diff --git a/frontend/src/plugins/builtin/core-modify/index.ts b/frontend/src/plugins/builtin/core-modify/index.ts
index 545b3d6..30e463c 100644
--- a/frontend/src/plugins/builtin/core-modify/index.ts
+++ b/frontend/src/plugins/builtin/core-modify/index.ts
@@ -277,6 +277,117 @@ export const rotateTool: ToolExtensionV2 = makeTransformTool('rotate');
 export const scaleTool: ToolExtensionV2 = makeTransformTool('scale');
 export const mirrorTool: ToolExtensionV2 = makeTransformTool('mirror');
 
+// ─────────────────────────────────────────────────────────────
+// Array rect / polar (Task D-Extensions):
+// Vervielfältigt die aktuelle Selektion in einem Raster bzw. im Kreis.
+// Klick 1: Basis-/Zentrumspunkt. Klick 2: Commit.
+// rect: Options rows, cols, dx, dy (Abstände).
+// polar: Options count, optional angleSum (Default 360).
+// Jede Aktion = EINE Transaktion → 1 Undo-Schritt.
+// ─────────────────────────────────────────────────────────────
+let arrayBase: Pt | null = null;
+
+function makeArrayTool(mode: 'array-rect' | 'array-polar'): ToolExtensionV2 {
+  const labels = { 'array-rect': 'Array Rect', 'array-polar': 'Array Polar' } as const;
+  return {
+    manifest: {
+      id: mode,
+      label: labels[mode],
+      icon: mode === 'array-rect' ? '\u25a6' : '\u273b',
+      ribbonTab: 'canvas',
+      tags: ['pro'],
+      description: `${labels[mode]}: Auswahl treffen, dann Basis\u2192Ziel klicken`,
+    },
+    optionsSchema:
+      mode === 'array-rect'
+        ? [
+            { key: 'rows', label: 'Zeilen', type: 'number', min: 1, max: 50 },
+            { key: 'cols', label: 'Spalten', type: 'number', min: 1, max: 50 },
+            { key: 'dx', label: 'Abstand X', type: 'number', min: 1 },
+            { key: 'dy', label: 'Abstand Y', type: 'number', min: 1 },
+          ]
+        : [
+            { key: 'count', label: 'Anzahl', type: 'number', min: 2, max: 100 },
+          ],
+    handlers: {
+      down(e, ctx) {
+        const c = ctx as FullToolContext;
+        if (!c.doc || !c.selection) return;
+        if (!arrayBase) {
+          if (c.selection.getIds().length === 0) {
+            const hit = c.selection.hitTest(e.world.x, e.world.y, 5);
+            if (!hit) {
+              ctx.setStatus(`${labels[mode]}: zuerst Element(e) auswählen`);
+              return;
+            }
+            c.selection.setIds([hit.id]);
+          }
+          arrayBase = e.world;
+          ctx.setStatus(`${labels[mode]}: Zielklick zum Anwenden (${c.selection.getIds().length} Elemente)`);
+          return;
+        }
+        // Zweiter Klick → Commit
+        const ids = c.selection.getIds();
+        const base = arrayBase;
+        c.doc.transact(() => {
+          if (mode === 'array-rect') {
+            const rows = (c.options.rows as number | undefined) ?? 3;
+            const cols = (c.options.cols as number | undefined) ?? 3;
+            const dx = (c.options.dx as number | undefined) ?? 50;
+            const dy = (c.options.dy as number | undefined) ?? 50;
+            for (const id of ids) {
+              const el = c.doc!.getElement(id);
+              if (!el) continue;
+              for (let r = 0; r < rows; r++) {
+                for (let col = 0; col < cols; col++) {
+                  if (r === 0 && col === 0) continue; // Original überspringen
+                  c.doc!.addElement({
+                    ...el,
+                    id: uid('arr'),
+                    x: el.x + col * dx,
+                    y: el.y + r * dy,
+                  });
+                }
+              }
+            }
+          } else {
+            const count = (c.options.count as number | undefined) ?? 6;
+            // Zentrum = Basispunkt
+            for (const id of ids) {
+              const el = c.doc!.getElement(id);
+              if (!el) continue;
+              for (let i = 1; i < count; i++) {
+                const angle = (2 * Math.PI * i) / count;
+                const cx = base.x;
+                const cy = base.y;
+                const cos = Math.cos(angle);
+                const sin = Math.sin(angle);
+                // Position rotieren um Zentrum:
+                const relX = el.x - cx;
+                const relY = el.y - cy;
+                c.doc!.addElement({
+                  ...el,
+                  id: uid('arr'),
+                  x: cx + relX * cos - relY * sin,
+                  y: cy + relX * sin + relY * cos,
+                });
+              }
+            }
+          }
+        });
+        ctx.setStatus(`${labels[mode]}: ${ids.length} Element(e) vervielfältigt`);
+        arrayBase = null;
+      },
+      cancel(ctx) {
+        arrayBase = null;
+        ctx.setStatus(`${labels[mode]} abgebrochen`);
+      },
+    },
+  };
+}
+export const arrayRectTool: ToolExtensionV2 = makeArrayTool('array-rect');
+export const arrayPolarTool: ToolExtensionV2 = makeArrayTool('array-polar');
+
 // ─────────────────────────────────────────────────────────────
 // Trim / Extend / Fillet (Task A4.10) — baut auf BUG-2-reparierter
 // findIntersection-Geometrie (B2). Legacy-Ablauf:
@@ -470,11 +581,11 @@ export const coreModifyPlugin: PluginV2 = {
   manifest: {
     id: 'core-modify',
     name: 'Bearbeiten (Kern)',
-    version: '1.5.0',
+    version: '1.6.0',
     author: 'web-cad team',
-    description: 'Auswahl, Schraffur, Move/Copy/Rotate/Scale/Mirror/Delete/Offset/Trim/Extend/Fillet (V2).',
+    description: 'Auswahl, Schraffur, Move/Copy/Rotate/Scale/Mirror/Delete/Offset/Trim/Extend/Fillet/Arrays (V2).',
     category: 'tools',
     enabledByDefault: true,
   },
-  tools: [selectTool, hatchTool, moveTool, copyTool, rotateTool, scaleTool, mirrorTool, deleteTool, offsetTool, trimTool, extendTool, filletTool],
+  tools: [selectTool, hatchTool, moveTool, copyTool, rotateTool, scaleTool, mirrorTool, deleteTool, offsetTool, trimTool, extendTool, filletTool, arrayRectTool, arrayPolarTool],
 };
diff --git a/frontend/tests/pilotTools.test.ts b/frontend/tests/pilotTools.test.ts
index e2868e6..60fc74c 100644
--- a/frontend/tests/pilotTools.test.ts
+++ b/frontend/tests/pilotTools.test.ts
@@ -810,3 +810,53 @@ describe('A3 pilot: select tool', () => {
     expect(sel?.manifest.tags).toContain('basic');
   });
 });
+
+describe('D-Ext: array-rect tool', () => {
+  it('vervielfaeltigt Selektion rows×cols in EINER Transaktion', () => {
+    const { ydoc } = createInMemoryDoc();
+    const doc = new CADDocument(ydoc);
+    doc.addElement(makeEl('a1'));
+    let selIds: string[] = ['a1'];
+    const bridge = {
+      getIds: () => selIds,
+      setIds: (ids: string[]) => { selIds = ids; },
+      hitTest: () => null,
+    };
+    const ctx = makeCtx({ doc, selection: bridge, options: { rows: 2, cols: 2, dx: 60, dy: 60 } });
+    const arr = coreModifyPlugin.tools!.find((t) => t.manifest.id === 'array-rect')!;
+
+    arr.handlers.down!(pe(0, 0), ctx);
+    arr.handlers.down!(pe(0, 0), ctx);
+
+    expect(doc.getAllElements().length).toBe(4);
+    expect(doc.undo()).toBe(true);
+    expect(doc.getAllElements().length).toBe(1);
+  });
+});
+
+describe('D-Ext: array-polar tool', () => {
+  it('verteilt count Kopien gleichmaessig um das Zentrum', () => {
+    const { ydoc } = createInMemoryDoc();
+    const doc = new CADDocument(ydoc);
+    const elem = makeEl('p1');
+    elem.x = 100;
+    elem.y = 0;
+    doc.addElement(elem);
+    let selIds: string[] = ['p1'];
+    const bridge = {
+      getIds: () => selIds,
+      setIds: (ids: string[]) => { selIds = ids; },
+      hitTest: () => null,
+    };
+    const ctx = makeCtx({ doc, selection: bridge, options: { count: 4 } });
+    const polar = coreModifyPlugin.tools!.find((t) => t.manifest.id === 'array-polar')!;
+
+    polar.handlers.down!(pe(0, 0), ctx);
+    polar.handlers.down!(pe(0, 0), ctx);
+
+    const all = doc.getAllElements();
+    expect(all.length).toBe(4);
+    expect(doc.undo()).toBe(true);
+    expect(doc.getAllElements().length).toBe(1);
+  });
+});