockReturnValue([
+      {
+        kind: 'message',
+        msg: {
+          id: 'reasoning-1',
+          ts: 2_000,
+          role: 'assistant',
+          kind: 'reasoning',
+          partial: false,
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'todo-1',
+          ts: 3_000,
+          role: 'assistant',
+          kind: 'todo_section',
+          partial: false,
+          data: {
+            todoId: 'todo-1',
+            content: 'Inspect repository guidance',
+          },
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'reasoning-2',
+          ts: 4_000,
+          role: 'assistant',
+          kind: 'reasoning',
+          partial: false,
+        },
+      },
+      {
+        kind: 'message',
+        msg: {
+          id: 'assistant-text-1',
+          ts: 12_000,
+          role: 'assistant',
+          kind: 'text',
+          partial: false,
+        },
+      },
+    ] as never);
+
+    render(
+      <Messages
+        session={
+          {
+            taskId: 'task-1',
+            prompt: null,
+            taskRun: null,
+            artifacts: [],
+          } as never
+        }
+      />,
+    );
+
+    expect(screen.getByText('Worked for 8s')).toBeInTheDocument();
+    expect(screen.getByText('reasoning-1')).toBeInTheDocument();
+    expect(screen.getByText('todo-1')).toBeInTheDocument();
+    expect(screen.getByText('reasoning-2')).toBeInTheDocument();
+  });
 });
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/Messages.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/Messages.tsx
index 70ae33ec..2c6e81c8 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/Messages.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/Messages.tsx
@@ -40,8 +40,13 @@ import { SleepWakeMessages } from './messages/index';
 import {
   AcpMessageItem,
   AcpGroupedToolMessage,
+  AcpActivityGroupMessage,
   AcpTextMessage,
 } from './messages/acp';
+import {
+  buildAcpActivityRenderBlocks,
+  type AcpConversationRenderBlock,
+} from './messages/acp/activity-groups';
 import {
   buildAcpRenderBlocks,
   type AcpRenderBlock,
@@ -120,7 +125,11 @@ function DebugTimestamp({
   );
 }
 
-function blockUsesOwnTimestamp(block: AcpRenderBlock): boolean {
+function blockUsesOwnTimestamp(block: AcpConversationRenderBlock): boolean {
+  if (block.kind === 'activity_group') {
+    return false;
+  }
+
   if (block.kind === 'tool_group') {
     return false;
   }
@@ -139,8 +148,14 @@ function blockUsesOwnTimestamp(block: AcpRenderBlock): boolean {
   }
 }
 
-function hasVisibleAssistantOutput(blocks: AcpRenderBlock[]): boolean {
+function hasVisibleAssistantOutput(
+  blocks: AcpConversationRenderBlock[],
+): boolean {
   return blocks.some((block) => {
+    if (block.kind === 'activity_group') {
+      return hasVisibleAssistantOutput(block.blocks);
+    }
+
     if (block.kind === 'tool_group') {
       return false;
     }
@@ -211,24 +226,30 @@ const MessagesBase = ({
   const resolvedHideFirstAcpUserPrompt =
     hideFirstAcpUserPrompt ?? shouldRenderSessionPrompt;
 
-  const renderBlocks = useMemo(
-    () =>
-      buildAcpRenderBlocks(messages, {
-        displayMode: resolvedMessageUiOptions.displayMode,
-        initialPrompt: resolvedHideFirstAcpUserPrompt ? sessionPrompt : null,
-        shouldHideFirstMessage: resolvedHideFirstAcpUserPrompt,
-        showInternalMessages,
-        suppressedMessageIds,
-      }),
-    [
-      messages,
-      resolvedHideFirstAcpUserPrompt,
-      resolvedMessageUiOptions.displayMode,
-      sessionPrompt,
+  const renderBlocks = useMemo(() => {
+    const acpBlocks = buildAcpRenderBlocks(messages, {
+      displayMode: resolvedMessageUiOptions.displayMode,
+      initialPrompt: resolvedHideFirstAcpUserPrompt ? sessionPrompt : null,
+      shouldHideFirstMessage: resolvedHideFirstAcpUserPrompt,
       showInternalMessages,
       suppressedMessageIds,
-    ],
-  );
+    });
+
+    return buildAcpActivityRenderBlocks(acpBlocks, {
+      artifacts: session.artifacts,
+      displayMode: resolvedMessageUiOptions.displayMode,
+      hasLeadingTextBoundary: shouldRenderSessionPrompt,
+    });
+  }, [
+    messages,
+    resolvedHideFirstAcpUserPrompt,
+    resolvedMessageUiOptions.displayMode,
+    session.artifacts,
+    sessionPrompt,
+    shouldRenderSessionPrompt,
+    showInternalMessages,
+    suppressedMessageIds,
+  ]);
   const hasVisibleAssistantOutputInTranscript =
     hasVisibleAssistantOutput(renderBlocks);
   const shouldShowNarrationWorkingReasoning =
@@ -244,25 +265,72 @@ const MessagesBase = ({
     ));
   }
 
-  function renderRenderBlock(block: AcpRenderBlock, nested: boolean) {
+  function renderRenderBlock(
+    block: AcpConversationRenderBlock,
+    nested: boolean,
+  ) {
     const timestamp =
       showInternalMessages && !blockUsesOwnTimestamp(block) ? (
         <DebugTimestamp
-          ts={block.kind === 'tool_group' ? block.ts : block.msg.ts}
+          ts={
+            block.kind === 'activity_group'
+              ? block.ts
+              : block.kind === 'tool_group'
+                ? block.ts
+                : block.msg.ts
+          }
           previousTs={
-            block.kind === 'tool_group'
-              ? block.items[0]?.msg.previousTs
-              : block.msg.previousTs
+            block.kind === 'activity_group'
+              ? block.blocks[0]?.kind === 'tool_group'
+                ? block.blocks[0].items[0]?.msg.previousTs
+                : block.blocks[0]?.msg.previousTs
+              : block.kind === 'tool_group'
+                ? block.items[0]?.msg.previousTs
+                : block.msg.previousTs
           }
           anchorId={
-            block.kind === 'tool_group'
+            block.kind === 'activity_group'
               ? messageAnchorId(block.ts)
-              : messageAnchorId(block.msg.ts)
+              : block.kind === 'tool_group'
+                ? messageAnchorId(block.ts)
+                : messageAnchorId(block.msg.ts)
           }
           isUser={block.kind === 'message' && block.msg.role === 'user'}
         />
       ) : null;
 
+    if (block.kind === 'activity_group') {
+      const content = (
+        <AcpActivityGroupMessage
+          group={block}
+          anchorIds={collectBlockAnchorIds(block.blocks, [
+            messageAnchorId(block.ts),
+          ])}
+        >
+          {renderNestedBlocks(block.blocks)}
+        </AcpActivityGroupMessage>
+      );
+
+      const blockWithTimestamp = (
+        <>
+          {content}
+          {timestamp}
+        </>
+      );
+
+      return nested ? (
+        blockWithTimestamp
+      ) : (
+        <LazyMessage
+          key={block.id}
+          anchorId={messageAnchorId(block.ts)}
+          forceVisible={block.blocks.some(blockHasPartialMessage)}
+        >
+          {blockWithTimestamp}
+        </LazyMessage>
+      );
+    }
+
     if (block.kind === 'tool_group') {
       const content = (
         <AcpGroupedToolMessage
@@ -351,3 +419,56 @@ const MessagesBase = ({
 export const Messages = memo(MessagesBase);
 
 Messages.displayName = 'Messages';
+
+function collectBlockAnchorIds(
+  blocks: AcpRenderBlock[],
+  excludedAnchorIds: string[] = [],
+): string[] {
+  const excluded = new Set(excludedAnchorIds);
+  const anchorIds: string[] = [];
+
+  const pushAnchor = (anchorId: string) => {
+    if (excluded.has(anchorId)) {
+      return;
+    }
+
+    excluded.add(anchorId);
+    anchorIds.push(anchorId);
+  };
+
+  collectBlockAnchorIdsInto(blocks, pushAnchor);
+
+  return anchorIds;
+}
+
+function collectBlockAnchorIdsInto(
+  blocks: AcpRenderBlock[],
+  pushAnchor: (anchorId: string) => void,
+): void {
+  for (const block of blocks) {
+    if (block.kind === 'tool_group') {
+      pushAnchor(messageAnchorId(block.ts));
+      for (const item of block.items) {
+        pushAnchor(messageAnchorId(item.msg.ts));
+      }
+      continue;
+    }
+
+    pushAnchor(messageAnchorId(block.msg.ts));
+
+    if (block.childBlocks) {
+      collectBlockAnchorIdsInto(block.childBlocks, pushAnchor);
+    }
+  }
+}
+
+function blockHasPartialMessage(block: AcpRenderBlock): boolean {
+  if (block.kind === 'tool_group') {
+    return block.items.some((item) => item.msg.partial);
+  }
+
+  return (
+    block.msg.partial ||
+    Boolean(block.childBlocks?.some(blockHasPartialMessage))
+  );
+}
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/PendingEnvVarRequestPanel.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/PendingEnvVarRequestPanel.tsx
index 7c292702..9b2586f3 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/PendingEnvVarRequestPanel.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/PendingEnvVarRequestPanel.tsx
@@ -271,7 +271,7 @@ export function PendingEnvVarRequestPanel({
 
   return (
     <div className="min-h-80 md:min-h-auto border-b border-background">
-      <div className="w-full p-4 text-foreground">
+      <div className="mx-auto w-full max-w-4xl p-4 text-foreground">
         <div className="md:space-y-2">
           <div className="flex items-start justify-between gap-3 mb-2 md:mb-0">
             <div className="flex items-center gap-2">
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/PendingUserInputRequestCard.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/PendingUserInputRequestCard.tsx
index c4fa7fad..21be3c25 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/PendingUserInputRequestCard.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/PendingUserInputRequestCard.tsx
@@ -241,7 +241,7 @@ export function PendingUserInputRequestCard({
   }
 
   return (
-    <div className="w-full px-4 pt-3 pb-3.5 text-foreground">
+    <div className="mx-auto w-full max-w-4xl px-4 pt-3 pb-3.5 text-foreground">
       <div className="space-y-3.5">
         <div className="flex items-start justify-between gap-3">
           <div className="flex items-start gap-1.5 text-xs leading-5 text-foreground">
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/QueuedMessages.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/QueuedMessages.tsx
index a56e877d..9ca67aa1 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/QueuedMessages.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/QueuedMessages.tsx
@@ -209,7 +209,7 @@ export const QueuedMessagesContent = ({
   }
 
   return (
-    <div className="2xl:max-w-5xl mx-auto w-full">
+    <div className="mx-auto w-full max-w-4xl">
       <QueuedMessagesList>
         <QueuedMessagesSectionLabel />
         <QueuedMessagesItems>
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/TaskInputStack.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/TaskInputStack.tsx
index f9275bfe..345d3389 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/TaskInputStack.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/TaskInputStack.tsx
@@ -54,7 +54,7 @@ export function TaskInputStack({
       />
       <QueuedMessages />
       {bootingTaskRun ? (
-        <div className="flex max-h-[50vh] min-h-0 flex-col">
+        <div className="mx-auto flex max-h-[50vh] min-h-0 w-full max-w-4xl flex-col">
           <Startup
             runId={bootingTaskRun.id}
             initialTaskRun={bootingTaskRun}
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.client.test.tsx
index 6ce50a42..c0b7d31c 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.client.test.tsx
@@ -1,4 +1,4 @@
-import { act, render, screen } from '@testing-library/react';
+import { fireEvent, render, screen } from '@testing-library/react';
 import type { AcpPlanTodo } from '@roomote/types';
 
 const {
@@ -43,7 +43,7 @@ describe('TodoList', () => {
     useSandboxTaskPhaseMock.mockReturnValue('running');
   });
 
-  it('opens populated todos by default', () => {
+  it('starts collapsed by default', () => {
     useSandboxTodosMock.mockReturnValue([
       { id: '1', content: 'Inspect layout', status: 'in_progress' },
       { id: '2', content: 'Move the todo block', status: 'pending' },
@@ -55,9 +55,17 @@ describe('TodoList', () => {
     expect(
       screen.getByRole('button', { name: /1 of 3 to-dos done/i }),
     ).toBeVisible();
+    expect(screen.queryByText('Inspect layout')).not.toBeInTheDocument();
+    expect(screen.queryByText('Move the todo block')).not.toBeInTheDocument();
+    expect(
+      screen.queryByText('Verify prompt alignment'),
+    ).not.toBeInTheDocument();
+
+    fireEvent.click(
+      screen.getByRole('button', { name: /1 of 3 to-dos done/i }),
+    );
+
     expect(screen.getByText('Inspect layout')).toBeVisible();
-    expect(screen.getByText('Move the todo block')).toBeVisible();
-    expect(screen.getByText('Verify prompt alignment')).toBeVisible();
   });
 
   it('starts collapsed on mobile task entry', () => {
@@ -93,7 +101,7 @@ describe('TodoList', () => {
       const { rerender } = render(<TodoList taskEntryKey="task-1" />);
 
       expect(
-        screen.getByRole('button', { name: /2 to-dos done/i }),
+        screen.getByRole('button', { name: /All 2 to-dos done/i }),
       ).toBeVisible();
       expect(screen.queryByText('Inspect layout')).not.toBeInTheDocument();
 
@@ -127,52 +135,29 @@ describe('TodoList', () => {
     expect(container).toBeEmptyDOMElement();
   });
 
-  it('collapses when the last todo completes, then hides it after 10 seconds', () => {
-    vi.useFakeTimers();
-
-    try {
-      useSandboxTodosMock.mockReturnValue([
-        { id: '1', content: 'Inspect layout', status: 'in_progress' },
-        { id: '2', content: 'Move the todo block', status: 'completed' },
-      ]);
-
-      const { rerender } = render(<TodoList taskEntryKey="task-1" />);
-
-      expect(
-        screen.getByRole('button', { name: /1 of 2 to-dos done/i }),
-      ).toBeVisible();
-      expect(screen.getByText('Inspect layout')).toBeVisible();
-
-      useSandboxTodosMock.mockReturnValue([
-        { id: '1', content: 'Inspect layout', status: 'completed' },
-        { id: '2', content: 'Move the todo block', status: 'completed' },
-      ]);
-
-      rerender(<TodoList taskEntryKey="task-1" />);
+  it('collapses when the last todo completes and stays visible', () => {
+    useSandboxTodosMock.mockReturnValue([
+      { id: '1', content: 'Inspect layout', status: 'in_progress' },
+      { id: '2', content: 'Move the todo block', status: 'completed' },
+    ]);
 
-      expect(
-        screen.getByRole('button', { name: /2 to-dos done/i }),
-      ).toBeVisible();
-      expect(screen.queryByText('Inspect layout')).not.toBeInTheDocument();
+    const { rerender } = render(<TodoList taskEntryKey="task-1" />);
 
-      act(() => {
-        vi.advanceTimersByTime(9_000);
-      });
+    expect(
+      screen.getByRole('button', { name: /1 of 2 to-dos done/i }),
+    ).toBeVisible();
 
-      expect(
-        screen.getByRole('button', { name: /2 to-dos done/i }),
-      ).toBeVisible();
+    useSandboxTodosMock.mockReturnValue([
+      { id: '1', content: 'Inspect layout', status: 'completed' },
+      { id: '2', content: 'Move the todo block', status: 'completed' },
+    ]);
 
-      act(() => {
-        vi.advanceTimersByTime(1_000);
-      });
+    rerender(<TodoList taskEntryKey="task-1" />);
 
-      expect(
-        screen.queryByRole('button', { name: /2 to-dos done/i }),
-      ).not.toBeInTheDocument();
-    } finally {
-      vi.useRealTimers();
-    }
+    expect(
+      screen.getByRole('button', { name: /All 2 to-dos done/i }),
+    ).toBeVisible();
+    expect(screen.queryByText('Inspect layout')).not.toBeInTheDocument();
   });
 
   it('does not present stale unfinished todos as active when the task is idle', () => {
@@ -184,6 +169,10 @@ describe('TodoList', () => {
 
     const { container } = render(<TodoList taskEntryKey="task-1" />);
 
+    fireEvent.click(
+      screen.getByRole('button', { name: /0 of 2 to-dos done/i }),
+    );
+
     const items = Array.from(container.querySelectorAll('li'));
 
     expect(items).toHaveLength(2);
@@ -201,6 +190,10 @@ describe('TodoList', () => {
 
     const { container } = render(<TodoList taskEntryKey="task-1" />);
 
+    fireEvent.click(
+      screen.getByRole('button', { name: /1 of 3 to-dos done/i }),
+    );
+
     const items = Array.from(container.querySelectorAll('li'));
 
     expect(items).toHaveLength(3);
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.tsx
index 5d0ab3ea..acf1a6b8 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/TodoList.tsx
@@ -21,7 +21,6 @@ import {
 } from './hooks/SandboxProvider';
 import { getDisplayedTodoStatus } from './todo-status';
 
-const HIDE_COMPLETED_TODOS_DELAY_MS = 10_000;
 const TODO_INACTIVE_TASK_PHASES: ReadonlySet<string> = new Set([
   'idle',
   'waiting_for_prompt',
@@ -67,8 +66,7 @@ const TodoListContent = ({ autoCollapseKey, taskEntryKey }: TodoListProps) => {
 
   const completedCount = todos.filter((t) => t.status === 'completed').length;
   const allDone = todos.length > 0 && completedCount === todos.length;
-  const [isHiddenAfterCompletion, setIsHiddenAfterCompletion] = useState(false);
-  const [isOpen, setIsOpen] = useState(() => !allDone);
+  const [isOpen, setIsOpen] = useState(false);
   const autoCollapsedKeysRef = useRef(new Set<string>());
   const wasAllDoneRef = useRef(allDone);
 
@@ -104,7 +102,6 @@ const TodoListContent = ({ autoCollapseKey, taskEntryKey }: TodoListProps) => {
 
   useEffect(() => {
     if (!allDone) {
-      setIsHiddenAfterCompletion(false);
       if (wasAllDoneRef.current) {
         setIsOpen(true);
       }
@@ -114,22 +111,15 @@ const TodoListContent = ({ autoCollapseKey, taskEntryKey }: TodoListProps) => {
 
     wasAllDoneRef.current = true;
     setIsOpen(false);
-    setIsHiddenAfterCompletion(false);
-
-    const hideTimer = window.setTimeout(() => {
-      setIsHiddenAfterCompletion(true);
-    }, HIDE_COMPLETED_TODOS_DELAY_MS);
-
-    return () => window.clearTimeout(hideTimer);
   }, [allDone, todoStatusSignature]);
 
-  if (todos.length === 0 || isHiddenAfterCompletion) {
+  if (todos.length === 0) {
     return null;
   }
 
   return (
     <div className="overflow-hidden border-b border-background">
-      <TodoListPrimitive>
+      <TodoListPrimitive className="mx-auto w-full max-w-4xl">
         <TodoListSection
           allCompleted={allDone}
           onOpenChange={setIsOpen}
@@ -139,7 +129,7 @@ const TodoListContent = ({ autoCollapseKey, taskEntryKey }: TodoListProps) => {
             <TodoListSectionLabel
               label={
                 allDone
-                  ? `${completedCount} to-dos done`
+                  ? `All ${completedCount} to-dos done`
                   : `${completedCount} of ${todos.length} to-dos done`
               }
             />
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.client.test.tsx
index 3a6abe00..0be3d59d 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.client.test.tsx
@@ -24,6 +24,8 @@ const {
 let capturedPlaceholder: string | undefined;
 let capturedSuggestion: unknown;
 let capturedSubmitWithMetaKey: boolean | undefined;
+let capturedSubmitIcon: unknown;
+let capturedSurface: string | undefined;
 const submittedFilesRef: {
   current: Array<{
     url?: string;
@@ -83,6 +85,8 @@ vi.mock('@/components/tasks', () => ({
     placeholder,
     suggestion,
     submitWithMetaKey,
+    submitIcon,
+    surface,
   }: {
     isBusy: boolean;
     promptText: string;
@@ -98,10 +102,14 @@ vi.mock('@/components/tasks', () => ({
     placeholder?: string;
     suggestion?: unknown;
     submitWithMetaKey?: boolean;
+    submitIcon?: unknown;
+    surface?: string;
   }) => {
     capturedPlaceholder = placeholder;
     capturedSuggestion = suggestion;
     capturedSubmitWithMetaKey = submitWithMetaKey;
+    capturedSubmitIcon = submitIcon;
+    capturedSurface = surface;
 
     return (
       <div>
@@ -140,6 +148,8 @@ describe('WakeTaskInput', () => {
     capturedPlaceholder = undefined;
     capturedSuggestion = undefined;
     capturedSubmitWithMetaKey = undefined;
+    capturedSubmitIcon = undefined;
+    capturedSurface = undefined;
     submittedFilesRef.current = [];
     preparePromptAttachmentsMock.mockResolvedValue({
       text: 'Wake up and keep going',
@@ -152,6 +162,47 @@ describe('WakeTaskInput', () => {
     useSandboxCurrentUserInfoMock.mockReturnValue(null);
   });
 
+  it('shows a wake icon until the user types a message', () => {
+    const queryClient = new QueryClient({
+      defaultOptions: {
+        queries: { retry: false },
+      },
+    });
+
+    renderWithQueryClient(
+      <WakeTaskInput
+        taskRun={{ id: 42, snapshotId: 'snap-42', taskId: 'task-42' }}
+      />,
+      queryClient,
+    );
+
+    expect(capturedSubmitIcon).toBeTruthy();
+
+    fireEvent.change(screen.getByLabelText('Wake prompt'), {
+      target: { value: 'keep going' },
+    });
+
+    expect(capturedSubmitIcon).toBeUndefined();
+  });
+
+  it('uses an embedded prompt surface when rendered inside a tray', () => {
+    const queryClient = new QueryClient({
+      defaultOptions: {
+        queries: { retry: false },
+      },
+    });
+
+    renderWithQueryClient(
+      <WakeTaskInput
+        taskRun={{ id: 42, snapshotId: 'snap-42', taskId: 'task-42' }}
+        embedded
+      />,
+      queryClient,
+    );
+
+    expect(capturedSurface).toBe('embedded');
+  });
+
   it('prefills the sleeping draft, appends an optimistic transcript row, and resumes the task with a deferred prompt', async () => {
     const queryClient = new QueryClient({
       defaultOptions: {
@@ -209,7 +260,7 @@ describe('WakeTaskInput', () => {
       }),
     ]);
     expect(toastErrorMock).not.toHaveBeenCalled();
-    expect(capturedPlaceholder).toBe('Wake up Roomote with this message');
+    expect(capturedPlaceholder).toBe('Wake up Roomote with a message...');
     expect(capturedSuggestion).toBeUndefined();
     expect(capturedSubmitWithMetaKey).toBe(false);
   });
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.tsx
index fff0f555..36b1d3af 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/WakeTaskInput.tsx
@@ -5,20 +5,24 @@ import { toast } from 'sonner';
 
 import type { PromptInputMessage } from '@/components/ai-elements';
 import { TaskPromptInput } from '@/components/tasks';
+import { Sun } from '@/components/system';
 import { useRestoreTaskRunSnapshot } from '@/hooks/snapshots';
 import { preparePromptAttachments } from '@/lib/prompt-attachments';
 import type { TaskRunDetail } from '@/lib/server';
+import { cn } from '@/lib/utils';
 
 import { useOptimisticPromptSubmission } from './prompt-input/useOptimisticPromptSubmission';
 
 interface WakeTaskInputProps {
   taskRun: Pick<TaskRunDetail, 'id' | 'snapshotId' | 'taskId'>;
   initialPrompt?: string;
+  embedded?: boolean;
 }
 
 export function WakeTaskInput({
   taskRun,
   initialPrompt = '',
+  embedded = false,
 }: WakeTaskInputProps) {
   const {
     rollbackOptimisticPromptSubmission,
@@ -115,19 +119,26 @@ export function WakeTaskInput({
     }
   };
 
-  return (
-    <div className="border-t">
-      <div className="mx-auto w-full max-w-4xl px-4 pt-4 pb-5">
-        <TaskPromptInput
-          isBusy={isBusy}
-          promptText={promptText}
-          onPromptTextChange={setPromptText}
-          onSubmit={handleSubmit}
-          placeholder="Wake up Roomote with this message"
-          animateContainer={false}
-          submitWithMetaKey={false}
-        />
-      </div>
+  const input = (
+    <div
+      className={cn(
+        'mx-auto w-full max-w-4xl',
+        embedded ? '' : 'px-4 pt-4 pb-5',
+      )}
+    >
+      <TaskPromptInput
+        isBusy={isBusy}
+        promptText={promptText}
+        onPromptTextChange={setPromptText}
+        onSubmit={handleSubmit}
+        placeholder="Wake up Roomote with a message..."
+        animateContainer={false}
+        submitWithMetaKey={false}
+        submitIcon={promptText.trim().length === 0 ? <Sun /> : undefined}
+        surface={embedded ? 'embedded' : 'default'}
+      />
     </div>
   );
+
+  return embedded ? input : <div className="border-t">{input}</div>;
 }
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpActivityGroupMessage.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpActivityGroupMessage.tsx
new file mode 100644
index 00000000..16062174
--- /dev/null
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpActivityGroupMessage.tsx
@@ -0,0 +1,81 @@
+'use client';
+
+import type { ReactNode } from 'react';
+
+import {
+  ChevronRight,
+  Collapsible,
+  CollapsibleContent,
+  CollapsibleTrigger,
+} from '@/components/system';
+import { cn } from '@/lib/utils';
+
+import type { AcpActivityGroupRenderBlock } from './activity-groups';
+
+interface AcpActivityGroupMessageProps {
+  group: AcpActivityGroupRenderBlock;
+  anchorIds?: string[];
+  children: ReactNode;
+}
+
+export function AcpActivityGroupMessage({
+  group,
+  anchorIds = [],
+  children,
+}: AcpActivityGroupMessageProps) {
+  return (
+    <Collapsible
+      defaultOpen={false}
+      className="group/acp-activity my-3"
+      data-testid="acp-activity-group"
+    >
+      {anchorIds.map((anchorId) => (
+        <div
+          key={anchorId}
+          id={anchorId}
+          aria-hidden="true"
+          className="h-0 overflow-hidden"
+        />
+      ))}
+      <div className="flex items-center gap-3">
+        <CollapsibleTrigger
+          className={cn(
+            'flex shrink-0 cursor-pointer items-center gap-1.5 text-sm font-light text-muted-foreground transition-colors hover:text-foreground',
+            'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring/40',
+          )}
+        >
+          <ChevronRight className="size-4 transition-transform group-data-[state=open]/acp-activity:rotate-90" />
+          <span>Worked for {formatWorkedDuration(group.endTs - group.ts)}</span>
+        </CollapsibleTrigger>
+        <div
+          className="h-px min-w-8 flex-1 border-t border-border/20 relative top-px"
+          aria-hidden="true"
+        />
+      </div>
+      <CollapsibleContent className="mt-4 space-y-0 border-l border-border pl-4 ml-2 data-[state=closed]:fade-out-0 data-[state=closed]:slide-out-to-top-2 data-[state=open]:slide-in-from-top-2 data-[state=closed]:animate-out data-[state=open]:animate-in">
+        {children}
+      </CollapsibleContent>
+    </Collapsible>
+  );
+}
+
+function formatWorkedDuration(durationMs: number): string {
+  const totalSeconds = Math.max(1, Math.round(durationMs / 1000));
+  const hours = Math.floor(totalSeconds / 3600);
+  const minutes = Math.floor((totalSeconds % 3600) / 60);
+  const seconds = totalSeconds % 60;
+
+  if (totalSeconds < 13) {
+    return 'a bit';
+  }
+
+  if (hours > 0) {
+    return minutes > 0 ? `${hours}h ${minutes}m` : `${hours}h`;
+  }
+
+  if (minutes > 0) {
+    return seconds > 0 ? `${minutes}m ${seconds}s` : `${minutes}m`;
+  }
+
+  return `${seconds}s`;
+}
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpCommandOutputMessage.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpCommandOutputMessage.tsx
index b570c3bf..adeb906c 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpCommandOutputMessage.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpCommandOutputMessage.tsx
@@ -60,9 +60,7 @@ export const AcpCommandOutputMessage = ({
         : `exit ${cmd.exitCode}`
       : status === 'failed'
         ? 'failed'
-        : status === 'completed'
-          ? 'completed'
-          : null;
+        : null;
 
   return (
     <Message from="assistant" className={cn('chat-command-output-message')}>
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpGroupedToolMessage.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpGroupedToolMessage.tsx
index 71092882..607db3db 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpGroupedToolMessage.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpGroupedToolMessage.tsx
@@ -7,6 +7,9 @@ import {
   FolderIcon,
   Loader2,
   Search,
+  SquarePen,
+  Terminal,
+  Wrench,
 } from '@/components/system';
 import {
   Message,
@@ -21,8 +24,8 @@ import { messageAnchorId } from '../message-anchor';
 import { AcpToolDetails } from './AcpToolDetails';
 import { hidesExpandedToolResult } from './tool-detail-visibility';
 import type {
-  ExplorationStepKind,
   GroupedToolCallRenderBlock,
+  GroupedToolDisplayKind,
 } from './render-blocks';
 
 interface AcpGroupedToolMessageProps {
@@ -58,7 +61,11 @@ export function AcpGroupedToolMessage({
       ? 'input-available'
       : 'output-available';
 
-  const ToolIcon = groupedToolIcon({ hasFailed, hasRunning });
+  const ToolIcon = groupedToolIcon({
+    displayKind: group.displayKind,
+    hasFailed,
+    hasRunning,
+  });
 
   return (
     <Message from="assistant" className="chat-tool-use-message">
@@ -80,7 +87,7 @@ export function AcpGroupedToolMessage({
             collapsible={showExpandedDetails}
           />
           {showExpandedDetails ? (
-            <ToolContent className="mt-2 space-y-4">
+            <ToolContent className="space-y-3 px-4 ml-1.5 mb-4 mt-2 border-l text-sm font-light text-muted-foreground">
               {group.items.map((item) => {
                 const sectionTitle = sanitizeSandboxPathString(
                   item.objectLabel,
@@ -93,7 +100,7 @@ export function AcpGroupedToolMessage({
                   <section key={item.msg.id} className="space-y-2">
                     <div className="flex min-w-0 items-center gap-1.5 text-xs font-medium tracking-wide text-muted-foreground">
                       <GroupedToolItemIcon
-                        stepKind={item.stepKind}
+                        displayKind={item.displayKind}
                         className="size-3 shrink-0"
                       />
                       <span className="truncate">{sectionTitle}</span>
@@ -117,28 +124,48 @@ export function AcpGroupedToolMessage({
 }
 
 function groupedToolIcon(params: {
+  displayKind: GroupedToolDisplayKind;
   hasRunning: boolean;
   hasFailed: boolean;
 }): LucideIcon {
   if (params.hasRunning) return Loader2;
   if (params.hasFailed) return AlertCircle;
-  return Search;
+  return groupedDisplayKindIcon(params.displayKind);
 }
 
 function GroupedToolItemIcon({
-  stepKind,
+  displayKind,
   className,
 }: {
-  stepKind: ExplorationStepKind;
+  displayKind: GroupedToolDisplayKind;
   className?: string;
 }) {
-  if (stepKind === 'search') {
-    return <Search className={className} />;
+  const Icon = groupedDisplayKindIcon(displayKind);
+  return <Icon className={className} />;
+}
+
+function groupedDisplayKindIcon(
+  displayKind: GroupedToolDisplayKind,
+): LucideIcon {
+  if (displayKind === 'search') {
+    return Search;
+  }
+
+  if (displayKind === 'list') {
+    return FolderIcon;
+  }
+
+  if (displayKind === 'read') {
+    return FileIcon;
+  }
+
+  if (displayKind === 'execute') {
+    return Terminal;
   }
 
-  if (stepKind === 'list') {
-    return <FolderIcon className={className} />;
+  if (displayKind === 'edit') {
+    return SquarePen;
   }
 
-  return <FileIcon className={className} />;
+  return Wrench;
 }
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpTodoSectionMessage.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpTodoSectionMessage.tsx
index 117e4bd9..3d0a9780 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpTodoSectionMessage.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpTodoSectionMessage.tsx
@@ -2,7 +2,7 @@ import { Message, MessageContent } from '@/components/ai-elements';
 
 import { messageAnchorId } from '../message-anchor';
 import type { AcpTodoSectionUiMessage } from './types';
-import { ArrowRight } from 'lucide-react';
+import { SquareDashed } from 'lucide-react';
 
 interface AcpTodoSectionMessageProps {
   msg: AcpTodoSectionUiMessage;
@@ -12,16 +12,16 @@ export function AcpTodoSectionMessage({ msg }: AcpTodoSectionMessageProps) {
   const anchorId = messageAnchorId(msg.ts);
   return (
     <Message from="assistant" className="chat-todo-section-message">
-      <MessageContent id={anchorId} className="py-4">
+      <MessageContent id={anchorId} className="cursor-default">
         <div className="flex min-w-0 items-center gap-2 text-muted-foreground">
-          <ArrowRight className="size-3 shrink-0" />
           <p className="min-w-0 truncate text-sm font-medium">
+            <SquareDashed className="inline size-3 mr-2" />
             <span className="font-light">Starting on </span>
             {msg.data.content}
           </p>
           <div
             aria-hidden="true"
-            className="h-0.5 min-w-8 grow border-t-1 border-border dark:border-border/50 border-dashed relative top-0.5"
+            className="h-0.5 min-w-8 grow border-t border-border relative top-0.5"
           />
         </div>
       </MessageContent>
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolDetails.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolDetails.tsx
index 0b30629d..3f4a21ba 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolDetails.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolDetails.tsx
@@ -49,7 +49,7 @@ export function AcpToolDetails({
   if (isSubagent && subagentPrompt) {
     return (
       <div
-        className="rounded-xl border px-4 py-2 text-sm whitespace-pre-wrap text-foreground/80"
+        className="whitespace-pre-wrap text-sm font-light text-muted-foreground"
         style={{ maxHeight, overflow: 'auto' }}
       >
         {sanitizeSandboxPathString(subagentPrompt)}
@@ -58,7 +58,14 @@ export function AcpToolDetails({
   }
 
   return sanitizedText ? (
-    <CodeBlock code={sanitizedText} language="bash" maxHeight={maxHeight} />
+    <CodeBlock
+      code={sanitizedText}
+      language="bash"
+      maxHeight={maxHeight}
+      variant="compact"
+      highlight={false}
+      className="[&>div]:rounded-none [&>div]:bg-transparent [&_pre]:px-0 [&_pre]:py-0"
+    />
   ) : (
     <ToolInput
       input={sanitizedToolData}
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolMessage.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolMessage.tsx
index 3136ca4f..9a5cdd9e 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolMessage.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/AcpToolMessage.tsx
@@ -135,7 +135,7 @@ export function AcpToolMessage({
             </div>
           ) : null}
           {showCollapsibleContent ? (
-            <ToolContent className="mt-2">
+            <ToolContent className="px-4 ml-1.5 mb-4 mt-2 border-l text-sm font-light text-muted-foreground">
               {showExpandedDetails ? (
                 <AcpToolDetails
                   msg={msg}
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpActivityGroupMessage.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpActivityGroupMessage.client.test.tsx
new file mode 100644
index 00000000..4fda3398
--- /dev/null
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpActivityGroupMessage.client.test.tsx
@@ -0,0 +1,37 @@
+import { fireEvent, render, screen } from '@testing-library/react';
+
+import { AcpActivityGroupMessage } from '../AcpActivityGroupMessage';
+import type { AcpActivityGroupRenderBlock } from '../activity-groups';
+
+function buildGroup(): AcpActivityGroupRenderBlock {
+  return {
+    kind: 'activity_group',
+    id: 'activity-1',
+    ts: 1_000,
+    endTs: 18_000,
+    blocks: [],
+  };
+}
+
+describe('AcpActivityGroupMessage', () => {
+  it('starts collapsed and expands to reveal activity details', () => {
+    render(
+      <AcpActivityGroupMessage
+        group={buildGroup()}
+        anchorIds={['activity-anchor']}
+      >
+        <div>Hidden activity</div>
+      </AcpActivityGroupMessage>,
+    );
+
+    expect(
+      screen.getByRole('button', { name: /Worked for 17s/ }),
+    ).toBeInTheDocument();
+    expect(screen.queryByText('Hidden activity')).not.toBeInTheDocument();
+    expect(document.getElementById('activity-anchor')).toBeInTheDocument();
+
+    fireEvent.click(screen.getByRole('button', { name: /Worked for 17s/ }));
+
+    expect(screen.getByText('Hidden activity')).toBeVisible();
+  });
+});
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.anchors.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.anchors.client.test.tsx
index 18bde42e..2edeaacf 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.anchors.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.anchors.client.test.tsx
@@ -40,9 +40,13 @@ function buildGroup(): GroupedToolCallRenderBlock {
     ts: 100,
     action: 'Exploring',
     objectSummary: '3 files',
+    groupKey: 'mcp:roomote:read_file',
+    displayKind: 'read',
     items: [
       {
         objectLabel: 'file_a.txt',
+        groupKey: 'mcp:roomote:read_file',
+        displayKind: 'read',
         stepKind: 'read',
         msg: {
           id: 'tool-1',
@@ -72,6 +76,8 @@ function buildGroup(): GroupedToolCallRenderBlock {
       },
       {
         objectLabel: 'file_b.txt',
+        groupKey: 'mcp:roomote:read_file',
+        displayKind: 'read',
         stepKind: 'read',
         msg: {
           id: 'tool-2',
@@ -101,6 +107,8 @@ function buildGroup(): GroupedToolCallRenderBlock {
       },
       {
         objectLabel: 'file_c.txt',
+        groupKey: 'mcp:roomote:read_file',
+        displayKind: 'read',
         stepKind: 'read',
         msg: {
           id: 'tool-3',
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.client.test.tsx
index e38ff68b..6985d216 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpGroupedToolMessage.client.test.tsx
@@ -46,9 +46,13 @@ function buildGroup(): GroupedToolCallRenderBlock {
     ts: 100,
     action: 'Exploring',
     objectSummary: '2 files',
+    groupKey: 'mcp:roomote:read_file',
+    displayKind: 'read',
     items: [
       {
         objectLabel: 'file_a.txt',
+        groupKey: 'mcp:roomote:read_file',
+        displayKind: 'read',
         stepKind: 'read',
         msg: {
           id: 'tool-1',
@@ -78,6 +82,8 @@ function buildGroup(): GroupedToolCallRenderBlock {
       },
       {
         objectLabel: 'file_b.txt',
+        groupKey: 'mcp:roomote:read_file',
+        displayKind: 'read',
         stepKind: 'read',
         msg: {
           id: 'tool-2',
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpToolDetails.client.test.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpToolDetails.client.test.tsx
index 6d1be36e..85dad6ae 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpToolDetails.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/AcpToolDetails.client.test.tsx
@@ -8,7 +8,12 @@ const codeBlockSpy = vi.fn();
 const toolInputSpy = vi.fn();
 
 vi.mock('@/components/ai-elements', () => ({
-  CodeBlock: (props: { code: string }) => {
+  CodeBlock: (props: {
+    code: string;
+    variant?: string;
+    highlight?: boolean;
+    className?: string;
+  }) => {
     codeBlockSpy(props);
     return <div>{props.code}</div>;
   },
@@ -136,7 +141,7 @@ describe('AcpToolDetails', () => {
     expect(codeBlockSpy).not.toHaveBeenCalled();
   });
 
-  it('keeps using a code block for non-subagent tool output text', () => {
+  it('uses a light compact code block for non-subagent tool output text', () => {
     render(
       <AcpToolDetails
         msg={buildMessage({
@@ -149,7 +154,12 @@ describe('AcpToolDetails', () => {
 
     expect(screen.getByText('Spawning subagent')).toBeInTheDocument();
     expect(codeBlockSpy).toHaveBeenCalledWith(
-      expect.objectContaining({ code: 'Spawning subagent' }),
+      expect.objectContaining({
+        code: 'Spawning subagent',
+        variant: 'compact',
+        highlight: false,
+        className: expect.stringContaining('bg-transparent'),
+      }),
     );
   });
 
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/activity-groups.client.test.ts b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/activity-groups.client.test.ts
new file mode 100644
index 00000000..547a71a2
--- /dev/null
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/activity-groups.client.test.ts
@@ -0,0 +1,461 @@
+import { ACP_ENVELOPE_EVENT_TYPES } from '@roomote/types';
+
+import type { TaskArtifact } from '@/types';
+
+import {
+  buildAcpActivityRenderBlocks,
+  isActivityCollapsibleBlock,
+} from '../activity-groups';
+import type {
+  AcpRenderBlock,
+  GroupedToolCallRenderBlock,
+} from '../render-blocks';
+import type { AcpToolResultUiMessage } from '../types';
+
+function textBlock(id: string, ts: number): AcpRenderBlock {
+  return {
+    kind: 'message',
+    msg: {
+      id,
+      ts,
+      role: 'assistant',
+      kind: 'text',
+      partial: false,
+      sessionId: 'session-1',
+      updateType: 'roomote_runtime.assistant_message',
+      text: id,
+      data: {},
+    },
+  };
+}
+
+function messageBlock(
+  id: string,
+  ts: number,
+  kind: 'reasoning' | 'todo_section' | 'task_cancelled',
+): AcpRenderBlock {
+  if (kind === 'todo_section') {
+    return {
+      kind: 'message',
+      msg: {
+        id,
+        ts,
+        role: 'assistant',
+        kind,
+        partial: false,
+        sessionId: 'session-1',
+        updateType: ACP_ENVELOPE_EVENT_TYPES.Plan,
+        text: id,
+        data: { todoId: id, content: id },
+      },
+    };
+  }
+
+  return {
+    kind: 'message',
+    msg: {
+      id,
+      ts,
+      role: kind === 'task_cancelled' ? 'system' : 'assistant',
+      kind,
+      partial: false,
+      sessionId: 'session-1',
+      updateType:
+        kind === 'task_cancelled'
+          ? ACP_ENVELOPE_EVENT_TYPES.TaskCancelled
+          : ACP_ENVELOPE_EVENT_TYPES.AssistantMessage,
+      text: id,
+      data: kind === 'task_cancelled' ? { sessionId: 'session-1' } : {},
+    },
+  };
+}
+
+function toolResultBlock(params: {
+  id: string;
+  ts: number;
+  toolName?: string;
+  output?: string;
+  kind?: string;
+}): AcpRenderBlock {
+  return {
+    kind: 'message',
+    msg: buildToolResult(params),
+  };
+}
+
+function buildToolResult(params: {
+  id: string;
+  ts: number;
+  toolName?: string;
+  output?: string;
+  kind?: string;
+}): AcpToolResultUiMessage {
+  return {
+    id: params.id,
+    ts: params.ts,
+    role: 'tool',
+    kind: 'tool_result',
+    partial: false,
+    sessionId: 'session-1',
+    updateType: 'roomote_runtime.tool_result',
+    text: params.output,
+    data: {
+      toolCallId: `call-${params.id}`,
+      kind: params.kind ?? 'mcp',
+      title: params.toolName ?? 'read_file',
+      status: 'completed',
+      isExecute: false,
+      isMcp: true,
+      mcpServerName: 'roomote',
+      mcpToolName: params.toolName ?? 'read_file',
+      serverName: 'roomote',
+      toolName: params.toolName ?? 'read_file',
+      command: null,
+      output: params.output ?? '',
+      exitCode: null,
+    },
+  };
+}
+
+function toolGroupBlock(params: {
+  id: string;
+  ts: number;
+  items: AcpToolResultUiMessage[];
+}): GroupedToolCallRenderBlock {
+  return {
+    kind: 'tool_group',
+    id: params.id,
+    ts: params.ts,
+    action: 'Exploring',
+    objectSummary: `${params.items.length} files`,
+    groupKey: 'mcp:roomote:read_file',
+    displayKind: 'read',
+    items: params.items.map((msg) => ({
+      msg,
+      objectLabel: msg.data.title ?? 'Tool',
+      groupKey: 'mcp:roomote:read_file',
+      displayKind: 'read',
+      stepKind: 'read',
+    })),
+  };
+}
+
+const visualProofArtifact: TaskArtifact = {
+  id: 'artifact-1',
+  path: 'tmp/proof.png',
+  version: 1,
+  artifactType: 'visual-proof',
+  contentType: 'image/png',
+  size: 123,
+  createdAt: new Date('2026-01-01T00:00:00Z'),
+  thumbnailUrl: 'https://example.test/thumb.png',
+};
+
+describe('buildAcpActivityRenderBlocks', () => {
+  it('collapses one eligible activity block between text messages', () => {
+    const entries = buildAcpActivityRenderBlocks([
+      textBlock('text-1', 1_000),
+      messageBlock('reasoning-1', 2_000, 'reasoning'),
+      textBlock('text-2', 19_000),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'activity_group',
+      'message',
+    ]);
+    expect(entries[1]).toMatchObject({
+      kind: 'activity_group',
+      ts: 2_000,
+      endTs: 19_000,
+    });
+  });
+
+  it('keeps live partial reasoning and tools outside collapsed activity groups', () => {
+    const partialReasoning: AcpRenderBlock = {
+      kind: 'message',
+      msg: {
+        id: 'reasoning-partial',
+        ts: 2_000,
+        role: 'assistant',
+        kind: 'reasoning',
+        partial: true,
+        sessionId: 'session-1',
+        updateType: ACP_ENVELOPE_EVENT_TYPES.AssistantMessage,
+        text: 'thinking…',
+        data: {},
+      },
+    };
+
+    const inProgressTool: AcpRenderBlock = {
+      kind: 'message',
+      msg: {
+        id: 'tool-partial',
+        ts: 3_000,
+        role: 'tool',
+        kind: 'tool_call',
+        partial: true,
+        sessionId: 'session-1',
+        updateType: 'roomote_runtime.tool_call',
+        data: {
+          toolCallId: 'call-tool-partial',
+          kind: 'mcp',
+          title: 'read_file',
+          status: 'in_progress',
+          isExecute: false,
+          isRead: true,
+          isMcp: true,
+          mcpServerName: 'roomote',
+          mcpToolName: 'read_file',
+          serverName: 'roomote',
+          toolName: 'read_file',
+          command: null,
+        },
+      },
+    };
+
+    const entries = buildAcpActivityRenderBlocks([
+      textBlock('text-1', 1_000),
+      partialReasoning,
+      inProgressTool,
+      textBlock('text-2', 4_000),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
+      'message',
+    ]);
+  });
+
+  it('collapses mixed eligible activity blocks into one group', () => {
+    const entries = buildAcpActivityRenderBlocks([
+      textBlock('text-1', 1_000),
+      messageBlock('reasoning-1', 2_000, 'reasoning'),
+      toolGroupBlock({
+        id: 'group-1',
+        ts: 4_000,
+        items: [
+          buildToolResult({ id: 'tool-1', ts: 4_000 }),
+          buildToolResult({ id: 'tool-2', ts: 5_000 }),
+        ],
+      }),
+      textBlock('text-2', 10_000),
+    ]);
+
+    expect(entries).toHaveLength(3);
+    expect(entries[1]?.kind).toBe('activity_group');
+
+    if (entries[1]?.kind !== 'activity_group') {
+      throw new Error('Expected activity group');
+    }
+
+    expect(entries[1].blocks.map((block) => block.kind)).toEqual([
+      'message',
+      'tool_group',
+    ]);
+  });
+
+  it('keeps todo section markers visible and starts a new activity boundary after them', () => {
+    const entries = buildAcpActivityRenderBlocks([
+      textBlock('text-1', 1_000),
+      messageBlock('reasoning-1', 2_000, 'reasoning'),
+      messageBlock('todo-1', 3_000, 'todo_section'),
+      toolGroupBlock({
+        id: 'group-1',
+        ts: 4_000,
+        items: [
+          buildToolResult({ id: 'tool-1', ts: 4_000 }),
+          buildToolResult({ id: 'tool-2', ts: 5_000 }),
+        ],
+      }),
+      textBlock('text-2', 10_000),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
+      'activity_group',
+      'message',
+    ]);
+
+    expect(entries[3]).toMatchObject({
+      kind: 'activity_group',
+      ts: 4_000,
+      endTs: 10_000,
+    });
+  });
+
+  it('keeps task cancellation visible and uses it as a boundary', () => {
+    const entries = buildAcpActivityRenderBlocks([
+      textBlock('text-1', 1_000),
+      messageBlock('reasoning-1', 2_000, 'reasoning'),
+      messageBlock('cancel-1', 3_000, 'task_cancelled'),
+      messageBlock('reasoning-2', 4_000, 'reasoning'),
+      textBlock('text-2', 5_000),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
+      'message',
+      'message',
+    ]);
+  });
+
+  it('keeps manage_artifacts rows visible and uses them as a boundary', () => {
+    const manageArtifacts = toolResultBlock({
+      id: 'artifact-tool',
+      ts: 3_000,
+      toolName: 'manage_artifacts',
+    });
+
+    expect(isActivityCollapsibleBlock(manageArtifacts)).toBe(false);
+
+    const entries = buildAcpActivityRenderBlocks([
+      textBlock('text-1', 1_000),
+      messageBlock('reasoning-1', 2_000, 'reasoning'),
+      manageArtifacts,
+      messageBlock('reasoning-2', 4_000, 'reasoning'),
+      textBlock('text-2', 5_000),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
+      'message',
+      'message',
+    ]);
+  });
+
+  it('keeps visual-proof preview rows visible and uses them as a boundary', () => {
+    const visualProof = toolResultBlock({
+      id: 'subagent-proof',
+      ts: 3_000,
+      toolName: 'subagent',
+      kind: 'subagent',
+      output:
+        'Uploaded proof https://example.test/task/task-1/artifacts/tmp/proof.png?v=1',
+    });
+
+    if (
+      visualProof.kind !== 'message' ||
+      visualProof.msg.kind !== 'tool_result'
+    ) {
+      throw new Error('Expected tool result');
+    }
+
+    visualProof.msg.data = {
+      ...visualProof.msg.data,
+      isMcp: false,
+      isSubagentSpawn: true,
+      receiverThreadIds: [],
+    };
+
+    expect(isActivityCollapsibleBlock(visualProof, [visualProofArtifact])).toBe(
+      false,
+    );
+
+    const entries = buildAcpActivityRenderBlocks(
+      [
+        textBlock('text-1', 1_000),
+        messageBlock('reasoning-1', 2_000, 'reasoning'),
+        visualProof,
+        messageBlock('reasoning-2', 4_000, 'reasoning'),
+        textBlock('text-2', 5_000),
+      ],
+      { artifacts: [visualProofArtifact] },
+    );
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
+      'message',
+      'message',
+    ]);
+  });
+
+  it('collapses leading eligible activity before the first text message', () => {
+    const entries = buildAcpActivityRenderBlocks([
+      messageBlock('leading', 1_000, 'reasoning'),
+      textBlock('text-1', 2_000),
+      messageBlock('trailing', 3_000, 'reasoning'),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'activity_group',
+      'message',
+      'message',
+    ]);
+
+    expect(entries[0]).toMatchObject({
+      kind: 'activity_group',
+      ts: 1_000,
+      endTs: 2_000,
+    });
+  });
+
+  it('keeps leading todo section markers visible and starts a new activity boundary after them', () => {
+    const entries = buildAcpActivityRenderBlocks([
+      messageBlock('leading', 1_000, 'reasoning'),
+      messageBlock('todo-1', 1_500, 'todo_section'),
+      messageBlock('reasoning-2', 1_700, 'reasoning'),
+      textBlock('text-1', 2_000),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'activity_group',
+      'message',
+    ]);
+
+    expect(entries[2]).toMatchObject({
+      kind: 'activity_group',
+      ts: 1_700,
+      endTs: 2_000,
+    });
+  });
+
+  it('collapses leading activity when an external session prompt provides the left text boundary', () => {
+    const entries = buildAcpActivityRenderBlocks(
+      [
+        messageBlock('reasoning-1', 2_000, 'reasoning'),
+        textBlock('text-1', 10_000),
+      ],
+      { hasLeadingTextBoundary: true },
+    );
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'activity_group',
+      'message',
+    ]);
+    expect(entries[0]).toMatchObject({
+      kind: 'activity_group',
+      ts: 2_000,
+      endTs: 10_000,
+    });
+  });
+
+  it('bypasses grouping in narration mode', () => {
+    const entries = buildAcpActivityRenderBlocks(
+      [
+        textBlock('text-1', 1_000),
+        messageBlock('reasoning-1', 2_000, 'reasoning'),
+        textBlock('text-2', 3_000),
+      ],
+      { displayMode: 'narration' },
+    );
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
+    ]);
+  });
+});
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/tool-call-grouping.client.test.ts b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/tool-call-grouping.client.test.ts
index dc111afa..9b754e5f 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/tool-call-grouping.client.test.ts
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/__tests__/tool-call-grouping.client.test.ts
@@ -387,7 +387,7 @@ describe('buildAcpRenderBlocks', () => {
       'evaluator.ts',
       'task-runs.ts',
     ]);
-    expect(entries[0].items.map((item) => item.stepKind)).toEqual([
+    expect(entries[0].items.map((item) => item.displayKind)).toEqual([
       'read',
       'read',
       'read',
@@ -453,7 +453,8 @@ describe('buildAcpRenderBlocks', () => {
   });
 
   it('keeps a stable group id and ts as results stream in', () => {
-    // Before the results arrive, only the tool_call messages are present.
+    // Before either result arrives, fewer than two calls are complete so the
+    // run stays expanded as individual messages.
     const streamingEntries = buildAcpRenderBlocks([
       readFileToolCallMessage({
         id: 'tool-1-call',
@@ -469,8 +470,13 @@ describe('buildAcpRenderBlocks', () => {
       }),
     ]);
 
-    // After the results arrive, the deduped items flip to tool_result, but the
-    // group id/ts must stay anchored to the first message in the run.
+    expect(streamingEntries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+    ]);
+
+    // After the results arrive, the run collapses. The group id/ts must stay
+    // anchored to the first message in the consecutive run.
     const settledEntries = buildAcpRenderBlocks([
       readFileToolCallMessage({
         id: 'tool-1-call',
@@ -500,29 +506,19 @@ describe('buildAcpRenderBlocks', () => {
       }),
     ]);
 
-    if (
-      streamingEntries[0]?.kind !== 'tool_group' ||
-      settledEntries[0]?.kind !== 'tool_group'
-    ) {
-      throw new Error('Expected tool_group entries');
+    if (settledEntries[0]?.kind !== 'tool_group') {
+      throw new Error('Expected tool_group entry');
     }
 
-    expect(streamingEntries[0].id).toBe('tool-1-call');
-    expect(streamingEntries[0].ts).toBe(1);
     expect(settledEntries[0].id).toBe('tool-1-call');
     expect(settledEntries[0].ts).toBe(1);
-    // The representative items did flip from tool_call to tool_result.
-    expect(streamingEntries[0].items.map((item) => item.msg.kind)).toEqual([
-      'tool_call',
-      'tool_call',
-    ]);
     expect(settledEntries[0].items.map((item) => item.msg.kind)).toEqual([
       'tool_result',
       'tool_result',
     ]);
   });
 
-  it('keeps an in-progress tool_call when no paired tool_result has arrived', () => {
+  it('does not collapse until the second same-type call completes', () => {
     const entries = buildAcpRenderBlocks([
       readFileToolMessage({
         id: 'tool-1-result',
@@ -538,19 +534,47 @@ describe('buildAcpRenderBlocks', () => {
       }),
     ]);
 
-    expect(entries).toHaveLength(1);
-    expect(entries[0]).toMatchObject({
-      kind: 'tool_group',
-      objectSummary: '2 files',
-    });
+    expect(entries.map((entry) => entry.kind)).toEqual(['message', 'message']);
+    if (entries[0]?.kind !== 'message' || entries[1]?.kind !== 'message') {
+      throw new Error('Expected plain message entries');
+    }
+
+    expect(entries[0].msg.kind).toBe('tool_result');
+    expect(entries[1].msg.kind).toBe('tool_call');
+  });
 
+  it('appends later the third completed same-type call into the collapsed group', () => {
+    const entries = buildAcpRenderBlocks([
+      readFileToolMessage({
+        id: 'tool-1',
+        ts: 1,
+        title: 'Read server.ts',
+        text: 'server content',
+      }),
+      readFileToolMessage({
+        id: 'tool-2',
+        ts: 2,
+        title: 'Read evaluator.ts',
+        text: 'evaluator content',
+      }),
+      readFileToolMessage({
+        id: 'tool-3',
+        ts: 3,
+        title: 'Read task-runs.ts',
+        text: 'task runs content',
+      }),
+    ]);
+
+    expect(entries).toHaveLength(1);
     if (entries[0]?.kind !== 'tool_group') {
       throw new Error('Expected tool_group entry');
     }
 
-    expect(entries[0].items.map((item) => item.msg.kind)).toEqual([
-      'tool_result',
-      'tool_call',
+    expect(entries[0].objectSummary).toBe('3 files');
+    expect(entries[0].items.map((item) => item.msg.id)).toEqual([
+      'tool-1',
+      'tool-2',
+      'tool-3',
     ]);
   });
 
@@ -588,7 +612,7 @@ describe('buildAcpRenderBlocks', () => {
     expect(entries[0].msg.data.title).toBe('Read server.ts');
   });
 
-  it('groups search, list, and read steps into one exploration block', () => {
+  it('does not mix different tool types into one collapsed group', () => {
     const entries = buildAcpRenderBlocks([
       searchFilesToolMessage({
         id: 'tool-search',
@@ -607,43 +631,26 @@ describe('buildAcpRenderBlocks', () => {
       }),
     ]);
 
-    expect(entries).toHaveLength(1);
-    expect(entries[0]).toMatchObject({
-      kind: 'tool_group',
-      action: 'Exploring',
-      objectSummary: '1 search, 1 listing and 1 file',
-    });
-
-    if (entries[0]?.kind !== 'tool_group') {
-      throw new Error('Expected tool_group entry');
-    }
-
-    expect(entries[0].items.map((item) => item.stepKind)).toEqual([
-      'search',
-      'list',
-      'read',
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'message',
+      'message',
+      'message',
     ]);
   });
 
   it('uses payload labels when grouped MCP items have no descriptive title', () => {
     const entries = buildAcpRenderBlocks([
-      searchFilesToolMessage({
-        id: 'tool-search',
+      readFileToolMessage({
+        id: 'tool-read-1',
         ts: 1,
         title: null,
-        payload: { query: 'Button.tsx' },
-      }),
-      listFilesToolMessage({
-        id: 'tool-list',
-        ts: 2,
-        title: null,
-        payload: { path: 'src/components' },
+        payload: { path: 'src/components/Button.tsx' },
       }),
       readFileToolMessage({
-        id: 'tool-read',
-        ts: 3,
+        id: 'tool-read-2',
+        ts: 2,
         title: null,
-        payload: { path: 'src/components/Button.tsx' },
+        payload: { path: 'src/components/Input.tsx' },
       }),
     ]);
 
@@ -654,44 +661,32 @@ describe('buildAcpRenderBlocks', () => {
     }
 
     expect(entries[0].items.map((item) => item.objectLabel)).toEqual([
-      'Button.tsx',
-      'src/components',
       'src/components/Button.tsx',
+      'src/components/Input.tsx',
     ]);
   });
 
   it('uses nested rawInput arguments when grouped MCP items omit top-level labels', () => {
     const entries = buildAcpRenderBlocks([
-      searchFilesToolMessage({
-        id: 'tool-search',
+      readFileToolMessage({
+        id: 'tool-read-1',
         ts: 1,
         title: null,
         payload: {
           rawInput: {
-            tool: 'search_files',
-            arguments: { query: 'Button.tsx' },
-          },
-        },
-      }),
-      listFilesToolMessage({
-        id: 'tool-list',
-        ts: 2,
-        title: null,
-        payload: {
-          rawInput: {
-            tool: 'list_files',
-            arguments: { path: 'src/components' },
+            tool: 'read_file',
+            arguments: { path: 'src/components/Button.tsx' },
           },
         },
       }),
       readFileToolMessage({
-        id: 'tool-read',
-        ts: 3,
+        id: 'tool-read-2',
+        ts: 2,
         title: null,
         payload: {
           rawInput: {
             tool: 'read_file',
-            arguments: { path: 'src/components/Button.tsx' },
+            arguments: { path: 'src/components/Input.tsx' },
           },
         },
       }),
@@ -704,9 +699,8 @@ describe('buildAcpRenderBlocks', () => {
     }
 
     expect(entries[0].items.map((item) => item.objectLabel)).toEqual([
-      'Button.tsx',
-      'src/components',
       'src/components/Button.tsx',
+      'src/components/Input.tsx',
     ]);
   });
 
@@ -742,7 +736,7 @@ describe('buildAcpRenderBlocks', () => {
     ]);
   });
 
-  it('does not group execute tools even when commands look like exploration', () => {
+  it('groups consecutive completed shell commands into one block', () => {
     const entries = buildAcpRenderBlocks([
       executeExplorationToolMessage({
         id: 'tool-search',
@@ -758,7 +752,255 @@ describe('buildAcpRenderBlocks', () => {
       }),
     ]);
 
-    expect(entries.map((entry) => entry.kind)).toEqual(['message', 'message']);
+    expect(entries).toHaveLength(1);
+    expect(entries[0]).toMatchObject({
+      kind: 'tool_group',
+      action: 'Ran',
+      objectSummary: '2 commands',
+      displayKind: 'execute',
+    });
+
+    if (entries[0]?.kind !== 'tool_group') {
+      throw new Error('Expected tool_group entry');
+    }
+
+    expect(entries[0].items.map((item) => item.objectLabel)).toEqual([
+      'rg Button src/components',
+      'cat src/components/Button.tsx',
+    ]);
+  });
+
+  it('does not mix shell commands with other tool types', () => {
+    const entries = buildAcpRenderBlocks([
+      executeExplorationToolMessage({
+        id: 'tool-execute-1',
+        ts: 1,
+        title: 'Run ls',
+        command: 'ls',
+      }),
+      executeExplorationToolMessage({
+        id: 'tool-execute-2',
+        ts: 2,
+        title: 'Run pwd',
+        command: 'pwd',
+      }),
+      readFileToolMessage({
+        id: 'tool-read',
+        ts: 3,
+        title: 'Read package.json',
+      }),
+    ]);
+
+    expect(entries.map((entry) => entry.kind)).toEqual([
+      'tool_group',
+      'message',
+    ]);
+  });
+
+  it('uses lowercase plural-friendly labels for generic MCP tool groups', () => {
+    const entries = buildAcpRenderBlocks([
+      explorationToolMessage({
+        id: 'tool-1',
+        ts: 1,
+        title: null,
+        kind: 'mcp',
+        toolName: 'get_issue',
+      }),
+      explorationToolMessage({
+        id: 'tool-2',
+        ts: 2,
+        title: null,
+        kind: 'mcp',
+        toolName: 'get_issue',
+      }),
+    ]);
+
+    expect(entries).toHaveLength(1);
+    expect(entries[0]).toMatchObject({
+      kind: 'tool_group',
+      action: 'Used',
+      objectSummary: '2 get issue calls',
+      displayKind: 'tool',
+    });
+  });
+
+  it('groups edit tools with edit-specific summary labels', () => {
+    const entries = buildAcpRenderBlocks([
+      explorationToolMessage({
+        id: 'tool-edit-1',
+        ts: 1,
+        title: 'Edit src/a.ts',
+        mcp: false,
+        kind: 'edit',
+      }),
+      explorationToolMessage({
+        id: 'tool-edit-2',
+        ts: 2,
+        title: 'Edit src/b.ts',
+        mcp: false,
+        kind: 'edit',
+      }),
+    ]);
+
+    expect(entries).toHaveLength(1);
+    expect(entries[0]).toMatchObject({
+      kind: 'tool_group',
+      action: 'Edited',
+      objectSummary: '2 files',
+      displayKind: 'edit',
+    });
+  });
+
+  it('dedupes call/result pairs without a toolCallId via payload signature', () => {
+    const callWithoutId = {
+      ...readFileToolCallMessage({
+        id: 'tool-1-call',
+        ts: 1,
+        title: 'Read server.ts',
+        toolCallId: '',
+      }),
+      data: {
+        ...readFileToolCallMessage({
+          id: 'tool-1-call',
+          ts: 1,
+          title: 'Read server.ts',
+          toolCallId: '',
+        }).data,
+        toolCallId: null,
+      },
+    } as AcpToolCallUiMessage;
+
+    const resultWithoutId = {
+      ...readFileToolMessage({
+        id: 'tool-1-result',
+        ts: 2,
+        title: 'Read server.ts',
+        text: 'server content',
+        toolCallId: '',
+      }),
+      data: {
+        ...readFileToolMessage({
+          id: 'tool-1-result',
+          ts: 2,
+          title: 'Read server.ts',
+          text: 'server content',
+          toolCallId: '',
+        }).data,
+        toolCallId: null,
+      },
+    } as AcpToolResultUiMessage;
+
+    const call2WithoutId = {
+      ...readFileToolCallMessage({
+        id: 'tool-2-call',
+        ts: 3,
+        title: 'Read evaluator.ts',
+        toolCallId: '',
+      }),
+      data: {
+        ...readFileToolCallMessage({
+          id: 'tool-2-call',
+          ts: 3,
+          title: 'Read evaluator.ts',
+          toolCallId: '',
+        }).data,
+        toolCallId: null,
+      },
+    } as AcpToolCallUiMessage;
+
+    const result2WithoutId = {
+      ...readFileToolMessage({
+        id: 'tool-2-result',
+        ts: 4,
+        title: 'Read evaluator.ts',
+        text: 'evaluator content',
+        toolCallId: '',
+      }),
+      data: {
+        ...readFileToolMessage({
+          id: 'tool-2-result',
+          ts: 4,
+          title: 'Read evaluator.ts',
+          text: 'evaluator content',
+          toolCallId: '',
+        }).data,
+        toolCallId: null,
+      },
+    } as AcpToolResultUiMessage;
+
+    const entries = buildAcpRenderBlocks([
+      callWithoutId,
+      resultWithoutId,
+      call2WithoutId,
+      result2WithoutId,
+    ]);
+
+    expect(entries).toHaveLength(1);
+    if (entries[0]?.kind !== 'tool_group') {
+      throw new Error('Expected tool_group entry');
+    }
+
+    expect(entries[0].items).toHaveLength(2);
+    expect(entries[0].items.map((item) => item.msg.kind)).toEqual([
+      'tool_result',
+      'tool_result',
+    ]);
+    expect(entries[0].objectSummary).toBe('2 files');
+  });
+
+  it('keeps distinct no-toolCallId results with the same signature separate', () => {
+    const firstRead = {
+      ...readFileToolMessage({
+        id: 'tool-1-result',
+        ts: 1,
+        title: 'Read server.ts',
+        text: 'first pass',
+        toolCallId: '',
+      }),
+      data: {
+        ...readFileToolMessage({
+          id: 'tool-1-result',
+          ts: 1,
+          title: 'Read server.ts',
+          text: 'first pass',
+          toolCallId: '',
+        }).data,
+        toolCallId: null,
+      },
+    } as AcpToolResultUiMessage;
+
+    const secondRead = {
+      ...readFileToolMessage({
+        id: 'tool-2-result',
+        ts: 2,
+        title: 'Read server.ts',
+        text: 'second pass',
+        toolCallId: '',
+      }),
+      data: {
+        ...readFileToolMessage({
+          id: 'tool-2-result',
+          ts: 2,
+          title: 'Read server.ts',
+          text: 'second pass',
+          toolCallId: '',
+        }).data,
+        toolCallId: null,
+      },
+    } as AcpToolResultUiMessage;
+
+    const entries = buildAcpRenderBlocks([firstRead, secondRead]);
+
+    expect(entries).toHaveLength(1);
+    if (entries[0]?.kind !== 'tool_group') {
+      throw new Error('Expected tool_group entry');
+    }
+
+    expect(entries[0].items).toHaveLength(2);
+    expect(entries[0].items.map((item) => item.msg.id)).toEqual([
+      'tool-1-result',
+      'tool-2-result',
+    ]);
   });
 
   it('does not group across non-tool messages', () => {
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/activity-groups.ts b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/activity-groups.ts
new file mode 100644
index 00000000..399335b9
--- /dev/null
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/activity-groups.ts
@@ -0,0 +1,202 @@
+import type { TaskArtifact } from '@/types';
+
+import type {
+  AcpToolCallUiMessage,
+  AcpToolResultUiMessage,
+  AcpUiMessage,
+} from './types';
+import type { AcpRenderBlock } from './render-blocks';
+import { resolveVisualProofMediaForToolMessage } from './visual-proof-tool-result';
+
+const COLLAPSIBLE_ACP_MESSAGE_KINDS = [
+  'reasoning',
+  'tool_call',
+  'tool_result',
+] as const;
+
+const COLLAPSIBLE_ACP_MESSAGE_KIND_SET = new Set<string>(
+  COLLAPSIBLE_ACP_MESSAGE_KINDS,
+);
+
+const MANAGE_ARTIFACTS_TOOL_NAME = 'manage_artifacts';
+
+export interface AcpActivityGroupRenderBlock {
+  kind: 'activity_group';
+  id: string;
+  ts: number;
+  endTs: number;
+  blocks: AcpRenderBlock[];
+}
+
+export type AcpConversationRenderBlock =
+  | AcpRenderBlock
+  | AcpActivityGroupRenderBlock;
+
+interface BuildAcpActivityRenderBlocksOptions {
+  artifacts?: readonly TaskArtifact[] | null;
+  displayMode?: 'default' | 'narration';
+  hasLeadingTextBoundary?: boolean;
+  collapseLeadingActivity?: boolean;
+}
+
+function isToolMessage(
+  msg: AcpUiMessage,
+): msg is AcpToolCallUiMessage | AcpToolResultUiMessage {
+  return msg.kind === 'tool_call' || msg.kind === 'tool_result';
+}
+
+function getBlockId(block: AcpRenderBlock): string {
+  return block.kind === 'tool_group' ? block.id : block.msg.id;
+}
+
+function getBlockTs(block: AcpRenderBlock): number {
+  return block.kind === 'tool_group' ? block.ts : block.msg.ts;
+}
+
+function isTextBoundaryBlock(block: AcpRenderBlock): boolean {
+  return block.kind === 'message' && block.msg.kind === 'text';
+}
+
+function isProgressBoundaryBlock(block: AcpRenderBlock): boolean {
+  return block.kind === 'message' && block.msg.kind === 'todo_section';
+}
+
+function getToolName(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+): string | null {
+  const rawName = msg.data.toolName ?? msg.data.mcpToolName;
+  const normalized = rawName?.trim().toLowerCase();
+
+  return normalized && normalized.length > 0 ? normalized : null;
+}
+
+function isArtifactToolMessage(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+  artifacts: readonly TaskArtifact[] | null | undefined,
+): boolean {
+  if (getToolName(msg) === MANAGE_ARTIFACTS_TOOL_NAME) {
+    return true;
+  }
+
+  return resolveVisualProofMediaForToolMessage(msg, artifacts).length > 0;
+}
+
+function isLivePartialBlock(block: AcpRenderBlock): boolean {
+  if (block.kind === 'tool_group') {
+    return block.items.some(
+      (item) =>
+        item.msg.partial === true || item.msg.data.status === 'in_progress',
+    );
+  }
+
+  if (block.msg.partial === true) {
+    return true;
+  }
+
+  return isToolMessage(block.msg) && block.msg.data.status === 'in_progress';
+}
+
+export function isActivityCollapsibleBlock(
+  block: AcpRenderBlock,
+  artifacts?: readonly TaskArtifact[] | null,
+): boolean {
+  // Keep in-flight reasoning/tool rows outside default-closed groups so current
+  // activity stays visible without a manual expand.
+  if (isLivePartialBlock(block)) {
+    return false;
+  }
+
+  if (block.kind === 'tool_group') {
+    return !block.items.some((item) =>
+      isArtifactToolMessage(item.msg, artifacts),
+    );
+  }
+
+  const { msg } = block;
+
+  if (!COLLAPSIBLE_ACP_MESSAGE_KIND_SET.has(msg.kind)) {
+    return false;
+  }
+
+  if (isToolMessage(msg) && isArtifactToolMessage(msg, artifacts)) {
+    return false;
+  }
+
+  return true;
+}
+
+export function buildAcpActivityRenderBlocks(
+  blocks: AcpRenderBlock[],
+  options: BuildAcpActivityRenderBlocksOptions = {},
+): AcpConversationRenderBlock[] {
+  if (options.displayMode === 'narration') {
+    return blocks;
+  }
+
+  const groupedBlocks: AcpConversationRenderBlock[] = [];
+  let cursor = 0;
+  let hasLeftTextBoundary =
+    options.hasLeadingTextBoundary === true ||
+    options.collapseLeadingActivity !== false;
+
+  while (cursor < blocks.length) {
+    const current = blocks[cursor]!;
+
+    if (isTextBoundaryBlock(current)) {
+      groupedBlocks.push(current);
+      hasLeftTextBoundary = true;
+      cursor += 1;
+      continue;
+    }
+
+    if (isProgressBoundaryBlock(current)) {
+      groupedBlocks.push(current);
+      hasLeftTextBoundary = true;
+      cursor += 1;
+      continue;
+    }
+
+    if (
+      !hasLeftTextBoundary ||
+      !isActivityCollapsibleBlock(current, options.artifacts)
+    ) {
+      groupedBlocks.push(current);
+      hasLeftTextBoundary = false;
+      cursor += 1;
+      continue;
+    }
+
+    const activityStart = cursor;
+    let activityEnd = activityStart;
+
+    while (
+      activityEnd < blocks.length &&
+      isActivityCollapsibleBlock(blocks[activityEnd]!, options.artifacts)
+    ) {
+      activityEnd += 1;
+    }
+
+    const activityBlocks = blocks.slice(activityStart, activityEnd);
+    const next = blocks[activityEnd];
+
+    if (activityBlocks.length > 0 && next && isTextBoundaryBlock(next)) {
+      const firstActivity = activityBlocks[0]!;
+
+      groupedBlocks.push({
+        kind: 'activity_group',
+        id: `activity-${getBlockId(firstActivity)}`,
+        ts: getBlockTs(firstActivity),
+        endTs: getBlockTs(next),
+        blocks: activityBlocks,
+      });
+      cursor = activityEnd;
+      continue;
+    }
+
+    groupedBlocks.push(...activityBlocks);
+    hasLeftTextBoundary = false;
+    cursor = activityEnd;
+  }
+
+  return groupedBlocks;
+}
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/index.ts b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/index.ts
index d6749c31..9f8ff22f 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/index.ts
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/index.ts
@@ -2,4 +2,5 @@ export * from './types';
 export * from './AcpMessageItem';
 export * from './AcpTextMessage';
 export * from './AcpGroupedToolMessage';
+export * from './AcpActivityGroupMessage';
 export * from './AcpTodoSectionMessage';
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/render-blocks.ts b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/render-blocks.ts
index 71898c02..511621c1 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/render-blocks.ts
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/messages/acp/render-blocks.ts
@@ -17,10 +17,17 @@ import type {
 import {
   isSubagentSpawnRowMessage,
   isSubagentToolMessage,
+  isSubagentToolPayload,
 } from './subagent-tool';
 
 export type ExplorationStepKind = 'list' | 'read' | 'search';
 
+export type GroupedToolDisplayKind =
+  | ExplorationStepKind
+  | 'execute'
+  | 'edit'
+  | 'tool';
+
 const EXPLORATION_TOOL_NAMES: Record<ExplorationStepKind, Set<string>> = {
   search: new Set(['search', 'search_file', 'search_files']),
   list: new Set(['glob', 'list', 'list_dir', 'list_directory', 'list_files']),
@@ -52,10 +59,33 @@ const STEP_KIND_DATA_KEYS: Record<ExplorationStepKind, string[]> = {
   read: ['path', 'filePath', 'file_path', 'filename', 'file', 'uri'],
 };
 
+const GENERIC_TOOL_DATA_KEYS = [
+  'path',
+  'filePath',
+  'file_path',
+  'filename',
+  'file',
+  'uri',
+  'query',
+  'pattern',
+  'search',
+  'directory',
+  'dir',
+  'cwd',
+  'target',
+  'command',
+];
+
+/** Minimum completed/failed same-type tool invocations before collapsing. */
+const TOOL_GROUP_MIN_SETTLED = 2;
+
 export interface GroupedToolCallItem {
   msg: AcpToolCallUiMessage | AcpToolResultUiMessage;
   objectLabel: string;
-  stepKind: ExplorationStepKind;
+  groupKey: string;
+  displayKind: GroupedToolDisplayKind;
+  /** @deprecated Prefer displayKind; kept for exploration-item icons. */
+  stepKind: ExplorationStepKind | null;
 }
 
 interface SingleAcpRenderBlock {
@@ -70,6 +100,8 @@ export interface GroupedToolCallRenderBlock {
   ts: number;
   action: string;
   objectSummary: string;
+  groupKey: string;
+  displayKind: GroupedToolDisplayKind;
   items: GroupedToolCallItem[];
 }
 
@@ -124,7 +156,7 @@ type HiddenBehavior = 'boundary' | 'transparent';
 type MessageRenderState =
   | {
       visibility: 'render';
-      stepKind: ExplorationStepKind | null;
+      groupKey: string | null;
     }
   | {
       visibility: 'hidden';
@@ -254,6 +286,17 @@ function extractLabelFromToolData(
   return extractStringByKeys(argumentsRecord as Record<string, unknown>, keys);
 }
 
+function isExecuteToolMessage(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+): boolean {
+  const data = msg.data as unknown as Record<string, unknown>;
+  return (
+    msg.data.kind === 'execute' ||
+    msg.data.kind === 'execute_command' ||
+    data.isExecute === true
+  );
+}
+
 function resolveExplorationStepKind(
   msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
 ): ExplorationStepKind | null {
@@ -271,6 +314,10 @@ function resolveExplorationStepKind(
     return 'search';
   }
 
+  if (msg.data.kind === 'list') {
+    return 'list';
+  }
+
   if (msg.data.kind === 'read') {
     return 'read';
   }
@@ -278,31 +325,96 @@ function resolveExplorationStepKind(
   return null;
 }
 
-function formatHumanList(values: string[]): string {
-  if (values.length === 0) {
-    return '';
+/**
+ * Stable identity for consecutive same-type collapsing. Different tools never
+ * share a key, even when both are MCP exploration-style helpers.
+ */
+function resolveToolGroupKey(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+): string | null {
+  // Subagent rows own nested child-session output and should stay standalone.
+  if (isSubagentToolPayload(msg.data)) {
+    return null;
+  }
+
+  if (isExecuteToolMessage(msg)) {
+    return 'execute';
+  }
+
+  const toolName = (msg.data.toolName ?? msg.data.mcpToolName ?? '')
+    .trim()
+    .toLowerCase();
+  const serverName = (msg.data.serverName ?? msg.data.mcpServerName ?? '')
+    .trim()
+    .toLowerCase();
+
+  if (toolName) {
+    return serverName ? `mcp:${serverName}:${toolName}` : `tool:${toolName}`;
+  }
+
+  const kind = (msg.data.kind ?? '').trim().toLowerCase();
+
+  if (kind && kind !== 'mcp') {
+    return `kind:${kind}`;
+  }
+
+  return null;
+}
+
+function resolveGroupedToolDisplayKind(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+  groupKey: string,
+): GroupedToolDisplayKind {
+  if (groupKey === 'execute' || isExecuteToolMessage(msg)) {
+    return 'execute';
   }
 
-  if (values.length === 1) {
-    return values[0]!;
+  const explorationStep = resolveExplorationStepKind(msg);
+
+  if (explorationStep) {
+    return explorationStep;
   }
 
-  if (values.length === 2) {
-    return `${values[0]} and ${values[1]}`;
+  if (msg.data.kind === 'edit') {
+    return 'edit';
   }
 
-  const head = values.slice(0, -1).join(', ');
-  const tail = values[values.length - 1];
-  return `${head} and ${tail}`;
+  return 'tool';
 }
 
-const TITLE_PREFIX_RE = /^(?:search|read|list|find)\s+(.+)$/i;
+function isSettledToolMessage(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+): boolean {
+  if (msg.partial === true) {
+    return false;
+  }
+
+  return msg.data.status === 'completed' || msg.data.status === 'failed';
+}
+
+function formatGenericToolLabel(value: string): string {
+  return value.split(/[_-]+/).filter(Boolean).join(' ').toLowerCase();
+}
+
+const TITLE_PREFIX_RE =
+  /^(?:search|read|list|find|run|using|used|ran|running)\s+(.+)$/i;
 
 function extractObjectLabel(
   msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
-  stepKind: ExplorationStepKind,
+  displayKind: GroupedToolDisplayKind,
 ): string {
+  if (displayKind === 'execute') {
+    const command = msg.data.command?.trim();
+    if (command) {
+      return command;
+    }
+  }
+
   const title = msg.data.title?.trim();
+  const dataKeys =
+    displayKind === 'search' || displayKind === 'list' || displayKind === 'read'
+      ? STEP_KIND_DATA_KEYS[displayKind]
+      : GENERIC_TOOL_DATA_KEYS;
 
   if (title) {
     const match = TITLE_PREFIX_RE.exec(title);
@@ -311,91 +423,159 @@ function extractObjectLabel(
       return match[1].trim();
     }
 
-    const payloadLabel = extractLabelFromToolData(
-      msg.data,
-      STEP_KIND_DATA_KEYS[stepKind],
-    );
+    const payloadLabel = extractLabelFromToolData(msg.data, dataKeys);
 
     return payloadLabel ?? title;
   }
 
-  return (
-    extractLabelFromToolData(msg.data, STEP_KIND_DATA_KEYS[stepKind]) ?? 'Tool'
-  );
+  return extractLabelFromToolData(msg.data, dataKeys) ?? 'Tool';
 }
 
-function summarizeGroupObject(items: GroupedToolCallItem[]): string {
-  const counts = new Map<ExplorationStepKind, number>();
+function summarizeSameTypeGroup(
+  items: GroupedToolCallItem[],
+  displayKind: GroupedToolDisplayKind,
+  groupKey: string,
+): { action: string; objectSummary: string } {
+  const count = items.length;
 
-  for (const item of items) {
-    counts.set(item.stepKind, (counts.get(item.stepKind) ?? 0) + 1);
+  if (displayKind === 'execute') {
+    return {
+      action: 'Ran',
+      objectSummary: `${count} ${count === 1 ? 'command' : 'commands'}`,
+    };
+  }
+
+  if (
+    displayKind === 'search' ||
+    displayKind === 'list' ||
+    displayKind === 'read'
+  ) {
+    const labels = STEP_KIND_LABELS[displayKind];
+    return {
+      action: 'Exploring',
+      objectSummary: `${count} ${count === 1 ? labels.singular : labels.plural}`,
+    };
   }
 
-  const summaryParts = STEP_KIND_ORDER.flatMap((stepKind) => {
-    const count = counts.get(stepKind) ?? 0;
+  if (displayKind === 'edit') {
+    return {
+      action: 'Edited',
+      objectSummary: `${count} ${count === 1 ? 'file' : 'files'}`,
+    };
+  }
 
-    if (count === 0) {
-      return [];
-    }
+  const toolNameMatch = /^(?:mcp:[^:]+:|tool:)(.+)$/.exec(groupKey);
+  const toolLabel = toolNameMatch?.[1]
+    ? formatGenericToolLabel(toolNameMatch[1])
+    : null;
 
-    const labels = STEP_KIND_LABELS[stepKind];
-    return [`${count} ${count === 1 ? labels.singular : labels.plural}`];
-  });
+  if (toolLabel) {
+    return {
+      action: 'Used',
+      objectSummary:
+        count === 1 ? `1 ${toolLabel}` : `${count} ${toolLabel} calls`,
+    };
+  }
+
+  return {
+    action: 'Used',
+    objectSummary: `${count} ${count === 1 ? 'tool' : 'tools'}`,
+  };
+}
+
+function buildGroupedToolItem(
+  msg: AcpToolCallUiMessage | AcpToolResultUiMessage,
+  groupKey: string,
+): GroupedToolCallItem {
+  const displayKind = resolveGroupedToolDisplayKind(msg, groupKey);
+  const stepKind =
+    displayKind === 'search' || displayKind === 'list' || displayKind === 'read'
+      ? displayKind
+      : null;
 
-  return formatHumanList(summaryParts) || `${items.length} exploration steps`;
+  return {
+    msg,
+    groupKey,
+    displayKind,
+    stepKind,
+    objectLabel: extractObjectLabel(msg, displayKind),
+  };
 }
 
 /**
  * Collapse the paired `tool_call` and `tool_result` messages for the same
- * invocation into a single group item so the exploration summary counts each
+ * invocation into a single group item so the collapsed summary counts each
  * invocation once instead of twice. The `tool_result` is preferred when both
  * are present because it carries the populated title and output; the
  * `tool_call` is kept as a fallback for in-progress invocations that have not
- * yet produced a result. Items without a usable `toolCallId` are kept as-is.
+ * yet produced a result.
+ *
+ * Items with a `toolCallId` are matched globally by that id. Items without one
+ * only merge a consecutive `tool_call` + `tool_result` pair that share the same
+ * payload signature, so two legitimate repeated operations stay distinct.
  */
 function dedupeGroupItemsByToolCallId(
   items: GroupedToolCallItem[],
 ): GroupedToolCallItem[] {
-  const chosen = new Map<string, GroupedToolCallItem>();
+  const preferredByToolCallId = new Map<string, GroupedToolCallItem>();
 
   for (const item of items) {
-    const key = extractToolCallIdKey(item.msg.data.toolCallId);
+    const toolCallId = extractToolCallIdKey(item.msg.data.toolCallId);
 
-    if (key === null) {
+    if (!toolCallId) {
       continue;
     }
 
-    const existing = chosen.get(key);
+    const existing = preferredByToolCallId.get(toolCallId);
 
     if (
       !existing ||
       (item.msg.kind === 'tool_result' && existing.msg.kind !== 'tool_result')
     ) {
-      chosen.set(key, item);
+      preferredByToolCallId.set(toolCallId, item);
     }
   }
 
-  if (chosen.size === 0) {
-    return items;
-  }
-
-  const emittedKeys = new Set<string>();
   const result: GroupedToolCallItem[] = [];
+  const emittedToolCallIds = new Set<string>();
+  let index = 0;
 
-  for (const item of items) {
-    const key = extractToolCallIdKey(item.msg.data.toolCallId);
+  while (index < items.length) {
+    const item = items[index]!;
+    const toolCallId = extractToolCallIdKey(item.msg.data.toolCallId);
 
-    if (key === null) {
-      result.push(item);
+    if (toolCallId) {
+      if (!emittedToolCallIds.has(toolCallId)) {
+        emittedToolCallIds.add(toolCallId);
+        result.push(preferredByToolCallId.get(toolCallId)!);
+      }
+
+      index += 1;
       continue;
     }
 
-    if (emittedKeys.has(key)) {
+    const next = items[index + 1];
+    const signature = extractPayloadSignature(item);
+    const nextToolCallId = next
+      ? extractToolCallIdKey(next.msg.data.toolCallId)
+      : null;
+
+    if (
+      next &&
+      nextToolCallId === null &&
+      item.msg.kind === 'tool_call' &&
+      next.msg.kind === 'tool_result' &&
+      signature !== null &&
+      signature === extractPayloadSignature(next)
+    ) {
+      // Prefer the settled result for a single unpaired call/result stream.
+      result.push(next);
+      index += 2;
       continue;
     }
 
-    emittedKeys.add(key);
-    result.push(chosen.get(key)!);
+    result.push(item);
+    index += 1;
   }
 
   return result;
@@ -407,6 +587,18 @@ function extractToolCallIdKey(toolCallId: unknown): string | null {
     : null;
 }
 
+function extractPayloadSignature(item: GroupedToolCallItem): string | null {
+  const title = item.msg.data.title?.trim() ?? '';
+  const command = item.msg.data.command?.trim() ?? '';
+  const label = item.objectLabel.trim();
+
+  if (!title && !command && !label) {
+    return null;
+  }
+
+  return `${item.groupKey}|${title}|${command}|${label}`;
+}
+
 function isEmptyCompletedTextMessage(msg: AcpUiMessage): boolean {
   return (
     msg.kind === 'text' &&
@@ -557,13 +749,13 @@ function resolveMessageRenderState(
   if (!isToolMessage(msg)) {
     return {
       visibility: 'render',
-      stepKind: null,
+      groupKey: null,
     };
   }
 
   return {
     visibility: 'render',
-    stepKind: resolveExplorationStepKind(msg),
+    groupKey: resolveToolGroupKey(msg),
   };
 }
 
@@ -598,6 +790,38 @@ function buildAcpRenderBlocksInScope(
   const blocks: AcpRenderBlock[] = [];
   let cursor = 0;
 
+  const pushSingleMessage = (msg: AcpUiMessage): boolean => {
+    const currentMessage = dedupeRenderableMessageImages(msg, seenImageUris);
+
+    if (isEmptyCompletedTextMessage(currentMessage)) {
+      return false;
+    }
+
+    state.hasRenderedVisibleBlock = true;
+    const childMessages =
+      subagentChildSessionLookup.parentMessageToChildMessages.get(
+        currentMessage.id,
+      ) ?? [];
+    const childBlocks =
+      childMessages.length > 0
+        ? buildAcpRenderBlocksInScope(
+            childMessages,
+            options,
+            subagentChildSessionLookup,
+            seenImageUris,
+            state,
+            currentMessage.id,
+          )
+        : undefined;
+
+    blocks.push({
+      kind: 'message',
+      msg: currentMessage,
+      ...(childBlocks?.length ? { childBlocks } : {}),
+    });
+    return true;
+  };
+
   while (cursor < messages.length) {
     const current = messages[cursor]!;
     const currentParentMessageId = current.sessionId
@@ -628,49 +852,15 @@ function buildAcpRenderBlocksInScope(
       continue;
     }
 
-    if (!currentState.stepKind || !isToolMessage(current)) {
-      const currentMessage = dedupeRenderableMessageImages(
-        current,
-        seenImageUris,
-      );
-
-      if (isEmptyCompletedTextMessage(currentMessage)) {
-        cursor += 1;
-        continue;
-      }
-
-      state.hasRenderedVisibleBlock = true;
-      const childMessages =
-        subagentChildSessionLookup.parentMessageToChildMessages.get(
-          current.id,
-        ) ?? [];
-      const childBlocks =
-        childMessages.length > 0
-          ? buildAcpRenderBlocksInScope(
-              childMessages,
-              options,
-              subagentChildSessionLookup,
-              seenImageUris,
-              state,
-              current.id,
-            )
-          : undefined;
-
-      blocks.push({
-        kind: 'message',
-        msg: currentMessage,
-        ...(childBlocks?.length ? { childBlocks } : {}),
-      });
+    if (!currentState.groupKey || !isToolMessage(current)) {
+      pushSingleMessage(current);
       cursor += 1;
       continue;
     }
 
+    const runGroupKey = currentState.groupKey;
     const items: GroupedToolCallItem[] = [
-      {
-        msg: current,
-        objectLabel: extractObjectLabel(current, currentState.stepKind),
-        stepKind: currentState.stepKind,
-      },
+      buildGroupedToolItem(current, runGroupKey),
     ];
     let runCursor = cursor + 1;
 
@@ -702,60 +892,58 @@ function buildAcpRenderBlocksInScope(
         continue;
       }
 
-      if (!nextState.stepKind || !isToolMessage(next)) {
+      // Only collapse identical tool types consecutively.
+      if (
+        !nextState.groupKey ||
+        nextState.groupKey !== runGroupKey ||
+        !isToolMessage(next)
+      ) {
         break;
       }
 
-      items.push({
-        msg: next,
-        objectLabel: extractObjectLabel(next, nextState.stepKind),
-        stepKind: nextState.stepKind,
-      });
+      items.push(buildGroupedToolItem(next, nextState.groupKey));
       runCursor += 1;
     }
 
     if (items.length < 2) {
-      const currentMessage = dedupeRenderableMessageImages(
-        current,
-        seenImageUris,
-      );
-
-      if (isEmptyCompletedTextMessage(currentMessage)) {
-        cursor += 1;
-        continue;
-      }
-
-      blocks.push({ kind: 'message', msg: currentMessage });
-      state.hasRenderedVisibleBlock = true;
+      pushSingleMessage(current);
       cursor += 1;
       continue;
     }
 
     const dedupedItems = dedupeGroupItemsByToolCallId(items);
-
-    if (dedupedItems.length < 2) {
-      const representativeMessage = dedupeRenderableMessageImages(
-        dedupedItems[0]!.msg,
-        seenImageUris,
-      );
-
-      if (isEmptyCompletedTextMessage(representativeMessage)) {
-        cursor += 1;
-        continue;
+    const settledCount = dedupedItems.filter((item) =>
+      isSettledToolMessage(item.msg),
+    ).length;
+
+    // Keep individuals until the second same-type call has completed. Once the
+    // threshold is met, the whole consecutive same-type run collapses — including
+    // trailing in-progress invocations so later completions append into the same
+    // multi-call entry instead of spawning a new separate row.
+    if (dedupedItems.length < 2 || settledCount < TOOL_GROUP_MIN_SETTLED) {
+      for (const item of dedupedItems) {
+        pushSingleMessage(item.msg);
       }
 
-      blocks.push({ kind: 'message', msg: representativeMessage });
-      state.hasRenderedVisibleBlock = true;
       cursor = runCursor;
       continue;
     }
 
+    const displayKind = dedupedItems[0]!.displayKind;
+    const summary = summarizeSameTypeGroup(
+      dedupedItems,
+      displayKind,
+      runGroupKey,
+    );
+
     blocks.push({
       kind: 'tool_group',
       id: items[0]!.msg.id,
       ts: items[0]!.msg.ts,
-      action: 'Exploring',
-      objectSummary: summarizeGroupObject(dedupedItems),
+      action: summary.action,
+      objectSummary: summary.objectSummary,
+      groupKey: runGroupKey,
+      displayKind,
       items: dedupedItems,
     });
     state.hasRenderedVisibleBlock = true;
diff --git a/apps/web/src/app/(sandbox)/task/[taskId]/prompt-input/PromptInput.tsx b/apps/web/src/app/(sandbox)/task/[taskId]/prompt-input/PromptInput.tsx
index 4fdbdd19..2e5b611b 100644
--- a/apps/web/src/app/(sandbox)/task/[taskId]/prompt-input/PromptInput.tsx
+++ b/apps/web/src/app/(sandbox)/task/[taskId]/prompt-input/PromptInput.tsx
@@ -651,7 +651,7 @@ export const PromptInput = forwardRef<PromptInputHandle, PromptInputProps>(
     );
 
     return (
-      <div className="2xl:max-w-5xl mx-auto w-full">
+      <div className="mx-auto w-full max-w-4xl">
         <PromptInputRoot
           onSubmit={handleSubmit}
           accept={ROOMOTE_FILE_ATTACHMENT_ACCEPT}
diff --git a/apps/web/src/components/tasks/TaskPromptInput.tsx b/apps/web/src/components/tasks/TaskPromptInput.tsx
index 8327e9b3..069224ad 100644
--- a/apps/web/src/components/tasks/TaskPromptInput.tsx
+++ b/apps/web/src/components/tasks/TaskPromptInput.tsx
@@ -34,9 +34,11 @@ import { cn } from '@/lib/utils';
 function SubmitButton({
   isBusy,
   disabledReason,
+  icon,
 }: {
   isBusy: boolean;
   disabledReason?: string;
+  icon?: ReactNode;
 }) {
   const isDisabled = isBusy || Boolean(disabledReason);
   const button = (
@@ -46,7 +48,9 @@ function SubmitButton({
       size="sm"
       className="group size-8 overflow-clip"
     >
-      <SendHorizontal className="fill-background group-[:not(:disabled):hover]:animate-fly-through" />
+      {icon ?? (
+        <SendHorizontal className="fill-background group-[:not(:disabled):hover]:animate-fly-through" />
+      )}
     </PromptInputSubmit>
   );
 
@@ -112,6 +116,8 @@ type TaskPromptInputProps = {
   submitDisabledReason?: string;
   /** When true, submit on Cmd/Ctrl+Enter instead of plain Enter. */
   submitWithMetaKey?: boolean;
+  submitIcon?: ReactNode;
+  surface?: 'default' | 'embedded';
 };
 
 export function TaskPromptInput({
@@ -127,6 +133,8 @@ export function TaskPromptInput({
   suggestion,
   submitDisabledReason,
   submitWithMetaKey = true,
+  submitIcon,
+  surface = 'default',
 }: TaskPromptInputProps) {
   const voiceDictation = useVoiceDictation({
     onTranscript: (text) => onPromptTextChange(text),
@@ -137,8 +145,12 @@ export function TaskPromptInput({
   return (
     <div
       className={cn(
-        'flex flex-col gap-2 border rounded-lg p-2 bg-card border-input focus-within:border-accent-bright-foreground',
-        animateContainer && 'animate-[enter-down_1s_1_200ms_backwards]',
+        'flex flex-col gap-2',
+        surface === 'default' &&
+          'border rounded-lg p-2 bg-card border-input focus-within:border-accent-bright-foreground',
+        animateContainer &&
+          surface === 'default' &&
+          'animate-[enter-down_1s_1_200ms_backwards]',
       )}
     >
       <PromptInputRoot
@@ -154,7 +166,7 @@ export function TaskPromptInput({
             autoFocus={autoFocus}
             placeholder={placeholder}
             disabled={isBusy}
-            className="min-h-30"
+            className={surface === 'default' ? 'min-h-30' : undefined}
             style={
               textareaMaxHeight != null
                 ? { maxHeight: textareaMaxHeight }
@@ -165,7 +177,9 @@ export function TaskPromptInput({
             onChange={(e) => onPromptTextChange(e.target.value)}
           />
         </PromptInputBody>
-        <PromptInputFooter className="p-0">
+        <PromptInputFooter
+          className={surface === 'default' ? 'p-0' : 'pt-0 pb-4 px-4'}
+        >
           <PromptInputTools>
             <PromptInputActionMenu>
               <PromptInputActionMenuTrigger />
@@ -187,6 +201,7 @@ export function TaskPromptInput({
               <SubmitButton
                 isBusy={isBusy}
                 disabledReason={submitDisabledReason}
+                icon={submitIcon}
               />
             </div>
           </div>
diff --git a/knip.ts b/knip.ts
index cc01d0e6..621d61cc 100644
--- a/knip.ts
+++ b/knip.ts
@@ -40,8 +40,6 @@ const config: KnipConfig = {
     },
     'apps/preview-proxy': {
       project: ['src/**/*.ts'],
-      // Loaded by Pino transport resolution from the target string in logger.ts.
-      ignoreDependencies: ['pino-pretty'],
     },
     'apps/web': {
       entry: [