@@ -0,0 +1,13 @@
+---
+'@object-ui/plugin-detail': patch
+---
+
+feat(record page): the timeline's Changes chip holds the audit's field changes only, and is offered only while the record shows its field history
+
+Clause-②: no
+Metadata-protocol: none
+
+- **`@object-ui/plugin-detail`: what Changes holds.** The timeline stream's Changes chip, and the activity panel's `changes_only` filter, hold the field changes read from the audit log (each with its before and after values) and nothing else. The activity rows that share their look (created, updated, deleted, assigned, shared) are events, so they sit under Activity whether or not the record shows its field history; before, they sat under Changes and, on the panel, under `changes_only`.
+- **`@object-ui/plugin-detail`: `RecordFieldHistoryContext`.** A host tells the record page's timeline stream whether it shows the record's field history; while it says `false`, the stream draws the All / Activity / Discussion chips and no Changes chip, and a stream left on Changes goes back to All. With no provider every chip draws, as before. `RecordActivityTimeline` takes the chips to offer as `streamFilters` (all four when absent).
+- **The Console's record page** hands over its `enable.trackHistory` gate, so an object that does not opt in no longer offers a Changes chip on its timeline tab.
+- **The CRM example** opens `enable.trackHistory` on `crm_lead`, `crm_account`, `crm_contact` and `crm_opportunity`, so their record pages show each field change with its before and after values. The flag stays opt-in for every other object.
@@ -15,6 +15,11 @@ export const Account = ObjectSchema.create({
   description: 'A company that the org sells to or supports.',
   // What the record page shows at a glance, under the title.
   highlightFields: ['industry', 'annual_revenue', 'website'],
+  // Field history on the record page: the timeline shows each field change
+  // with its before and after values, and offers the Changes filter. The audit
+  // log records every change either way; this opt-in flag is what makes the
+  // record page show it.
+  enable: { trackHistory: true },
 
   fields: {
     name: Field.text({
 
@@ -21,6 +21,11 @@ export const Contact = ObjectSchema.create({
   nameField: 'full_name',
   // What the record page shows at a glance, under the title.
   highlightFields: ['account', 'email'],
+  // Field history on the record page: the timeline shows each field change
+  // with its before and after values, and offers the Changes filter. The audit
+  // log records every change either way; this opt-in flag is what makes the
+  // record page show it.
+  enable: { trackHistory: true },
 
   fields: {
     first_name: Field.text({
 
@@ -17,6 +17,11 @@ export const Lead = ObjectSchema.create({
   // What the record page shows at a glance, under the title. The stage is
   // not here: the record page already draws it as the stage path.
   highlightFields: ['company', 'source', 'lead_score', 'assigned_to'],
+  // Field history on the record page: the timeline shows each field change
+  // with its before and after values, and offers the Changes filter. The audit
+  // log records every change either way; this opt-in flag is what makes the
+  // record page show it.
+  enable: { trackHistory: true },
 
   fields: {
     name: Field.text({
 
@@ -17,6 +17,11 @@ export const Opportunity = ObjectSchema.create({
   // What the record page shows at a glance, under the title. The stage is
   // not here: the record page already draws it as the stage path.
   highlightFields: ['account', 'amount', 'close_date', 'probability'],
+  // Field history on the record page: the timeline shows each field change
+  // with its before and after values, and offers the Changes filter. The audit
+  // log records every change either way; this opt-in flag is what makes the
+  // record page show it.
+  enable: { trackHistory: true },
 
   fields: {
     name: Field.text({
 
@@ -155,12 +155,18 @@ function makeDataSource() {
   };
 }
 
-function renderPage({ width, embedded = false, search = '', windowWidth = 1440 }: { width: number; embedded?: boolean; search?: string; windowWidth?: number }) {
+function renderPage({
+  width,
+  embedded = false,
+  search = '',
+  windowWidth = 1440,
+  objects = OBJECTS,
+}: { width: number; embedded?: boolean; search?: string; windowWidth?: number; objects?: typeof OBJECTS }) {
   rootWidth = width;
   Object.defineProperty(window, 'innerWidth', { value: windowWidth, configurable: true, writable: true });
   dataSource = makeDataSource();
   const metadata = {
-    objects: OBJECTS,
+    objects,
     pages: [],
     loading: false,
     error: null,
@@ -175,7 +181,7 @@ function renderPage({ width, embedded = false, search = '', windowWidth = 1440 }
       <MetadataCtx.Provider value={metadata}>
         <RecordDetailView
           dataSource={dataSource as never}
-          objects={OBJECTS}
+          objects={objects}
           onEdit={() => {}}
           objectNameOverride={PARENT}
           recordIdOverride={RECORD_ID}
@@ -358,3 +364,28 @@ describe('RecordDetailView — one record page, laid out by its width (objectsta
     await waitFor(() => expect(auditReads()).toBeGreaterThan(0));
   });
 });
+
+describe('RecordDetailView — the 动态 tab offers 变更 only while the record shows its field history (objectstack#30074)', () => {
+  /** The full stream's chips, in order, once the 动态 tab has drawn. */
+  const streamChips = async (container: HTMLElement) =>
+    waitFor(
+      () => {
+        const chips = container.querySelectorAll('[data-related-enlarged="timeline"] [data-stream-filter]');
+        expect(chips.length).toBeGreaterThan(0);
+        return Array.from(chips).map((chip) => chip.getAttribute('data-stream-filter'));
+      },
+      { timeout: 5000 },
+    );
+
+  it('an object with `enable.trackHistory`: 全部 / 活动 / 讨论 / 变更', async () => {
+    const { container } = renderPage({ width: 1440, search: '?related=timeline' });
+    expect(await streamChips(container)).toEqual(['all', 'activity', 'discussion', 'changes']);
+  });
+
+  it('the same object without it: no 变更 chip, and no audit read', async () => {
+    const untracked = OBJECTS.map((o) => (o.name === PARENT ? { ...o, enable: undefined } : o)) as typeof OBJECTS;
+    const { container } = renderPage({ width: 1440, search: '?related=timeline', objects: untracked });
+    expect(await streamChips(container)).toEqual(['all', 'activity', 'discussion']);
+    expect(auditReads()).toBe(0);
+  });
+});
@@ -10,7 +10,7 @@
 
 import { useState, useEffect, useLayoutEffect, useCallback, useContext, useMemo, useRef, type ReactElement } from 'react';
 import { useParams, useNavigate, useLocation, useSearchParams, Link } from 'react-router-dom';
-import { activityRowToFeedItem, auditEntriesToFeedItems, bodyTableIdsOf, claimQueuedRecord, RECORD_PAGE_TIMELINE_PANEL, RECORD_TIMELINE_PANEL_MAX_ENTRIES, RecordFieldChangesContext, RecordTimelineTotalContext, DefaultRecordPageContext, EMPTY_RELATED_ARRANGEMENT, InlineEditSaveBar, RecordBodyTablesContext, RecordMetaFooter, RecordPageColumns, buildDefaultPageColumns, buildDefaultPageSchema, extractMentions, isRefusedFeedRead, recordPageTierHasRightColumn, recordSitsInQueue, resolveTitleField, useQueueClaimOffered, useRecordEditable, useRecordPageTier } from '@object-ui/plugin-detail';
+import { activityRowToFeedItem, auditEntriesToFeedItems, bodyTableIdsOf, claimQueuedRecord, RECORD_PAGE_TIMELINE_PANEL, RECORD_TIMELINE_PANEL_MAX_ENTRIES, RecordFieldChangesContext, RecordFieldHistoryContext, RecordTimelineTotalContext, DefaultRecordPageContext, EMPTY_RELATED_ARRANGEMENT, InlineEditSaveBar, RecordBodyTablesContext, RecordMetaFooter, RecordPageColumns, buildDefaultPageColumns, buildDefaultPageSchema, extractMentions, isRefusedFeedRead, recordPageTierHasRightColumn, recordSitsInQueue, resolveTitleField, useQueueClaimOffered, useRecordEditable, useRecordPageTier } from '@object-ui/plugin-detail';
 import { Empty, EmptyTitle, EmptyDescription, Button, PageHeaderActions, PageHeaderPhoneContext, PageHeaderTrailingContext, PanelToggles, RecordTopBar, cn, useRecordStepKeys, type PanelToggleItem, type RecordTopBarStepper } from '@object-ui/components';
 import { useAuth, createAuthenticatedFetch } from '@object-ui/auth';
 import { usePermissions } from '@object-ui/permissions';
@@ -5044,6 +5044,9 @@ export function RecordDetailView({ dataSource, objects, onEdit, objectNameOverri
         {/* objectstack#27055 — the field changes of the timeline stream,
             for the synthesized page's `record:activity`. */}
         <RecordFieldChangesContext.Provider value={assignedPage ? null : timelineFieldChanges}>
+        {/* objectstack#30074 — whether this record shows its field history:
+            the stream offers its 变更 chip only while it does. */}
+        <RecordFieldHistoryContext.Provider value={historyEnabled}>
         {/* objectstack#28737 — the whole stream's count, for the 动态 panel,
             its tab and the tab row's probe. */}
         <RecordTimelineTotalContext.Provider value={assignedPage ? null : timelineTotal}>
@@ -5321,6 +5324,7 @@ export function RecordDetailView({ dataSource, objects, onEdit, objectNameOverri
           {modalElement}
         </ActionProvider>
         </RecordTimelineTotalContext.Provider>
+        </RecordFieldHistoryContext.Provider>
         </RecordFieldChangesContext.Provider>
         </DiscussionContextProvider>
         </HighlightFieldsProvider>
 
@@ -816,8 +816,11 @@ the header row opens the panel's whole face, the host's `?related=`): first
 **动态** (Activity) — one stream of the discussion, the activity and, with
 `enable.trackHistory`, the field changes, shown as a one-line composer, the
 newest entries and 「查看全部 N 条 →」, which opens the stream in full with its
-All / Activity / Discussion / Changes chips and paging (`?related=timeline`) —
-then each related list in the reader's arrangement, then Approvals and
+All / Activity / Discussion chips, a Changes chip while the record shows its
+field history (the host's `RecordFieldHistoryContext`; it holds the audit's
+field changes with their before and after values, and every activity event,
+`created` and `updated` included, sits under Activity), and paging
+(`?related=timeline`) — then each related list in the reader's arrangement, then Approvals and
 Attachments. The reader's ⊟ (`rightColumn`) takes the right column out of the
 two-column tiers; there is no tabbed tier.
 
 
@@ -45,6 +45,7 @@ import { foldFeedItems, type ActivityTimelineEntry } from './renderers/recordAct
 import {
   TIMELINE_STREAM_FILTERS,
   filterTimelineStream,
+  isFieldHistoryEntry,
   isSystemStreamEntry,
   type TimelineStreamFilter,
 } from './recordTimelineStream';
@@ -158,6 +159,8 @@ export interface RecordActivityTimelineProps {
   variant?: 'panel' | 'stream' | 'peek';
   /** The stream's chip (controlled); `all` when absent. */
   streamFilter?: TimelineStreamFilter;
+  /** The chips the stream offers, in order; all four when absent (objectstack#30074). */
+  streamFilters?: readonly TimelineStreamFilter[];
   onStreamFilterChange?: (filter: TimelineStreamFilter) => void;
   /** How many entries the whole stream holds, for the peek's 「查看全部 N 条 →」. */
   totalCount?: number;
@@ -282,8 +285,10 @@ function filterItems(items: FeedItem[], mode: FeedFilterMode): FeedItem[] {
   switch (mode) {
     case 'comments_only':
       return items.filter((i) => i.type === 'comment');
+    // The stream's 变更 rule (objectstack#30074, ruling C): the audit's field
+    // changes only, so the panel and the stream agree on what a change is.
     case 'changes_only':
-      return items.filter((i) => i.type === 'field_change');
+      return items.filter(isFieldHistoryEntry);
     case 'tasks_only':
       return items.filter((i) => i.type === 'task');
     default:
@@ -339,6 +344,7 @@ export const RecordActivityTimeline: React.FC<RecordActivityTimelineProps> = ({
   onRetryFeed,
   variant = 'panel',
   streamFilter = 'all',
+  streamFilters = TIMELINE_STREAM_FILTERS,
   onStreamFilterChange,
   totalCount,
   onViewAll,
@@ -979,7 +985,7 @@ export const RecordActivityTimeline: React.FC<RecordActivityTimelineProps> = ({
                 className="flex flex-wrap items-center gap-1"
                 data-stream-filters=""
               >
-                {TIMELINE_STREAM_FILTERS.map((chip) => (
+                {streamFilters.map((chip) => (
                   <button
                     key={chip}
                     type="button"
 
@@ -25,6 +25,7 @@ import {
   filterTimelineStream,
   mergeTimelineStream,
   RecordFieldChangesContext,
+  RecordFieldHistoryContext,
 } from '../recordTimelineStream';
 import { RecordActivityTimeline } from '../RecordActivityTimeline';
 import { RecordActivityRenderer } from '../renderers/record-activity';
@@ -58,12 +59,17 @@ describe('the stream, pure (objectstack#27055)', () => {
     expect(mergeTimelineStream([comment, updated], null).map((i) => i.id)).toEqual(['a2', 'c1']);
   });
 
-  it('the four chips', () => {
+  it("the four chips: 变更 holds the audit's field changes, the activity's `created` row is 活动 (objectstack#30074, ruling C)", () => {
     const stream = mergeTimelineStream([comment, call, created], audit);
     expect(filterTimelineStream(stream, 'all')).toHaveLength(4);
     expect(filterTimelineStream(stream, 'discussion').map((i) => i.id)).toEqual(['c1']);
-    expect(filterTimelineStream(stream, 'changes').map((i) => i.id)).toEqual(['audit:1', 'a3']);
-    expect(filterTimelineStream(stream, 'activity').map((i) => i.id)).toEqual(['a1']);
+    // Judged by source, not by the shared `field_change` presentation: the
+    // `created` row (a3) is an event, so it is not a change.
+    expect(filterTimelineStream(stream, 'changes').map((i) => i.id)).toEqual(['audit:1']);
+    expect(filterTimelineStream(stream, 'activity').map((i) => i.id)).toEqual(['a1', 'a3']);
+    // Every entry sits under exactly one of 活动 / 讨论 / 变更.
+    const sliced = (['activity', 'discussion', 'changes'] as const).flatMap((chip) => filterTimelineStream(stream, chip));
+    expect(sliced.map((i) => i.id).sort()).toEqual(stream.map((i) => i.id).sort());
   });
 });
 
@@ -139,3 +145,104 @@ describe('record:activity on the default record page is the stream', () => {
     expect(container.querySelector('[data-stream-system-row]')).toBeNull();
   });
 });
+
+describe('the 变更 chip is offered only while the record shows its field history (objectstack#30074)', () => {
+  const chips = (container: HTMLElement) =>
+    Array.from(container.querySelectorAll('[data-stream-filter]')).map((chip) => chip.getAttribute('data-stream-filter'));
+  const page = (fieldHistory: boolean | undefined) => {
+    const block = (
+      <DiscussionContextProvider items={[call, comment, created] as any[]} loading={false}>
+        <RecordFieldChangesContext.Provider value={fieldHistory === false ? null : audit}>
+          <RecordActivityRenderer schema={{ type: 'record:activity', showCompleted: true } as any} />
+        </RecordFieldChangesContext.Provider>
+      </DiscussionContextProvider>
+    );
+    return (
+      <DefaultRecordPageContext.Provider value>
+        {fieldHistory === undefined ? block : <RecordFieldHistoryContext.Provider value={fieldHistory}>{block}</RecordFieldHistoryContext.Provider>}
+      </DefaultRecordPageContext.Provider>
+    );
+  };
+
+  it('history shown: the four chips', () => {
+    const { container } = render(page(true));
+    expect(chips(container)).toEqual(['all', 'activity', 'discussion', 'changes']);
+  });
+
+  it('history not shown: no 变更 chip, and 全部 still draws every entry', () => {
+    const { container } = render(page(false));
+    expect(chips(container)).toEqual(['all', 'activity', 'discussion']);
+    expect(container.querySelector('[data-stream-filter="all"]')?.getAttribute('aria-pressed')).toBe('true');
+    expect(screen.getByText('Logged a call')).toBeTruthy();
+    expect(screen.getByText('Budget is set')).toBeTruthy();
+  });
+
+  it('CONTROL: no host saying, every chip draws, as before', () => {
+    const { container } = render(page(undefined));
+    expect(chips(container)).toEqual(['all', 'activity', 'discussion', 'changes']);
+  });
+
+  it('a 变更 chip taken away while chosen leaves the stream on 全部', () => {
+    const { container, rerender } = render(page(true));
+    fireEvent.click(container.querySelector('[data-stream-filter="changes"]')!);
+    expect(screen.queryByText('Logged a call')).toBeNull();
+    rerender(page(false));
+    expect(container.querySelector('[data-stream-filter="all"]')?.getAttribute('aria-pressed')).toBe('true');
+    expect(screen.getByText('Logged a call')).toBeTruthy();
+  });
+});
+
+describe('an activity row sits under 活动 whatever the history flag; 变更 holds the audit only (objectstack#30074, ruling C)', () => {
+  // The five activity types that share the `field_change` presentation.
+  const events = (['created', 'updated', 'deleted', 'assigned', 'shared'] as const).map(
+    (activityType, i) =>
+      ({
+        id: `ev-${activityType}`,
+        type: 'field_change',
+        actor: 'Dev',
+        body: `Event ${activityType}`,
+        createdAt: new Date(Date.UTC(2026, 9, 10, 0, i)).toISOString(),
+        activityType,
+      }) as FeedItem,
+  );
+  const page = (fieldHistory: boolean) => (
+    <DefaultRecordPageContext.Provider value>
+      <RecordFieldHistoryContext.Provider value={fieldHistory}>
+        <DiscussionContextProvider items={[call, ...events] as any[]} loading={false}>
+          <RecordFieldChangesContext.Provider value={fieldHistory ? audit : null}>
+            <RecordActivityRenderer schema={{ type: 'record:activity', showCompleted: true } as any} />
+          </RecordFieldChangesContext.Provider>
+        </DiscussionContextProvider>
+      </RecordFieldHistoryContext.Provider>
+    </DefaultRecordPageContext.Provider>
+  );
+  const choose = (container: HTMLElement, chip: string) =>
+    fireEvent.click(container.querySelector(`[data-stream-filter="${chip}"]`)!);
+
+  for (const fieldHistory of [true, false]) {
+    it(`history ${fieldHistory ? 'on' : 'off'}: 活动 lists every activity event, and no audit change`, () => {
+      const { container } = render(page(fieldHistory));
+      choose(container, 'activity');
+      // With history on the audit says the update with its values, so the
+      // activity's own `updated` row steps aside (mergeTimelineStream).
+      const shown = events.filter((e) => !(fieldHistory && e.activityType === 'updated'));
+      for (const event of shown) expect(screen.getByText(`Event ${event.activityType}`)).toBeTruthy();
+      expect(screen.getByText('Logged a call')).toBeTruthy();
+      expect(screen.queryByText(/New → Contacted/)).toBeNull();
+    });
+  }
+
+  it('CONTROL, history on: 变更 holds the field change with its old and new values, and no activity event', () => {
+    const { container } = render(page(true));
+    choose(container, 'changes');
+    expect(screen.getByText(/Status New → Contacted/)).toBeTruthy();
+    for (const event of events) expect(screen.queryByText(`Event ${event.activityType}`)).toBeNull();
+  });
+
+  it("the panel's `changes_only` keeps the same rule as the stream", () => {
+    render(<RecordActivityTimeline items={[call, created, ...audit]} filterMode="changes_only" />);
+    expect(screen.getByText('Status')).toBeTruthy();
+    expect(screen.queryByText('Created the lead')).toBeNull();
+    expect(screen.queryByText('Logged a call')).toBeNull();
+  });
+});