@@ -0,0 +1,15 @@
+---
+'@object-ui/app-shell': patch
+'@object-ui/i18n': patch
+---
+
+feat(studio): an external object's fields show their datasource and write state, and the object designer offers no control that would reshape the remote table
+
+Clause-②: no
+Metadata-protocol: none
+
+An object that carries an `external` binding (ADR-0015) is never a DDL target: its table belongs to the remote database. The object designer now says so instead of offering edits the platform cannot carry out.
+
+- **Every field is marked.** On the field canvas and in the field inspector, each field of an external object carries a mark such as "From plan_gantt · Read-only", and a note above the canvas names the datasource. Read-only is settled from the object alone when it does not set `external.writable: true`. When it does, the datasource is read for `external.allowWrites`: both set reads "Writable", otherwise "Read-only", and a datasource that cannot be read reads "Writes unconfirmed" rather than a guess.
+- **No DDL controls.** On an external object the canvas offers no "Add field" (bottom bar, empty state, section header) and its bulk bar has no Delete. The field inspector disables the API name and the Type picker and offers no Duplicate and no Remove. In the Studio Data pillar, the Records grid's "+" column and the Form toolbar's "Add field" are not offered, and a note above the grid or form names the datasource. Label, section, order and the other display settings stay editable.
+- **Strings.** Six new `designer.external.*` rows in the `studio` namespace of `@object-ui/i18n`, in English and Chinese.
@@ -102,6 +102,11 @@ import {
   type FieldTypeId,
 } from '../previews/field-types.js';
 import { FieldTypePicker } from './FieldTypePicker.js';
+import {
+  ExternalFieldBadge,
+  readExternalBinding,
+  useExternalWriteState,
+} from '../previews/external-object.js';
 import { CelPredicateField } from '../CelPredicateField.js';
 import type { CelLintIssue } from '../celAuthoring.js';
 import { t, tFormat, type SupportedLocale } from '../i18n.js';
@@ -664,6 +669,13 @@ export function ObjectFieldInspector({
   /** The object this field belongs to — `draft` is the object document. */
   const objectName = String(draft.name ?? '');
 
+  // ADR-0015 — on an external object the field is a remote column: no rename,
+  // retype, duplicate or remove (each would reshape the remote table), and the
+  // field says where it comes from. A hook, so above the `!entry` return.
+  const external = readExternalBinding(draft);
+  const externalWriteState = useExternalWriteState(external);
+  const ddlLocked = readOnly || !!external;
+
   /* ─── Blocking CEL verdicts → the host's Save gate (objectui#4306) ─────
    *
    * Mirrors the shape PermissionAdvancedFacets uses for its per-clause map:
@@ -875,7 +887,7 @@ export function ObjectFieldInspector({
   // since two separate writeView() calls from the same stale `entry` closure
   // would have the second clobber the first.
   const deriveNameFor = (label: string): string | null => {
-    if (readOnly) return null;
+    if (ddlLocked) return null;
     const owner = recordedOwner();
     // The author's own value wins outright — including one that happens to be
     // SHAPED like a placeholder (objectui#7615).
@@ -1012,7 +1024,7 @@ export function ObjectFieldInspector({
 
   const headerActions = (
     <div className="flex items-center gap-1">
-      {!readOnly && (
+      {!ddlLocked && (
         <Button
           variant="ghost"
           size="sm"
@@ -1033,7 +1045,7 @@ export function ObjectFieldInspector({
     </div>
   );
 
-  const footer = (
+  const footer = external ? undefined : (
     <InspectorRemoveButton
       label={tFormat('designer.field.remove', locale, {
         label: typeof def.label === 'string' ? def.label : entry.name,
@@ -1058,11 +1070,16 @@ export function ObjectFieldInspector({
     >
       {/* Basic */}
       <Section title={tr('designer.field.section.basic')}>
+        {external && (
+          <div>
+            <ExternalFieldBadge binding={external} state={externalWriteState} locale={locale} />
+          </div>
+        )}
         <InspectorTextField
           label={tr('designer.field.apiName')}
           value={entry.name}
           onCommit={setKey}
-          disabled={readOnly}
+          disabled={ddlLocked}
           mono
           testId="field-apiname-input"
         />
@@ -1105,7 +1122,7 @@ export function ObjectFieldInspector({
           label={tr('designer.field.type')}
           value={type}
           onCommit={changeType}
-          disabled={readOnly}
+          disabled={ddlLocked}
           locale={locale}
         />
         <div className="flex items-center gap-4 pt-1">
 
@@ -72,6 +72,12 @@ import {
   type FieldTypeCategory,
 } from './field-types.js';
 import { FieldStub } from './FieldStub.js';
+import {
+  ExternalFieldBadge,
+  ExternalObjectNotice,
+  readExternalBinding,
+  useExternalWriteState,
+} from './external-object.js';
 import { t, tFormat } from '../i18n.js';
 
 /* ─── locale helpers ─── */
@@ -104,6 +110,12 @@ export function ObjectFormCanvas({
   locale,
 }: ObjectFormCanvasProps) {
   const readOnly = !onPatch;
+  // ADR-0015 — an external object's fields mirror a remote table, so the
+  // controls that would reshape it (add a field, delete fields) are not
+  // offered; each field says where it comes from instead.
+  const external = readExternalBinding(draft);
+  const writeState = useExternalWriteState(external);
+  const canAddFields = !readOnly && !external;
   // The "Ask AI" affordances arm the global chat FAB (requestAssistantOpen).
   // Hide them when the runtime serves no AI — otherwise they'd dead-end with no
   // FAB to open. Same server-pushed signal the FAB itself gates on.
@@ -448,12 +460,13 @@ export function ObjectFormCanvas({
           count={multiSel.size}
           groups={declaredGroups}
           onMoveToGroup={bulkSetGroup}
-          onDelete={bulkDelete}
+          onDelete={external ? undefined : bulkDelete}
           onClear={clearMulti}
           locale={locale}
         />
       )}
       <div className="mx-auto max-w-3xl px-6 py-6 space-y-4" onClick={handleBgClick}>
+        {external && <ExternalObjectNotice binding={external} state={writeState} locale={locale} />}
         {!emptyState && (
           <CanvasToolbar
             fieldCount={view.entries.length}
@@ -470,7 +483,7 @@ export function ObjectFormCanvas({
         )}
 
         {emptyState ? (
-          <EmptyCanvas onAdd={readOnly ? undefined : addField} locale={locale} aiEnabled={aiEnabled} />
+          <EmptyCanvas onAdd={canAddFields ? addField : undefined} locale={locale} aiEnabled={aiEnabled} />
         ) : (
           <div className="space-y-5">
             {groups.map((g) => {
@@ -493,7 +506,7 @@ export function ObjectFormCanvas({
                   onRename={g.key ? (label) => renameSection(g.key!, label) : undefined}
                   onRemove={g.key ? () => removeSection(g.key!) : undefined}
                   onMove={g.key ? (dir) => moveSection(g.key!, dir) : undefined}
-                  onAddField={readOnly ? undefined : (type) => addField(type, g.key)}
+                  onAddField={canAddFields ? (type) => addField(type, g.key) : undefined}
                   onDropField={readOnly ? undefined : moveToGroup}
                 >
                   {g.entries.map((entry) => (
@@ -504,6 +517,11 @@ export function ObjectFormCanvas({
                       multiSelected={multiSel.has(entry.name)}
                       diffStatus={statusOf(entry.name)}
                       changedKeys={changedKeysOf(entry.name)}
+                      sourceBadge={
+                        external ? (
+                          <ExternalFieldBadge binding={external} state={writeState} locale={locale} />
+                        ) : undefined
+                      }
                       readOnly={readOnly}
                       locale={locale}
                       onClick={(e) => handleRowClick(entry, e)}
@@ -538,7 +556,7 @@ export function ObjectFormCanvas({
 
         {!emptyState && !readOnly && (
           <div className="flex items-center gap-2 pt-1">
-            <AddFieldButton onPick={(type) => addField(type)} locale={locale} />
+            {canAddFields && <AddFieldButton onPick={(type) => addField(type)} locale={locale} />}
             <Button
               variant="ghost"
               size="sm"
@@ -681,7 +699,8 @@ function BulkActionBar({
   count: number;
   groups: ObjectFieldGroup[];
   onMoveToGroup: (groupKey: string | null) => void;
-  onDelete: () => void;
+  /** Absent on an external object: deleting a field would drop a remote column. */
+  onDelete?: () => void;
   onClear: () => void;
   locale?: string;
 }) {
@@ -725,15 +744,17 @@ function BulkActionBar({
             </PopoverContent>
           </Popover>
         )}
-        <Button
-          variant="outline"
-          size="sm"
-          className="h-7 gap-1.5 bg-background/70 text-destructive hover:text-destructive"
-          onClick={onDelete}
-        >
-          <Trash2 className="h-3.5 w-3.5" />
-          {t('designer.canvas.bulkDelete', locale)}
-        </Button>
+        {onDelete && (
+          <Button
+            variant="outline"
+            size="sm"
+            className="h-7 gap-1.5 bg-background/70 text-destructive hover:text-destructive"
+            onClick={onDelete}
+          >
+            <Trash2 className="h-3.5 w-3.5" />
+            {t('designer.canvas.bulkDelete', locale)}
+          </Button>
+        )}
         <Button variant="ghost" size="sm" className="h-7 gap-1.5" onClick={onClear}>
           <X className="h-3.5 w-3.5" />
           {t('designer.canvas.bulkClear', locale)}
@@ -1001,6 +1022,7 @@ function FieldRow({
   multiSelected,
   diffStatus,
   changedKeys,
+  sourceBadge,
   readOnly,
   locale,
   onClick,
@@ -1014,6 +1036,8 @@ function FieldRow({
   /** Review mode: how this field differs from the published baseline. */
   diffStatus?: FieldDiffStatus;
   changedKeys?: string[];
+  /** ADR-0015 — where an external object's field comes from, and its write state. */
+  sourceBadge?: React.ReactNode;
   readOnly: boolean;
   locale?: string;
   /** Receives the mouse event so the host can branch on Ctrl/⌘/Shift. */
@@ -1200,6 +1224,7 @@ function FieldRow({
                 {t('designer.canvas.diffChanged', locale)}
               </Badge>
             )}
+            {sourceBadge}
             <Badge variant="outline" className={cn('text-[10px] font-medium', tone.badge)}>
               {typeLabel(meta, locale) ?? typeStr}
             </Badge>