diff --git a/vue3example/Chapter01/devtools/index.html b/vue3example/Chapter01/devtools/index.html
new file mode 100644
index 0000000000000000000000000000000000000000..0cc32afdb0862199dbf27c8a020f04f3c0a65bba
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+++ b/vue3example/Chapter01/devtools/index.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <title>Vue App</title>
+    <script src="https://unpkg.com/vue@next"></script>
+  </head>
+  <body>
+
+    <div id="app">
+      <foo></foo>
+    </div>
+
+    <script>
+      const App = {
+        data() {
+          return {};
+        },
+      };
+      const app = Vue.createApp(App);
+
+      app.component("foo", {
+        data() {
+          return {
+            message: "I am foo.",
+          };
+        },
+        name: "foo",
+        template: `<p>{{message}}</p>`,
+      });
+      app.mount("#app");
+    </script>
+    
+  </body>
+</html>
