diff --git a/frontend/src/components/SidePanel.tsx b/frontend/src/components/SidePanel.tsx
index 0f1453b..816c272 100644
--- a/frontend/src/components/SidePanel.tsx
+++ b/frontend/src/components/SidePanel.tsx
@@ -2,13 +2,23 @@ import React, { useState, useEffect, useRef } from 'react';
 import './SidePanel.css';
 import LayerPanel from './LayerPanel';
 import BlockLibrary from './BlockLibrary';
+import PropertiesPanel from './PropertiesPanel/PropertiesPanel';
 
-const SidePanel: React.FC = () => {
+interface SidePanelProps {
+  canvasRef?: React.RefObject<unknown>;
+  yjsDoc?: React.RefObject<unknown>;
+}
+
+const SidePanel: React.FC<SidePanelProps> = ({ canvasRef, yjsDoc }) => {
   const [activeTab, setActiveTab] = useState('blocks');
   const [layers, setLayers] = useState([]);
   const [activeLayer, setActiveLayer] = useState('');
-  const canvasRef = useRef(null);
-  const yjsDocRef = useRef(null);
+  const localCanvasRef = useRef(null);
+  const localYjsDocRef = useRef(null);
+
+  // Use props if provided, otherwise fall back to local refs
+  const effectiveCanvasRef = (canvasRef ?? localCanvasRef) as React.RefObject<unknown>;
+  const effectiveYjsDocRef = (yjsDoc ?? localYjsDocRef) as React.RefObject<unknown>;
 
   const tabs = [
     { id: 'blocks', label: 'Blocks', icon: '🧱' },
@@ -19,16 +29,17 @@ const SidePanel: React.FC = () => {
 
   // Observe changes in yjsDoc.layers
   useEffect(() => {
-    if (yjsDocRef.current) {
-      const yjsDoc = yjsDocRef.current;
+    const yjsDocInstance = effectiveYjsDocRef?.current as { layers?: { forEach: (cb: (layer: Record<string, unknown>, id: string) => void) => void; observe: (cb: () => void) => void; unobserve: (cb: () => void) => void } } | null;
+    if (yjsDocInstance?.layers) {
+      const yjsDoc = yjsDocInstance;
       
       // Function to update layers from yjsDoc
       const updateLayers = () => {
-        const layersArray = [];
+        const layersArray: Array<Record<string, unknown> & { id: string }> = [];
         yjsDoc.layers.forEach((layer, id) => {
           layersArray.push({ ...layer, id });
         });
-        setLayers(layersArray);
+        setLayers(layersArray as never);
         
         // Set active layer if none is set or if current active layer doesn't exist
         if (!activeLayer || !layersArray.some(layer => layer.id === activeLayer)) {
@@ -49,24 +60,24 @@ const SidePanel: React.FC = () => {
         yjsDoc.layers.unobserve(updateLayers);
       };
     }
-  }, [activeLayer, yjsDocRef]);
+  }, [activeLayer, effectiveYjsDocRef]);
 
   const renderContent = () => {
     switch (activeTab) {
       case 'blocks':
-        return <BlockLibrary canvasRef={canvasRef} yjsDoc={yjsDocRef.current} />;
+        return <BlockLibrary canvasRef={effectiveCanvasRef as never} yjsDoc={(effectiveYjsDocRef as React.MutableRefObject<unknown>).current} />;
       case 'layers':
         return (
           <LayerPanel 
-            layers={layers} 
-            setLayers={setLayers} 
-            activeLayer={activeLayer} 
-            setActiveLayer={setActiveLayer} 
-            yjsDoc={yjsDocRef.current}
+            layers={layers as never}
+            setLayers={setLayers as never}
+            activeLayer={activeLayer}
+            setActiveLayer={setActiveLayer}
+            yjsDoc={(effectiveYjsDocRef as React.MutableRefObject<unknown>).current}
           />
         );
       case 'properties':
-        return <div className="panel-content">Properties content goes here</div>;
+        return <PropertiesPanel canvasRef={effectiveCanvasRef} yjsDocRef={effectiveYjsDocRef} />;
       case 'copilot':
         return <div className="panel-content">KI Copilot content goes here</div>;
       default: