@@ -0,0 +1,15 @@
+---
+'@object-ui/app-shell': patch
+'@object-ui/core': patch
+---
+
+fix(app-shell): a member takes back their own comment reaction through the unreact door, with no object delete grant
+
+A member whose grants are the every-member ones could add a reaction on the record feed and never take it back. The reaction chip removed through the generic data door's `DELETE /api/v1/data/sys_comment_reaction/:id`, which needs an object-level `delete` grant that no every-member set may carry (ADR-0090 D5), and the `feedReactionRemove` row of the affordance-to-grant map read that grant, so the chip offered no take-back at all.
+
+Clause-②: no
+Metadata-protocol: none
+
+- The record page now removes the caller's own reaction row through the unreact door, `DELETE /api/v1/comments/reactions/:id`, which `@objectstack/plugin-audit` mounts. The door removes only the caller's own row; a refused take-back puts the reaction back on screen and says it was not saved, as before.
+- `feedReactionRemove` in `@object-ui/core`'s `AFFORDANCE_GRANTS` now reads `{ crud: null, grant: 'create' }`: its write no longer goes through the data door, so no CRUD bit is read, and it asks the grant the reaction was added under. Whose reaction a chip shows still decides which chips offer the take-back: a click on another member's reaction adds the caller's own.
+- A member who holds the `delete` grant sees the same behaviour: the take-back goes through the same door.
@@ -222,7 +222,10 @@ Three sources, in precedence order:
    hands each handler over only where the caller may make that write
    (objectui#12082): the composer and the reply input need the **create** grant
    on `sys_comment`; the reaction control needs the **create** grant on
-   `sys_comment_reaction`, and taking a reaction back its **delete** grant; on a
+   `sys_comment_reaction`, and taking the caller's own reaction back needs the
+   same grant: it goes through the unreact door
+   (`DELETE /api/v1/comments/reactions/:id`), which removes only the caller's
+   own row and asks no **delete** grant. On a
    deployment with no `sys_comment_reaction` the control needs the **update**
    grant on `sys_comment`. These are the `feedComment`, `feedReactionAdd`,
    `feedReactionRemove` and `feedReactionColumn` rows of the affordance-to-grant
 
@@ -16,8 +16,10 @@
  *
  *  - the composer: `feedComment`, the create grant on `sys_comment`;
  *  - the reaction control: `feedReactionAdd`, the create grant on
- *    `sys_comment_reaction`, with a take-back asking `feedReactionRemove`, its
- *    delete grant, per click;
+ *    `sys_comment_reaction`, with a take-back asking `feedReactionRemove` per
+ *    click: the same create grant, since the take-back goes through the
+ *    unreact door (`DELETE /api/v1/comments/reactions/:id`), which removes the
+ *    caller's own row with no `delete` grant;
  *  - on a deployment with no `sys_comment_reaction` (the column store), the
  *    reaction control: `feedReactionColumn`, the update grant on `sys_comment`.
  *
@@ -36,10 +38,13 @@ import { MePermissionsProvider, type MePermissionsResponse } from '@object-ui/pe
 import { DETAIL_DEFAULT_TRANSLATIONS } from '@object-ui/plugin-detail';
 import { effectiveOperationsArray, resolveEffectiveApiMethods } from '@objectstack/spec/data';
 
+/** The page's authenticated fetch: the unreact door is called through it. */
+const authFetch = vi.hoisted(() => vi.fn());
+
 vi.mock('@object-ui/auth', async (importOriginal) => ({
   ...(await importOriginal<Record<string, unknown>>()),
   useAuth: () => ({ user: { id: 'u1', name: 'u1', image: null }, activeOrganization: null }),
-  createAuthenticatedFetch: () => vi.fn(),
+  createAuthenticatedFetch: () => authFetch,
 }));
 
 vi.mock('@object-ui/collaboration', async (importOriginal) => ({
@@ -69,6 +74,7 @@ vi.mock('./MetadataInspector', () => ({
 }));
 
 import { RecordDetailView } from './RecordDetailView';
+import { toast } from 'sonner';
 
 const COMMENT = 'sys_comment';
 const REACTION = 'sys_comment_reaction';
@@ -127,18 +133,21 @@ function answer(feed: { [COMMENT]?: Bits; [REACTION]?: Bits }): MePermissionsRes
   } as MePermissionsResponse;
 }
 
-/** One comment by another member; the caller (`u1`) has already reacted 👍 on it. */
-function makeDataSource() {
+/**
+ * One comment by another member; `reactor` (the caller `u1` unless named) has
+ * already reacted 👍 on it.
+ */
+function makeDataSource(reactor = 'u1') {
   const comment = {
     id: COMMENT_ID,
     thread_id: THREAD,
     author_id: 'u3',
     author_name: 'u3',
     body: COMMENT_BODY,
     created_at: '2026-10-10T08:00:00.000Z',
-    reactions: JSON.stringify({ '👍': ['u1'] }),
+    reactions: JSON.stringify({ '👍': [reactor] }),
   };
-  const ownReaction = { id: 'r1', comment_id: COMMENT_ID, emoji: '👍', user_id: 'u1', created_at: '2026-10-10T09:00:00.000Z' };
+  const ownReaction = { id: 'r1', comment_id: COMMENT_ID, emoji: '👍', user_id: reactor, created_at: '2026-10-10T09:00:00.000Z' };
   return {
     find: vi.fn(async (objectName: string) => {
       if (objectName === COMMENT) return { data: [{ ...comment }] };
@@ -210,7 +219,23 @@ const thumbsChip = (view: View) =>
     (b) => !!b.getAttribute('aria-label') && b.children.length === 2 && b.children[0].textContent === '👍',
   );
 
+/** The unreact door's answer to a removal of the caller's own row. */
+const unreacted = (id: string) =>
+  new Response(JSON.stringify({ success: true, data: { id, deleted: true } }), {
+    status: 200,
+    headers: { 'content-type': 'application/json' },
+  });
+
+/** The calls that reached the unreact door: `[url, init]`. */
+const unreactCalls = () =>
+  authFetch.mock.calls.filter(([url]) => String(url).includes('/api/v1/comments/reactions/'));
+
 beforeEach(() => {
+  authFetch.mockImplementation(async (url: string) =>
+    String(url).includes('/api/v1/comments/reactions/')
+      ? unreacted(String(url).split('/').pop() as string)
+      : new Response(JSON.stringify({ data: [] }), { status: 200, headers: { 'content-type': 'application/json' } }),
+  );
   vi.stubGlobal(
     'fetch',
     vi.fn(async () =>
@@ -267,19 +292,22 @@ describe("the record feed's reaction control reads feedReactionAdd / feedReactio
     expect((thumbsChip(view) as HTMLButtonElement).disabled).toBe(!offered);
   });
 
-  it('a take-back asks the delete grant: with create but not delete, clicking the own reaction writes nothing and keeps it shown', async () => {
+  it('a take-back reads no delete grant: with create but not delete, clicking the own reaction removes it through the unreact door', async () => {
     const { view, dataSource } = await mount(answer({ [COMMENT]: SHAPE.full, [REACTION]: SHAPE.createOnly }));
     fireEvent.click(thumbsChip(view)!);
     await act(async () => {});
+    expect(unreactCalls()).toEqual([['/api/v1/comments/reactions/r1', { method: 'DELETE', credentials: 'include' }]]);
     expect(dataSource.delete).not.toHaveBeenCalled();
-    expect(thumbsChip(view)!.children[1].textContent).toBe('1');
+    expect(thumbsChip(view)).toBeUndefined();
   });
 
-  it('CONTROL — with the delete grant the same click takes the reaction back by deleting the own row', async () => {
+  it('CONTROL — with the delete grant the same click takes the reaction back through the same door, never the data door', async () => {
     const { view, dataSource } = await mount(answer({ [COMMENT]: SHAPE.full, [REACTION]: SHAPE.full }));
     fireEvent.click(thumbsChip(view)!);
     await act(async () => {});
-    expect(dataSource.delete.mock.calls).toEqual([[REACTION, 'r1']]);
+    expect(unreactCalls()).toEqual([['/api/v1/comments/reactions/r1', { method: 'DELETE', credentials: 'include' }]]);
+    expect(dataSource.delete).not.toHaveBeenCalled();
+    expect(thumbsChip(view)).toBeUndefined();
   });
 
   it('adding through the picker creates the own row where create is held', async () => {
@@ -291,6 +319,51 @@ describe("the record feed's reaction control reads feedReactionAdd / feedReactio
   });
 });
 
+describe("a take-back goes through the unreact door, and only on the caller's own reaction (objectstack#26346)", () => {
+  it('a member with no grant beyond create on sys_comment_reaction adds a reaction and takes it back', async () => {
+    const { view, dataSource } = await mount(answer({ [COMMENT]: SHAPE.readOnly, [REACTION]: SHAPE.createOnly }));
+    fireEvent.click(addReaction(view)!);
+    fireEvent.click(within(screen.getByRole('listbox')).getByRole('option', { name: '🎉' }));
+    await act(async () => {});
+    const party = () =>
+      (view.queryAllByRole('button') as HTMLElement[]).find(
+        (b) => !!b.getAttribute('aria-label') && b.children.length === 2 && b.children[0].textContent === '🎉',
+      );
+    expect(party()).toBeDefined();
+    fireEvent.click(party()!);
+    await act(async () => {});
+    expect(dataSource.create.mock.calls).toEqual([[REACTION, { comment_id: COMMENT_ID, emoji: '🎉' }]]);
+    expect(unreactCalls()).toEqual([['/api/v1/comments/reactions/new-row', { method: 'DELETE', credentials: 'include' }]]);
+    expect(dataSource.delete).not.toHaveBeenCalled();
+    expect(party()).toBeUndefined();
+  });
+
+  it("another member's reaction offers no take-back: a click on their chip adds the caller's own row and reaches no door that removes", async () => {
+    const { view, dataSource } = await mount(answer({ [COMMENT]: SHAPE.full, [REACTION]: SHAPE.full }), makeDataSource('u2'));
+    fireEvent.click(thumbsChip(view)!);
+    await act(async () => {});
+    expect(dataSource.create.mock.calls).toEqual([[REACTION, { comment_id: COMMENT_ID, emoji: '👍' }]]);
+    expect(unreactCalls()).toEqual([]);
+    expect(dataSource.delete).not.toHaveBeenCalled();
+    expect(thumbsChip(view)!.children[1].textContent).toBe('2');
+  });
+
+  it('a take-back the door refuses puts the reaction back and says it was not saved', async () => {
+    authFetch.mockImplementation(async () =>
+      new Response(JSON.stringify({ success: false, error: { code: 'PERMISSION_DENIED' } }), {
+        status: 403,
+        headers: { 'content-type': 'application/json' },
+      }),
+    );
+    const { view } = await mount(answer({ [COMMENT]: SHAPE.full, [REACTION]: SHAPE.createOnly }));
+    fireEvent.click(thumbsChip(view)!);
+    await act(async () => {});
+    expect(unreactCalls().map(([url]) => url)).toEqual(['/api/v1/comments/reactions/r1']);
+    expect(thumbsChip(view)!.children[1].textContent).toBe('1');
+    expect(toast.error).toHaveBeenCalledTimes(1);
+  });
+});
+
 /**
  * The two feed objects as objectstack registers them (`plugin-audit`): their
  * policy keys (`managedBy`, `userActions`) and the `enable` block the server
@@ -336,7 +409,8 @@ describe('against the registered feed schemas in the page objects (objectui#1208
     expect(addReaction(view)).not.toBeNull();
     fireEvent.click(thumbsChip(view)!);
     await act(async () => {});
-    expect(dataSource.delete.mock.calls).toEqual([[REACTION, 'r1']]);
+    expect(unreactCalls().map(([url]) => url)).toEqual(['/api/v1/comments/reactions/r1']);
+    expect(dataSource.delete).not.toHaveBeenCalled();
   });
 });
 
 
@@ -10,7 +10,8 @@
  * left only the later write stored. Now, where the deployment has the object,
  * the chatter reads every comment's reaction rows in one batched `comment_id`
  * `$in` read, groups them into the shape the panel already renders, and a click
- * creates or deletes the clicker's own row. Where the deployment has no such
+ * creates the clicker's own row, or removes it through the unreact door
+ * (`DELETE /api/v1/comments/reactions/:id`, objectstack#26346). Where the deployment has no such
  * object (a framework that predates it), the column path stays, unchanged: the
  * `objectui#11019` / `objectui#10899` / `objectui#11035` pins beside this file
  * run on that path.
@@ -20,7 +21,8 @@
  * source is a fake SERVER shared by every mounted view: each view's adapter is
  * bound to its signed-in member, and the server keeps the object's declared
  * rules: `user_id` stamped from that member, one row per (comment, emoji,
- * user), and a member deletes only their own row. Which store the page uses is
+ * user), and a member removes only their own row, through the unreact door
+ * the page's authenticated fetch reaches. Which store the page uses is
  * read from the object registry the page's metadata context serves.
  */
 
@@ -36,6 +38,9 @@ import { toast } from 'sonner';
 /** The signed-in member is read from a context, so two views can be two members at once. */
 const signedIn = vi.hoisted(() => ({ ctx: null as unknown as React.Context<string> }));
 
+/** The unreact door of the member a view is being mounted as: the page's authenticated fetch reaches it. */
+const mounting = vi.hoisted(() => ({ door: null as unknown as (url: string, init?: RequestInit) => Promise<Response> }));
+
 vi.mock('@object-ui/auth', async (importOriginal) => {
   const ReactModule = await import('react');
   signedIn.ctx = ReactModule.createContext('u1');
@@ -45,7 +50,12 @@ vi.mock('@object-ui/auth', async (importOriginal) => {
       const id = ReactModule.useContext(signedIn.ctx);
       return { user: { id, name: id, image: null }, activeOrganization: null };
     },
-    createAuthenticatedFetch: () => vi.fn(),
+    // Only the unreact door is answered; every other call answers nothing, as before.
+    createAuthenticatedFetch: () => {
+      const door = mounting.door;
+      return (url: string, init?: RequestInit) =>
+        String(url).includes('/api/v1/comments/reactions/') ? door(url, init) : undefined;
+    },
   };
 });
 
@@ -136,7 +146,8 @@ const refusal = (status: number, code: string) =>
 /**
  * One server shared by every view a case mounts. `as(member)` is that member's
  * adapter: what they create is stamped as theirs, and they delete only rows
- * that are theirs.
+ * that are theirs. Its `unreact` is that member's unreact door: it removes the
+ * member's own row and refuses anyone else's, as the server's door does.
  */
 function makeServer(init: { comments?: CommentRow[]; reactions?: Omit<ReactionRow, 'id' | 'created_at'>[] } = {}) {
   const comments: CommentRow[] = init.comments ?? [
@@ -192,6 +203,18 @@ function makeServer(init: { comments?: CommentRow[]; reactions?: Omit<ReactionRo
       reactions.splice(at, 1);
       return true;
     }),
+    unreact: vi.fn(async (url: string, init?: RequestInit) => {
+      const answer = (status: number, body: unknown) =>
+        new Response(JSON.stringify(body), { status, headers: { 'content-type': 'application/json' } });
+      const id = decodeURIComponent(String(url).split('/api/v1/comments/reactions/')[1]);
+      if (init?.method !== 'DELETE') return answer(404, { success: false });
+      const at = reactions.findIndex((r) => r.id === id);
+      if (at < 0) return answer(404, { success: false, error: { code: 'RECORD_NOT_FOUND' } });
+      // The door's own rule: the row's reactor is the caller.
+      if (reactions[at].user_id !== member) return answer(403, { success: false, error: { code: 'PERMISSION_DENIED' } });
+      reactions.splice(at, 1);
+      return answer(200, { success: true, data: { id, deleted: true } });
+    }),
   });
 
   return { comments, reactions, as };
@@ -234,6 +257,7 @@ function tree(member: string, dataSource: any, metadata: any) {
 
 /** Mounts the record page as `member` and waits for the comment to show. */
 async function mountAs(member: string, dataSource: any, objects: unknown[] = REGISTRY.present) {
+  mounting.door = dataSource.unreact;
   const view = render(tree(member, dataSource, metadataFor(objects)));
   await within(view.container).findByText(COMMENT_BODY);
   // Let the reaction read that follows the comment read land.
@@ -283,6 +307,11 @@ async function click(run: () => void) {
   await act(async () => {});
 }
 
+/** The row ids a member's take-backs removed through the unreact door, in order. */
+function unreacted(dataSource: any): string[] {
+  return dataSource.unreact.mock.calls.map(([url]: [string]) => decodeURIComponent(url.split('/').pop() as string));
+}
+
 /** Every `sys_comment_reaction` read a data source was asked, as its `$in` id lists. */
 function reactionReads(dataSource: any): string[][] {
   return dataSource.find.mock.calls
@@ -332,7 +361,7 @@ describe("a comment's reactions are each member's own sys_comment_reaction recor
     expect(isOwn(again, '👍')).toBe(true);
   });
 
-  it('a second click removes it: the clicker deletes their own row, by the id the create returned and by the id the read returned', async () => {
+  it('a second click removes it: the clicker removes their own row through the unreact door, by the id the create returned and by the id the read returned', async () => {
     const server = makeServer({ reactions: [{ comment_id: COMMENT_ID, emoji: '👍', user_id: 'u2' }] });
     const u1 = server.as('u1');
     const view = await mountAs('u1', u1);
@@ -342,11 +371,12 @@ describe("a comment's reactions are each member's own sys_comment_reaction recor
     expect(chips(view)).toEqual(['👍 1', '🎉 1']);
 
     await click(() => fireEvent.click(chip(view, '🎉')));
-    expect(u1.delete.mock.calls).toEqual([[REACTION, created.id]]);
+    expect(unreacted(u1)).toEqual([created.id]);
+    expect(u1.delete).not.toHaveBeenCalled();
     expect(server.reactions.map((r) => [r.emoji, r.user_id])).toEqual([['👍', 'u2']]);
     expect(chips(view)).toEqual(['👍 1']);
 
-    // A row the read found: its id is the one the take-back deletes.
+    // A row the read found: its id is the one the take-back removes.
     cleanup();
     const before = makeServer({
       reactions: [
@@ -359,7 +389,8 @@ describe("a comment's reactions are each member's own sys_comment_reaction recor
     const read = await mountAs('u1', reader);
     expect(chips(read)).toEqual(['👍 2']);
     await click(() => fireEvent.click(chip(read, '👍')));
-    expect(reader.delete.mock.calls).toEqual([[REACTION, mine.id]]);
+    expect(unreacted(reader)).toEqual([mine.id]);
+    expect(reader.delete).not.toHaveBeenCalled();
     expect(before.reactions.map((r) => r.user_id)).toEqual(['u2']);
     expect(chips(read)).toEqual(['👍 1']);
     expect(toast.error).not.toHaveBeenCalled();
@@ -452,7 +483,7 @@ describe("a comment's reactions are each member's own sys_comment_reaction recor
     expect(server.reactions.map((r) => r.user_id)).toEqual(['u2']);
   });
 
-  it('a take-back clicked before the create answers deletes the row that create made', async () => {
+  it('a take-back clicked before the create answers removes the row that create made', async () => {
     const server = makeServer();
     const u1 = server.as('u1');
     let answer!: () => void;
@@ -471,11 +502,12 @@ describe("a comment's reactions are each member's own sys_comment_reaction recor
     expect(chips(view)).toEqual([]);
     await act(async () => {});
     // The take-back waits for the row it takes back.
-    expect(u1.delete).not.toHaveBeenCalled();
+    expect(u1.unreact).not.toHaveBeenCalled();
 
     await act(async () => answer());
-    await waitFor(() => expect(u1.delete).toHaveBeenCalledTimes(1));
-    expect(u1.delete.mock.calls[0]).toEqual([REACTION, 'r1']);
+    await waitFor(() => expect(u1.unreact).toHaveBeenCalledTimes(1));
+    expect(unreacted(u1)).toEqual(['r1']);
+    expect(u1.delete).not.toHaveBeenCalled();
     expect(server.reactions).toEqual([]);
     expect(chips(view)).toEqual([]);
     expect(toast.error).not.toHaveBeenCalled();