diff --git a/packages/chrome-extension/src/background.ts b/packages/chrome-extension/src/background.ts
index b636452..d79a5bf 100644
--- a/packages/chrome-extension/src/background.ts
+++ b/packages/chrome-extension/src/background.ts
@@ -6,18 +6,29 @@ import ConfigStorageService from './services/config-storage-service';
 
 let elementSender: ElementSenderService;
 let currentConfig: ExtensionConfig;
+let initPromise: Promise<void> | null = null;
 
-// Initialize when service worker starts
-async function initialize() {
-  currentConfig = await ConfigStorageService.load();
+// Idempotent initialization. The MV3 service worker is terminated when idle and
+// woken by the very message we need to handle, so the onMessage listener must
+// AWAIT this before touching elementSender/currentConfig — otherwise the first
+// click after the SW sleeps races the async config load and is silently lost
+// (elementSender is still undefined -> TypeError).
+function ensureInitialized(): Promise<void> {
+  if (!initPromise) {
+    initPromise = (async () => {
+      currentConfig = await ConfigStorageService.load();
 
-  // Create the service (no connection on startup)
-  elementSender = new ElementSenderService();
+      // Create the service (no connection on startup)
+      elementSender = new ElementSenderService();
 
-  logger.info('🚀 MCP Pointer background script loaded', {
-    enabled: currentConfig.enabled,
-    port: currentConfig.websocket.port,
-  });
+      logger.info('🚀 MCP Pointer background script loaded', {
+        enabled: currentConfig.enabled,
+        port: currentConfig.websocket.port,
+      });
+    })();
+  }
+
+  return initPromise;
 }
 
 // Listen for config changes
@@ -34,42 +45,57 @@ ConfigStorageService.onChange((newConfig: ExtensionConfig) => {
   }
 });
 
-// Listen for messages from content script
+// Listen for messages from content script.
+// NOTE: the listener itself is registered synchronously at the top level and is
+// NOT async; the async work runs in an inner IIFE and we return true to keep the
+// channel open (per MV3 messaging guidance).
 chrome.runtime.onMessage
   .addListener((request: any, _sender: any, sendResponse: (response: any) => void) => {
     if (request.type === 'DOM_ELEMENT_POINTED' && request.data) {
-      // Send element with current port and status callback
-      elementSender.sendElement(
-        request.data,
-        currentConfig.websocket.port,
-        (status, error) => {
-          // Status flow: CONNECTING -> CONNECTED -> SENDING -> SENT
-          switch (status) {
-            case ConnectionStatus.CONNECTING:
-              logger.info('🔄 Connecting to WebSocket...');
-              break;
-            case ConnectionStatus.CONNECTED:
-              logger.info('✅ Connected');
-              break;
-            case ConnectionStatus.SENDING:
-              logger.info('📤 Sending element...');
-              break;
-            case ConnectionStatus.SENT:
-              logger.info('✓ Element sent successfully');
-              break;
-            case ConnectionStatus.ERROR:
-              logger.error('❌ Failed:', error);
-              break;
-            default:
-              break;
-          }
-        },
-      );
-
-      sendResponse({ success: true });
+      (async () => {
+        try {
+          // Ensure config + sender are ready even on a cold SW start.
+          await ensureInitialized();
+
+          // Send element with current port and status callback
+          await elementSender.sendElement(
+            request.data,
+            currentConfig.websocket.port,
+            (status, error) => {
+              // Status flow: CONNECTING -> CONNECTED -> SENDING -> SENT
+              switch (status) {
+                case ConnectionStatus.CONNECTING:
+                  logger.info('🔄 Connecting to WebSocket...');
+                  break;
+                case ConnectionStatus.CONNECTED:
+                  logger.info('✅ Connected');
+                  break;
+                case ConnectionStatus.SENDING:
+                  logger.info('📤 Sending element...');
+                  break;
+                case ConnectionStatus.SENT:
+                  logger.info('✓ Element sent successfully');
+                  break;
+                case ConnectionStatus.ERROR:
+                  logger.error('❌ Failed:', error);
+                  break;
+                default:
+                  break;
+              }
+            },
+          );
+
+          sendResponse({ success: true });
+        } catch (error) {
+          logger.error('❌ Failed to handle pointed element:', error);
+          sendResponse({ success: false, error: (error as Error).message });
+        }
+      })();
+
+      return true; // Keep message channel open for async response
     }
 
-    return true; // Keep message channel open for async response
+    return true;
   });
 
 // Handle extension install/update
@@ -88,5 +114,5 @@ chrome.runtime.onInstalled.addListener((details) => {
   }
 });
 
-// Start initialization
-initialize();
+// Best-effort warm start (messages also trigger ensureInitialized)
+ensureInitialized();