diff --git a/src/docManager.js b/src/docManager.js
index 4e0095f..a57a3a2 100644
--- a/src/docManager.js
+++ b/src/docManager.js
@@ -8,7 +8,10 @@ import { BrowserWebSocketClientAdapter } from "@automerge/automerge-repo-network
 
 let handle
 
-export function initRepo() {
+// Define the current schema version
+const CURRENT_SCHEMA_VERSION = 1;
+
+export async function initRepo() {
   const repo = new Repo({
     network: [
       new BrowserWebSocketClientAdapter("wss://automerge.rheinheim.fraction.ch")
@@ -21,19 +24,35 @@ export function initRepo() {
   
   if (rootDocUrl && isValidAutomergeUrl(rootDocUrl)) {
     handle = repo.find(rootDocUrl)
+    // Wait for handle to be ready
+    await handle.whenReady()
+    
+    // Check and upgrade schema if needed
+    handle.change(doc => {
+      if (!doc.schemaVersion) {
+        // Handle legacy documents (pre-versioning)
+        doc.schemaVersion = 1
+      }
+      // Add future upgrade logic here
+      // if (doc.schemaVersion < 2) {
+      //   // Example: upgrade shapes to include a new required field
+      //   doc.shapes.forEach(shape => {
+      //     shape.opacity = 1.0  // Add new field with default value
+      //   })
+      //   doc.schemaVersion = 2
+      // }
+    })
   } else {
-    // Create new document if none exists
+    // Create new document with current schema version
     handle = repo.create({
+      schemaVersion: CURRENT_SCHEMA_VERSION,
       shapes: []
     })
-    // Set the URL hash to the new document's URL
+    // Wait for handle to be ready
+    await handle.whenReady()
     document.location.hash = handle.url
   }
 
-  // handle.on("change", ({doc}) => {
-  //   console.log("Document changed!", doc)
-  // })
-
   return handle
 }
 
diff --git a/src/main.js b/src/main.js
index cb5c41a..5ec625d 100644
--- a/src/main.js
+++ b/src/main.js
@@ -21,9 +21,9 @@ function throttle(func, limit) {
   }
 }
 
-// 1. Init the repo & document handle
-const handle = initRepo()
-await handle.whenReady()
+  // Initialize the document
+const handle = await initRepo()
+  
 
 // draw current state
 createOrUpdateShapes(container, handle.docSync().shapes)