diff --git a/.changeset/adapt-atomic-publish-and-honest-discovery.md b/.changeset/adapt-atomic-publish-and-honest-discovery.md
new file mode 100644
index 000000000..789343681
--- /dev/null
+++ b/.changeset/adapt-atomic-publish-and-honest-discovery.md
@@ -0,0 +1,6 @@
+---
+"@object-ui/react": minor
+"@object-ui/app-shell": minor
+---
+
+Adapt to framework 15.1: (1) ADR-0067 D2 all-or-nothing publishes — `formatPublishFailures` renders a rolled-back batch as ONE banner anchored on the causal item (`batch_aborted` entries are summarized, not listed as parallel errors); PackagesPage says "rolled back because X" instead of "{n} failed"; the AI chat publish toast surfaces the real reason instead of a bare count. Pre-15.1 partial-publish responses keep their per-item rendering. (2) ADR-0076 D12 honest discovery — `DiscoveryServiceStatus` gains `handlerReady` + `degraded`/`stub` statuses, new backward-tolerant `isServiceUsable()` helper (absent fields keep the pre-15.1 default; `stub`/`handlerReady:false` gate off; `degraded` stays usable), consumed by `isAuthEnabled`/`isAiEnabled` and `ConditionalAuthWrapper`.
diff --git a/packages/app-shell/src/chrome/ConditionalAuthWrapper.tsx b/packages/app-shell/src/chrome/ConditionalAuthWrapper.tsx
index 5e18a3de3..08f47e9a0 100644
--- a/packages/app-shell/src/chrome/ConditionalAuthWrapper.tsx
+++ b/packages/app-shell/src/chrome/ConditionalAuthWrapper.tsx
@@ -11,7 +11,7 @@ import { getSharedDiscovery } from '@object-ui/data-objectstack';
 import { AuthProvider } from '@object-ui/auth';
 import type { PreviewModeOptions } from '@object-ui/auth';
 import { LoadingScreen } from './LoadingScreen';
-import type { DiscoveryInfo } from '@object-ui/react';
+import { isServiceUsable, type DiscoveryInfo } from '@object-ui/react';
 
 interface ConditionalAuthWrapperProps {
   children: ReactNode;
@@ -73,7 +73,11 @@ export function ConditionalAuthWrapper({ children, authUrl }: ConditionalAuthWra
           return body;
         } catch (e) {
           if ((e as Error).name === 'AbortError') {
-            throw new Error('timeout');
+            // Manual `cause` assignment — the two-arg Error constructor needs
+            // an ES2022 lib this package's tsconfig doesn't target.
+            const timeoutErr = new Error('timeout');
+            (timeoutErr as Error & { cause?: unknown }).cause = e;
+            throw timeoutErr;
           }
           throw e;
         } finally {
@@ -101,7 +105,15 @@ export function ConditionalAuthWrapper({ children, authUrl }: ConditionalAuthWra
         });
         setAuthEnabled(false);
       } else {
-        const isAuthEnabled = discovery?.services?.auth?.enabled ?? true;
+        // ADR-0076 D12 (honest capabilities): trust the 15.1+ signals when
+        // present — a `stub` or `handlerReady:false` auth service must NOT
+        // wrap the app in a real AuthProvider (login against a dev fake).
+        // Pre-15.1 servers carry none of these fields → historical default
+        // (enabled) is preserved by isServiceUsable.
+        const isAuthEnabled = isServiceUsable(discovery?.services?.auth);
+        if (discovery?.services?.auth?.status === 'degraded') {
+          console.warn('[ConditionalAuthWrapper] auth service reports degraded — keeping auth enabled (it still serves).');
+        }
         setAuthEnabled(isAuthEnabled);
       }
       setIsLoading(false);
diff --git a/packages/app-shell/src/console/ai/AiChatPage.tsx b/packages/app-shell/src/console/ai/AiChatPage.tsx
index e18d0f97f..cda7c20c2 100644
--- a/packages/app-shell/src/console/ai/AiChatPage.tsx
+++ b/packages/app-shell/src/console/ai/AiChatPage.tsx
@@ -21,6 +21,7 @@ import { toast } from 'sonner';
 import { Package as PackageIcon, Sparkles as SparklesIcon } from 'lucide-react';
 import { useAdapter } from '../../providers/AdapterProvider';
 import { useMetadata } from '../../providers/MetadataProvider';
+import { formatPublishFailures, type PublishFailure } from '../../views/studio-design/metadataError';
 import { resolveI18nLabel } from '../../utils';
 import { ExcelImportBar } from './ExcelImportBar';
 import {
@@ -2109,8 +2110,17 @@ export function ChatPane({
             if (!res.ok || payload?.success === false) {
               throw new Error(payload?.error?.message || `HTTP ${res.status}`);
             }
-            const failed = payload?.data?.failedCount ?? payload?.failedCount ?? 0;
-            if (failed) throw new Error(String(failed));
+            const failedCount = payload?.data?.failedCount ?? payload?.failedCount ?? 0;
+            if (failedCount) {
+              // framework 15.1+ (ADR-0067 D2): a failed batch is ALL-OR-NOTHING
+              // (rolled back, nothing landed); `failed[]` carries the causal
+              // item plus batch_aborted markers. Surface the reason — the old
+              // `String(failedCount)` produced a toast that read just "3".
+              const failedList = (payload?.data?.failed ?? payload?.failed ?? []) as PublishFailure[];
+              throw new Error(
+                failedList.length > 0 ? formatPublishFailures(failedList) : String(failedCount),
+              );
+            }
             // Surface a seed-load problem (reported under `seedApplied`, never
             // thrown) so "Published!" can't hide silently empty tables.
             const seedApplied = payload?.data?.seedApplied ?? payload?.seedApplied;
diff --git a/packages/app-shell/src/views/metadata-admin/PackagesPage.tsx b/packages/app-shell/src/views/metadata-admin/PackagesPage.tsx
index b3092a6ce..5f86cd448 100644
--- a/packages/app-shell/src/views/metadata-admin/PackagesPage.tsx
+++ b/packages/app-shell/src/views/metadata-admin/PackagesPage.tsx
@@ -323,7 +323,11 @@ export function PackageDetailSheet({
     run(
       'publish-drafts',
       () =>
-        apiJson<{ publishedCount?: number; failedCount?: number; failed?: Array<{ name?: string }> }>(
+        apiJson<{
+          publishedCount?: number;
+          failedCount?: number;
+          failed?: Array<{ type?: string; name?: string; error?: string; code?: string }>;
+        }>(
           `${API}/${encodeURIComponent(id)}/publish-drafts`,
           { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({}) },
         ).then(async (r) => {
@@ -336,6 +340,19 @@ export function PackageDetailSheet({
             setDrafts([]);
           }
           if (r?.failedCount) {
+            // framework 15.1+ (ADR-0067 D2): the batch is all-or-nothing — a
+            // failure means NOTHING landed and `failed[]` marks the rolled-back
+            // drafts `batch_aborted`, with the causal item carrying the real
+            // error. Say "rolled back because X", not "{n} failed" (which reads
+            // as a partial publish that no longer exists).
+            const failedList = Array.isArray(r.failed) ? r.failed : [];
+            const causal = failedList.find((f) => f?.code !== 'batch_aborted' && f?.error);
+            if (failedList.some((f) => f?.code === 'batch_aborted')) {
+              throw new Error(tFormat('engine.packages.detail.publishDraftsRolledBack', locale, {
+                cause: causal ? `${causal.type ?? '?'}/${causal.name ?? '?'}: ${causal.error}` : String(r.failedCount),
+              }));
+            }
+            // pre-15.1 server — genuine partial publish.
             throw new Error(tFormat('engine.packages.detail.publishDraftsPartial', locale, {
               published: r.publishedCount ?? 0,
               failed: r.failedCount,
diff --git a/packages/app-shell/src/views/metadata-admin/i18n.ts b/packages/app-shell/src/views/metadata-admin/i18n.ts
index 0ee8f38ac..e8bc77043 100644
--- a/packages/app-shell/src/views/metadata-admin/i18n.ts
+++ b/packages/app-shell/src/views/metadata-admin/i18n.ts
@@ -712,6 +712,7 @@ const ENGINE_STRINGS_EN: Record<string, string> = {
   'engine.packages.detail.nothingToPublish': 'Nothing to publish.',
   'engine.packages.detail.published': 'Package published.',
   'engine.packages.detail.publishDraftsPartial': 'Published {published}; {failed} failed.',
+  'engine.packages.detail.publishDraftsRolledBack': 'Nothing was published — the batch rolled back (all-or-nothing): {cause}',
   'engine.packages.detail.publishDraftsOk': 'App published — all drafts are now live.',
   'engine.packages.detail.reverted': 'Reverted to last published state.',
   'engine.packages.detail.discardDraftsPartial': 'Discarded {discarded}; {failed} failed.',
@@ -2067,6 +2068,7 @@ const ENGINE_STRINGS_ZH: Record<string, string> = {
   'engine.packages.detail.nothingToPublish': '没有可发布的内容。',
   'engine.packages.detail.published': '软件包已发布。',
   'engine.packages.detail.publishDraftsPartial': '已发布 {published} 项；{failed} 项失败。',
+  'engine.packages.detail.publishDraftsRolledBack': '发布未生效 — 批次已整体回滚（全有或全无）：{cause}',
   'engine.packages.detail.publishDraftsOk': '应用已发布，所有草稿均已生效。',
   'engine.packages.detail.reverted': '已还原到上次发布状态。',
   'engine.packages.detail.discardDraftsPartial': '已丢弃 {discarded} 项；{failed} 项失败。',
diff --git a/packages/app-shell/src/views/studio-design/metadataError.test.ts b/packages/app-shell/src/views/studio-design/metadataError.test.ts
index e807e63c1..dc4d94cea 100644
--- a/packages/app-shell/src/views/studio-design/metadataError.test.ts
+++ b/packages/app-shell/src/views/studio-design/metadataError.test.ts
@@ -55,4 +55,33 @@ describe('formatPublishFailures', () => {
         'flow/notify: start node missing',
     );
   });
+
+  // framework 15.1+ (ADR-0067 D2) — the batch is all-or-nothing; `failed[]`
+  // carries the causal item + batch_aborted markers for the rolled-back rest.
+  it('15.1+ all-or-nothing: one rolled-back banner anchored on the causal item', () => {
+    const out = formatPublishFailures([
+      { type: 'object', name: 'crm_lead', error: 'not published — the batch is all-or-nothing…', code: 'batch_aborted' },
+      {
+        type: 'object', name: 'crm_deal', error: 'failed spec validation', code: 'invalid_metadata',
+        issues: [{ path: 'fields.amount.type', message: 'Required' }],
+      },
+      { type: 'view', name: 'lead_list', error: 'not published — …', code: 'batch_aborted' },
+    ]);
+    expect(out).toContain('Nothing was published — the batch rolled back');
+    // causal item with its real error and field-anchored issues…
+    expect(out).toContain('object/crm_deal: failed spec validation');
+    expect(out).toContain('fields.amount.type — Required');
+    // …aborted entries summarized, not listed as parallel errors
+    expect(out).not.toContain('crm_lead: not published');
+    expect(out).toContain('2 other drafts aborted with it');
+  });
+
+  it('all entries aborted (defensive): banner still renders with one sample', () => {
+    const out = formatPublishFailures([
+      { type: 'object', name: 'a', error: 'not published — …', code: 'batch_aborted' },
+      { type: 'object', name: 'b', error: 'not published — …', code: 'batch_aborted' },
+    ]);
+    expect(out).toContain('Nothing was published');
+    expect(out).toContain('object/a');
+  });
 });
diff --git a/packages/app-shell/src/views/studio-design/metadataError.ts b/packages/app-shell/src/views/studio-design/metadataError.ts
index 01e01c02c..623b867e5 100644
--- a/packages/app-shell/src/views/studio-design/metadataError.ts
+++ b/packages/app-shell/src/views/studio-design/metadataError.ts
@@ -38,20 +38,44 @@ export interface PublishFailure {
   type: string;
   name: string;
   error: string;
+  /** Machine code — `batch_aborted` marks a draft rolled back with the batch (ADR-0067 D2). */
+  code?: string;
   issues?: MetadataValidationIssue[];
 }
 
 /**
- * Format the `failed[]` from a partial publish (the server returns 200 with the
- * drafts that DIDN'T go live). Each failed draft gets a heading and, when the
- * failure was a validation error, its field-anchored issues indented below.
+ * framework 15.1+ (ADR-0067 D2): package publishes are ALL-OR-NOTHING. A
+ * failed batch reports every draft in `failed[]` — the causal item with its
+ * real error, the rest with this code — and `publishedCount: 0`.
+ */
+export const BATCH_ABORTED_CODE = 'batch_aborted';
+
+/**
+ * Format the `failed[]` from a publish response (the server returns 200 with
+ * the drafts that didn't go live).
+ *
+ * Two server generations produce two shapes (both handled):
+ * - **15.1+ all-or-nothing** (ADR-0067 D2): the batch rolled back atomically —
+ *   render ONE rolled-back banner anchored on the causal item(s), not N
+ *   parallel errors (`batch_aborted` entries are consequences, not causes).
+ * - **pre-15.1 partial publish**: each failed draft gets a heading and, when
+ *   the failure was a validation error, its field-anchored issues indented
+ *   below.
  */
 export function formatPublishFailures(failed: PublishFailure[]): string {
-  return failed
-    .map((f) => {
-      const head = `${f.type}/${f.name}: ${f.error}`;
-      const issues = Array.isArray(f.issues) ? f.issues : [];
-      return [head, ...issues.map((i) => `  ${issueLine(i)}`)].join('\n');
-    })
-    .join('\n');
+  const line = (f: PublishFailure): string => {
+    const head = `${f.type}/${f.name}: ${f.error}`;
+    const issues = Array.isArray(f.issues) ? f.issues : [];
+    return [head, ...issues.map((i) => `  ${issueLine(i)}`)].join('\n');
+  };
+  const aborted = failed.filter((f) => f.code === BATCH_ABORTED_CODE);
+  if (aborted.length > 0) {
+    const causal = failed.filter((f) => f.code !== BATCH_ABORTED_CODE);
+    return [
+      'Nothing was published — the batch rolled back (all-or-nothing).',
+      ...(causal.length > 0 ? causal.map(line) : aborted.slice(0, 1).map(line)),
+      `(${aborted.length} other draft${aborted.length === 1 ? '' : 's'} aborted with it — fix the cause and publish again.)`,
+    ].join('\n');
+  }
+  return failed.map(line).join('\n');
 }
diff --git a/packages/react/src/hooks/useDiscovery.ts b/packages/react/src/hooks/useDiscovery.ts
index 3468e6226..4f593af16 100644
--- a/packages/react/src/hooks/useDiscovery.ts
+++ b/packages/react/src/hooks/useDiscovery.ts
@@ -13,6 +13,41 @@ import { SchemaRendererContext } from '../context/SchemaRendererContext';
  * Discovery service information structure.
  * Represents server capabilities and service status.
  */
+/**
+ * Per-service availability entry (framework 15.1+, ADR-0076 D12 "honest
+ * capabilities"): discovery no longer hardcodes every registered service as
+ * `available` — a dev fake reports `stub`, a serving fallback reports
+ * `degraded`, and `handlerReady` says whether a real handler backs the route.
+ * Older servers omit `handlerReady` and only ever report
+ * `available`/`unavailable`, so consumers must treat the new fields as
+ * OPT-IN signals (see {@link isServiceUsable}), never require them.
+ */
+export interface DiscoveryServiceStatus {
+  enabled: boolean;
+  status?: 'available' | 'degraded' | 'stub' | 'unavailable';
+  handlerReady?: boolean;
+}
+
+/**
+ * The backward-compatible "can I actually use this service?" check
+ * (ADR-0076 D12 console slice):
+ *
+ * - absent entry / absent fields → usable (pre-15.1 servers say nothing —
+ *   keep their historical default);
+ * - `enabled: false` or `handlerReady: false` → not usable;
+ * - `status: 'stub'` → not usable (a dev fake must not be treated as the
+ *   real service — the exact dishonesty D12 removed);
+ * - `status: 'degraded'` → USABLE (a fallback that keeps serving; callers
+ *   may surface a warning but must not turn the feature off).
+ */
+export function isServiceUsable(svc: DiscoveryServiceStatus | undefined | null): boolean {
+  if (!svc) return true;
+  if (svc.enabled === false) return false;
+  if (svc.handlerReady === false) return false;
+  if (svc.status === 'stub' || svc.status === 'unavailable') return false;
+  return true;
+}
+
 export interface DiscoveryInfo {
   /** Server name and version */
   name?: string;
@@ -34,25 +69,13 @@ export interface DiscoveryInfo {
   /** Service availability status */
   services?: {
     /** Authentication service status */
-    auth?: {
-      enabled: boolean;
-      status?: 'available' | 'unavailable';
-      message?: string;
-    };
+    auth?: DiscoveryServiceStatus & { message?: string };
     /** Data access service status */
-    data?: {
-      enabled: boolean;
-      status?: 'available' | 'unavailable';
-    };
+    data?: DiscoveryServiceStatus;
     /** Metadata service status */
-    metadata?: {
-      enabled: boolean;
-      status?: 'available' | 'unavailable';
-    };
+    metadata?: DiscoveryServiceStatus;
     /** AI service configuration */
-    ai?: {
-      enabled: boolean;
-      status?: 'available' | 'unavailable';
+    ai?: DiscoveryServiceStatus & {
       /** AI service endpoint route (e.g. '/api/v1/ai') */
       route?: string;
     };
@@ -152,17 +175,21 @@ export function useDiscovery() {
     isLoading,
     error,
     /**
-     * Check if authentication is enabled on the server.
-     * Defaults to true if discovery data is not available.
+     * Check if authentication is enabled AND actually backed by a real
+     * handler (ADR-0076 D12 — a `stub`/`handlerReady:false` auth service is
+     * not treated as real auth). Defaults to true when discovery data is not
+     * available (pre-15.1 servers report nothing).
      */
-    isAuthEnabled: discovery?.services?.auth?.enabled ?? true,
+    isAuthEnabled: isServiceUsable(discovery?.services?.auth),
     /**
      * Check if AI service is enabled and available on the server.
-     * Defaults to false if discovery data is not available.
+     * Defaults to false if discovery data is not available; `degraded`
+     * still counts as available (it serves), `stub` never does.
      */
     isAiEnabled:
       discovery?.services?.ai?.enabled === true &&
-      discovery?.services?.ai?.status === 'available',
+      (discovery?.services?.ai?.status === 'available' || discovery?.services?.ai?.status === 'degraded') &&
+      discovery?.services?.ai?.handlerReady !== false,
   };
 }
 
diff --git a/packages/react/src/hooks/useDiscovery.usable.test.ts b/packages/react/src/hooks/useDiscovery.usable.test.ts
new file mode 100644
index 000000000..9af489c4e
--- /dev/null
+++ b/packages/react/src/hooks/useDiscovery.usable.test.ts
@@ -0,0 +1,44 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+//
+// isServiceUsable — the ADR-0076 D12 console slice. The contract is
+// BACKWARD-TOLERANT: 15.1+ honesty signals (handlerReady, status
+// degraded/stub) are trusted when present, never required — a pre-15.1
+// server that says nothing keeps its historical default (usable).
+
+import { describe, it, expect } from 'vitest';
+import { isServiceUsable } from './useDiscovery';
+
+describe('isServiceUsable (ADR-0076 D12)', () => {
+  it('absent entry → usable (pre-15.1 default preserved)', () => {
+    expect(isServiceUsable(undefined)).toBe(true);
+    expect(isServiceUsable(null)).toBe(true);
+  });
+
+  it('fields absent beyond enabled → usable', () => {
+    expect(isServiceUsable({ enabled: true })).toBe(true);
+  });
+
+  it('enabled:false → not usable', () => {
+    expect(isServiceUsable({ enabled: false })).toBe(false);
+  });
+
+  it('handlerReady:false → not usable (route exists, no real handler)', () => {
+    expect(isServiceUsable({ enabled: true, handlerReady: false })).toBe(false);
+  });
+
+  it('status stub → not usable (a dev fake is not the real service)', () => {
+    expect(isServiceUsable({ enabled: true, status: 'stub', handlerReady: true })).toBe(false);
+  });
+
+  it('status unavailable → not usable', () => {
+    expect(isServiceUsable({ enabled: true, status: 'unavailable' })).toBe(false);
+  });
+
+  it('status degraded → USABLE (a serving fallback must not turn the feature off)', () => {
+    expect(isServiceUsable({ enabled: true, status: 'degraded', handlerReady: true })).toBe(true);
+  });
+
+  it('fully honest available service → usable', () => {
+    expect(isServiceUsable({ enabled: true, status: 'available', handlerReady: true })).toBe(true);
+  });
+});