From 9cf26ababcb4bb27f92c736d1415ff32ba3f1f19 Mon Sep 17 00:00:00 2001
From: colafornia <colaforniaw@gmail.com>
Date: Tue, 8 Sep 2026 17:20:53 +0800
Subject: [PATCH] feat(desktop): improve tool output rendering

Refine WebFetch citation cards, bounded text previews, shell tail-following, archived output access, and tool invocation labels across the Desktop transcript surface.

Generated-by: OpenAI Codex
---
 .../runtime-host-artifacts-ipc-main.test.ts   |  29 +++
 .../runtime-host-client-operations.test.ts    |  15 ++
 .../main/runtime-host-artifacts-ipc-main.ts   |  26 ++-
 apps/desktop/src/main/runtime-host-client.ts  |  20 ++
 apps/desktop/src/preload/bridge-contract.d.ts |   2 +
 apps/desktop/src/preload/preload.ts           |   4 +
 .../composition/desktop-feature-services.tsx  |   6 +-
 .../controller/use-workbar-controller.ts      |  12 +
 .../src/renderer/features/workbar/index.ts    |   2 +
 .../src/renderer/features/workbar/ports.ts    |   2 +
 .../workbar/tools/artifacts/artifact-pane.tsx |  12 +-
 .../tools/artifacts/artifact-preview.tsx      |  10 +-
 .../artifacts/tool-output-preview-context.tsx |  48 ++++
 .../tools/artifacts/tool-output-preview.tsx   | 106 +++++++++
 .../desktop/create-workbar-services.ts        |   1 +
 .../src/renderer/styles/chat-message.css      |  33 +--
 .../src/renderer/styles/workbar/shell.css     |   7 +
 .../stories/session-workbar.stories.tsx       |  29 ++-
 docs/astryx-surface-file-inventory.md         |   6 +-
 docs/astryx-surface-file-inventory.paths      |   4 +
 .../src/__tests__/pty-output-view.test.ts     |  39 ++++
 .../src/__tests__/tool-quiet-preview.test.ts  |   8 +
 packages/core/src/artifacts.ts                |   6 +
 packages/core/src/events.ts                   |   1 +
 packages/core/src/pty-output-view.ts          |  13 +-
 packages/core/src/tool-quiet-preview.ts       | 101 ++++++++
 .../core/src/tool-result-record-schema.ts     |   3 +-
 .../__tests__/artifact-coordinator.test.ts    |  80 +++++++
 .../src/__tests__/execution-artifacts.test.ts |  79 ++++++-
 .../src/__tests__/web-fetch-tool.test.ts      |   2 +-
 .../runtime-host/src/protocol/artifact.ts     |  58 ++++-
 packages/runtime-host/src/protocol/index.ts   |   2 +-
 .../src/server/artifact-coordinator.ts        | 116 +++++++++-
 .../src/server/execution-composition.ts       |   1 +
 .../src/__tests__/web-fetch-tool.test.ts      |  15 +-
 packages/runtime/src/shell-run-tool-result.ts |   7 +-
 packages/runtime/src/web-fetch-tool.ts        |  19 +-
 .../tool-activity-presentation.test.ts        | 126 +++++++++-
 .../tool-output-interaction.test.tsx          | 132 +++++++++++
 packages/ui/src/chat-view.tsx                 |   3 +
 packages/ui/src/index.ts                      |   4 +
 packages/ui/src/styles.css                    |  12 +
 packages/ui/src/tool-activity.tsx             | 179 ++++++++-------
 packages/ui/src/tool-activity/copy.ts         |  77 ++++++-
 .../ui/src/tool-activity/preview-utils.ts     |  56 ++++-
 .../ui/src/tool-activity/result-projection.ts |  46 ++++
 .../ui/src/tool-activity/tool-code-block.tsx  |   2 +
 .../src/tool-activity/tool-result-context.tsx |  40 ++++
 .../src/tool-activity/tool-result-preview.tsx | 215 +++++++++++-------
 .../src/tool-activity/tool-text-preview.tsx   | 102 +++++++++
 .../ui/src/transcript-scroll-authority.tsx    |   6 +-
 packages/ui/stories/tool-activity.stories.tsx |  39 ++++
 52 files changed, 1711 insertions(+), 252 deletions(-)
 create mode 100644 apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview-context.tsx
 create mode 100644 apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview.tsx
 create mode 100644 packages/core/src/__tests__/pty-output-view.test.ts
 create mode 100644 packages/ui/src/__tests__/tool-output-interaction.test.tsx
 create mode 100644 packages/ui/src/tool-activity/tool-result-context.tsx
 create mode 100644 packages/ui/src/tool-activity/tool-text-preview.tsx

diff --git a/apps/desktop/src/main/__tests__/runtime-host-artifacts-ipc-main.test.ts b/apps/desktop/src/main/__tests__/runtime-host-artifacts-ipc-main.test.ts
index 77f5186af0..501522da80 100644
--- a/apps/desktop/src/main/__tests__/runtime-host-artifacts-ipc-main.test.ts
+++ b/apps/desktop/src/main/__tests__/runtime-host-artifacts-ipc-main.test.ts
@@ -23,6 +23,7 @@ import { syncBuiltinESMExports } from "node:module";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { test } from "node:test";
+import { createHash } from "node:crypto";
 import { registerRuntimeHostArtifactsIpc } from "../runtime-host-artifacts-ipc-main.js";
 
 type Handler = (event: unknown, ...args: any[]) => unknown;
@@ -32,6 +33,34 @@ type StreamArtifact = (
   writeChunk: (chunk: Uint8Array) => Promise<void>,
 ) => Promise<number>;
 
+test('routes archive reads to the Host and rejects inconsistent reference evidence', async () => {
+  const handlers = new Map<string, Handler>();
+  const text = JSON.stringify('中文 retained output '.repeat(4_000));
+  const bytes = Buffer.from(text);
+  const identity = { artifactId: 'archive-1', originalBytes: bytes.length,
+    bodySha256: createHash('sha256').update(bytes).digest('hex') };
+  registerRuntimeHostArtifactsIpc({
+    uiLocale: () => 'zh-CN' as const,
+    ipcMain: { handle: (channel, handler) => handlers.set(channel, handler as Handler) },
+    client: {
+      hostEpoch: 'host-1',
+      async readToolResult(sessionId: string, ref: string) {
+        assert.equal(sessionId, 'session-1');
+        assert.equal(ref, `maka://archive/archive-1/${identity.bodySha256}/${bytes.length}`);
+        return { ok: true, text };
+      },
+    } as never,
+    mainWindowController: {} as never,
+    showItemInFolder() {},
+  });
+  const read = handlers.get('artifacts:readToolResult');
+  assert.ok(read);
+  assert.deepEqual(await read({}, 'session-1', identity), { ok: true, text });
+  assert.deepEqual(await read({}, 'session-1', { ...identity,
+    resourceRef: `maka://archive/archive-1/${'0'.repeat(64)}/${bytes.length}` }),
+    { ok: false, reason: 'not_allowed' });
+});
+
 // Exercise the public Save As result and destination bytes together. Faults
 // use real temporary files; only the failing filesystem operation is mocked.
 for (const [fault, reason] of [
diff --git a/apps/desktop/src/main/__tests__/runtime-host-client-operations.test.ts b/apps/desktop/src/main/__tests__/runtime-host-client-operations.test.ts
index 302d644243..451f2f0f69 100644
--- a/apps/desktop/src/main/__tests__/runtime-host-client-operations.test.ts
+++ b/apps/desktop/src/main/__tests__/runtime-host-client-operations.test.ts
@@ -913,6 +913,21 @@ interface RecordedRequest {
   input: unknown;
 }
 
+test('assembles archived UTF-8 output across Host chunks and preserves read failures', async () => {
+  const bytes = Buffer.from('中文 retained output '.repeat(2000));
+  const split = 32768;
+  const responses = [0, split].map(offset => ({ kind: 'archive_chunk', sessionId: 'session-1',
+    offset, totalBytes: bytes.length, chunkBase64: bytes.subarray(offset, offset ? undefined : split).toString('base64'),
+    nextOffset: offset ? null : split }));
+  const { client, requests } = clientWithResponses(responses);
+  assert.deepEqual(await client.readToolResult('session-1', 'archive-ref'), { ok: true, text: bytes.toString('utf8') });
+  assert.deepEqual(requests.map(request => request.input), [0, split].map(offset => ({
+    kind: 'read_archive_chunk', sessionId: 'session-1', ref: 'archive-ref', offset,
+  })));
+  const failure = clientWithResponses([{ kind: 'archive_unavailable', sessionId: 'session-1', reason: 'not_found' }]);
+  assert.deepEqual(await failure.client.readToolResult('session-1', 'archive-ref'), { ok: false, reason: 'not_found' });
+});
+
 function clientWithResponses(responses: unknown[]): {
   client: DesktopRuntimeHostClient;
   requests: RecordedRequest[];
diff --git a/apps/desktop/src/main/runtime-host-artifacts-ipc-main.ts b/apps/desktop/src/main/runtime-host-artifacts-ipc-main.ts
index 6b136f81ba..1c65ffd4ad 100644
--- a/apps/desktop/src/main/runtime-host-artifacts-ipc-main.ts
+++ b/apps/desktop/src/main/runtime-host-artifacts-ipc-main.ts
@@ -27,7 +27,10 @@ import {
   normalizeArtifactImagePreviewMime,
   resolveArtifactImagePreview,
   type ArtifactSaveResult,
+  type ArtifactTextReadResult,
+  type ToolResultArchiveIdentity,
 } from '@maka/core/artifacts';
+import { buildToolResultArchiveResourceRef, parseToolResultArchiveResourceRef } from '@maka/runtime/tool-result-archive-resource';
 import { sanitizeArtifactName } from "@maka/storage/artifact-stores";
 import {
   handleReconnectableRead,
@@ -50,7 +53,7 @@ type RuntimeHostAttachmentPreviewIpcDeps = Pick<
   'ipcMain' | 'client'
 >;
 
-const ATTACHMENT_PREVIEW_LIMIT_EXCEEDED = Symbol("attachment-preview-limit-exceeded");
+const ARTIFACT_READ_LIMIT_EXCEEDED = Symbol("artifact-read-limit-exceeded");
 
 export function registerRuntimeHostArtifactsIpc(
   deps: RuntimeHostArtifactsIpcDeps,
@@ -76,6 +79,23 @@ export function registerRuntimeHostArtifactsIpc(
     (_event, sessionId: string, artifactId: string) =>
       deps.client.readArtifactBinary(sessionId, artifactId),
   );
+  handleReconnectableRead(
+    deps.ipcMain,
+    'artifacts:readToolResult',
+    async (_event, sessionId: string, identity: ToolResultArchiveIdentity): Promise<ArtifactTextReadResult> => {
+      if (!identity || (!identity.resourceRef && typeof identity.artifactId !== 'string')
+        || !Number.isSafeInteger(identity.originalBytes) || identity.originalBytes < 0
+        || typeof identity.bodySha256 !== 'string' || !/^[a-f0-9]{64}$/.test(identity.bodySha256)) return { ok: false, reason: 'not_allowed' };
+      const ref = identity.resourceRef ?? buildToolResultArchiveResourceRef({
+        artifactId: identity.artifactId!, originalBytes: identity.originalBytes, bodySha256: identity.bodySha256,
+      });
+      if (typeof ref !== 'string') return { ok: false, reason: 'not_allowed' };
+      const parsed = parseToolResultArchiveResourceRef(ref);
+      if (!parsed || parsed.originalBytes !== identity.originalBytes || parsed.bodySha256 !== identity.bodySha256)
+        return { ok: false, reason: 'not_allowed' };
+      return deps.client.readToolResult(sessionId, ref);
+    },
+  );
   deps.ipcMain.handle(
     "artifacts:delete",
     (_event, sessionId: string, artifactId: string) =>
@@ -163,12 +183,12 @@ export function registerRuntimeHostAttachmentPreviewIpc(
         await deps.client.streamArtifact(sessionId, artifactId, async (chunk) => {
           received += chunk.byteLength;
           if (received > ARTIFACT_IMAGE_PREVIEW_MAX_BYTES) {
-            throw ATTACHMENT_PREVIEW_LIMIT_EXCEEDED;
+            throw ARTIFACT_READ_LIMIT_EXCEEDED;
           }
           chunks.push(Buffer.from(chunk));
         });
       } catch (error) {
-        if (error === ATTACHMENT_PREVIEW_LIMIT_EXCEEDED) {
+        if (error === ARTIFACT_READ_LIMIT_EXCEEDED) {
           return { ok: false as const, reason: "too_large" };
         }
         throw error;
diff --git a/apps/desktop/src/main/runtime-host-client.ts b/apps/desktop/src/main/runtime-host-client.ts
index 966bc58334..cf8964a489 100644
--- a/apps/desktop/src/main/runtime-host-client.ts
+++ b/apps/desktop/src/main/runtime-host-client.ts
@@ -18,6 +18,8 @@
  */
 
 import { createHash, randomUUID } from "node:crypto";
+import type { ArtifactTextReadResult } from '@maka/core/artifacts';
+import { TOOL_RESULT_ARCHIVE_MAX_BYTES } from '@maka/runtime/tool-result-archive-resource';
 import type { AttachmentRef, ShellRunUpdate } from "@maka/core/events";
 import type { PlanSessionState, PlanUserControlInput } from "@maka/core/plan";
 import {
@@ -888,6 +890,24 @@ export class DesktopRuntimeHostClient {
     return result.preview;
   }
 
+  async readToolResult(sessionId: string, ref: string): Promise<ArtifactTextReadResult> {
+    const chunks: Buffer[] = [];
+    let offset = 0;
+    let total: number | undefined;
+    while (true) {
+      const result = await this.request('artifact.query', { kind: 'read_archive_chunk', sessionId, ref, offset });
+      if (result.kind === 'archive_unavailable' && result.sessionId === sessionId) return { ok: false, reason: result.reason };
+      if (result.kind !== 'archive_chunk' || result.sessionId !== sessionId || result.offset !== offset
+        || (total !== undefined && result.totalBytes !== total) || result.totalBytes > TOOL_RESULT_ARCHIVE_MAX_BYTES) {
+        throw invalidProjection('Archived output');
+      }
+      total = result.totalBytes;
+      chunks.push(Buffer.from(result.chunkBase64, 'base64'));
+      if (result.nextOffset === null) return { ok: true, text: Buffer.concat(chunks).toString('utf8') };
+      offset = result.nextOffset;
+    }
+  }
+
   async readArtifactBinary(
     sessionId: string,
     artifactId: string,
diff --git a/apps/desktop/src/preload/bridge-contract.d.ts b/apps/desktop/src/preload/bridge-contract.d.ts
index 68465dac92..0effcc11e9 100644
--- a/apps/desktop/src/preload/bridge-contract.d.ts
+++ b/apps/desktop/src/preload/bridge-contract.d.ts
@@ -84,6 +84,7 @@ import type {
   ArtifactDescriptor,
   ArtifactSaveResult,
   ArtifactTextReadResult,
+  ToolResultArchiveIdentity,
 } from '@maka/core/artifacts';
 import type { CapabilitySnapshotCollection, PermissionSnapshot } from '@maka/core/capabilities';
 import type { LocalMemoryState } from '@maka/core/local-memory';
@@ -1781,6 +1782,7 @@ export interface MakaBridge {
   };
   artifacts: {
     list(sessionId: string): Promise<ArtifactDescriptor[]>;
+    readToolResult(sessionId: string, identity: ToolResultArchiveIdentity): Promise<ArtifactTextReadResult>;
     readText(sessionId: string, artifactId: string): Promise<ArtifactTextReadResult>;
     readBinary(sessionId: string, artifactId: string): Promise<ArtifactBinaryReadResult>;
     delete(sessionId: string, artifactId: string): Promise<void>;
diff --git a/apps/desktop/src/preload/preload.ts b/apps/desktop/src/preload/preload.ts
index 23164f1de7..d9fec73d4f 100644
--- a/apps/desktop/src/preload/preload.ts
+++ b/apps/desktop/src/preload/preload.ts
@@ -165,6 +165,7 @@ import type {
   ArtifactDescriptor,
   ArtifactSaveResult,
   ArtifactTextReadResult,
+  ToolResultArchiveIdentity,
 } from '@maka/core/artifacts';
 import type { CapabilitySnapshotCollection, PermissionSnapshot } from '@maka/core/capabilities';
 import type { LocalMemoryState } from '@maka/core/local-memory';
@@ -3693,6 +3694,9 @@ const makaBridge = {
     list(sessionId: string): Promise<ArtifactDescriptor[]> {
       return invokeProjectedSessionRuntimeHost('artifacts:list', sessionId);
     },
+    readToolResult(sessionId: string, identity: ToolResultArchiveIdentity): Promise<ArtifactTextReadResult> {
+      return invokeSessionRuntimeHost('artifacts:readToolResult', sessionId, identity);
+    },
     readText(sessionId: string, artifactId: string): Promise<ArtifactTextReadResult> {
       return invokeSessionRuntimeHost('artifacts:readText', sessionId, artifactId);
     },
diff --git a/apps/desktop/src/renderer/composition/desktop-feature-services.tsx b/apps/desktop/src/renderer/composition/desktop-feature-services.tsx
index 70a402938b..64fed8bc9b 100644
--- a/apps/desktop/src/renderer/composition/desktop-feature-services.tsx
+++ b/apps/desktop/src/renderer/composition/desktop-feature-services.tsx
@@ -30,7 +30,7 @@ import { SessionNavigationServicesProvider } from '../features/session-navigatio
 import { WorkHubComposerServicesProvider } from '../features/workhub/index.js';
 import { SessionSettingsServicesProvider } from '../features/session-settings';
 import { TaskEntryServicesProvider } from '../features/task-entry';
-import { WorkbarServicesProvider } from '../features/workbar';
+import { WorkbarServicesProvider, ToolOutputPreviewProvider } from '../features/workbar';
 import { createDesktopAppUpdateServices } from '../platform/desktop/create-app-update-services';
 import { createDesktopGoalServices } from '../platform/desktop/create-goal-services';
 import { createDesktopConnectionSettingsServices } from '../platform/desktop/create-connection-settings-services';
@@ -77,7 +77,9 @@ export function DesktopFeatureServicesProvider(props: {
                     <GoalServicesProvider services={props.services.goal}>
                       <WorkbarServicesProvider services={props.services.workbar}>
                         <ConversationServicesProvider services={props.services.conversation}>
-                          {props.children}
+                          <ToolOutputPreviewProvider>
+                            {props.children}
+                          </ToolOutputPreviewProvider>
                         </ConversationServicesProvider>
                       </WorkbarServicesProvider>
                     </GoalServicesProvider>
diff --git a/apps/desktop/src/renderer/features/workbar/controller/use-workbar-controller.ts b/apps/desktop/src/renderer/features/workbar/controller/use-workbar-controller.ts
index 1ec9769211..956c451c22 100644
--- a/apps/desktop/src/renderer/features/workbar/controller/use-workbar-controller.ts
+++ b/apps/desktop/src/renderer/features/workbar/controller/use-workbar-controller.ts
@@ -36,6 +36,7 @@ import { safeLocalStorageGet, safeLocalStorageSet } from '../../../browser-stora
 import { getDesktopConversationCopy } from '../../../locales/conversation-copy.js';
 import { getShellCopy, localizedShellErrorMessage } from '../../../locales/shell-copy.js';
 import { sideChatTitleFromPrompt } from '../../../side-chat-command.js';
+import { useToolOutputPreview } from '../tools/artifacts/tool-output-preview-context.js';
 import { useWorkbarServices } from '../services-context.js';
 import type { WorkbarHostModel } from '../ui/workbar-host.js';
 import { SKIP_SIDE_CHAT_CLOSE_CONFIRMATION_KEY } from '../ui/side-chat-close-confirmation.js';
@@ -166,6 +167,8 @@ export function useWorkbarController(
   input: UseWorkbarControllerInput,
 ): WorkbarController {
   const locale = useUiLocale();
+  const toolOutput = useToolOutputPreview();
+  const openedOutput = useRef<unknown>(undefined);
   const terminalCopy = getDesktopConversationCopy(locale).terminalPanel;
   const { browser, sideChat, terminal } = useWorkbarServices();
   const activeSessionId = input.activeSession?.id;
@@ -649,6 +652,15 @@ export function useWorkbarController(
     return () => window.removeEventListener('keydown', handleShortcut, true);
   }, [activeSessionId, input.available, input.shellObscured, openTool]);
 
+  useEffect(() => {
+    if (!toolOutput?.preview?.visible) { openedOutput.current = undefined; return; }
+    if (openedOutput.current === toolOutput.preview) return;
+    openedOutput.current = toolOutput.preview;
+    openTool('files');
+  }, [toolOutput?.preview, openTool]);
+  const closeToolOutput = toolOutput?.close;
+  useLayoutEffect(() => () => closeToolOutput?.(), [activeSessionId, closeToolOutput]);
+
   const confirmPendingClose = useCallback(
     (skipFutureConfirmations: boolean) => {
       if (pendingSideChatClose.length === 0) return;
diff --git a/apps/desktop/src/renderer/features/workbar/index.ts b/apps/desktop/src/renderer/features/workbar/index.ts
index 2b2decd585..7620653a29 100644
--- a/apps/desktop/src/renderer/features/workbar/index.ts
+++ b/apps/desktop/src/renderer/features/workbar/index.ts
@@ -28,3 +28,5 @@ export { WorkbarServicesProvider } from './services-context';
 export { useWorkbarController } from './controller/use-workbar-controller';
 export type { SessionWorkbarTabKind } from './model/workbar-tabs';
 export type { WorkbarServices } from './ports';
+
+export { ToolOutputPreviewProvider } from './tools/artifacts/tool-output-preview-context.js';
diff --git a/apps/desktop/src/renderer/features/workbar/ports.ts b/apps/desktop/src/renderer/features/workbar/ports.ts
index 4ee8b1cd65..53e66ecfc2 100644
--- a/apps/desktop/src/renderer/features/workbar/ports.ts
+++ b/apps/desktop/src/renderer/features/workbar/ports.ts
@@ -17,6 +17,7 @@
  * under the License.
  */
 
+import type { ToolResultArchiveIdentity } from '@maka/core/artifacts';
 import type {
   QuoteRef,
   SessionEvent,
@@ -125,6 +126,7 @@ export type WorkbarOpenArtifactResult =
     };
 
 export interface WorkbarArtifactsService {
+  readToolResult?(sessionId: string, identity: ToolResultArchiveIdentity): Promise<ArtifactTextReadResult>;
   list(sessionId: string): Promise<ArtifactDescriptor[]>;
   readText(
     sessionId: string,
diff --git a/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-pane.tsx b/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-pane.tsx
index 135bc78349..4fa2d65b90 100644
--- a/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-pane.tsx
+++ b/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-pane.tsx
@@ -79,6 +79,8 @@ import { nextArtifactListAction } from './artifact-list-keyboard';
 import { filterUserVisibleArtifacts } from './artifact-visibility';
 import { openPathFailureCopy } from '../../../../open-path';
 import { getArtifactCopy, type ArtifactCopy } from '../../../../locales/artifact-copy';
+import { ToolOutputPreview } from './tool-output-preview.js';
+import { useToolOutputPreview } from './tool-output-preview-context.js';
 import { useWorkbarServices } from '../../services-context.js';
 
 export function ArtifactPane(props: {
@@ -88,6 +90,7 @@ export function ArtifactPane(props: {
   onDismiss?: () => void;
 }) {
   const { sessionId } = props;
+  const toolOutput = useToolOutputPreview();
   const { artifacts } = useWorkbarServices();
   const toast = useToast();
   const locale = useUiLocale();
@@ -446,7 +449,10 @@ export function ArtifactPane(props: {
     }
   }
 
-  return (
+  return <>
+    {toolOutput?.preview?.visible && <ToolOutputPreview key={toolOutput.preview.id} request={toolOutput.preview.request}
+        onClose={() => { setView({ kind: 'list' }); toolOutput.hide(); }} />}
+    {!toolOutput?.preview?.visible && (
     <div className="maka-artifact-pane" role="region" aria-label={copy.pane.panelAria} onKeyDown={handlePaneKeyDown}>
       {activeListError && (
         <Banner
@@ -589,8 +595,8 @@ export function ArtifactPane(props: {
           </div>
         </div>
       ) : null}
-    </div>
-  );
+    </div>)}
+  </>;
 }
 
 // ---- helpers ---------------------------------------------------------------
diff --git a/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview.tsx b/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview.tsx
index 4cf547a0d9..c42daa2ca8 100644
--- a/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview.tsx
+++ b/apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview.tsx
@@ -107,10 +107,10 @@ function FilePreview(props: { record: ArtifactDescriptor; copy: ArtifactCopy })
   return <TextFilePreview name={props.record.name} text={result.value.text} copy={props.copy} />;
 }
 
-function TextFilePreview(props: { name: string; text: string; copy: ArtifactCopy }) {
+export function TextFilePreview(props: { name: string; text: string; copy: ArtifactCopy; complete?: boolean }) {
   const markdown = /\.(?:md|markdown)$/i.test(props.name);
   const [mode, setMode] = useState<'rendered' | 'source'>(markdown ? 'rendered' : 'source');
-  const bounded = boundPreviewText(props.text);
+  const bounded = boundPreviewText(props.text, props.complete);
 
   return (
     <div className="maka-artifact-preview-text" data-mode={mode}>
@@ -255,10 +255,10 @@ type BoundedPreviewText = {
   isDisplayTruncated: boolean;
 };
 
-function boundPreviewText(text: string): BoundedPreviewText {
+function boundPreviewText(text: string, complete = false): BoundedPreviewText {
   const bytes = new TextEncoder().encode(text);
   const decoder = new TextDecoder();
-  const displayText = decoder.decode(utf8Prefix(bytes, TEXT_DISPLAY_LIMIT_BYTES));
+  const displayText = complete ? text : decoder.decode(utf8Prefix(bytes, TEXT_DISPLAY_LIMIT_BYTES));
   const highlightCandidate = decoder.decode(utf8Prefix(bytes, TEXT_HIGHLIGHT_LIMIT_BYTES));
   const lineBreak = highlightCandidate.lastIndexOf('\n');
   let highlightedText = bytes.length > TEXT_HIGHLIGHT_LIMIT_BYTES && lineBreak > 0
@@ -274,7 +274,7 @@ function boundPreviewText(text: string): BoundedPreviewText {
     highlightedText,
     plainRemainder,
     hasPlainRemainder: plainRemainder.length > 0,
-    isDisplayTruncated: bytes.length > TEXT_DISPLAY_LIMIT_BYTES,
+    isDisplayTruncated: !complete && bytes.length > TEXT_DISPLAY_LIMIT_BYTES,
   };
 }
 
diff --git a/apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview-context.tsx b/apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview-context.tsx
new file mode 100644
index 0000000000..28596bf718
--- /dev/null
+++ b/apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview-context.tsx
@@ -0,0 +1,48 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { createContext, useCallback, useContext, useMemo, useRef, useState, type ReactNode } from 'react';
+import { ToolResultHostProvider, type ToolOutputOpenRequest } from '@maka/ui';
+
+const ToolOutputPreviewContext = createContext<{
+  preview?: { request: ToolOutputOpenRequest; id: number; visible: boolean };
+  close(): void;
+  hide(): void;
+} | undefined>(undefined);
+
+export const useToolOutputPreview = () => useContext(ToolOutputPreviewContext);
+
+/** Retained tool output is a transient selection in the existing Files viewer. */
+export function ToolOutputPreviewProvider(props: { children?: ReactNode }) {
+  const [preview, setPreview] = useState<{ request: ToolOutputOpenRequest; id: number; visible: boolean }>();
+  const opener = useRef<HTMLElement | null>(null);
+  const close = useCallback(() => { setPreview(undefined); opener.current = null; }, []);
+  const hide = useCallback(() => {
+    setPreview(current => current ? { ...current, visible: false } : current);
+    if (opener.current?.isConnected) opener.current.focus();
+  }, []);
+  const openOutput = useCallback((request: ToolOutputOpenRequest) => {
+      opener.current = document.activeElement instanceof HTMLElement ? document.activeElement : null;
+      setPreview(current => ({ request, id: (current?.id ?? 0) + 1, visible: true }));
+  }, []);
+  const value = useMemo(() => ({ preview, close, hide }), [preview, close, hide]);
+  return <ToolOutputPreviewContext.Provider value={value}>
+    <ToolResultHostProvider value={openOutput}>{props.children}</ToolResultHostProvider>
+  </ToolOutputPreviewContext.Provider>;
+}
diff --git a/apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview.tsx b/apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview.tsx
new file mode 100644
index 0000000000..b75cc3355c
--- /dev/null
+++ b/apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview.tsx
@@ -0,0 +1,106 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import type { ArtifactReadFailureReason } from '@maka/core/artifacts';
+import { useEffect, useRef, useState } from 'react';
+import { Button, getToolActivityCopy, useClipboardCopyFeedback, useUiLocale, redactSecrets, type ToolOutputOpenRequest } from '@maka/ui';
+import { ArrowLeft, ICON_SIZE } from '@maka/ui/icons';
+import { formatSavedToolJson } from '@maka/core/tool-quiet-preview';
+import { getArtifactCopy } from '../../../../locales/artifact-copy.js';
+import { TextFilePreview } from './artifact-preview.js';
+import { useWorkbarServices } from '../../services-context.js';
+
+export function ToolOutputPreview(props: { request: ToolOutputOpenRequest; onClose(): void }) {
+  const locale = useUiLocale();
+  const copy = getToolActivityCopy(locale);
+  const artifactCopy = getArtifactCopy(locale);
+  const [result, setResult] = useState<{ text: string; partial: boolean } | 'failed' | 'unavailable' | ArtifactReadFailureReason>();
+  const [attempt, setAttempt] = useState(0);
+  const region = useRef<HTMLDivElement>(null);
+  const feedback = useClipboardCopyFeedback();
+  const { artifacts } = useWorkbarServices();
+  useEffect(() => {
+    let cancelled = false;
+    const source = props.request.source;
+    const load = source.kind === 'text'
+      ? Promise.resolve(source.text)
+      : (async () => {
+          const result = await artifacts.readToolResult?.(
+            source.sessionId,
+            source.identity,
+          );
+          return result?.ok ? result.text : result;
+        })();
+    load.then((raw) => {
+      if (cancelled) return;
+      if (raw === undefined) { setResult('unavailable'); return; }
+      if (typeof raw !== 'string') { setResult(raw.reason); return; }
+      let parsed: unknown;
+      try { parsed = JSON.parse(raw); } catch { /* Plain output is valid too. */ }
+      let partial = props.request.truncated === true;
+      // ArchiveRead wraps a retained page in protocol metadata. Only unwrap
+      // successful body responses; ordinary JSON and diagnostics stay intact.
+      if (props.request.toolName === 'ArchiveRead' && parsed && typeof parsed === 'object' && 'kind' in parsed && parsed.kind === 'tool_result_archive'
+        && 'ok' in parsed && parsed.ok === true && 'operation' in parsed
+        && (parsed.operation === 'read' || parsed.operation === 'query')
+        && 'content' in parsed && typeof parsed.content === 'string') {
+        partial ||= ('hasMore' in parsed && parsed.hasMore === true)
+          || ('offset' in parsed && typeof parsed.offset === 'number' && parsed.offset > 0)
+          || ('lineOffset' in parsed && typeof parsed.lineOffset === 'number' && parsed.lineOffset > 0);
+        parsed = parsed.content;
+      }
+      const text = parsed === undefined ? redactSecrets(raw)
+        : typeof parsed === 'string' ? redactSecrets(parsed) : formatSavedToolJson(parsed);
+      setResult({ text, partial });
+    }).catch(() => { if (!cancelled) setResult('failed'); });
+    return () => { cancelled = true; };
+  }, [artifacts, props.request, attempt]);
+  useEffect(() => {
+    region.current?.focus();
+  }, []);
+  const phase = feedback.phaseFor('output');
+  return <div className="maka-artifact-pane" onKeyDown={(event) => {
+    if (event.key === 'Escape') { event.stopPropagation(); props.onClose(); }
+  }}>
+    <div className="maka-artifact-preview-screen">
+      <header className="maka-artifact-preview-header">
+        <Button variant="ghost" size="sm" isIconOnly label={artifactCopy.pane.back}
+          icon={<ArrowLeft size={ICON_SIZE.chrome} aria-hidden="true" />} onClick={props.onClose} />
+        <div className="maka-artifact-preview-heading"><strong>{props.request.title}</strong></div>
+        {result && typeof result === 'object' && <Button variant="ghost" size="sm"
+          label={phase ? copy.copy[phase] : copy.detail.copySaved}
+          isDisabled={phase === 'pending'} onClick={() => void feedback.copy('output', result.text)} />}
+      </header>
+      <div ref={region} className="maka-artifact-preview" role="region"
+        aria-label={artifactCopy.pane.previewNamed(props.request.title)} tabIndex={-1}>
+        {!result && <p role="status">{copy.detail.loading}</p>}
+        {result === 'unavailable' && <p role="status">{copy.detail.unavailable}</p>}
+        {result && typeof result === 'string' && result !== 'read_failed' && result in copy.detail.readFailure &&
+          <p role="status">{copy.detail.readFailure[result as ArtifactReadFailureReason]}</p>}
+        {(result === 'failed' || result === 'read_failed') && <div role="alert"><p>{copy.detail.loadFailed}</p>
+          <Button variant="ghost" size="sm" label={copy.detail.retry} onClick={() => { setResult(undefined); setAttempt(value => value + 1); }} />
+        </div>}
+        {result && typeof result === 'object' && <>
+          {result.partial && <p role="status">{getToolActivityCopy(locale).result.outputTruncated}</p>}
+          <TextFilePreview name="output.txt" text={result.text} copy={artifactCopy} complete />
+        </>}
+      </div>
+    </div>
+  </div>;
+}
diff --git a/apps/desktop/src/renderer/platform/desktop/create-workbar-services.ts b/apps/desktop/src/renderer/platform/desktop/create-workbar-services.ts
index 39a6e490c5..cd692a7327 100644
--- a/apps/desktop/src/renderer/platform/desktop/create-workbar-services.ts
+++ b/apps/desktop/src/renderer/platform/desktop/create-workbar-services.ts
@@ -68,6 +68,7 @@ export function createDesktopWorkbarServices(
       subscribeLive: (handler) => bridge.browser.onLive(handler),
     },
     artifacts: {
+      readToolResult: (sessionId, identity) => bridge.artifacts.readToolResult(sessionId, identity),
       list: (sessionId) => bridge.artifacts.list(sessionId),
       readText: (sessionId, artifactId) =>
         bridge.artifacts.readText(sessionId, artifactId),
diff --git a/apps/desktop/src/renderer/styles/chat-message.css b/apps/desktop/src/renderer/styles/chat-message.css
index 1380bcac24..b704e5f194 100644
--- a/apps/desktop/src/renderer/styles/chat-message.css
+++ b/apps/desktop/src/renderer/styles/chat-message.css
@@ -210,34 +210,13 @@
 /* Cursor for tool/reasoning disclosure triggers is owned by
    styles/native-cursor.css (role=button + default !important). */
 
-.maka-turn .astryx-chat-tool-calls [role="button"] > span:nth-child(2) {
-  font: var(--maka-text-label);
-}
-
-/* Reasoning and tool-call rows read at BODY size, not supporting size.
-   Astryx puts the label and preview on inner spans styled as `supporting`
-   (12px on this scale). Measured on main they rendered at 9.75px — Astryx's
-   sm tier at 0.75rem against the old 13px root — which made them the least
-   legible text in the product, and they carry real content — what the agent is
-   thinking and which tool is running — not metadata.
-   Cursor makes the same call: its tool rows sit at body size and lean
-   entirely on --text-secondary/tertiary for de-emphasis. Weight and colour
-   already do that here, so size does not need to.
-
-   Rebinding the role token rather than restyling the spans. Astryx's
-   supporting atoms are `font-size: var(--text-supporting-size)` and
-   `line-height: var(--text-supporting-leading)`, so redefining those two on
-   the trigger reaches every span that opts into the role, at any depth,
-   through inheritance — no !important, since nothing else declares them
-   here, and no dependency on child order.
-   The earlier form of this rule selected `> span:not(:last-child)`, which
-   read as "every span except the chevron". It was wrong for exactly the
-   reason positional selectors are: ChatReasoning wraps its label, duration
-   and preview in a `<div>` (packages/ui/src/astryx-chat-reasoning.tsx), so
-   the rule enlarged the leading icon wrapper and left the reasoning text at
-   supporting size — the one row the retune was for. */
+/* Tool typography belongs to the activity container, independent of whether
+   a row has expandable details. Rebind Astryx's supporting tokens once so
+   group headers, interactive rows and static rows inherit the same body size.
+   Keep Astryx's font families and weights; detail CodeBlocks retain their
+   own code-role token override in packages/ui/src/styles.css. */
 .maka-turn .astryx-chat-reasoning [role="button"],
-.maka-turn .astryx-chat-tool-calls [role="button"] {
+.maka-turn .maka-tool-activity-card {
   --text-supporting-size: var(--text-body-size);
   --text-supporting-leading: var(--maka-line-body);
 }
diff --git a/apps/desktop/src/renderer/styles/workbar/shell.css b/apps/desktop/src/renderer/styles/workbar/shell.css
index 36fc0cd910..4460b4a51a 100644
--- a/apps/desktop/src/renderer/styles/workbar/shell.css
+++ b/apps/desktop/src/renderer/styles/workbar/shell.css
@@ -272,6 +272,13 @@
   overflow: hidden;
 }
 
+/* Section's inner container must shrink with the panel so its viewer scrolls. */
+.maka-session-workbar-panel > .astryx-section {
+  min-height: 0;
+  height: 100%;
+  overflow: hidden;
+}
+
 .maka-workbar-panel-loading {
   display: grid;
   place-items: center;
diff --git a/apps/desktop/stories/session-workbar.stories.tsx b/apps/desktop/stories/session-workbar.stories.tsx
index 645e408027..7e6faddc07 100644
--- a/apps/desktop/stories/session-workbar.stories.tsx
+++ b/apps/desktop/stories/session-workbar.stories.tsx
@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import { useState, type CSSProperties } from 'react';
+import { useState, type CSSProperties, type ReactNode } from 'react';
 import type { Decorator, Meta, StoryObj } from '@storybook/react-vite';
 import { expect, userEvent, waitFor, within } from 'storybook/test';
 import type { ArtifactRecord } from '@maka/core/artifacts';
@@ -26,8 +26,8 @@ import type { GitReviewReadResult, GitReviewSnapshot } from '@maka/core/git-revi
 import type { SessionSummary } from '@maka/core/session';
 import type { SessionTrace } from '@maka/core/session-trace';
 import type { ContextDiagnosticsResult } from '@maka/runtime-host/protocol';
-import { ToastProvider } from '@maka/ui';
-import { WorkbarServicesProvider, WorkbarTitlebarActions } from '../src/renderer/features/workbar';
+import { ToastProvider, ToolCallDetail } from '@maka/ui';
+import { WorkbarServicesProvider, WorkbarTitlebarActions, ToolOutputPreviewProvider } from '../src/renderer/features/workbar';
 import { WorkbarSurface } from '../src/renderer/features/workbar/stories';
 import {
   createFakeWorkbarServices,
@@ -920,6 +920,7 @@ function bridge(options: {
  * column. Its 990px media query is what stacks the column in narrow windows.
  */
 function Workbar(props: {
+  conversation?: ReactNode;
   tab?: SessionWorkbarTabKind;
   /** Extra faces opened after `tab`, so the strip can be seen with several. */
   alsoOpen?: readonly Exclude<SessionWorkbarTabKind, 'side-chat' | 'terminal'>[];
@@ -991,6 +992,7 @@ function Workbar(props: {
         } as CSSProperties}
       >
         <div className="mainColumn">
+          {props.conversation}
           {props.collapsible && (
             <WorkbarTitlebarActions
               available
@@ -1562,3 +1564,24 @@ export const TraceReadFailed: Story = {
   decorators: [bridge({ traceFail: true })],
   render: () => <Workbar tab="inspector" />,
 };
+
+
+// Real path: a retained-output action in chat opens the existing Files preview.
+export const RetainedToolOutput: Story = {
+  decorators: [(Story) => <ToolOutputPreviewProvider><Story /></ToolOutputPreviewProvider>, bridge()],
+  render: () => <Workbar tab="files" conversation={<div className="maka-turn" style={{ padding: 24 }}>
+    <ToolCallDetail item={{ toolUseId: 'retained-fetch', toolName: 'WebFetch', status: 'completed',
+      args: { url: 'https://example.com/docs' }, result: { kind: 'text',
+        text: 'DOCUMENT_START\n' + 'Documentation paragraph.\n'.repeat(12_000) + 'DOCUMENT_END',
+      },
+    }} />
+  </div>} />,
+  play: async ({ canvasElement }) => {
+    const canvas = within(canvasElement);
+    await userEvent.click(canvas.getByRole('button', { name: /打开完整输出|開啟完整輸出|Open full output/ }));
+    await waitFor(() => expect(canvasElement.querySelector('.maka-artifact-preview-plain-remainder')?.textContent).toContain('DOCUMENT_END'));
+    expect(canvasElement.querySelector('.mainColumn')?.textContent).not.toContain('DOCUMENT_END');
+    const viewer = canvasElement.querySelector<HTMLElement>('.maka-artifact-preview')!;
+    expect(viewer.scrollHeight).toBeGreaterThan(viewer.clientHeight);
+  },
+};
diff --git a/docs/astryx-surface-file-inventory.md b/docs/astryx-surface-file-inventory.md
index 8e8865ad5f..dbd9ca8a06 100644
--- a/docs/astryx-surface-file-inventory.md
+++ b/docs/astryx-surface-file-inventory.md
@@ -6,7 +6,7 @@ Generated against `@astryxdesign/core@0.5.2` (194 component exports).
 
 Wiki bar: Design Conventions · API Use-the-System · Theming · Container Padding.
 
-**Totals:** 260 files — blocker 0, reimplementation 0, polish 1, aligned 259.
+**Totals:** 264 files — blocker 0, reimplementation 0, polish 1, aligned 263.
 
 ## Exclusions (explicit)
 
@@ -88,6 +88,8 @@ Wiki bar: Design Conventions · API Use-the-System · Theming · Container Paddi
 | `apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-pane.tsx` | shell-chrome-or-panel | Banner, Button, EmptyState, MoreMenu | aligned — uses Astryx (Banner, Button, EmptyState, MoreMenu) | aligned |
 | `apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview-registry-shell.tsx` | shell-chrome-or-panel | Banner, Button, Spinner | aligned — uses Astryx (Banner, Button, Spinner) | aligned |
 | `apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview.tsx` | shell-chrome-or-panel | Banner, Button, CodeBlock, Spinner | aligned — uses Astryx (Banner, Button, CodeBlock, Spinner) | aligned |
+| `apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview-context.tsx` | shell-chrome-or-panel | none | aligned — no raw controls; no Astryx JSX usage | aligned |
+| `apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview.tsx` | shell-chrome-or-panel | Button | aligned — uses Astryx (Button) | aligned |
 | `apps/desktop/src/renderer/features/workbar/tools/browser/browser-panel.tsx` | shell-chrome-or-panel | EmptyState, IconButton, TextInput, Toolbar, Tooltip | aligned — uses Astryx (EmptyState, IconButton, TextInput, Toolbar, Tooltip) | aligned |
 | `apps/desktop/src/renderer/features/workbar/tools/inspector/live-context-usage-probe.tsx` | shell-chrome-or-panel | none | aligned — no raw controls; no Astryx JSX usage | aligned |
 | `apps/desktop/src/renderer/features/workbar/tools/inspector/session-inspector-panel.tsx` | shell-chrome-or-panel | Banner, Button, EmptyState, Heading, Section, Text, VStack | aligned — uses Astryx (Banner, Button, EmptyState, Heading, Section, Text, VStack) | aligned |
@@ -282,7 +284,9 @@ Wiki bar: Design Conventions · API Use-the-System · Theming · Container Paddi
 | `packages/ui/src/tool-activity.tsx` | ui-composition | Banner, Button, ChatToolCalls, List, ListItem, StatusDot, Text, VisuallyHidden | aligned — uses Astryx (Banner, Button, ChatToolCalls, List, ListItem, StatusDot, Text, VisuallyHidden) | aligned |
 | `packages/ui/src/tool-activity/diff-code-preview.tsx` | ui-composition | none | aligned — no raw controls; no Astryx JSX usage | aligned |
 | `packages/ui/src/tool-activity/tool-code-block.tsx` | ui-composition | CodeBlock | aligned — uses Astryx (CodeBlock) | aligned |
+| `packages/ui/src/tool-activity/tool-result-context.tsx` | ui-composition | none | aligned — no raw controls; no Astryx JSX usage | aligned |
 | `packages/ui/src/tool-activity/tool-result-preview.tsx` | ui-composition | Button, Link | aligned — uses Astryx (Button, Link) | aligned |
+| `packages/ui/src/tool-activity/tool-text-preview.tsx` | ui-composition | Button | aligned — uses Astryx (Button) | aligned |
 | `packages/ui/src/transcript-scroll-authority.tsx` | ui-composition | ChatLayoutScrollButton | aligned — uses Astryx (ChatLayoutScrollButton) | aligned |
 | `packages/ui/src/ui.tsx` | ui-composition | none | aligned — no raw controls; no Astryx JSX usage | aligned |
 | `packages/ui/src/user-question-prompt.tsx` | ui-composition | Button, RadioList, RadioListItem, TextInput | aligned — uses Astryx (Button, RadioList, RadioListItem, TextInput) | aligned |
diff --git a/docs/astryx-surface-file-inventory.paths b/docs/astryx-surface-file-inventory.paths
index 8855985d24..28bdcaafc1 100644
--- a/docs/astryx-surface-file-inventory.paths
+++ b/docs/astryx-surface-file-inventory.paths
@@ -59,6 +59,8 @@ apps/desktop/src/renderer/features/workbar/services-context.tsx
 apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-pane.tsx
 apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview-registry-shell.tsx
 apps/desktop/src/renderer/features/workbar/tools/artifacts/artifact-preview.tsx
+apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview-context.tsx
+apps/desktop/src/renderer/features/workbar/tools/artifacts/tool-output-preview.tsx
 apps/desktop/src/renderer/features/workbar/tools/browser/browser-panel.tsx
 apps/desktop/src/renderer/features/workbar/tools/inspector/live-context-usage-probe.tsx
 apps/desktop/src/renderer/features/workbar/tools/inspector/session-inspector-panel.tsx
@@ -253,7 +255,9 @@ packages/ui/src/toast.tsx
 packages/ui/src/tool-activity.tsx
 packages/ui/src/tool-activity/diff-code-preview.tsx
 packages/ui/src/tool-activity/tool-code-block.tsx
+packages/ui/src/tool-activity/tool-result-context.tsx
 packages/ui/src/tool-activity/tool-result-preview.tsx
+packages/ui/src/tool-activity/tool-text-preview.tsx
 packages/ui/src/transcript-scroll-authority.tsx
 packages/ui/src/ui.tsx
 packages/ui/src/user-question-prompt.tsx
diff --git a/packages/core/src/__tests__/pty-output-view.test.ts b/packages/core/src/__tests__/pty-output-view.test.ts
new file mode 100644
index 0000000000..51cc03d5d6
--- /dev/null
+++ b/packages/core/src/__tests__/pty-output-view.test.ts
@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import assert from 'node:assert/strict';
+import { it } from 'node:test';
+import type { PtyShellOutput } from '../shell-run.js';
+import { PTY_TRUNCATED_MARKER, ptyHumanTerminalText } from '../pty-output-view.js';
+
+it('keeps structured PTY truncation metadata out of the human-readable text', () => {
+  const output: PtyShellOutput = {
+    mode: 'pty',
+    screen: 'ALL_TESTS_PASSED',
+    scrollback: `${PTY_TRUNCATED_MARKER}\nretained output`,
+    cols: 80,
+    rows: 24,
+    cursor: { x: 0, y: 0, visible: true },
+    alternateScreen: false,
+    truncated: true,
+    redacted: false,
+  };
+
+  assert.equal(ptyHumanTerminalText(output), 'retained output\nALL_TESTS_PASSED');
+});
diff --git a/packages/core/src/__tests__/tool-quiet-preview.test.ts b/packages/core/src/__tests__/tool-quiet-preview.test.ts
index 1404b67ad2..3f8affa0ee 100644
--- a/packages/core/src/__tests__/tool-quiet-preview.test.ts
+++ b/packages/core/src/__tests__/tool-quiet-preview.test.ts
@@ -21,6 +21,7 @@ import { strict as assert } from 'node:assert';
 import { describe, it } from 'node:test';
 import {
   formatAsKeyValueLines,
+  formatBoundedQuietJsonValue,
   formatQuietJsonValue,
   formatToolInvocationLine,
   projectToolArgsPreview,
@@ -28,6 +29,13 @@ import {
 import { projectToolActivityArgs } from '../tool-activity-args.js';
 
 describe('tool quiet preview', () => {
+  it('reports omitted object fields when the preview budget is exactly exhausted', () => {
+    const retained = Object.fromEntries(['a', 'b', 'c', 'd'].map((key) => [key, 'x'.repeat(1999)]));
+    assert.equal(formatBoundedQuietJsonValue(retained, 'en').truncated, false);
+    const preview = formatBoundedQuietJsonValue({ ...retained, z: 'LAST_FIELD' }, 'en');
+    assert.doesNotMatch(preview.body, /LAST_FIELD/);
+    assert.equal(preview.truncated, true);
+  });
   it('redacts secrets in values and embedded keys', () => {
     const value = formatQuietJsonValue({ password: 'correct-horse', ok: true }, 'en').body;
     assert.doesNotMatch(value, /correct-horse/);
diff --git a/packages/core/src/artifacts.ts b/packages/core/src/artifacts.ts
index 43921173bc..e9ff3ee8c8 100644
--- a/packages/core/src/artifacts.ts
+++ b/packages/core/src/artifacts.ts
@@ -189,6 +189,12 @@ export type ArtifactTextReadResult =
   | { ok: true; text: string }
   | { ok: false; reason: ArtifactReadFailureReason };
 
+/** Identity retained by an archived tool result; verified before exposing its saved bytes. */
+export type ToolResultArchiveIdentity = {
+  originalBytes: number;
+  bodySha256: string;
+} & ({ resourceRef: string; artifactId?: never } | { artifactId: string; resourceRef?: never });
+
 export type ArtifactBinaryReadResult =
   | { ok: true; base64: string; mimeType: string }
   | { ok: false; reason: ArtifactBinaryReadFailureReason };
diff --git a/packages/core/src/events.ts b/packages/core/src/events.ts
index 889069e08a..2cbc76f119 100644
--- a/packages/core/src/events.ts
+++ b/packages/core/src/events.ts
@@ -822,6 +822,7 @@ export type ToolResultContent =
   | {
       kind: 'text';
       text: string;
+      truncated?: boolean;
       sandboxDenial?: SandboxDenialSignal;
       sandboxFailure?: SandboxBoundaryFailureSignal;
       uncertainOutcome?: ToolUncertainOutcomeSignal;
diff --git a/packages/core/src/pty-output-view.ts b/packages/core/src/pty-output-view.ts
index 22bddb6759..6fe37698f8 100644
--- a/packages/core/src/pty-output-view.ts
+++ b/packages/core/src/pty-output-view.ts
@@ -19,11 +19,22 @@
 
 import type { PtyShellOutput } from './shell-run.js';
 
+export const PTY_TRUNCATED_MARKER = '[terminal snapshot truncated to fit the output limit]';
+
 export function ptyHumanTerminalText(output: PtyShellOutput): string {
   const current = output.alternateScreen
     ? output.screen
     : joinNonEmpty(output.scrollback, output.screen);
-  return current.trim().length > 0 ? current : (output.lastAlternateScreen ?? '');
+  const text = current.trim().length > 0 ? current : (output.lastAlternateScreen ?? '');
+  return output.truncated ? stripTruncatedMarker(text) : text;
+}
+
+function stripTruncatedMarker(text: string): string {
+  return text === PTY_TRUNCATED_MARKER
+    ? ''
+    : text.startsWith(`${PTY_TRUNCATED_MARKER}\n`)
+      ? text.slice(PTY_TRUNCATED_MARKER.length + 1)
+      : text;
 }
 
 export function ptyTuiTerminalRows(output: PtyShellOutput, maxRows = 6): string[] {
diff --git a/packages/core/src/tool-quiet-preview.ts b/packages/core/src/tool-quiet-preview.ts
index 760d8990d4..a95d69c60b 100644
--- a/packages/core/src/tool-quiet-preview.ts
+++ b/packages/core/src/tool-quiet-preview.ts
@@ -520,6 +520,107 @@ export interface QuietPreview {
   body: string;
 }
 
+/** Explicit saved-output view: preserve JSON structure and ordinary user keys. */
+export function formatSavedToolJson(value: unknown): string {
+  return (
+    JSON.stringify(
+      value,
+      (_key, raw: unknown) => {
+        if (typeof raw === 'string') return redactSecrets(raw);
+        const record = asRecord(raw);
+        if (!record) return raw;
+        return Object.fromEntries(
+          Object.entries(record).map(([key, entry]) => [
+            maskSensitiveKeyPayload(key),
+            maskSensitiveValue(key, entry),
+          ]),
+        );
+      },
+      2,
+    ) ?? ''
+  );
+}
+
+const PREVIEW_DIAGNOSTIC_KEYS = [...REMAINDER_PRIORITY, 'warning', 'warnings', 'partial'] as const;
+
+/** Bound the value before quiet formatting; retain diagnostic fields before bulk lists. */
+export function formatBoundedQuietJsonValue(
+  value: unknown,
+  locale: UiLocale,
+): QuietPreview & { truncated: boolean } {
+  let remaining = 8_000;
+  let nodes = 100;
+  let truncated = false;
+  function visit(raw: unknown, depth: number): unknown {
+    if (--nodes < 0 || remaining <= 0) {
+      truncated = true;
+      return '…';
+    }
+    if (typeof raw === 'string') {
+      const safe = redactSecrets(raw);
+      const limit = Math.min(remaining, 2_000);
+      remaining -= Math.min(safe.length, limit);
+      if (safe.length <= limit) return safe;
+      truncated = true;
+      return `${safe.slice(0, limit).replace(/[\uD800-\uDBFF]$/, '')}…`;
+    }
+    if (!raw || typeof raw !== 'object') return raw;
+    if (depth > 3) {
+      truncated = true;
+      return '…';
+    }
+    if (Array.isArray(raw)) {
+      const result: unknown[] = [];
+      for (const item of raw) {
+        if (result.length >= 20 || nodes <= 0 || remaining <= 0) break;
+        result.push(visit(item, depth + 1));
+      }
+      truncated ||= result.length < raw.length;
+      return result;
+    }
+    const record = raw as Record<string, unknown>;
+    const result: Record<string, unknown> = Object.create(null);
+    const picked = new Set<string>();
+    const add = (key: string) => {
+      if (picked.has(key) || !Object.hasOwn(record, key)) return;
+      picked.add(key);
+      if (picked.size > 20 || remaining <= 0 || nodes <= 0) {
+        truncated = true;
+        return;
+      }
+      const safeKey = String(visit(safeKeyLabel(key), depth + 1));
+      result[safeKey] = visit(maskSensitiveValue(key, record[key]), depth + 1);
+    };
+    for (const key of [...PREVIEW_DIAGNOSTIC_KEYS, ...HEADLINE_KEYS, ...LIST_KEYS, ...BODY_KEYS])
+      add(key);
+    for (const key in record) {
+      add(key);
+      if (picked.size > 20 || remaining <= 0 || nodes <= 0) break;
+    }
+    truncated ||= picked.size < Object.keys(record).length;
+    return result;
+  }
+  const bounded = visit(value, 0);
+  const record = asRecord(bounded);
+  const diagnostics: Record<string, unknown> = {};
+  if (record) {
+    for (const key of PREVIEW_DIAGNOSTIC_KEYS) {
+      if (!Object.hasOwn(record, key)) continue;
+      diagnostics[key] = record[key];
+      delete record[key];
+    }
+  }
+  const preview = formatQuietJsonValue(bounded, locale);
+  const diagnosticText = formatAsKeyValueLines(diagnostics, 0, locale);
+  if (diagnosticText) {
+    preview.body =
+      record && Object.keys(record).length === 0
+        ? diagnosticText
+        : `${diagnosticText}\n${preview.body}`;
+  }
+  return { ...preview, truncated };
+}
+
 /**
  * Format any tool JSON/result payload for the quiet panel.
  * Always returns a body — never `undefined` for object values so callers
diff --git a/packages/core/src/tool-result-record-schema.ts b/packages/core/src/tool-result-record-schema.ts
index 4f75d318f0..20fa7a1b34 100644
--- a/packages/core/src/tool-result-record-schema.ts
+++ b/packages/core/src/tool-result-record-schema.ts
@@ -41,7 +41,7 @@ type RiveResult = Result<'rive_workflow'>;
 
 const TEXT_SHAPE = defineObjectShape<Result<'text'>>()(
   ['kind', 'text'],
-  ['sandboxDenial', 'sandboxFailure', 'uncertainOutcome'],
+  ['sandboxDenial', 'sandboxFailure', 'uncertainOutcome', 'truncated'],
 );
 const SANDBOX_FAILURE_SHAPE = defineObjectShape<NonNullable<Result<'text'>['sandboxFailure']>>()(
   ['reason'],
@@ -203,6 +203,7 @@ function isNonShellToolResultContent(value: unknown): value is ToolResultContent
       return (
         hasExactShape(value, TEXT_SHAPE) &&
         typeof value.text === 'string' &&
+        (value.truncated === undefined || typeof value.truncated === 'boolean') &&
         (value.sandboxDenial === undefined || isSandboxDenialSignal(value.sandboxDenial)) &&
         (value.sandboxFailure === undefined ||
           (isRecord(value.sandboxFailure) &&
diff --git a/packages/runtime-host/src/__tests__/artifact-coordinator.test.ts b/packages/runtime-host/src/__tests__/artifact-coordinator.test.ts
index 8e0dd1e7a5..7798ffa40a 100644
--- a/packages/runtime-host/src/__tests__/artifact-coordinator.test.ts
+++ b/packages/runtime-host/src/__tests__/artifact-coordinator.test.ts
@@ -29,6 +29,7 @@ import { HostArtifactCoordinator } from '../server/artifact-coordinator.js';
 import type { ConnectionContext } from '../server/operation-dispatcher.js';
 import { SessionAdmissionGate } from '../server/session-admission-gate.js';
 import { ARTIFACT_READ_CHUNK_MAX_BYTES } from '../protocol/index.js';
+import { buildToolResultArchiveResourceRef } from '@maka/runtime/tool-result-archive-resource';
 
 const connectionContext: ConnectionContext = {
   hostEpoch: 'host-epoch-1',
@@ -37,6 +38,85 @@ const connectionContext: ConnectionContext = {
   acquireResidency: () => ({ release: () => undefined }),
 };
 
+test('an archive transfer validates the full body once and releases it after the final chunk', async () => {
+  const root = await mkdtemp(join(tmpdir(), 'maka-archive-transfer-'));
+  const owner = await tryAcquireInteractiveRootOwner(
+    await resolveStorageRoot({ path: root, kind: 'interactive' }),
+  );
+  assert.ok(owner);
+  const store = await openInteractiveArtifactStoreForWrite(owner.lease);
+  try {
+    const serializedResult = 'x'.repeat(4 * 1024 * 1024);
+    const ref = buildToolResultArchiveResourceRef({
+      artifactId: 'archive-1',
+      bodySha256: createHash('sha256').update(serializedResult).digest('hex'),
+      originalBytes: serializedResult.length,
+    });
+    let reads = 0;
+    let now = 0;
+    let present = true;
+    const coordinator = new HostArtifactCoordinator(
+      store,
+      () => assert.fail('read must not drain'),
+      new SessionAdmissionGate(),
+      { probeSessionRemoval: async () => (present ? { kind: 'present' } : { kind: 'removed' }) },
+      () => now,
+      undefined,
+      async () => {
+        reads++;
+        return { ok: true, serializedResult };
+      },
+    );
+    const chunks: Buffer[] = [];
+    for (
+      let offset = 0;
+      offset < serializedResult.length;
+      offset += ARTIFACT_READ_CHUNK_MAX_BYTES
+    ) {
+      const result = await coordinator.handlers['artifact.query'](
+        { kind: 'read_archive_chunk', sessionId: 'session-1', ref, offset },
+        connectionContext,
+      );
+      assert.ok(result.ok && result.result.kind === 'archive_chunk');
+      chunks.push(Buffer.from(result.result.chunkBase64, 'base64'));
+    }
+    assert.equal(Buffer.concat(chunks).toString(), serializedResult);
+    assert.equal(reads, 1);
+    await coordinator.handlers['artifact.query'](
+      { kind: 'read_archive_chunk', sessionId: 'session-1', ref, offset: 0 },
+      connectionContext,
+    );
+    assert.equal(reads, 2);
+    const continueRead = (context = connectionContext, sessionId = 'session-1') =>
+      coordinator.handlers['artifact.query'](
+        { kind: 'read_archive_chunk', sessionId, ref, offset: ARTIFACT_READ_CHUNK_MAX_BYTES },
+        context,
+      );
+    await continueRead({ ...connectionContext, connectionId: 'other-connection' });
+    assert.equal(reads, 3, 'connections cannot reuse each other’s validated bodies');
+    await continueRead(connectionContext, 'other-session');
+    assert.equal(reads, 4, 'Sessions cannot reuse each other’s validated bodies');
+    coordinator.releaseConnection(connectionContext.connectionId);
+    await continueRead();
+    assert.equal(reads, 5, 'disconnect releases the transfer');
+    now = 60_000;
+    await continueRead();
+    assert.equal(reads, 6, 'expired transfers are revalidated');
+    present = false;
+    const removed = await continueRead();
+    assert.ok(!removed.ok && removed.error.code === 'not_found');
+    assert.equal(reads, 6);
+    present = true;
+    await continueRead();
+    assert.equal(reads, 7, 'a removed Session cannot leave a reusable snapshot');
+  } finally {
+    store.close();
+    await owner.close();
+    await rm(root, { recursive: true, force: true });
+    await rm(owner.controlDirectory, { recursive: true, force: true });
+  }
+});
+
 test('Artifact ingest is connection-bound, replay-safe, and commits one durable AttachmentRef', async () => {
   const root = await mkdtemp(join(tmpdir(), 'maka-artifact-ingest-'));
   const capability = await resolveStorageRoot({ path: root, kind: 'interactive' });
diff --git a/packages/runtime-host/src/__tests__/execution-artifacts.test.ts b/packages/runtime-host/src/__tests__/execution-artifacts.test.ts
index f939e91ec4..1242912919 100644
--- a/packages/runtime-host/src/__tests__/execution-artifacts.test.ts
+++ b/packages/runtime-host/src/__tests__/execution-artifacts.test.ts
@@ -27,7 +27,12 @@ import {
 } from '@maka/core/model-projection-transition';
 import { buildLedgerArchivedToolResultPlaceholder } from '@maka/runtime/tool-result-archive';
 import type { DurableToolResultProjection } from '@maka/core/durable-tool-result-projection';
-import { parseToolResultArchiveResourceRef } from '@maka/runtime/tool-result-archive-resource';
+import {
+  buildToolResultArchiveResourceRef,
+  parseToolResultArchiveResourceRef,
+} from '@maka/runtime/tool-result-archive-resource';
+import { HostArtifactCoordinator } from '../server/artifact-coordinator.js';
+import { decodeArtifactQueryInput, decodeArtifactQueryResult } from '../protocol/artifact.js';
 import { mkdir, mkdtemp, rm, stat, truncate, writeFile } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
@@ -225,6 +230,78 @@ for (const largeImage of [false, true]) {
       );
       const identity = parseToolResultArchiveResourceRef(placeholder.resourceRef!);
       assert.ok(identity);
+      const coordinator = new HostArtifactCoordinator(
+        artifacts,
+        () => assert.fail('read must not drain'),
+        new SessionAdmissionGate(),
+        { probeSessionRemoval: async () => ({ kind: 'present' }) },
+        Date.now,
+        undefined,
+        services.toolResultArchive.services.readArchivedToolResultResource,
+      );
+      const context = {
+        hostEpoch: 'epoch',
+        connectionId: 'desktop',
+        principal: 'local_os_user',
+        acquireResidency: () => ({ release() {} }),
+      };
+      for (const ref of [
+        placeholder.resourceRef!,
+        buildToolResultArchiveResourceRef({
+          artifactId: old.id,
+          bodySha256,
+          originalBytes: input.originalBytes,
+        }),
+      ]) {
+        const response = await coordinator.handlers['artifact.query'](
+          decodeArtifactQueryInput({
+            kind: 'read_archive_chunk',
+            sessionId: 'session',
+            ref,
+            offset: 0,
+          }),
+          context,
+        );
+        assert.ok(response.ok);
+        assert.deepEqual(decodeArtifactQueryResult(response.result), {
+          kind: 'archive_chunk',
+          sessionId: 'session',
+          offset: 0,
+          totalBytes: input.originalBytes,
+          chunkBase64: Buffer.from(serializedResult).toString('base64'),
+          nextOffset: null,
+        });
+        const denied = await coordinator.handlers['artifact.query'](
+          decodeArtifactQueryInput({
+            kind: 'read_archive_chunk',
+            sessionId: 'other',
+            ref,
+            offset: 0,
+          }),
+          context,
+        );
+        assert.ok(denied.ok);
+        assert.equal(denied.result.kind, 'archive_unavailable');
+        const corrupted = await coordinator.handlers['artifact.query'](
+          decodeArtifactQueryInput({
+            kind: 'read_archive_chunk',
+            sessionId: 'session',
+            ref: ref.replace(bodySha256, '0'.repeat(64)),
+            offset: 0,
+          }),
+          context,
+        );
+        assert.deepEqual(corrupted, {
+          ok: true,
+          result: {
+            kind: 'archive_unavailable',
+            sessionId: 'session',
+            // Ledger evidence rejects a mismatched identity before reading bytes;
+            // legacy artifacts detect the mismatch from the body digest.
+            reason: ref === placeholder.resourceRef ? 'not_allowed' : 'read_failed',
+          },
+        });
+      }
       assert.deepEqual(
         await services.toolResultArchive.services.readArchivedToolResultResource({
           ...identity,
diff --git a/packages/runtime-host/src/__tests__/web-fetch-tool.test.ts b/packages/runtime-host/src/__tests__/web-fetch-tool.test.ts
index c0fe8521da..f8471ca0ed 100644
--- a/packages/runtime-host/src/__tests__/web-fetch-tool.test.ts
+++ b/packages/runtime-host/src/__tests__/web-fetch-tool.test.ts
@@ -68,7 +68,7 @@ test('Host WebFetch uses the resolved proxy snapshot and closes its transport',
 
   const result = await tool.impl({ url: 'https://example.com/page' }, context());
 
-  assert.equal(result, 'fetched body');
+  assert.deepEqual(result, { kind: 'text', text: 'fetched body' });
   assert.deepEqual(proxy, {
     enabled: true,
     type: 'http',
diff --git a/packages/runtime-host/src/protocol/artifact.ts b/packages/runtime-host/src/protocol/artifact.ts
index 0c78f530ee..20a02a4a03 100644
--- a/packages/runtime-host/src/protocol/artifact.ts
+++ b/packages/runtime-host/src/protocol/artifact.ts
@@ -93,6 +93,12 @@ export type ArtifactQueryInput =
   | { readonly kind: 'get'; readonly sessionId: string; readonly artifactId: string }
   | { readonly kind: 'read_text'; readonly sessionId: string; readonly artifactId: string }
   | { readonly kind: 'read_binary'; readonly sessionId: string; readonly artifactId: string }
+  | {
+      readonly kind: 'read_archive_chunk';
+      readonly sessionId: string;
+      readonly ref: string;
+      readonly offset: number;
+    }
   | {
       readonly kind: 'read_chunk';
       readonly sessionId: string;
@@ -108,6 +114,19 @@ export type ArtifactBinaryPreview =
   | { readonly ok: false; readonly reason: ArtifactBinaryReadFailureReason };
 
 export type ArtifactQueryResult =
+  | {
+      readonly kind: 'archive_unavailable';
+      readonly sessionId: string;
+      readonly reason: ArtifactReadFailureReason;
+    }
+  | {
+      readonly kind: 'archive_chunk';
+      readonly sessionId: string;
+      readonly offset: number;
+      readonly totalBytes: number;
+      readonly chunkBase64: string;
+      readonly nextOffset: number | null;
+    }
   | {
       readonly kind: 'page';
       readonly sessionId: string;
@@ -361,6 +380,20 @@ export function decodeArtifactIngestResult(value: unknown): ArtifactIngestResult
 
 export function decodeArtifactQueryInput(value: unknown): ArtifactQueryInput {
   const input = requireRecord(value, 'artifact query input');
+  if (input.kind === 'read_archive_chunk') {
+    const exact = requireExactRecord(input, 'archive chunk query', [
+      'kind',
+      'sessionId',
+      'ref',
+      'offset',
+    ]);
+    return {
+      kind: 'read_archive_chunk',
+      sessionId: artifactEntityId(exact.sessionId, 'sessionId'),
+      ref: boundedText(exact.ref, 'archive ref', 16384),
+      offset: requireCount(exact.offset, 'archive offset'),
+    };
+  }
   if (input.kind === 'list_start') {
     const exact = requireExactRecord(input, 'artifact list start input', ['kind', 'sessionId']);
     return { kind: 'list_start', sessionId: artifactEntityId(exact.sessionId, 'sessionId') };
@@ -490,11 +523,24 @@ export function decodeArtifactQueryResult(value: unknown): ArtifactQueryResult {
       artifactId: artifactEntityId(exact.artifactId, 'artifactId'),
       preview: decodeBinaryPreview(exact.preview),
     };
-  } else if (result.kind === 'chunk') {
+  } else if (result.kind === 'archive_unavailable') {
+    const exact = requireExactRecord(result, 'archive unavailable', [
+      'kind',
+      'sessionId',
+      'reason',
+    ]);
+    const preview = decodeTextPreview({ ok: false, reason: exact.reason });
+    if (preview.ok) throw invalidProtocolFrame('Invalid archive failure');
+    decoded = {
+      kind: 'archive_unavailable',
+      sessionId: artifactEntityId(exact.sessionId, 'sessionId'),
+      reason: preview.reason,
+    };
+  } else if (result.kind === 'chunk' || result.kind === 'archive_chunk') {
     const exact = requireExactRecord(result, 'artifact chunk result', [
       'kind',
       'sessionId',
-      'artifactId',
+      ...(result.kind === 'chunk' ? ['artifactId'] : []),
       'offset',
       'totalBytes',
       'chunkBase64',
@@ -526,15 +572,17 @@ export function decodeArtifactQueryResult(value: unknown): ArtifactQueryResult {
     ) {
       throw invalidProtocolFrame('Invalid artifact chunk continuation');
     }
-    decoded = {
-      kind: 'chunk',
+    const chunk = {
       sessionId: artifactEntityId(exact.sessionId, 'sessionId'),
-      artifactId: artifactEntityId(exact.artifactId, 'artifactId'),
       offset,
       totalBytes,
       chunkBase64,
       nextOffset,
     };
+    decoded =
+      result.kind === 'chunk'
+        ? { ...chunk, kind: 'chunk', artifactId: artifactEntityId(exact.artifactId, 'artifactId') }
+        : { ...chunk, kind: 'archive_chunk' };
   } else {
     throw invalidProtocolFrame('Invalid artifact query result kind');
   }
diff --git a/packages/runtime-host/src/protocol/index.ts b/packages/runtime-host/src/protocol/index.ts
index 3078a049b2..cc9c1ecb05 100644
--- a/packages/runtime-host/src/protocol/index.ts
+++ b/packages/runtime-host/src/protocol/index.ts
@@ -101,7 +101,7 @@ export const RUNTIME_HOST_REGISTRATION_SCHEMA_VERSION = 1 as const;
 export const RUNTIME_HOST_PROTOCOL_VERSION = 0 as const;
 // Increment when the same protocol version no longer guarantees safe Client-Host
 // interoperability. Mismatches are rejected before domain commands are admitted.
-export const RUNTIME_HOST_COMPATIBILITY_EPOCH = 133 as const;
+export const RUNTIME_HOST_COMPATIBILITY_EPOCH = 134 as const;
 // 133: WorkHub actions carry attachments and new-Work model/permission defaults.
 // Epoch-132 peers reject these additional fields on strict action shapes.
 // 132: new Tool Result archives use versioned ledger references, not Artifact payloads.
diff --git a/packages/runtime-host/src/server/artifact-coordinator.ts b/packages/runtime-host/src/server/artifact-coordinator.ts
index 9b507ba550..e86fe0e98d 100644
--- a/packages/runtime-host/src/server/artifact-coordinator.ts
+++ b/packages/runtime-host/src/server/artifact-coordinator.ts
@@ -18,9 +18,18 @@
  */
 
 import { createHash } from 'node:crypto';
+import {
+  parseToolResultArchiveResourceRef,
+  TOOL_RESULT_ARCHIVE_MAX_BYTES,
+  type ToolResultArchiveResourceReader,
+} from '@maka/runtime/tool-result-archive-resource';
 import { attachmentKindFromMimeType } from '@maka/core/attachments';
 import type { AttachmentRef } from '@maka/core/events';
-import { isArtifactSharedSessionReadable, type ArtifactRecord } from '@maka/core/artifacts';
+import {
+  isArtifactSharedSessionReadable,
+  type ArtifactRecord,
+  type ArtifactReadFailureReason,
+} from '@maka/core/artifacts';
 import {
   authenticateInteractiveArtifactStoreWriter,
   sanitizeArtifactName,
@@ -47,6 +56,21 @@ import type { ArtifactOperationHandlerMap, ConnectionContext } from './operation
 import { SessionAdmissionGate } from './session-admission-gate.js';
 import type { SessionPresenceReader } from './session-presence.js';
 import { ConnectionBoundChunkUploads } from './connection-bound-chunk-uploads.js';
+import type { ToolResultArchiveReadFailureReason } from '@maka/runtime/tool-result-archive';
+
+// At most 16 MiB of verified bodies, scoped to active transfers rather than a
+// persistent ref cache. Eviction only costs a fresh validated read.
+const MAX_ARCHIVE_TRANSFERS = 4;
+const ARCHIVE_TRANSFER_TTL_MS = 60_000;
+interface ArchiveTransfer {
+  readonly connectionId: string;
+  readonly sessionId: string;
+  readonly ref: string;
+  readonly expiresAt: number;
+  readonly body: Promise<
+    { ok: true; bytes: Buffer } | { ok: false; reason: ToolResultArchiveReadFailureReason }
+  >;
+}
 
 const MAX_ACTIVE_ARTIFACT_UPLOADS = 16;
 const MAX_STAGED_ARTIFACT_UPLOAD_BYTES = 128 * 1024 * 1024;
@@ -77,6 +101,11 @@ export class HostArtifactCoordinator {
     | Pick<RuntimeHostAccessAuthority, 'activeSessionGrant'>
     | undefined;
   readonly #uploads: ConnectionBoundChunkUploads<ArtifactUploadMetadata>;
+  readonly #archiveTransfers = new Map<string, ArchiveTransfer>();
+  readonly #now: () => number;
+  readonly #readArchive:
+    | ToolResultArchiveResourceReader['readArchivedToolResultResource']
+    | undefined;
 
   constructor(
     store: InteractiveArtifactStoreWriter,
@@ -85,12 +114,15 @@ export class HostArtifactCoordinator {
     sessions: SessionPresenceReader,
     now: () => number = Date.now,
     sessionAccessAuthority?: Pick<RuntimeHostAccessAuthority, 'activeSessionGrant'>,
+    readArchive?: ToolResultArchiveResourceReader['readArchivedToolResultResource'],
   ) {
     this.#store = authenticateInteractiveArtifactStoreWriter(store);
     this.#requestDrain = requestDrain;
     this.#sessionAdmission = sessionAdmission;
     this.#sessions = sessions;
     this.#sessionAccessAuthority = sessionAccessAuthority;
+    this.#readArchive = readArchive;
+    this.#now = now;
     this.#uploads = new ConnectionBoundChunkUploads(
       {
         maxActive: MAX_ACTIVE_ARTIFACT_UPLOADS,
@@ -103,6 +135,9 @@ export class HostArtifactCoordinator {
 
   releaseConnection(connectionId: string): void {
     this.#uploads.releaseConnection(connectionId);
+    for (const [key, transfer] of this.#archiveTransfers) {
+      if (transfer.connectionId === connectionId) this.#archiveTransfers.delete(key);
+    }
   }
 
   async validateTurnAttachments(
@@ -321,6 +356,9 @@ export class HostArtifactCoordinator {
   ): Promise<OperationOutcome<'artifact.query'>> {
     try {
       if ((await this.#sessions.probeSessionRemoval(input.sessionId)).kind !== 'present') {
+        for (const [key, transfer] of this.#archiveTransfers) {
+          if (transfer.sessionId === input.sessionId) this.#archiveTransfers.delete(key);
+        }
         return notFound('artifact.query', 'Session was not found');
       }
       let sharedGrantId: string | undefined;
@@ -328,6 +366,82 @@ export class HostArtifactCoordinator {
         sharedGrantId = await this.#sharedArtifactGrantId(context.principal, input);
         if (!sharedGrantId) return notFound('artifact.query', 'Artifact was not found');
       }
+      if (input.kind === 'read_archive_chunk') {
+        const unavailable = (reason: ArtifactReadFailureReason) =>
+          querySuccess(
+            encodeArtifactQueryResult({
+              kind: 'archive_unavailable',
+              sessionId: input.sessionId,
+              reason,
+            }),
+          );
+        const identity = parseToolResultArchiveResourceRef(input.ref);
+        if (!identity) return unavailable('not_allowed');
+        if (identity.originalBytes > TOOL_RESULT_ARCHIVE_MAX_BYTES) return unavailable('too_large');
+        if (input.offset > identity.originalBytes) return invalidQuery('Archive offset is invalid');
+        if (!this.#readArchive) return unavailable('read_failed');
+        const now = this.#now();
+        for (const [key, transfer] of this.#archiveTransfers) {
+          if (transfer.expiresAt <= now) this.#archiveTransfers.delete(key);
+        }
+        const key = JSON.stringify([context.connectionId, input.sessionId, input.ref]);
+        let transfer = this.#archiveTransfers.get(key);
+        if (input.offset === 0 || transfer?.ref !== input.ref) {
+          this.#archiveTransfers.delete(key);
+          while (this.#archiveTransfers.size >= MAX_ARCHIVE_TRANSFERS) {
+            this.#archiveTransfers.delete(this.#archiveTransfers.keys().next().value!);
+          }
+          transfer = {
+            connectionId: context.connectionId,
+            sessionId: input.sessionId,
+            ref: input.ref,
+            expiresAt: now + ARCHIVE_TRANSFER_TTL_MS,
+            body: Promise.resolve()
+              .then(() =>
+                this.#readArchive!({
+                  ...identity,
+                  sessionId: input.sessionId,
+                  maxBytes: TOOL_RESULT_ARCHIVE_MAX_BYTES,
+                }),
+              )
+              .then((read) =>
+                read.ok ? { ok: true as const, bytes: Buffer.from(read.serializedResult) } : read,
+              ),
+          };
+          this.#archiveTransfers.set(key, transfer);
+        }
+        const release = () => {
+          // A disconnect or another request may have replaced the entry while
+          // the reader awaited I/O. Never resurrect it or remove its successor.
+          if (this.#archiveTransfers.get(key) === transfer) this.#archiveTransfers.delete(key);
+        };
+        const read = await transfer.body.catch((error) => {
+          release();
+          throw error;
+        });
+        if (!read.ok) release();
+        if (!read.ok)
+          return unavailable(
+            read.reason === 'not_found'
+              ? 'not_found'
+              : read.reason === 'source_mismatch'
+                ? 'not_allowed'
+                : 'read_failed',
+          );
+        const bytes = read.bytes;
+        const end = Math.min(bytes.length, input.offset + ARTIFACT_READ_CHUNK_MAX_BYTES);
+        if (end === bytes.length) release();
+        return querySuccess(
+          encodeArtifactQueryResult({
+            kind: 'archive_chunk',
+            sessionId: input.sessionId,
+            offset: input.offset,
+            totalBytes: bytes.length,
+            chunkBase64: bytes.subarray(input.offset, end).toString('base64'),
+            nextOffset: end < bytes.length ? end : null,
+          }),
+        );
+      }
       if (input.kind === 'read_text' || input.kind === 'read_binary') {
         if (input.kind === 'read_text') {
           const preview = await this.#store.readTextInSession(input.sessionId, input.artifactId, {
diff --git a/packages/runtime-host/src/server/execution-composition.ts b/packages/runtime-host/src/server/execution-composition.ts
index cfb2070c78..cd441aa942 100644
--- a/packages/runtime-host/src/server/execution-composition.ts
+++ b/packages/runtime-host/src/server/execution-composition.ts
@@ -1203,6 +1203,7 @@ export async function createExecutionRuntimeHostComposition(
       stores.sessionStore,
       Date.now,
       context.sessionAccessAuthority,
+      executionArtifacts.toolResultArchive.services.readArchivedToolResultResource,
     );
     rootCoordinator = new RootTurnCoordinator(
       manager,
diff --git a/packages/runtime/src/__tests__/web-fetch-tool.test.ts b/packages/runtime/src/__tests__/web-fetch-tool.test.ts
index 3d7d32d2f6..d2ff14cbeb 100644
--- a/packages/runtime/src/__tests__/web-fetch-tool.test.ts
+++ b/packages/runtime/src/__tests__/web-fetch-tool.test.ts
@@ -39,7 +39,7 @@ test('WebFetch forwards the canonical URL to its executor', async () => {
 
   const result = await tool.impl({ url: 'https://example.com/a/../page' }, context(abort.signal));
 
-  assert.equal(result, 'page body');
+  assert.deepEqual(result, { kind: 'text', text: 'page body' });
   assert.deepEqual(received, {
     url: 'https://example.com/page',
     sessionId: 'session-1',
@@ -66,11 +66,14 @@ test('WebFetch bounds model output with a head-truncation marker', async () => {
     context(new AbortController().signal),
   );
 
-  assert.ok(typeof result === 'string');
-  assert.match(result, /^begin:/);
-  assert.doesNotMatch(result, /:end$/);
-  assert.match(result, /WebFetch content truncated/);
-  assert.ok(Buffer.byteLength(result, 'utf8') <= WEB_FETCH_MODEL_OUTPUT_MAX_BYTES);
+  assert.equal(result.truncated, true);
+  assert.match(result.text, /^begin:/);
+  assert.doesNotMatch(result.text, /:end$|WebFetch content truncated/);
+  const model = tool.toModelOutput!({ toolCallId: 'fetch', input: {}, output: result });
+  assert.equal(model.type, 'text');
+  if (model.type !== 'text') throw new Error('Expected text projection');
+  assert.match(model.value, /WebFetch content truncated/);
+  assert.ok(Buffer.byteLength(model.value, 'utf8') <= WEB_FETCH_MODEL_OUTPUT_MAX_BYTES);
 });
 
 test('privacy mode removes WebFetch from a turn', () => {
diff --git a/packages/runtime/src/shell-run-tool-result.ts b/packages/runtime/src/shell-run-tool-result.ts
index 113360a002..d81888963e 100644
--- a/packages/runtime/src/shell-run-tool-result.ts
+++ b/packages/runtime/src/shell-run-tool-result.ts
@@ -32,6 +32,7 @@ import type {
   ToolResultContent,
 } from '@maka/core/events';
 import { encodedTerminalInputActionsByteLength } from '@maka/core/terminal-input';
+import { PTY_TRUNCATED_MARKER } from '@maka/core/pty-output-view';
 
 import { isActiveShellRunStatus } from '@maka/core/shell-run';
 
@@ -41,8 +42,6 @@ import { isLikelySandboxDenial } from './sandbox/detect.js';
 
 export const PTY_MODEL_TEXT_BUDGET_BYTES = 50 * 1024;
 
-const TRUNCATED_MARKER = '[terminal snapshot truncated to fit the output limit]';
-
 export type TerminalToolResult = Extract<ToolResultContent, { kind: 'terminal' }>;
 export type ShellRunToolResult = Extract<ToolResultContent, { kind: 'shell_run' }>;
 
@@ -258,10 +257,10 @@ function takePrioritizedText(text: string, budget: number): { text: string; trun
 function takeTailText(text: string, budget: number): { text: string; truncated: boolean } {
   if (Buffer.byteLength(text, 'utf8') <= budget) return { text, truncated: false };
   if (budget <= 0) return { text: '', truncated: text.length > 0 };
-  const markerBytes = Buffer.byteLength(TRUNCATED_MARKER, 'utf8');
+  const markerBytes = Buffer.byteLength(PTY_TRUNCATED_MARKER, 'utf8');
   if (budget <= markerBytes) return { text: '', truncated: true };
   const tail = sliceUtf8Tail(text, budget - markerBytes - 1);
-  return { text: `${TRUNCATED_MARKER}\n${tail}`, truncated: true };
+  return { text: `${PTY_TRUNCATED_MARKER}\n${tail}`, truncated: true };
 }
 
 function sliceUtf8Tail(text: string, budget: number): string {
diff --git a/packages/runtime/src/web-fetch-tool.ts b/packages/runtime/src/web-fetch-tool.ts
index 18abc15bcf..64b63a7bbc 100644
--- a/packages/runtime/src/web-fetch-tool.ts
+++ b/packages/runtime/src/web-fetch-tool.ts
@@ -18,6 +18,7 @@
  */
 
 import { z } from 'zod';
+import type { ToolResultContent } from '@maka/core/events';
 import type { MakaTool } from './tool-runtime.js';
 
 const WEB_FETCH_TOOL_NAME = 'WebFetch';
@@ -41,7 +42,9 @@ export interface WebFetchExecutor {
 }
 
 /** Builds the model-facing tool while the host owns policy and transport. */
-export function buildWebFetchTool(executor: WebFetchExecutor): MakaTool {
+export function buildWebFetchTool(
+  executor: WebFetchExecutor,
+): MakaTool<{ url: string }, Extract<ToolResultContent, { kind: 'text' }>> {
   return {
     name: WEB_FETCH_TOOL_NAME,
     categoryHint: 'web_read',
@@ -49,6 +52,13 @@ export function buildWebFetchTool(executor: WebFetchExecutor): MakaTool {
     description:
       'Read the main content of a specific HTTP or HTTPS URL. Use it when a concrete URL is already known.',
     parameters: z.object({ url: httpUrlSchema }).strict(),
+    toModelOutput: ({ output }) => {
+      const result = output as Extract<ToolResultContent, { kind: 'text' }>;
+      return {
+        type: 'text',
+        value: result.text + (result.truncated ? WEB_FETCH_TRUNCATION_MARKER : ''),
+      };
+    },
     impl: async ({ url }, context) => {
       const canonicalUrl = new URL(httpUrlSchema.parse(url)).toString();
       const content = await executor.fetch({
@@ -71,12 +81,13 @@ export function routeWebFetchTools(
     : [...tools];
 }
 
-function truncateWebFetchOutput(content: string): string {
-  if (Buffer.byteLength(content, 'utf8') <= WEB_FETCH_MODEL_OUTPUT_MAX_BYTES) return content;
+function truncateWebFetchOutput(content: string): Extract<ToolResultContent, { kind: 'text' }> {
+  if (Buffer.byteLength(content, 'utf8') <= WEB_FETCH_MODEL_OUTPUT_MAX_BYTES)
+    return { kind: 'text', text: content };
   const markerBytes = Buffer.byteLength(WEB_FETCH_TRUNCATION_MARKER, 'utf8');
   const kept = Buffer.from(content, 'utf8')
     .subarray(0, WEB_FETCH_MODEL_OUTPUT_MAX_BYTES - markerBytes)
     .toString('utf8')
     .replace(/�+$/, '');
-  return kept + WEB_FETCH_TRUNCATION_MARKER;
+  return { kind: 'text', text: kept, truncated: true };
 }
diff --git a/packages/ui/src/__tests__/tool-activity-presentation.test.ts b/packages/ui/src/__tests__/tool-activity-presentation.test.ts
index 349c60a1ad..b7cf4f8a52 100644
--- a/packages/ui/src/__tests__/tool-activity-presentation.test.ts
+++ b/packages/ui/src/__tests__/tool-activity-presentation.test.ts
@@ -21,6 +21,7 @@ import assert from 'node:assert/strict';
 import { describe, it } from 'node:test';
 import { createElement, type ReactNode } from 'react';
 import { renderToStaticMarkup as renderReactToStaticMarkup } from 'react-dom/server';
+import { parseHTML } from 'linkedom';
 import { computerUseModelCallArgs } from '@maka/core/computer-use';
 import { UI_LOCALES, type UiCatalog, type UiLocale } from '@maka/core/ui-locale';
 import { ToolCallDetail, ToolTrow } from '../tool-activity.js';
@@ -42,6 +43,125 @@ function renderToStaticMarkup(node: ReactNode, locale: UiLocale = 'zh-CN'): stri
 }
 
 describe('tool activity presentation', () => {
+  it('projects semantic collapsed targets without dumping generic arguments', () => {
+    const rowText = (item: ToolActivityItem) => parseHTML(renderToStaticMarkup(
+      createElement(ToolTrow, { items: [item] }), 'en',
+    )).document.querySelector('[data-slot="chat-tool-call-row"]')?.textContent ?? '';
+    const running = (toolName: string, args: unknown): ToolActivityItem => ({
+      toolUseId: toolName, toolName, status: 'running', args,
+    });
+
+    assert.match(rowText(running('Read', { path: '/repo/a/index.ts', offset: 20, limit: 10 })), /index\.ts · L20\+10/);
+    assert.doesNotMatch(rowText(running('Read', { path: '/repo/a/index.ts' })), /\/repo\/a/);
+    assert.match(rowText(running('Read', { ref: `maka:\/\/archive\/artifact\/${'a'.repeat(64)}\/42` })), /Archived result/);
+    assert.doesNotMatch(rowText(running('Read', { ref: 'maka://runtime/background-tasks/task-1' })), /maka:\/\//);
+    assert.match(rowText(running('Grep', { pattern: 'needle', path: '/repo/src', glob: '*.ts' })), /needle in \/repo\/src \(\*\.ts\)/);
+    assert.match(rowText(running('WebFetch', { url: 'https://example.com/docs' })), /https:\/\/example\.com\/docs/);
+    assert.equal(rowText(running('CustomTool', { opaque: { nested: true } })).includes('opaque'), false);
+
+    const command = `printf ${'x'.repeat(180)}`;
+    assert.match(rowText(running('Bash', { command })), new RegExp(`printf x{180}`));
+  });
+
+  it('pairs collapsed targets with result-specific stats', () => {
+    const rowText = (item: ToolActivityItem) => parseHTML(renderToStaticMarkup(
+      createElement(ToolTrow, { items: [item] }), 'en',
+    )).document.querySelector('[data-slot="chat-tool-call-row"]')?.textContent ?? '';
+    const completed = (toolName: string, args: unknown, result: ToolActivityItem['result']): ToolActivityItem => ({
+      toolUseId: toolName, toolName, status: 'completed', args, result,
+    });
+
+    assert.match(rowText(completed('WebFetch', { url: 'https://example.com/docs' }, { kind: 'text', text: '# API docs\nbody' })), /example\.com\/docs.*API docs|API docs.*example\.com\/docs/);
+    assert.match(rowText(completed('Grep', { pattern: 'needle', path: '/repo' }, { kind: 'json', value: ['one', 'two'] })), /needle in \/repo.*2 items returned|2 items returned.*needle in \/repo/);
+    assert.match(rowText(completed('Write', { path: '/repo/out.txt' }, { kind: 'file_write', path: '/repo/out.txt', bytes: 42 })), /out\.txt.*42 B|42 B.*out\.txt/);
+    assert.match(rowText(completed('Read', { path: '/repo/index.ts' }, { kind: 'text', text: 'source\nsecond' })), /index\.ts.*2 lines|2 lines.*index\.ts/);
+  });
+
+  it('shows native Read JSON bodies as text with line counts in existing sessions', () => {
+    const item: ToolActivityItem = {
+      toolUseId: 'read-json', toolName: 'Read', status: 'completed',
+      args: { path: '/repo/events.ts', offset: 118, limit: 60 },
+      result: { kind: 'json', value: { content: 'first line\n\nthird line' } },
+    };
+    const row = parseHTML(renderToStaticMarkup(createElement(ToolTrow, { items: [item] }), 'en'))
+      .document.querySelector('[data-slot="chat-tool-call-row"]')!.textContent ?? '';
+    assert.match(row, /3 lines/);
+    assert.equal(row.match(/events\.ts/g)?.length, 1);
+    const detail = renderToStaticMarkup(createElement(ToolCallDetail, { item }), 'en');
+    assert.match(detail, /data-kind="text"/);
+    assert.doesNotMatch(detail, /data-kind="json"/);
+    assert.match(detail, /first line/);
+    for (const [text, count] of [['', 0], ['one\n', 2], ['one\r\ntwo', 2]] as const) {
+      const markup = renderToStaticMarkup(createElement(ToolTrow, { items: [{
+        ...item, result: { kind: 'json', value: { content: text } },
+      }] }), 'zh-CN');
+      assert.match(markup, new RegExp(`${count} 行`));
+    }
+  });
+
+  it('omits redundant success disclosure but keeps additional diagnostic fields inspectable', () => {
+    const item: ToolActivityItem = {
+      toolUseId: 'receipt', toolName: 'Update', status: 'completed', args: {},
+      result: { kind: 'json', value: { ok: true } },
+    };
+    const row = (value: ToolActivityItem) => parseHTML(renderToStaticMarkup(
+      createElement(ToolTrow, { items: [value] }), 'en',
+    )).document.querySelector('[data-slot="chat-tool-call-row"]')!;
+    assert.equal(row(item).getAttribute('aria-expanded'), null);
+    assert.match(row(item).textContent ?? '', /Succeeded/);
+    const diagnostic = row({ ...item, result: { kind: 'json', value: { ok: true, warning: 'Partial update' } } });
+    assert.equal(diagnostic.getAttribute('aria-expanded'), 'false');
+    assert.equal(row({ ...item, status: 'running', result: undefined }).getAttribute('aria-expanded'), 'false');
+  });
+
+  it('does not expose an empty disclosure for a failed boundary request', () => {
+    const markup = renderToStaticMarkup(createElement(ToolTrow, { items: [{
+      toolUseId: 'sandbox-boundary',
+      toolName: 'request_sandbox_boundary',
+      status: 'errored',
+      args: undefined,
+    }] }), 'en');
+    const row = parseHTML(markup).document.querySelector('[data-slot="chat-tool-call-row"]')!;
+    assert.equal(row.getAttribute('aria-expanded'), null);
+  });
+
+  it('renders fetched pages as references and preserves failure diagnostics', () => {
+    const item: ToolActivityItem = {
+      toolUseId: 'fetch', toolName: 'WebFetch', status: 'completed',
+      args: { url: 'https://example.com/docs' }, result: { kind: 'text', text: 'FETCHED_BODY_SENTINEL\n' + 'body\n'.repeat(100) + 'FETCHED_TAIL' },
+    };
+    const markup = renderToStaticMarkup(createElement(ToolCallDetail, { item }), 'en');
+    assert.doesNotMatch(markup, /Open full output/);
+    assert.match(markup, /href="https:\/\/example.com\/docs"/);
+    assert.match(markup, /534 B.*102 lines/);
+    assert.doesNotMatch(markup, /FETCHED_BODY_SENTINEL/);
+    assert.doesNotMatch(markup, /FETCHED_TAIL/);
+    const failed = renderToStaticMarkup(createElement(ToolCallDetail, {
+      item: { ...item, status: 'errored', result: { kind: 'text', text: 'HTTP 403: Forbidden' } },
+    }), 'en');
+    assert.match(failed, /HTTP 403/);
+    assert.doesNotMatch(failed, /Open full output/);
+  });
+
+  it('bounds ordinary JSON and fallback previews while retaining diagnostics', () => {
+    const content = {
+      kind: 'json' as const,
+      value: { rows: Array.from({ length: 2000 }, (_, i) => `entry-${i}`), error: 'Partial result', token: 'private-value' },
+    };
+    for (const node of [
+      createElement(ToolResultPreview, { content }),
+      createElement(ToolCallDetail, { item: {
+        toolUseId: 'large-json', toolName: 'Inspect', status: 'completed', args: {}, result: content,
+      } }),
+    ]) {
+      const markup = renderToStaticMarkup(node, 'en');
+      assert.match(markup, /Partial result/);
+      assert.match(markup, /entry-0/);
+      assert.doesNotMatch(markup, /entry-1999|private-value/);
+      assert.match(markup, /Open full output/);
+    }
+  });
+
   it('localizes client capability boundary failures and offers recovery', () => {
     const item: ToolActivityItem = {
       toolUseId: 'client-capability-boundary',
@@ -527,17 +647,17 @@ describe('collapsed tool row target', () => {
     assert.match(markup, /npm test/);
   });
 
-  it('caps a long command so the collapsed row stays single-line', async () => {
+  it('keeps ordinary commands intact and retains a generous DOM safety cap', async () => {
     const { ToolTrow } = await import('../tool-activity.js');
     const markup = renderToStaticMarkup(createElement(ToolTrow, {
       items: [{
         ...baseItem,
-        args: { command: `echo ${'x'.repeat(300)}` },
+        args: { command: `echo ${'x'.repeat(700)}` },
       }],
     }));
     const matches = markup.match(/x{100,}/g) ?? [];
     for (const run of matches) {
-      assert.ok(run.length <= 119, `expected a capped run, got ${run.length}`);
+      assert.ok(run.length <= 494, `expected a capped run, got ${run.length}`);
     }
     assert.match(markup, /…/);
   });
diff --git a/packages/ui/src/__tests__/tool-output-interaction.test.tsx b/packages/ui/src/__tests__/tool-output-interaction.test.tsx
new file mode 100644
index 0000000000..b5d24ed6e5
--- /dev/null
+++ b/packages/ui/src/__tests__/tool-output-interaction.test.tsx
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import assert from 'node:assert/strict';
+import { afterEach, it } from 'node:test';
+import { act } from 'react';
+import { createRoot } from 'react-dom/client';
+import { renderToStaticMarkup } from 'react-dom/server';
+import { parseHTML } from 'linkedom';
+import { SessionToolResultProvider, ToolResultHostProvider, type ToolOutputOpenRequest } from '../tool-activity/tool-result-context.js';
+import { LocaleProvider } from '../locale-context.js';
+import { ToolCallDetail, ToolTrow } from '../tool-activity.js';
+import { ToolResultPreview } from '../tool-activity/tool-result-preview.js';
+
+const navigatorDescriptor = Object.getOwnPropertyDescriptor(globalThis, 'navigator');
+const actEnvironmentDescriptor = Object.getOwnPropertyDescriptor(globalThis, 'IS_REACT_ACT_ENVIRONMENT');
+const globals = { document: globalThis.document, window: globalThis.window,
+  matchMedia: globalThis.matchMedia, requestAnimationFrame: globalThis.requestAnimationFrame,
+  cancelAnimationFrame: globalThis.cancelAnimationFrame, ResizeObserver: globalThis.ResizeObserver, MutationObserver: globalThis.MutationObserver };
+let root: ReturnType<typeof createRoot> | undefined;
+afterEach(async () => {
+  if (root) await act(() => root!.unmount());
+  root = undefined;
+  Object.assign(globalThis, globals);
+  if (navigatorDescriptor) Object.defineProperty(globalThis, 'navigator', navigatorDescriptor);
+  else Reflect.deleteProperty(globalThis, 'navigator');
+  if (actEnvironmentDescriptor) Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', actEnvironmentDescriptor);
+  else Reflect.deleteProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT');
+});
+function mount() {
+  const { document, window } = parseHTML('<div id="root"></div>');
+  window.getComputedStyle = () => ({ direction: 'ltr', writingMode: 'horizontal-tb', getPropertyValue: () => '' }) as unknown as CSSStyleDeclaration;
+  Object.assign(globalThis, { document, window, IS_REACT_ACT_ENVIRONMENT: true,
+    MutationObserver: window.MutationObserver,
+    ResizeObserver: class { observe() {} disconnect() {} },
+    matchMedia: () => ({ matches: false, addEventListener() {}, removeEventListener() {} }),
+    requestAnimationFrame: () => 1, cancelAnimationFrame() {} });
+  const container = document.querySelector('#root')!;
+  root = createRoot(container);
+  const click = async (label: string) => {
+    const button = Array.from(container.querySelectorAll('button')).find((el) => el.textContent === label);
+    assert.ok(button, `missing action: ${label}`);
+    await act(async () => { button.click(); });
+  };
+  return { container, click };
+}
+
+it('keeps all retained shell output in a tail-pinned viewport', () => {
+  const markup = renderToStaticMarkup(<LocaleProvider locale="en"><ToolResultPreview content={{
+    kind: 'terminal', cwd: '/repo', cmd: 'npm test', status: 'completed', exitCode: 0,
+    output: { mode: 'pipes', stdout: 'FIRST_LINE\n' + 'progress\n'.repeat(40) + 'ALL_TESTS_PASSED', stderr: '', redacted: false, stdoutTruncated: false, stderrTruncated: false },
+  }} /></LocaleProvider>);
+  assert.match(markup, /ALL_TESTS_PASSED/);
+  assert.match(markup, /FIRST_LINE/);
+  assert.match(markup, /role="region"/);
+  assert.match(markup, /tabindex="0"/);
+  assert.doesNotMatch(markup, /Open full output|more lines/);
+});
+
+it('pauses on a one-pixel upward scroll and resumes only through Jump to bottom', async () => {
+  const { container, click } = mount();
+  const render = (seq: number) => <LocaleProvider locale="en"><ToolCallDetail item={{
+    toolUseId: 'stream', toolName: 'Bash', status: 'running', args: { command: 'npm test' },
+    outputChunks: [{ seq, stream: 'stdout', text: `progress ${seq}`, redacted: false, createdAt: seq }],
+  }} /></LocaleProvider>;
+  await act(async () => { root!.render(render(1)); });
+  const pre = container.querySelector('pre')!;
+  let top = 0;
+  Object.defineProperties(pre, { scrollHeight: { value: 1000 }, clientHeight: { value: 200 },
+    scrollTop: { get: () => top, set: (value: number) => { top = Math.min(800, Math.max(0, value)); } } });
+  await act(async () => { root!.render(render(2)); });
+  assert.equal(pre.scrollTop, 800);
+  pre.scrollTop = 799;
+  await act(async () => { pre.dispatchEvent(new window.Event('scroll')); });
+  await act(async () => { root!.render(render(3)); });
+  assert.equal(pre.scrollTop, 799);
+  pre.scrollTop = 800;
+  await act(async () => { pre.dispatchEvent(new window.Event('scroll')); });
+  await click('Jump to bottom');
+  await act(async () => { root!.render(render(4)); });
+  assert.equal(pre.scrollTop, 800);
+  assert.doesNotMatch(container.textContent!, /Jump to bottom/);
+});
+
+it('passes the archive source bound to the originating session', async () => {
+  const { click } = mount();
+  const requests: ToolOutputOpenRequest[] = [];
+  const render = (sessionId: string) => <LocaleProvider locale="en"><ToolResultHostProvider
+    value={request => requests.push(request)}
+  ><SessionToolResultProvider value={sessionId}><ToolResultPreview content={{
+    kind: 'archived_tool_result', status: 'not_loaded', resourceRef: 'maka://archive-ledger/v1/evidence', bodySha256: '0'.repeat(64),
+    originalBytes: 42, originalEstimatedTokens: 10, runtimeEventId: 'event', toolCallId: 'tool', toolName: 'Inspect',
+    rewriteVersion: 2, reason: 'stale_tool_result_pruned_before_compact',
+  }} /></SessionToolResultProvider></ToolResultHostProvider></LocaleProvider>;
+  await act(() => root!.render(render('old')));
+  await click('Open full output');
+  await act(() => root!.render(render('new')));
+  await click('Open full output');
+  assert.deepEqual(requests.map(request => request.source), [
+    { kind: 'archive', sessionId: 'old', identity: {
+      resourceRef: 'maka://archive-ledger/v1/evidence', bodySha256: '0'.repeat(64), originalBytes: 42,
+    } },
+    { kind: 'archive', sessionId: 'new', identity: {
+      resourceRef: 'maka://archive-ledger/v1/evidence', bodySha256: '0'.repeat(64), originalBytes: 42,
+    } },
+  ]);
+});
+
+it('keeps complete diff hunks when only the following hunk is outside the budget', () => {
+  const diff = '@@ -1,1 +1,1 @@\n-old\n+new\n@@ -10,27 +10,27 @@\n'
+    + Array.from({ length: 27 }, (_, i) => `-old${i}\n+new${i}`).join('\n')
+    + '\n context\n context\n@@ -100,1 +100,1 @@\n-last\n+last';
+  const markup = renderToStaticMarkup(<LocaleProvider locale="en"><ToolResultPreview
+    content={{ kind: 'file_diff', paths: ['a.txt'], diff }} /></LocaleProvider>);
+  assert.match(markup, /new26/);
+});
diff --git a/packages/ui/src/chat-view.tsx b/packages/ui/src/chat-view.tsx
index a6d69f683e..de40ca7083 100644
--- a/packages/ui/src/chat-view.tsx
+++ b/packages/ui/src/chat-view.tsx
@@ -17,6 +17,7 @@
  * under the License.
  */
 
+import { SessionToolResultProvider } from './tool-activity/tool-result-context.js';
 import { Fragment, useCallback, useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
 import {
   ICON_SIZE,
@@ -764,6 +765,7 @@ export function ChatView(props: {
         );
 
   return (
+    <SessionToolResultProvider value={props.activeSession.id}>
     <SessionAttachmentProvider
       sessionId={props.activeSession.id}
       readBytes={props.onReadAttachmentBytes}
@@ -1006,6 +1008,7 @@ export function ChatView(props: {
       </div>
       </section>
     </SessionAttachmentProvider>
+    </SessionToolResultProvider>
   );
 }
 
diff --git a/packages/ui/src/index.ts b/packages/ui/src/index.ts
index 187a1084ae..da5cf52423 100644
--- a/packages/ui/src/index.ts
+++ b/packages/ui/src/index.ts
@@ -190,3 +190,7 @@ export {
 } from '@astryxdesign/core';
 
 export { PromptAnchorRail, type PromptAnchorRailTurn } from './prompt-anchor-rail.js';
+
+export type { ToolOutputOpenRequest } from './tool-activity/tool-result-context.js';
+export { useClipboardCopyFeedback } from './clipboard-feedback.js';
+export { ToolResultHostProvider } from './tool-activity/tool-result-context.js';
diff --git a/packages/ui/src/styles.css b/packages/ui/src/styles.css
index cc267fd5b3..dc346064f2 100644
--- a/packages/ui/src/styles.css
+++ b/packages/ui/src/styles.css
@@ -665,6 +665,11 @@
 .maka-tool-output-command-copy[data-copy-feedback="pending"] { cursor: progress; }
 .maka-tool-output-command-copy[data-copy-feedback="copied"] { color: var(--link); }
 .maka-tool-output-command-copy[data-copy-feedback="failed"] { color: var(--destructive); }
+@media (hover: hover) {
+  .maka-tool-call-detail :is(.maka-tool-output-command-copy, .astryx-code-block-copy-button) { opacity: 0; }
+  .maka-tool-call-detail:hover :is(.maka-tool-output-command-copy, .astryx-code-block-copy-button),
+  .maka-tool-call-detail:focus-within :is(.maka-tool-output-command-copy, .astryx-code-block-copy-button) { opacity: 1; }
+}
 .maka-tool-output-body {
   font: var(--maka-text-code);
  max-height: 256px; margin: 0; overflow-y: auto; color: var(--muted-foreground); font-variant-ligatures: none; scroll-behavior: auto; white-space: pre-wrap; word-break: break-word; }
@@ -1159,3 +1164,10 @@
   outline: none;
   box-shadow: inset 0 0 0 var(--focus-ring-width) var(--focus-ring);
 }
+
+.maka-tool-output-scroller { position: relative; min-height: 0; }
+.maka-tool-output-jump { position: absolute; bottom: var(--space-2); right: var(--space-2); }
+
+/* Readability headings can be much longer than the reference card. */
+.maka-tool-web-fetch-title {
+  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
diff --git a/packages/ui/src/tool-activity.tsx b/packages/ui/src/tool-activity.tsx
index 340f7eda2b..df55912408 100644
--- a/packages/ui/src/tool-activity.tsx
+++ b/packages/ui/src/tool-activity.tsx
@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import { useEffect, useRef, useState } from 'react';
+import { useState } from 'react';
 import { countDiffLineStats } from '@maka/core/unified-diff';
 import { isInFlightToolStatus } from '@maka/core/tool-result-status';
 import { type ToolResultContent } from '@maka/core/events';
@@ -53,6 +53,8 @@ import {
 } from './tool-activity/computer-action-label.js';
 import {
   extractErrorText,
+  toolHasDetail,
+  toolResultStats,
   isCancelledToolResult,
   isPermissionDeniedToolResult,
   isRequiresBypassToolResult,
@@ -73,6 +75,7 @@ import {
   type ChatToolCallItem,
   VisuallyHidden,
 } from '@astryxdesign/core';
+import { ToolOutputScroller } from './tool-activity/tool-text-preview.js';
 import { ToolCodeBlock, ToolDetailReveal } from './tool-activity/tool-code-block.js';
 import { cn } from './ui.js';
 import {
@@ -219,25 +222,9 @@ export function ToolCallDetail({
       locale,
     })
     : undefined;
-  const quietJson =
-    displayResult?.kind === 'json'
-      ? formatQuietJsonValue(displayResult.value, locale)
-      : undefined;
-  // Drop headline when it duplicates the invocation (e.g. Write path === path).
-  const showInvocation = invocationLine !== undefined;
-  const resultHeadline = quietJson?.headline
-    && quietJson.headline !== invocationLine
-    ? quietJson.headline
-    : undefined;
-  // Live streaming has its own surface below, so this covers only the settled
-  // stack.
-  const hasSharedPanelContent =
-    !ownsPanel && !showLiveStream && (
-      showInvocation
-      || !!resultHeadline
-      || showResult
-      || (!!item.args && !permissionDenied && !invocationLine)
-    );
+  const hasSharedPanelContent = !ownsPanel && !showLiveStream && (
+    invocationLine !== undefined || showResult || (!!item.args && !permissionDenied)
+  );
 
   return (
     <div className="maka-tool-call-detail">
@@ -258,6 +245,7 @@ export function ToolCallDetail({
           <ToolResultPreview
             content={displayResult}
             toolName={item.toolName}
+            failed={failedOutcome}
             args={item.args}
             shellRunSource={item.shellRunSource}
             actionIdentity={outputActionIdentity}
@@ -271,7 +259,8 @@ export function ToolCallDetail({
       {showLiveStream && (
         <ToolOutputSurface
           kind="live_stream"
-          heading={showInvocation ? invocationLine : undefined}
+          body={redactSecrets(item.outputChunks!.map(chunk => chunk.text).join(''))}
+          heading={invocationLine}
           actionIdentity={outputActionIdentity}
         >
           <ToolOutputStream
@@ -283,41 +272,22 @@ export function ToolCallDetail({
       )}
       {hasSharedPanelContent && (
         <div data-slot="tool-output" className="maka-tool-output-stack">
-          {(() => {
-            const argsBody = !showInvocation && !resultHeadline && item.args !== undefined
-              && !permissionDenied && !showResult
-              ? formatQuietJsonValue(item.args, locale).body
-              : undefined;
-            const body = quietJson?.body ?? argsBody;
-            const title = resultHeadline ?? (showInvocation ? invocationLine : undefined);
-            if (body) {
-              return (
-                <ToolCodeBlock
-                  code={body}
-                  // Only raw args dumps are JSON; quiet bodies stay untokenized.
-                  language={argsBody ? 'json' : undefined}
-                  title={title}
-                  actionIdentity={outputActionIdentity}
-                />
-              );
-            }
-            if (showInvocation && invocationLine && !showResult) {
-              return <ToolCodeBlock code={invocationLine} actionIdentity={outputActionIdentity} />;
-            }
-            if (showResult && !ownsPanel && displayResult) {
-              return (
-                <ToolResultPreview
-                  content={displayResult}
-                  toolName={item.toolName}
-                  actionIdentity={outputActionIdentity}
-                />
-              );
-            }
-            if (showInvocation && invocationLine) {
-              return <ToolCodeBlock code={invocationLine} actionIdentity={outputActionIdentity} />;
-            }
-            return null;
-          })()}
+          {showResult && displayResult ? (
+            <ToolResultPreview
+              content={displayResult}
+              toolName={item.toolName}
+              failed={failedOutcome}
+              args={item.args}
+              heading={invocationLine}
+              actionIdentity={outputActionIdentity}
+            />
+          ) : (
+            <ToolCodeBlock
+              code={invocationLine ?? formatQuietJsonValue(item.args, locale).body}
+              language={invocationLine ? undefined : 'json'}
+              actionIdentity={outputActionIdentity}
+            />
+          )}
         </div>
       )}
     </div>
@@ -486,6 +456,8 @@ function standardToolCall(
   inferredTarget?: string,
   onSwitchToBypassAndRetry?: () => void | Promise<void>,
 ): ChatToolCallItem {
+  const target = collapsedToolTarget(item, locale, inferredTarget);
+  const resultStats = toolResultStats(item, locale);
   return {
     key: item.toolUseId,
     // The name is what a person reads to tell one call from the next, and for
@@ -494,31 +466,30 @@ function standardToolCall(
     // arguments says what happened instead.
     name: computerActionLabel(item, locale) ?? resolveToolDisplayName(item, locale),
     status: astryxToolStatus(item),
-    target: collapsedToolTarget(item, locale, inferredTarget),
+    target,
     duration: formatDuration(item.durationMs) ?? undefined,
     errorMessage: toolCallErrorMessage(item, locale),
     stats: item.progress && isInFlightToolStatus(toolActivityPresentationStatus(item))
       ? `${item.progress.current}/${item.progress.total}`
-      : outcomeWord(item, locale),
+      : outcomeWord(item, locale) ?? (resultStats === target ? undefined : resultStats),
     ...diffStats(itemDiffs(item)),
-    resultDetail: (
+    resultDetail: toolHasDetail(item) ? (
       <ToolDetailReveal>
         <ToolCallDetail
           item={item}
           onSwitchToBypassAndRetry={onSwitchToBypassAndRetry}
         />
       </ToolDetailReveal>
-    ),
+    ) : undefined,
   };
 }
 
 /**
  * What the collapsed row (and a collapsed group's header) says about the call.
  * `intent` wins when the runtime authored one; otherwise fall back to the
- * shared invocation line derived from the call's args — or, during the live
- * window, from the bounded wire args preview (full args arrive at turn end).
- * Only the first line is shown, hard-capped so a long command cannot stretch
- * the group header (Astryx ellipsizes too, but the header row is shared).
+ * tool-specific semantic projection of the call's args — or, during the live
+ * window, its bounded wire args preview (full args arrive at turn end).
+ * Expanded details keep the shared invocation formatter and its full paths.
  */
 function collapsedToolTarget(
   item: ToolActivityItem,
@@ -526,11 +497,67 @@ function collapsedToolTarget(
   preferred?: string,
 ): string | undefined {
   if (item.intent) return formatToolIntent(item.intent);
-  const line = preferred ?? formatToolInvocationLine(item, locale);
+  const args = item.args ?? item.argsPreview;
+  const record = args && typeof args === 'object' && !Array.isArray(args)
+    ? args as Record<string, unknown>
+    : undefined;
+  const scalar = (key: string) => {
+    const value = record?.[key];
+    return typeof value === 'string' && value.trim() ? value : undefined;
+  };
+  const path = scalar('path') ?? scalar('file');
+  const baseName = path?.split(/[\\/]/).filter(Boolean).at(-1);
+  const invocation = () => formatToolInvocationLine({ toolName: item.toolName, args }, locale);
+  let line = preferred;
+  if (!line) {
+    switch (item.toolName) {
+      case 'Read': {
+        const offset = typeof record?.offset === 'number' ? record.offset : undefined;
+        const limit = typeof record?.limit === 'number' ? record.limit : undefined;
+        const range = offset === undefined && limit === undefined
+          ? ''
+          : ` · L${offset ?? 0}${limit === undefined ? '' : `+${limit}`}`;
+        line = baseName ? `${baseName}${range}` : semanticInternalRef(scalar('ref'), locale);
+        break;
+      }
+      case 'Write':
+      case 'Edit':
+        line = baseName;
+        break;
+      case 'Bash':
+      case 'Grep':
+      case 'Glob':
+      case 'Find':
+      case 'WriteStdin':
+      case 'deep_research_start':
+      case 'GoalSet':
+      case 'AskUserQuestion':
+        line = invocation();
+        break;
+      case 'WebFetch':
+        line = scalar('url');
+        break;
+      default: {
+        const ref = scalar('ref');
+        line = (ref?.startsWith('maka://') ? semanticInternalRef(ref, locale) : undefined)
+          ?? ['query', 'pattern', 'url', 'name', 'title', 'path', 'file', 'id']
+            .map(scalar)
+            .find(Boolean)
+          ?? ref;
+      }
+    }
+  }
   if (!line) return undefined;
-  const firstLine = line.split('\n')[0]!.trim();
+  const firstLine = redactSecrets(line).split('\n')[0]!.trim();
   if (!firstLine) return undefined;
-  return firstLine.length > 120 ? `${firstLine.slice(0, 119)}…` : firstLine;
+  return firstLine.length > 500 ? `${firstLine.slice(0, 499)}…` : firstLine;
+}
+
+function semanticInternalRef(ref: string | undefined, locale: UiLocale): string | undefined {
+  if (!ref?.startsWith('maka://')) return ref;
+  return ref.startsWith('maka://archive/')
+    ? getToolActivityCopy(locale).detail.archivedResult
+    : undefined;
 }
 
 function linkedAgentRows(
@@ -713,18 +740,14 @@ function ToolOutputStream(props: {
   live: boolean;
   truncated: boolean;
 }) {
-  const copy = getToolActivityCopy(useUiLocale()).output;
-  const preRef = useRef<HTMLPreElement>(null);
-  useEffect(() => {
-    if (!props.live) return;
-    const el = preRef.current;
-    if (!el) return;
-    el.scrollTop = el.scrollHeight;
-  }, [props.chunks, props.live]);
-
+  const activityCopy = getToolActivityCopy(useUiLocale());
+  const copy = activityCopy.output;
   return (
     <>
-      <pre ref={preRef} className={TOOL_OUTPUT_BODY_CLASS} data-live={props.live ? 'true' : undefined}>
+      <ToolOutputScroller
+        className={TOOL_OUTPUT_BODY_CLASS}
+        data-live={props.live ? 'true' : undefined}
+      >
         {props.chunks.map((chunk) => (
           <span
             key={chunk.seq}
@@ -744,7 +767,7 @@ function ToolOutputStream(props: {
             )}
           </span>
         ))}
-      </pre>
+      </ToolOutputScroller>
       {props.truncated && (
         <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.truncated}</p>
       )}
diff --git a/packages/ui/src/tool-activity/copy.ts b/packages/ui/src/tool-activity/copy.ts
index 8b042f8a71..52d6c8217f 100644
--- a/packages/ui/src/tool-activity/copy.ts
+++ b/packages/ui/src/tool-activity/copy.ts
@@ -17,6 +17,7 @@
  * under the License.
  */
 
+import type { ArtifactReadFailureReason } from '@maka/core/artifacts';
 import type { UiCatalog, UiLocale } from '@maka/core/ui-locale';
 
 type BackgroundTerminalStatus = 'running' | 'completed' | 'failed' | 'timed_out' | 'cancelled' | 'orphaned';
@@ -24,6 +25,23 @@ type WebCredentialCopyKey = 'env' | 'settings' | 'missing' | 'unknown';
 type WebGuidanceKey = 'env' | 'settings' | 'rate_limited' | 'not_configured' | 'timed_out' | 'privacy_mode' | 'unknown';
 
 export interface ToolActivityCopy {
+  detail: {
+    viewSaved: string;
+    loading: string;
+    loadFailed: string;
+    unavailable: string;
+    retry: string;
+    copySaved: string;
+    jumpToBottom: string;
+    outputRegion: string;
+    archivedResult: string;
+    previewTruncated: string;
+    jsonHidden: string;
+    lines: (count: number) => string;
+    readFailure: Record<ArtifactReadFailureReason, string>;
+    sourceTruncated: string;
+    returned: ((count: number) => string);
+  };
   errorLabel: string;
   /** The two outcomes a tool row spells out next to its name. */
   status: {
@@ -155,8 +173,6 @@ export interface ToolActivityCopy {
     disconnected: string;
     terminalTruncated: string;
     terminalRedacted: string;
-    streamHidden: (stream: 'stdout' | 'stderr', count: number) => string;
-    streamsTruncated: (limit: number) => string;
     outputTruncated: string;
     outputRedacted: string;
     backgroundStatus: Record<BackgroundTerminalStatus, string>;
@@ -183,6 +199,23 @@ export interface ToolActivityCopy {
 
 const TOOL_ACTIVITY_COPY = {
   'zh-CN': {
+    detail: {
+      viewSaved: '打开完整输出',
+      loading: '正在加载…',
+      loadFailed: '无法加载输出',
+      unavailable: '已保存输出不可用',
+      retry: '重试',
+      copySaved: '复制全部输出',
+      jumpToBottom: '跳到底部',
+      outputRegion: '工具输出',
+      archivedResult: '归档结果',
+      previewTruncated: '预览已截断',
+      jsonHidden: '部分内容未展示',
+      lines: (count) => `${count} 行`,
+      readFailure: { not_found: '输出不存在或已删除', not_allowed: '输出未通过访问或完整性校验', too_large: '输出超过查看器的 4 MB 上限', read_failed: '读取输出失败，请重试' },
+      sourceTruncated: '工具输出已截断，以下仅为已保留内容',
+      returned: (count) => `返回 ${count} 项`,
+    },
     errorLabel: '错误',
     status: { sandboxBlocked: '可能被沙箱阻止', interrupted: '已中断' },
     output: { redacted: '[已脱敏]', truncated: '输出已截断' },
@@ -278,7 +311,7 @@ const TOOL_ACTIVITY_COPY = {
     },
     permissionDenied: '用户已拒绝权限请求',
     result: {
-      hiddenLines: (n) => `… 已隐藏 ${n} 行`, ptyFailed: '后台终端交互失败', queued: '已输入', notQueued: '未输入', queuedPreview: (action, preview, bytes) => bytes === undefined ? `${action}：${preview}` : `${action}：${preview}… · 共 ${bytes} 字节`, byteCount: (action, bytes) => `${action} ${bytes} 字节`, resizeNotApplied: (size) => `未调整为 ${size}`, resized: (size) => `已调整为 ${size}`, sizeUnchanged: (size) => `尺寸已是 ${size}`, ptyCompleted: '后台终端交互已完成', terminalUnavailable: '终端输出不可用', noTerminalFrame: '（无可用终端画面）', noOutputYet: '（尚无输出）', noOutput: '（无输出）', exitCode: (code) => `退出码 ${code}`, managedBySource: '由源任务管理', sourceUnavailable: '源任务不可用', running: '运行中', success: '成功', failed: '失败', timedOut: '已超时', cancelled: '已取消', disconnected: '已断开', terminalTruncated: '终端输出已截断', terminalRedacted: '终端输出已脱敏', streamHidden: (stream, n) => `… ${stream} 已隐藏 ${n} 行`, streamsTruncated: (limit) => `输出已截断 · 每路仅展示前 ${limit} 行`, outputTruncated: '输出已截断', outputRedacted: '输出已脱敏',
+      hiddenLines: (n) => `… 已隐藏 ${n} 行`, ptyFailed: '后台终端交互失败', queued: '已输入', notQueued: '未输入', queuedPreview: (action, preview, bytes) => bytes === undefined ? `${action}：${preview}` : `${action}：${preview}… · 共 ${bytes} 字节`, byteCount: (action, bytes) => `${action} ${bytes} 字节`, resizeNotApplied: (size) => `未调整为 ${size}`, resized: (size) => `已调整为 ${size}`, sizeUnchanged: (size) => `尺寸已是 ${size}`, ptyCompleted: '后台终端交互已完成', terminalUnavailable: '终端输出不可用', noTerminalFrame: '（无可用终端画面）', noOutputYet: '（尚无输出）', noOutput: '（无输出）', exitCode: (code) => `退出码 ${code}`, managedBySource: '由源任务管理', sourceUnavailable: '源任务不可用', running: '运行中', success: '成功', failed: '失败', timedOut: '已超时', cancelled: '已取消', disconnected: '已断开', terminalTruncated: '终端输出已截断', terminalRedacted: '终端输出已脱敏', outputTruncated: '输出已截断', outputRedacted: '输出已脱敏',
       backgroundStatus: { running: '后台运行中', completed: '后台已完成', failed: '后台失败', timed_out: '后台超时', cancelled: '后台已取消', orphaned: '后台任务已断开' }, backgroundUnknown: (status) => `后台 · ${status}`,
       workflow: { action: '动作', status: '状态', error: '错误', nodes: '节点摘要', diagnostics: '诊断片段' }, webNoResults: '没有结果', webResults: (n) => `${n} 条结果`, credentialSource: { env: '环境变量', settings: '本机已保存 key', missing: '未配置', unknown: '来源未知' }, webFailure: '搜索失败', webSearch: '联网搜索', webGuidance: { env: '请检查 TAVILY_API_KEY / MAKA_TAVILY_API_KEY 后重启。', settings: '请在 设置 · 联网搜索 中更新 Tavily key。', rate_limited: 'Tavily 当前限流，请稍后重试或更换可用凭据。', not_configured: '请先完成联网搜索配置后再重试。', timed_out: '请求超时，请稍后重试。', privacy_mode: '隐私模式下不会发起联网搜索。', unknown: '请检查网络或稍后重试。' },
       workflowCompleted: 'Rive 工作流已完成',
@@ -291,6 +324,23 @@ const TOOL_ACTIVITY_COPY = {
     },
   },
   'zh-TW': {
+    detail: {
+      viewSaved: '開啟完整輸出',
+      loading: '正在載入…',
+      loadFailed: '無法載入輸出',
+      unavailable: '已儲存輸出無法使用',
+      retry: '重試',
+      copySaved: '複製全部輸出',
+      jumpToBottom: '跳到底部',
+      outputRegion: '工具輸出',
+      archivedResult: '封存結果',
+      previewTruncated: '預覽已截斷',
+      jsonHidden: '部分內容未顯示',
+      lines: (count) => `${count} 行`,
+      readFailure: { not_found: '輸出不存在或已刪除', not_allowed: '輸出未通過存取或完整性校驗', too_large: '輸出超過檢視器的 4 MB 上限', read_failed: '讀取輸出失敗，請重試' },
+      sourceTruncated: '工具輸出已截斷，以下僅為已保留內容',
+      returned: (count) => `傳回 ${count} 項`,
+    },
     errorLabel: '錯誤',
     status: { sandboxBlocked: '可能被沙箱阻止', interrupted: '已中斷' },
     output: { redacted: '[已脫敏]', truncated: '輸出已截斷' },
@@ -386,7 +436,7 @@ const TOOL_ACTIVITY_COPY = {
     },
     permissionDenied: '使用者已拒絕權限請求',
     result: {
-      hiddenLines: (n) => `… 已隱藏 ${n} 行`, ptyFailed: '後臺終端互動失敗', queued: '已輸入', notQueued: '未輸入', queuedPreview: (action, preview, bytes) => bytes === undefined ? `${action}：${preview}` : `${action}：${preview}… · 共 ${bytes} 位元組`, byteCount: (action, bytes) => `${action} ${bytes} 位元組`, resizeNotApplied: (size) => `未調整為 ${size}`, resized: (size) => `已調整為 ${size}`, sizeUnchanged: (size) => `尺寸已是 ${size}`, ptyCompleted: '後臺終端互動已完成', terminalUnavailable: '終端輸出不可用', noTerminalFrame: '（無可用終端畫面）', noOutputYet: '（尚無輸出）', noOutput: '（無輸出）', exitCode: (code) => `退出碼 ${code}`, managedBySource: '由源任務管理', sourceUnavailable: '源任務不可用', running: '執行中', success: '成功', failed: '失敗', timedOut: '已超時', cancelled: '已取消', disconnected: '已斷開', terminalTruncated: '終端輸出已截斷', terminalRedacted: '終端輸出已脫敏', streamHidden: (stream, n) => `… ${stream} 已隱藏 ${n} 行`, streamsTruncated: (limit) => `輸出已截斷 · 每路僅展示前 ${limit} 行`, outputTruncated: '輸出已截斷', outputRedacted: '輸出已脫敏',
+      hiddenLines: (n) => `… 已隱藏 ${n} 行`, ptyFailed: '後臺終端互動失敗', queued: '已輸入', notQueued: '未輸入', queuedPreview: (action, preview, bytes) => bytes === undefined ? `${action}：${preview}` : `${action}：${preview}… · 共 ${bytes} 位元組`, byteCount: (action, bytes) => `${action} ${bytes} 位元組`, resizeNotApplied: (size) => `未調整為 ${size}`, resized: (size) => `已調整為 ${size}`, sizeUnchanged: (size) => `尺寸已是 ${size}`, ptyCompleted: '後臺終端互動已完成', terminalUnavailable: '終端輸出不可用', noTerminalFrame: '（無可用終端畫面）', noOutputYet: '（尚無輸出）', noOutput: '（無輸出）', exitCode: (code) => `退出碼 ${code}`, managedBySource: '由源任務管理', sourceUnavailable: '源任務不可用', running: '執行中', success: '成功', failed: '失敗', timedOut: '已超時', cancelled: '已取消', disconnected: '已斷開', terminalTruncated: '終端輸出已截斷', terminalRedacted: '終端輸出已脫敏', outputTruncated: '輸出已截斷', outputRedacted: '輸出已脫敏',
       backgroundStatus: { running: '後臺執行中', completed: '後臺已完成', failed: '後臺失敗', timed_out: '後臺超時', cancelled: '後臺已取消', orphaned: '後臺任務已斷開' }, backgroundUnknown: (status) => `後臺 · ${status}`,
       workflow: { action: '動作', status: '狀態', error: '錯誤', nodes: '節點摘要', diagnostics: '診斷片段' }, webNoResults: '沒有結果', webResults: (n) => `${n} 條結果`, credentialSource: { env: '環境變數', settings: '本機已儲存 key', missing: '未設定', unknown: '來源未知' }, webFailure: '搜尋失敗', webSearch: '聯網搜尋', webGuidance: { env: '請檢查 TAVILY_API_KEY / MAKA_TAVILY_API_KEY 後重啟。', settings: '請在 設定 · 聯網搜尋 中更新 Tavily key。', rate_limited: 'Tavily 目前限流，請稍後重試或更換可用憑據。', not_configured: '請先完成聯網搜尋設定後再重試。', timed_out: '請求超時，請稍後重試。', privacy_mode: '隱私模式下不會發起聯網搜尋。', unknown: '請檢查網路或稍後重試。' },
       workflowCompleted: 'Rive 工作流已完成',
@@ -399,6 +449,23 @@ const TOOL_ACTIVITY_COPY = {
     },
   },
   en: {
+    detail: {
+      viewSaved: 'Open full output',
+      loading: 'Loading…',
+      loadFailed: 'Could not load output',
+      unavailable: 'Saved output unavailable',
+      retry: 'Retry',
+      copySaved: 'Copy full output',
+      jumpToBottom: 'Jump to bottom',
+      outputRegion: 'Tool output',
+      archivedResult: 'Archived result',
+      previewTruncated: 'Preview truncated',
+      jsonHidden: 'Some content is not shown',
+      lines: (count) => `${count} lines`,
+      readFailure: { not_found: 'Output does not exist or was deleted', not_allowed: 'Output failed access or integrity validation', too_large: 'Output exceeds the viewer’s 4 MB limit', read_failed: 'Could not read output; try again' },
+      sourceTruncated: 'Tool output was truncated; only retained content is available',
+      returned: (count) => `${count} items returned`,
+    },
     errorLabel: 'Error',
     status: { sandboxBlocked: 'Possibly blocked by sandbox', interrupted: 'Interrupted' },
     output: { redacted: '[Redacted]', truncated: 'Output truncated' },
@@ -491,7 +558,7 @@ const TOOL_ACTIVITY_COPY = {
     },
     permissionDenied: 'User denied the permission request',
     result: {
-      hiddenLines: (n) => `… ${n} ${n === 1 ? 'line' : 'lines'} hidden`, ptyFailed: 'Background terminal interaction failed', queued: 'Entered', notQueued: 'Not entered', queuedPreview: (action, preview, bytes) => bytes === undefined ? `${action}: ${preview}` : `${action}: ${preview}… · ${bytes} bytes total`, byteCount: (action, bytes) => `${action} ${bytes} bytes`, resizeNotApplied: (size) => `Not resized to ${size}`, resized: (size) => `Resized to ${size}`, sizeUnchanged: (size) => `Size already ${size}`, ptyCompleted: 'Background terminal interaction completed', terminalUnavailable: 'Terminal output unavailable', noTerminalFrame: '(No terminal frame available)', noOutputYet: '(No output yet)', noOutput: '(No output)', exitCode: (code) => `exit code ${code}`, managedBySource: 'Managed by the source task', sourceUnavailable: 'Source task unavailable', running: 'Running', success: 'Succeeded', failed: 'Failed', timedOut: 'Timed out', cancelled: 'Cancelled', disconnected: 'Disconnected', terminalTruncated: 'Terminal output truncated', terminalRedacted: 'Terminal output redacted', streamHidden: (stream, n) => `… ${n} ${stream} ${n === 1 ? 'line' : 'lines'} hidden`, streamsTruncated: (limit) => `Output truncated · showing the first ${limit} lines of each stream`, outputTruncated: 'Output truncated', outputRedacted: 'Output redacted',
+      hiddenLines: (n) => `… ${n} ${n === 1 ? 'line' : 'lines'} hidden`, ptyFailed: 'Background terminal interaction failed', queued: 'Entered', notQueued: 'Not entered', queuedPreview: (action, preview, bytes) => bytes === undefined ? `${action}: ${preview}` : `${action}: ${preview}… · ${bytes} bytes total`, byteCount: (action, bytes) => `${action} ${bytes} bytes`, resizeNotApplied: (size) => `Not resized to ${size}`, resized: (size) => `Resized to ${size}`, sizeUnchanged: (size) => `Size already ${size}`, ptyCompleted: 'Background terminal interaction completed', terminalUnavailable: 'Terminal output unavailable', noTerminalFrame: '(No terminal frame available)', noOutputYet: '(No output yet)', noOutput: '(No output)', exitCode: (code) => `exit code ${code}`, managedBySource: 'Managed by the source task', sourceUnavailable: 'Source task unavailable', running: 'Running', success: 'Succeeded', failed: 'Failed', timedOut: 'Timed out', cancelled: 'Cancelled', disconnected: 'Disconnected', terminalTruncated: 'Terminal output truncated', terminalRedacted: 'Terminal output redacted', outputTruncated: 'Output truncated', outputRedacted: 'Output redacted',
       backgroundStatus: { running: 'Running in background', completed: 'Background task completed', failed: 'Background task failed', timed_out: 'Background task timed out', cancelled: 'Background task cancelled', orphaned: 'Background task disconnected' }, backgroundUnknown: (status) => `Background · ${status}`,
       workflow: { action: 'Action', status: 'Status', error: 'Error', nodes: 'Node summary', diagnostics: 'Diagnostic excerpts' }, webNoResults: 'No results', webResults: (n) => `${n} ${n === 1 ? 'result' : 'results'}`, credentialSource: { env: 'Environment variable', settings: 'Locally saved key', missing: 'Not configured', unknown: 'Unknown source' }, webFailure: 'Search failed', webSearch: 'Web search', webGuidance: { env: 'Check TAVILY_API_KEY / MAKA_TAVILY_API_KEY and restart.', settings: 'Update the Tavily key in Settings · Web search.', rate_limited: 'Tavily is rate-limiting requests. Try again later or use another credential.', not_configured: 'Configure web search before retrying.', timed_out: 'The request timed out. Try again later.', privacy_mode: 'Web search is disabled in privacy mode.', unknown: 'Check the network connection or try again later.' },
       workflowCompleted: 'Rive workflow completed',
diff --git a/packages/ui/src/tool-activity/preview-utils.ts b/packages/ui/src/tool-activity/preview-utils.ts
index 61a1db266f..c358edd97a 100644
--- a/packages/ui/src/tool-activity/preview-utils.ts
+++ b/packages/ui/src/tool-activity/preview-utils.ts
@@ -17,18 +17,49 @@
  * under the License.
  */
 
+import { normalizeSearchUrl } from '@maka/core/search';
+import type { ToolResultContent } from '@maka/core/events';
+import { redactSecrets } from '../redact.js';
 import type { UiLocale } from '@maka/core/ui-locale';
 import { getToolActivityCopy } from './copy.js';
 
 export const TOOL_LINE_CAP = 500;
 
-export function capLines(text: string): { body: string; capped: number } {
+/** Read persists its file body inside a JSON content envelope. */
+export function readResultText(result: ToolResultContent | undefined): string | undefined {
+  if (result?.kind === 'text') return result.text;
+  if (result?.kind !== 'json' || !result.value || typeof result.value !== 'object' || Array.isArray(result.value)) return undefined;
+  const record = result.value as Record<string, unknown>;
+  // Preserve other fields (including diagnostics) in the generic JSON preview.
+  return Object.keys(record).length === 1 && typeof record.content === 'string' ? record.content : undefined;
+}
+
+export function capLines(
+  text: string,
+  options: { lines?: number; chars?: number; tail?: boolean; paragraphs?: boolean } = {},
+): { body: string; capped: number; hiddenChars: number } {
+  const limit = options.lines ?? TOOL_LINE_CAP;
   const lines = text.split('\n');
-  if (lines.length <= TOOL_LINE_CAP) return { body: text, capped: 0 };
-  return {
-    body: lines.slice(0, TOOL_LINE_CAP).join('\n'),
-    capped: lines.length - TOOL_LINE_CAP,
-  };
+  const kept = options.tail ? lines.slice(-limit) : lines.slice(0, limit);
+  const joined = kept.join('\n');
+  const chars = options.chars ?? Number.POSITIVE_INFINITY;
+  let body = options.tail ? joined.slice(-chars) : joined.slice(0, chars);
+  if (!options.tail && body.length < text.length) {
+    // Prefer complete paragraphs for prose, then complete lines. A single
+    // oversized line still needs a hard budget, but can end at a word boundary.
+    const paragraph = options.paragraphs ? body.lastIndexOf('\n\n') : -1;
+    const line = body.lastIndexOf('\n');
+    if (paragraph > 0) body = body.slice(0, paragraph);
+    else if (joined.length > chars && line > 0) body = body.slice(0, line);
+    else if (options.paragraphs && joined.length > chars) {
+      const word = body.search(/\s+\S*$/);
+      if (word > 0) body = body.slice(0, word);
+    }
+  }
+  // Never leave half a surrogate at a display boundary.
+  if (options.tail && /^[\uDC00-\uDFFF]/.test(body)) body = body.slice(1);
+  if (!options.tail && /[\uD800-\uDBFF]$/.test(body)) body = body.slice(0, -1);
+  return { body, capped: Math.max(0, lines.length - body.split('\n').length), hiddenChars: text.length - body.length };
 }
 
 export function formatBytes(bytes: number): string {
@@ -64,3 +95,16 @@ export function summarizeErrorText(text: string): string {
   const trimmed = lines.slice(0, MAX_LINES).join('\n').slice(0, MAX_CHARS);
   return `${trimmed}…`;
 }
+
+/** A citation label shared by the collapsed row and the expanded fetch card. */
+export function webFetchReference(text: string, args: unknown) {
+  const rawUrl = args && typeof args === 'object' && 'url' in args ? args.url : undefined;
+  const normalized = typeof rawUrl === 'string' ? normalizeSearchUrl(redactSecrets(rawUrl)) : undefined;
+  const url = normalized?.ok ? new URL(normalized.value) : undefined;
+  const heading = /^ {0,3}#{1,6}[ \t]+(.+?)(?:[ \t]+#+)?[ \t]*$/m.exec(text.slice(0, 16_000))?.[1];
+  return {
+    title: redactSecrets(heading ?? url?.hostname ?? 'WebFetch').slice(0, 160),
+    href: url?.href,
+    location: url ? `${url.host}${url.pathname}` : undefined,
+  };
+}
diff --git a/packages/ui/src/tool-activity/result-projection.ts b/packages/ui/src/tool-activity/result-projection.ts
index 7c23c2feee..ed184b6471 100644
--- a/packages/ui/src/tool-activity/result-projection.ts
+++ b/packages/ui/src/tool-activity/result-projection.ts
@@ -23,6 +23,52 @@ import type { ToolActivityItem } from '../materialize.js';
 import { formatQuietJsonValue } from './builtin-preview.js';
 import { isConnectorTool } from './display-name.js';
 import { getToolActivityCopy } from './copy.js';
+import { redactSecrets } from '../redact.js';
+import { formatBytes, readResultText, webFetchReference } from './preview-utils.js';
+
+function isSuccessReceipt(result: ToolActivityItem['result']): boolean {
+  if (result?.kind === 'file_write') return true;
+  if (result?.kind !== 'json' || !result.value || typeof result.value !== 'object' || Array.isArray(result.value)) return false;
+  const record = result.value as Record<string, unknown>;
+  const keys = Object.keys(record);
+  return keys.length > 0 && keys.every((key) =>
+    key === 'ok' && record.ok === true
+    || key === 'status' && (record.status === 'completed' || record.status === 'success'),
+  );
+}
+
+export function toolHasDetail(item: ToolActivityItem): boolean {
+  if (item.outputChunks?.length || item.outputTruncated) return true;
+  if (item.status !== 'completed' && item.args !== undefined) return true;
+  if (item.status === 'completed' && isSuccessReceipt(item.result)) return false;
+  if (item.result?.kind === 'text') return item.result.text.trim().length > 0;
+  return item.result !== undefined;
+}
+
+export function toolResultStats(item: ToolActivityItem, locale: UiLocale): string | undefined {
+  if (item.status !== 'completed') return undefined;
+  const copy = getToolActivityCopy(locale);
+  const result = item.result;
+  if (result?.kind === 'file_write') return formatBytes(result.bytes);
+  if (isSuccessReceipt(result)) return copy.result.success;
+  if (item.toolName === 'WebFetch') return webFetchReference(result?.kind === 'text' ? result.text : '', item.args).title;
+  if (item.toolName === 'Read' && item.args && typeof item.args === 'object' && 'path' in item.args && typeof item.args.path === 'string') {
+    const name = redactSecrets(item.args.path.split(/[\\/]/).pop() ?? item.args.path);
+    const text = readResultText(result);
+    return text === undefined ? name : copy.detail.lines(text === '' ? 0 : text.split('\n').length);
+  }
+  if (result?.kind === 'web_search') return copy.detail.returned(result.rows.length);
+  if (['Grep', 'Glob', 'Find'].includes(item.toolName) && result?.kind === 'json') {
+    if (Array.isArray(result.value)) return copy.detail.returned(result.value.length);
+    if (result.value && typeof result.value === 'object') {
+      const record = result.value as Record<string, unknown>;
+      for (const key of ['matches', 'files', 'results', 'items', 'paths']) {
+        if (Array.isArray(record[key])) return copy.detail.returned(record[key].length);
+      }
+    }
+  }
+  return undefined;
+}
 
 export function extractErrorText(result: ToolActivityItem['result'], locale: UiLocale): string {
   if (!result) return '';
diff --git a/packages/ui/src/tool-activity/tool-code-block.tsx b/packages/ui/src/tool-activity/tool-code-block.tsx
index 3ff31ffb4a..ade74e932e 100644
--- a/packages/ui/src/tool-activity/tool-code-block.tsx
+++ b/packages/ui/src/tool-activity/tool-code-block.tsx
@@ -30,6 +30,7 @@ export function ToolCodeBlock(props: {
   title?: string;
   maxHeight?: string | number;
   actionIdentity?: string;
+  hasCopyButton?: boolean;
 }) {
   const copy = getToolActivityCopy(useUiLocale()).copy;
   const actionIdentity = props.actionIdentity?.trim();
@@ -41,6 +42,7 @@ export function ToolCodeBlock(props: {
   const codeBlock = (
     <CodeBlock
       code={props.code}
+      hasCopyButton={props.hasCopyButton}
       language={props.language}
       title={props.title}
       // Absolute, like every other length the type-scale convergence
diff --git a/packages/ui/src/tool-activity/tool-result-context.tsx b/packages/ui/src/tool-activity/tool-result-context.tsx
new file mode 100644
index 0000000000..34c6a8394a
--- /dev/null
+++ b/packages/ui/src/tool-activity/tool-result-context.tsx
@@ -0,0 +1,40 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { createContext } from 'react';
+import type { ToolResultArchiveIdentity } from '@maka/core/artifacts';
+
+export type ToolOutputSource =
+  | { kind: 'text'; text: string }
+  | { kind: 'archive'; sessionId: string; identity: ToolResultArchiveIdentity };
+
+export interface ToolOutputOpenRequest {
+  title: string;
+  truncated?: boolean;
+  toolName?: string;
+  source: ToolOutputSource;
+}
+
+export const ToolResultHostContext = createContext<
+  ((request: ToolOutputOpenRequest) => void) | undefined
+>(undefined);
+export const ToolResultSessionContext = createContext<string | undefined>(undefined);
+
+export const ToolResultHostProvider = ToolResultHostContext.Provider;
+export const SessionToolResultProvider = ToolResultSessionContext.Provider;
diff --git a/packages/ui/src/tool-activity/tool-result-preview.tsx b/packages/ui/src/tool-activity/tool-result-preview.tsx
index 014f0db9bd..1f63c7137b 100644
--- a/packages/ui/src/tool-activity/tool-result-preview.tsx
+++ b/packages/ui/src/tool-activity/tool-result-preview.tsx
@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import { useEffect, useRef, type ReactNode } from 'react';
+import { useContext, type ReactNode } from 'react';
 import { isShellOutput, type ShellOutput } from '@maka/core/shell-run';
 import { normalizeSearchUrl } from '@maka/core/search';
 import { ptyHumanTerminalText } from '@maka/core/pty-output-view';
@@ -26,13 +26,16 @@ import { type ToolResultContent } from '@maka/core/events';
 import { Button as UiButton, Link } from '@astryxdesign/core';
 import { ICON_SIZE, AlertCircle, Ban, Check, Clock, Copy, GitBranch, Loader2, Plug, ShieldAlert } from '../icons.js';
 import { redactSecrets } from '../redact.js';
+import { parseUnifiedDiffRows } from '@maka/core/unified-diff';
+import { ToolResultHostContext, ToolResultSessionContext } from './tool-result-context.js';
 import { useClipboardCopyFeedback } from '../clipboard-feedback.js';
 import { useUiLocale } from '../locale-context.js';
 import { cn } from '../ui.js';
-import { formatQuietJsonValue } from './builtin-preview.js';
+import { formatBoundedQuietJsonValue } from '@maka/core/tool-quiet-preview';
+import { SavedToolOutput, ToolTextPreview, ToolOutputScroller } from './tool-text-preview.js';
 import { ToolCodeBlock } from './tool-code-block.js';
 import { DiffCodePreview } from './diff-code-preview.js';
-import { TOOL_LINE_CAP, capLines, formatUserVisibleToolText } from './preview-utils.js';
+import { capLines, formatBytes, readResultText, webFetchReference, formatUserVisibleToolText } from './preview-utils.js';
 import { getToolActivityCopy } from './copy.js';
 import { isSandboxDeniedToolResult } from './sandbox-denial.js';
 
@@ -139,17 +142,59 @@ export function ToolOutputSurface(props: {
   );
 }
 
+function WebFetchPreview(props: {
+  content: Extract<ToolResultContent, { kind: 'text' | 'archived_tool_result' }>;
+  args?: unknown;
+}) {
+  const copy = getToolActivityCopy(useUiLocale());
+  const text = props.content.kind === 'text' ? props.content.text : undefined;
+  const bytes = props.content.kind === 'archived_tool_result' ? props.content.originalBytes : new TextEncoder().encode(props.content.text).byteLength;
+  const truncated = props.content.kind === 'text' && props.content.truncated;
+  const reference = webFetchReference(text ?? '', props.args);
+  return <div data-kind="web_fetch" className="maka-tool-output-stack">
+    <strong className="maka-tool-web-fetch-title">{reference.title}</strong>
+    {reference.href && <Link href={reference.href} isExternalLink>{reference.location}</Link>}
+    <p className={TOOL_OUTPUT_NOTE_CLASS}>
+      {formatBytes(bytes)}{text !== undefined && ` · ${copy.detail.lines(text.split('\n').length)}`}
+      {truncated && ` · ${copy.result.outputTruncated}`}
+    </p>
+  </div>;
+}
+
 /** Routes persisted tool results to bounded, kind-specific preview cards. */
 export function ToolResultPreview(props: {
   content: ToolResultContent;
   toolName?: string;
   args?: unknown;
+  failed?: boolean;
   shellRunSource?: 'owned' | 'unavailable';
   fileDiffActions?: ReactNode;
   actionIdentity?: string;
+  heading?: string;
 }) {
-  const { content } = props;
+  const readText = props.toolName === 'Read' && !props.failed ? readResultText(props.content) : undefined;
+  const content = props.content.kind === 'json' && readText !== undefined
+    ? { kind: 'text' as const, text: readText }
+    : props.content;
   const locale = useUiLocale();
+  const openOutput = useContext(ToolResultHostContext);
+  const sessionId = useContext(ToolResultSessionContext);
+
+  if (content.kind === 'archived_tool_result') {
+    if (props.toolName === 'WebFetch' && !props.failed) {
+      return <WebFetchPreview content={content} args={props.args} />;
+    }
+    const copy = getToolActivityCopy(locale).detail;
+    if (content.status !== 'not_loaded' || (!content.resourceRef && !content.artifactId) || !content.bodySha256 || !openOutput || !sessionId) {
+      return <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.unavailable}</p>;
+    }
+    const identity = { ...(content.resourceRef
+      ? { resourceRef: content.resourceRef }
+      : { artifactId: content.artifactId! }),
+      bodySha256: content.bodySha256, originalBytes: content.originalBytes };
+    return <SavedToolOutput toolName={props.toolName} actionIdentity={props.actionIdentity}
+      source={{ kind: 'archive', sessionId, identity }} />;
+  }
 
   if (content.kind === 'file_diff') {
     return (
@@ -212,12 +257,17 @@ export function ToolResultPreview(props: {
 
   if (content.kind === 'json') {
     // No language: quiet text must stay contiguous (tokenizer splits words).
-    const quiet = formatQuietJsonValue(content.value, locale);
+    const quiet = formatBoundedQuietJsonValue(content.value, locale);
     return (
       <div data-kind="json">
-        <ToolCodeBlock
-          code={formatUserVisibleToolText(quiet.body, locale)}
-          title={quiet.headline ? formatUserVisibleToolText(quiet.headline, locale) : undefined}
+        <ToolTextPreview
+          toolName={props.toolName}
+          text={formatUserVisibleToolText(quiet.body, locale)}
+          truncated={quiet.truncated}
+          savedText={JSON.stringify(content.value)}
+          heading={quiet.headline
+            ? formatUserVisibleToolText(quiet.headline, locale)
+            : props.heading}
           actionIdentity={props.actionIdentity}
         />
       </div>
@@ -225,16 +275,28 @@ export function ToolResultPreview(props: {
   }
 
   if (content.kind === 'text') {
-    const copy = getToolActivityCopy(locale).result;
-    const { body, capped } = capLines(formatUserVisibleToolText(redactSecrets(content.text), locale));
-    const code = capped > 0 ? `${body}\n\n${copy.hiddenLines(capped)}` : body;
+    if (props.toolName === 'WebFetch' && !props.failed) {
+      return <WebFetchPreview content={content} args={props.args} />;
+    }
     return (
       <div data-kind="text">
-        <ToolCodeBlock code={code} actionIdentity={props.actionIdentity} />
+        <ToolTextPreview
+          // No heading: the collapsed row above already carries the invocation,
+          // and it can be an archive ref — repeating it here wraps a raw URI
+          // across the block's title slot.
+          text={formatUserVisibleToolText(redactSecrets(content.text), locale)}
+          sourceTruncated={content.truncated}
+          savedText={content.text}
+          actionIdentity={props.actionIdentity}
+        />
       </div>
     );
   }
 
+  if (content.kind === 'summary') {
+    return <ToolTextPreview text={content.original} actionIdentity={props.actionIdentity} />;
+  }
+
   // image / summary / unknown — show a compact descriptor so the user knows
   // what kind landed without dumping binary or storage refs.
   if (content.kind === 'file_write') {
@@ -319,23 +381,42 @@ function FileDiffPreview(props: {
   actions?: ReactNode;
   actionIdentity?: string;
 }) {
-  const copy = getToolActivityCopy(useUiLocale()).result;
+  const activityCopy = getToolActivityCopy(useUiLocale());
   // Apply UI-level redaction then cap the displayed lines. Both are
   // @kenji's PR76 review items: never echo a token a tool happened to dump
   // into a diff (commit body, .env file diff, etc.), and never let a
   // 10k-line diff create 10k React elements.
-  const { body, capped } = capLines(redactSecrets(props.diff));
+  const safe = redactSecrets(props.diff);
+  const preview = capLines(safe, { lines: 60, chars: 6_000 });
+  let body = preview.body;
+  if (preview.hiddenChars > 0) {
+    const rows = parseUnifiedDiffRows(body);
+    const lastHunk = rows.findLastIndex((row) => row.kind === 'hunk');
+    const header = rows[lastHunk]?.text.match(/^@@ -\d+(?:,(\d+))? \+\d+(?:,(\d+))? @@/);
+    if (header && rows.slice(0, lastHunk).some((row) => row.kind === 'hunk')) {
+      const tail = rows.slice(lastHunk + 1);
+      const oldCount = tail.filter((row) => row.oldLine !== undefined).length;
+      const newCount = tail.filter((row) => row.newLine !== undefined).length;
+      if (oldCount < Number(header[1] ?? 1) || newCount < Number(header[2] ?? 1)) {
+        body = body.slice(0, body.lastIndexOf(rows[lastHunk]!.text)).trimEnd();
+      }
+    }
+  }
+  const hiddenChars = safe.length - body.length;
   return (
     <ToolOutputSurface
       kind="file_diff"
       heading={props.paths.length > 0 ? props.paths.join(', ') : undefined}
-      body={body}
+      body={safe}
       actions={props.actions}
       actionIdentity={props.actionIdentity}
     >
       <DiffCodePreview diff={body} paths={props.paths} />
-      {capped > 0 && (
-        <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.hiddenLines(capped)}</p>
+      {hiddenChars > 0 && (
+        <>
+          <p className={TOOL_OUTPUT_NOTE_CLASS}>{activityCopy.detail.previewTruncated}</p>
+          <SavedToolOutput source={{ kind: 'text', text: safe }} actionIdentity={props.actionIdentity} />
+        </>
       )}
     </ToolOutputSurface>
   );
@@ -362,7 +443,7 @@ function TerminalPreview(props: {
     <ToolOutputSurface
       kind="terminal"
       heading={safeCmd}
-      body={props.output ? shellOutputText(props.output, copy) : undefined}
+      body={props.output ? shellOutputText(props.output) : undefined}
       actionIdentity={props.actionIdentity}
     >
       {props.output ? (
@@ -435,7 +516,7 @@ function ShellRunPreview(props: {
     <ToolOutputSurface
       kind="shell_run"
       heading={safeCmd}
-      body={pipeOutput ? shellOutputText(pipeOutput, copy) : undefined}
+      body={pipeOutput ? shellOutputText(pipeOutput) : undefined}
       actionIdentity={props.actionIdentity}
     >
       <p className={TOOL_OUTPUT_NOTE_CLASS}>
@@ -545,50 +626,24 @@ function ShellRunStatus(props: {
   }
 }
 
-/**
- * The output half of a `ToolOutputSurface` — never the command. The command is
- * the surface's header now, so this renders the same `<pre>` well the live
- * stream uses instead of its own bordered CodeBlock card, which used to nest a
- * second border inside the panel and put the command in its title slot.
- */
-/**
- * The plain text a shell body renders, so the surface's copy action can offer
- * the same string the reader is looking at — capped and redacted, with the
- * per-stream "hidden lines" markers the body shows.
- *
- * The body used to be an Astryx CodeBlock, whose own copy button carried this
- * text; the panel replaced that chrome, so the text has to reach the panel's
- * button instead. One function owns it, and the body renders from the same
- * call — a copy that quietly diverged from the pixels would be worse than none.
- */
-function shellOutputText(
-  output: ShellOutput,
-  copy: ReturnType<typeof getToolActivityCopy>['result'],
-): string {
+/** Copy and the bounded viewport use the same retained, redacted output. */
+function shellOutputText(output: ShellOutput): string {
   if (output.mode === 'pty') return redactSecrets(ptyHumanTerminalText(output));
-  const stdout = capLines(redactSecrets(output.stdout));
-  const stderr = capLines(redactSecrets(output.stderr));
-  const parts: string[] = [];
-  if (stdout.body) {
-    parts.push(stdout.capped > 0
-      ? `${stdout.body}\n\n${copy.streamHidden('stdout', stdout.capped)}`
-      : stdout.body);
-  }
-  if (stderr.body) {
-    parts.push(stderr.capped > 0
-      ? `${stderr.body}\n\n${copy.streamHidden('stderr', stderr.capped)}`
-      : stderr.body);
-  }
-  return parts.join('\n');
+  return [output.stdout, output.stderr]
+    .filter(Boolean)
+    .map(text => redactSecrets(text))
+    .join('\n');
 }
 
 function ShellOutputBody(props: {
   output: ShellOutput;
   failed: boolean;
 }) {
-  const copy = getToolActivityCopy(useUiLocale()).result;
-  if (props.output.mode === 'pty') {
-    const text = shellOutputText(props.output, copy);
+  const { output } = props;
+  const activityCopy = getToolActivityCopy(useUiLocale());
+  const copy = activityCopy.result;
+  if (output.mode === 'pty') {
+    const text = shellOutputText(output);
     return (
       <>
         {text ? <PtyTerminalSurface text={text} /> : (
@@ -596,53 +651,37 @@ function ShellOutputBody(props: {
             {props.failed ? copy.noTerminalFrame : copy.noOutputYet}
           </p>
         )}
-        {props.output.truncated && <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.terminalTruncated}</p>}
-        {props.output.redacted && <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.terminalRedacted}</p>}
+        {output.truncated && <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.terminalTruncated}</p>}
+        {output.redacted && <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.terminalRedacted}</p>}
       </>
     );
   }
-  const stdout = capLines(redactSecrets(props.output.stdout));
-  const stderr = capLines(redactSecrets(props.output.stderr));
-  const hiddenLines = stdout.capped + stderr.capped;
-  const runtimeTruncated = props.output.stdoutTruncated || props.output.stderrTruncated;
-  const hasOutput = props.output.stdout.length > 0 || props.output.stderr.length > 0;
-  const code = shellOutputText(props.output, copy);
+  const runtimeTruncated = output.stdoutTruncated || output.stderrTruncated;
+  const hasOutput = output.stdout.length > 0 || output.stderr.length > 0;
+  const code = shellOutputText(output);
   return (
     <>
       {hasOutput
-        ? <pre className={TOOL_OUTPUT_BODY_CLASS}>{code}</pre>
+        ? <ToolOutputScroller
+            className={TOOL_OUTPUT_BODY_CLASS}
+          >{code}</ToolOutputScroller>
         : <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.noOutput}</p>}
-      {(runtimeTruncated || hiddenLines > 0) && (
+      {runtimeTruncated && (
         <p className={TOOL_OUTPUT_NOTE_CLASS}>
-          {hiddenLines > 0 ? copy.streamsTruncated(TOOL_LINE_CAP) : copy.outputTruncated}
+          {copy.outputTruncated}
         </p>
       )}
-      {props.output.redacted && <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.outputRedacted}</p>}
+      {output.redacted && <p className={TOOL_OUTPUT_NOTE_CLASS}>{copy.outputRedacted}</p>}
     </>
   );
 }
 
 function PtyTerminalSurface(props: { text: string }) {
-  const ref = useRef<HTMLPreElement>(null);
-  const followTail = useRef(true);
-  useEffect(() => {
-    const element = ref.current;
-    if (element && followTail.current) element.scrollTop = element.scrollHeight;
-  }, [props.text]);
-  return (
-    <pre
-      ref={ref}
-      className={cn(TOOL_OUTPUT_BODY_CLASS, 'maka-pty-terminal-body')}
-      data-stream="pty"
-      style={{ whiteSpace: 'pre', wordBreak: 'normal' }}
-      onScroll={(event) => {
-        const element = event.currentTarget;
-        followTail.current = element.scrollHeight - element.scrollTop - element.clientHeight <= 2;
-      }}
-    >
-      {props.text}
-    </pre>
-  );
+  return <ToolOutputScroller
+    className={cn(TOOL_OUTPUT_BODY_CLASS, 'maka-pty-terminal-body')}
+    data-stream="pty"
+    style={{ whiteSpace: 'pre', wordBreak: 'normal' }}
+  >{props.text}</ToolOutputScroller>;
 }
 
 function isCancelledStatus(status: string | undefined): boolean {
diff --git a/packages/ui/src/tool-activity/tool-text-preview.tsx b/packages/ui/src/tool-activity/tool-text-preview.tsx
new file mode 100644
index 0000000000..4be8bf7fc6
--- /dev/null
+++ b/packages/ui/src/tool-activity/tool-text-preview.tsx
@@ -0,0 +1,102 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { useContext, useEffect, useRef, useSyncExternalStore, type ComponentProps } from 'react';
+import { createTranscriptScrollAuthority } from '../transcript-scroll-authority.js';
+import { Button } from '@astryxdesign/core';
+import { FileText, ICON_SIZE } from '../icons.js';
+import { useUiLocale } from '../locale-context.js';
+import { redactSecrets } from '../redact.js';
+import type { ToolOutputSource } from './tool-result-context.js';
+import { ToolResultHostContext } from './tool-result-context.js';
+import { getToolActivityCopy } from './copy.js';
+import { ToolCodeBlock } from './tool-code-block.js';
+import { capLines } from './preview-utils.js';
+
+/** Reading retained output belongs to the host's artifact viewer. */
+export function SavedToolOutput(props: {
+  source: ToolOutputSource;
+  toolName?: string;
+  truncated?: boolean;
+  actionIdentity?: string;
+}) {
+  const copy = getToolActivityCopy(useUiLocale()).detail;
+  const host = useContext(ToolResultHostContext);
+  return <span title={!host ? copy.unavailable : undefined}><Button variant="secondary" size="sm" label={copy.viewSaved}
+    icon={<FileText size={ICON_SIZE.chrome} aria-hidden="true" />}
+    isDisabled={!host}
+    onClick={(event) => {
+      // Pointer activation does not focus buttons in every browser. The host
+      // records this element before transferring focus into the viewer.
+      event.currentTarget.focus();
+      host?.({ title: props.actionIdentity ?? copy.viewSaved, toolName: props.toolName,
+        truncated: props.truncated, source: props.source });
+    }}
+  /></span>;
+}
+
+/** Full in-memory text in a height-bounded CodeBlock; only structured JSON
+ * truncation keeps an escape hatch to a separate viewer. */
+export function ToolTextPreview(props: {
+  text: string;
+  heading?: string;
+  actionIdentity?: string;
+  truncated?: boolean;
+  sourceTruncated?: boolean;
+  toolName?: string;
+  savedText?: string;
+}) {
+  const copy = getToolActivityCopy(useUiLocale()).detail;
+  const safe = redactSecrets(props.text);
+  const capped = capLines(safe, { chars: 120_000 });
+  const code = capped.body;
+  const previewTruncated = capped.capped > 0 || capped.hiddenChars > 0;
+  const needsSavedOutput = props.truncated || previewTruncated;
+  return (
+    <>
+      <ToolCodeBlock code={code} title={props.heading} actionIdentity={props.actionIdentity} />
+      {needsSavedOutput && <>
+        <p className="maka-tool-output-note">{props.sourceTruncated ? copy.sourceTruncated : copy.previewTruncated}</p>
+        <SavedToolOutput toolName={props.toolName} truncated={props.sourceTruncated}
+          source={{ kind: 'text', text: props.savedText ?? safe }} actionIdentity={props.actionIdentity} />
+      </>}
+    </>
+  );
+}
+
+
+/** The transcript's scroll owner, scoped to one tool output viewport. */
+export function ToolOutputScroller(props: ComponentProps<'pre'>) {
+  const { role = 'region', 'aria-label': ariaLabel, tabIndex = 0, ...preProps } = props;
+  const ref = useRef<HTMLPreElement>(null);
+  const authority = useRef<ReturnType<typeof createTranscriptScrollAuthority> | undefined>(undefined);
+  authority.current ??= createTranscriptScrollAuthority({ explicitResume: true });
+  const scroll = authority.current;
+  const snapshot = useSyncExternalStore(scroll.subscribe, scroll.getSnapshot, scroll.getSnapshot);
+  const copy = getToolActivityCopy(useUiLocale());
+  useEffect(() => scroll.attach(ref.current), [scroll]);
+  useEffect(() => {
+    if (scroll.getSnapshot().pinned) scroll.pinToTail();
+  }, [props.children, scroll]);
+  return <div className="maka-tool-output-scroller">
+    <pre {...preProps} ref={ref} role={role} aria-label={ariaLabel ?? copy.detail.outputRegion} tabIndex={tabIndex} />
+    {!snapshot.pinned && <Button className="maka-tool-output-jump" variant="ghost" size="sm" label={copy.detail.jumpToBottom}
+      onClick={() => scroll.pinToTail()} />}
+  </div>;
+}
diff --git a/packages/ui/src/transcript-scroll-authority.tsx b/packages/ui/src/transcript-scroll-authority.tsx
index 1332908750..ed64d85c2d 100644
--- a/packages/ui/src/transcript-scroll-authority.tsx
+++ b/packages/ui/src/transcript-scroll-authority.tsx
@@ -102,7 +102,7 @@ export interface TranscriptScrollAuthority {
   getSnapshot(): TranscriptScrollSnapshot;
 }
 
-export function createTranscriptScrollAuthority(): TranscriptScrollAuthority {
+export function createTranscriptScrollAuthority(options: { explicitResume?: boolean } = {}): TranscriptScrollAuthority {
   let root: HTMLElement | null = null;
   let pinned = true;
   let awayFromTail = false;
@@ -171,7 +171,7 @@ export function createTranscriptScrollAuthority(): TranscriptScrollAuthority {
         // scrollers (a tool output box, a terminal) never reach here at all:
         // `scroll` does not bubble, and there is no `wheel` listener to catch
         // instead.
-        if (lastWrittenTop !== undefined && Math.abs(target.scrollTop - lastWrittenTop) < 1) {
+        if (lastWrittenTop !== undefined && (options.explicitResume ? target.scrollTop === lastWrittenTop : Math.abs(target.scrollTop - lastWrittenTop) < 1)) {
           lastScrollHeight = target.scrollHeight;
           lastClientHeight = target.clientHeight;
           lastScrollTop = target.scrollTop;
@@ -216,7 +216,7 @@ export function createTranscriptScrollAuthority(): TranscriptScrollAuthority {
           publish();
           return;
         }
-        pinned = distance <= PIN_THRESHOLD_PX;
+        pinned = options.explicitResume ? pinned && unexplained >= 0 : distance <= PIN_THRESHOLD_PX;
         publish();
         for (const listener of [...readerListeners]) listener(unexplained < 0 ? 'up' : 'down');
       };
diff --git a/packages/ui/stories/tool-activity.stories.tsx b/packages/ui/stories/tool-activity.stories.tsx
index 44ddbfa4ab..5f1f0a843f 100644
--- a/packages/ui/stories/tool-activity.stories.tsx
+++ b/packages/ui/stories/tool-activity.stories.tsx
@@ -282,3 +282,42 @@ export const LongIntentGroupNarrow: Story = {
     );
   },
 };
+
+
+// Real path: completed tool calls in a conversation, with retained bodies disclosed on demand.
+export const RetainedToolOutput: Story = {
+  args: { items: [
+    { toolUseId: 'fetch-preview', toolName: 'WebFetch', status: 'completed',
+      args: { url: 'https://example.com/docs' },
+      result: { kind: 'text', text: 'Fetched documentation\n' + 'Documentation paragraph.\n'.repeat(500) } },
+    { toolUseId: 'json-preview', toolName: 'Inspect', status: 'completed', args: {},
+      result: { kind: 'json', value: { warning: 'Results are partial',
+        items: Array.from({ length: 100 }, (_, index) => ({ path: `src/module-${index}.ts`, matches: index })) } } },
+    { toolUseId: 'shell-preview', toolName: 'Bash', status: 'completed', args: { command: 'npm test' },
+      result: { kind: 'terminal', cwd: '/repo', cmd: 'npm test', status: 'completed', exitCode: 0,
+        output: { mode: 'pipes', stdout: 'Starting tests\n' + 'Test passed\n'.repeat(60) + 'All tests passed',
+          stderr: '', stdoutTruncated: false, stderrTruncated: false, redacted: false } } },
+  ] },
+  render: (args) => <div style={{ padding: 16 }}><ToolRowBoard items={args.items} width={860} /></div>,
+};
+
+// Real path: a tool group mixes captured output and a completed call with no output.
+export const MixedToolDisclosure: Story = {
+  args: { items: [' M file.ts', ''].map((text, index) => ({
+    toolUseId: `mixed-disclosure-${index}`, toolName: 'Bash', status: 'completed',
+    args: { command: index ? 'git diff --cached --stat' : 'git status' },
+    result: { kind: 'text', text },
+  })) },
+  render: (args) => <div className="maka-turn" style={{ padding: 16 }}><ToolTrow {...args} /></div>,
+  play: async ({ canvasElement }) => {
+    const names = within(canvasElement).getAllByText('Bash', { exact: true });
+    expect(names).toHaveLength(2);
+    expect(names[0].closest('[role="button"]')).not.toBeNull();
+    expect(names[1].closest('[role="button"]')).toBeNull();
+    const first = getComputedStyle(names[0]);
+    const second = getComputedStyle(names[1]);
+    expect(first.fontSize).toBe(second.fontSize);
+    expect(first.fontFamily).toBe(second.fontFamily);
+    expect(first.fontWeight).toBe(second.fontWeight);
+  },
+};