diff --git a/framework/core/js/package-lock.json b/framework/core/js/package-lock.json
index 1eb3fe378..db8dbabeb 100644
--- a/framework/core/js/package-lock.json
+++ b/framework/core/js/package-lock.json
@@ -5153,6 +5153,11 @@
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.10.tgz",
       "integrity": "sha512-UejweD1pDoXu+AD825lWwp4ZGtSwgnpZxb3JDViD7StjQz+Nb/6l093lx4OQ0foGWNRoc19mWy7BzL+UAK2iVg=="
     },
+    "lodash-es": {
+      "version": "4.17.10",
+      "resolved": "https://registry.npmjs.org/lodash-es/-/lodash-es-4.17.10.tgz",
+      "integrity": "sha512-iesFYPmxYYGTcmQK0sL8bX3TGHyM6b2qREaB4kamHfQyfPJP0xgoGxp19nsH16nsfquLdiyKyX3mQkfiSGV8Rg=="
+    },
     "log-symbols": {
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/log-symbols/-/log-symbols-2.2.0.tgz",
diff --git a/framework/core/js/package.json b/framework/core/js/package.json
index 62604b61f..b9d25ff98 100644
--- a/framework/core/js/package.json
+++ b/framework/core/js/package.json
@@ -9,6 +9,7 @@
     "flarum-webpack-config": "^0.1.0-beta.8",
     "jquery": "^3.3.1",
     "jquery.hotkeys": "^0.1.0",
+    "lodash-es": "^4.17.10",
     "m.attrs.bidi": "github:tobscure/m.attrs.bidi",
     "mithril": "^0.2.8",
     "moment": "^2.22.2",
diff --git a/framework/core/js/src/admin/AdminApplication.js b/framework/core/js/src/admin/AdminApplication.js
index 6212eec09..ca71ee2c2 100644
--- a/framework/core/js/src/admin/AdminApplication.js
+++ b/framework/core/js/src/admin/AdminApplication.js
@@ -17,13 +17,10 @@ export default class AdminApplication extends Application {
     }
   };
 
-  /**
-   * @inheritdoc
-   */
-  boot(data) {
-    routes(this);
+  constructor() {
+    super();
 
-    super.boot(data);
+    routes(this);
   }
 
   /**
diff --git a/framework/core/js/src/admin/index.js b/framework/core/js/src/admin/index.js
index ca7d19d02..b17a192ef 100644
--- a/framework/core/js/src/admin/index.js
+++ b/framework/core/js/src/admin/index.js
@@ -1,13 +1,3 @@
-import 'expose-loader?$!expose-loader?jQuery!jquery';
-import 'expose-loader?m!mithril';
-import 'expose-loader?moment!moment';
-import 'expose-loader?m.bidi!m.attrs.bidi';
-import 'bootstrap/js/affix';
-import 'bootstrap/js/dropdown';
-import 'bootstrap/js/modal';
-import 'bootstrap/js/tooltip';
-import 'bootstrap/js/transition';
-
 import AdminApplication from './AdminApplication';
 
 const app = new AdminApplication();
diff --git a/framework/core/js/src/common/Application.js b/framework/core/js/src/common/Application.js
index 05df4d6cb..4a7799110 100644
--- a/framework/core/js/src/common/Application.js
+++ b/framework/core/js/src/common/Application.js
@@ -10,7 +10,6 @@ import Session from './Session';
 import extract from './utils/extract';
 import Drawer from './utils/Drawer';
 import mapRoutes from './utils/mapRoutes';
-import patchMithril from './utils/patchMithril';
 import RequestError from './utils/RequestError';
 import ScrollListener from './utils/ScrollListener';
 import { extend } from './extend';
@@ -21,6 +20,7 @@ import Discussion from './models/Discussion';
 import Post from './models/Post';
 import Group from './models/Group';
 import Notification from './models/Notification';
+import { flattenDeep } from 'lodash-es';
 
 /**
  * The `App` class provides a container for an application, as well as various
@@ -115,16 +115,17 @@ export default class Application {
    */
   requestError = null;
 
+  data;
+
   title = '';
   titleCount = 0;
 
-  boot(data) {
-    this.data = data;
-
-    this.translator.locale = data.locale;
-
-    patchMithril(window);
+  load(payload) {
+    this.data = payload;
+    this.translator.locale = payload.locale;
+  }
 
+  boot() {
     this.initializers.toArray().forEach(initializer => initializer(this));
 
     this.store.pushPayload({data: this.data.resources});
@@ -139,6 +140,18 @@ export default class Application {
     this.mount();
   }
 
+  bootExtensions(extensions) {
+    Object.keys(extensions).forEach(name => {
+      const extension = extensions[name];
+      
+      const extenders = flattenDeep(extension.extend);
+
+      for (const extender of extenders) {
+        extender.extend(this, { name, exports: extension });
+      }
+    });
+  }
+
   mount() {
     this.modal = m.mount(document.getElementById('modal'), <ModalManager/>);
     this.alerts = m.mount(document.getElementById('alerts'), <AlertManager/>);
diff --git a/framework/core/js/src/common/extend/Model.js b/framework/core/js/src/common/extend/Model.js
new file mode 100644
index 000000000..240be8384
--- /dev/null
+++ b/framework/core/js/src/common/extend/Model.js
@@ -0,0 +1,41 @@
+export default class Routes {
+  type;
+  attributes = [];
+  hasOnes = [];
+  hasManys = [];
+
+  constructor(type, model = null) {
+    this.type = type;
+    this.model = model;
+  }
+
+  attribute(name) {
+    this.attributes.push(name);
+
+    return this;
+  }
+
+  hasOne(type) {
+    this.hasOnes.push(type);
+
+    return this;
+  }
+
+  hasMany(type) {
+    this.hasManys.push(type);
+
+    return this;
+  }
+
+  extend(app, extension) {
+    if (this.model) {
+      app.store.models[this.type] = this.model;
+    }
+    
+    const model = app.store.models[this.type];
+
+    this.attributes.forEach(name => model.prototype[name] = model.attribute(name));
+    this.hasOnes.forEach(name => model.prototype[name] = model.hasOne(name));
+    this.hasManys.forEach(name => model.prototype[name] = model.hasMany(name));
+  }
+}
\ No newline at end of file
diff --git a/framework/core/js/src/common/extend/PostTypes.js b/framework/core/js/src/common/extend/PostTypes.js
new file mode 100644
index 000000000..4d9df731f
--- /dev/null
+++ b/framework/core/js/src/common/extend/PostTypes.js
@@ -0,0 +1,13 @@
+export default class PostTypes {
+  postComponents = {};
+
+  add(name, component) {
+    this.postComponents[name] = component;
+
+    return this;
+  }
+
+  extend(app, extension) {
+    Object.assign(app.postComponents, this.postComponents);
+  }
+}
\ No newline at end of file
diff --git a/framework/core/js/src/common/extend/Routes.js b/framework/core/js/src/common/extend/Routes.js
new file mode 100644
index 000000000..013e52836
--- /dev/null
+++ b/framework/core/js/src/common/extend/Routes.js
@@ -0,0 +1,13 @@
+export default class Routes {
+  routes = {};
+
+  add(name, path, component) {
+    this.routes[name] = { path, component };
+
+    return this;
+  }
+
+  extend(app, extension) {
+    Object.assign(app.routes, this.routes);
+  }
+}
\ No newline at end of file
diff --git a/framework/core/js/src/common/extend/index.js b/framework/core/js/src/common/extend/index.js
new file mode 100644
index 000000000..6d17eb79a
--- /dev/null
+++ b/framework/core/js/src/common/extend/index.js
@@ -0,0 +1,3 @@
+export { default as Model } from './Model';
+export { default as PostTypes } from './PostTypes';
+export { default as Routes } from './Routes';
diff --git a/framework/core/js/src/common/index.js b/framework/core/js/src/common/index.js
index e69de29bb..00bc255bd 100644
--- a/framework/core/js/src/common/index.js
+++ b/framework/core/js/src/common/index.js
@@ -0,0 +1,18 @@
+import 'expose-loader?$!expose-loader?jQuery!jquery';
+import 'expose-loader?m!mithril';
+import 'expose-loader?moment!moment';
+import 'expose-loader?m.bidi!m.attrs.bidi';
+import 'bootstrap/js/affix';
+import 'bootstrap/js/dropdown';
+import 'bootstrap/js/modal';
+import 'bootstrap/js/tooltip';
+import 'bootstrap/js/transition';
+import 'jquery.hotkeys/jquery.hotkeys';
+
+import patchMithril from './utils/patchMithril';
+
+patchMithril(window);
+
+import * as Extend from './extend/index';
+
+export { Extend };
diff --git a/framework/core/js/src/forum/ForumApplication.js b/framework/core/js/src/forum/ForumApplication.js
index e3c4ca5a2..34d685843 100644
--- a/framework/core/js/src/forum/ForumApplication.js
+++ b/framework/core/js/src/forum/ForumApplication.js
@@ -63,13 +63,10 @@ export default class ForumApplication extends Application {
    */
   history = new History();
 
-  /**
-   * @inheritdoc
-   */
-  boot(data) {
-    routes(this);
+  constructor() {
+    super();
 
-    super.boot(data);
+    routes(this);
   }
 
   /**
diff --git a/framework/core/js/src/forum/index.js b/framework/core/js/src/forum/index.js
index f5946c7fe..2a5e26fbd 100644
--- a/framework/core/js/src/forum/index.js
+++ b/framework/core/js/src/forum/index.js
@@ -1,15 +1,5 @@
-import 'expose-loader?$!expose-loader?jQuery!jquery';
-import 'expose-loader?m!mithril';
-import 'expose-loader?moment!moment';
 import 'expose-loader?punycode!punycode';
 import 'expose-loader?ColorThief!color-thief-browser';
-import 'expose-loader?m.bidi!m.attrs.bidi';
-import 'bootstrap/js/affix';
-import 'bootstrap/js/dropdown';
-import 'bootstrap/js/modal';
-import 'bootstrap/js/tooltip';
-import 'bootstrap/js/transition';
-import 'jquery.hotkeys/jquery.hotkeys';
 
 import ForumApplication from './ForumApplication';
 
diff --git a/framework/core/src/Extend/Assets.php b/framework/core/src/Extend/Assets.php
index 0b8f70419..bd5fb6592 100644
--- a/framework/core/src/Extend/Assets.php
+++ b/framework/core/src/Extend/Assets.php
@@ -57,7 +57,7 @@ class Assets implements ExtenderInterface
                     $event->view->getJs()->addString(function () use ($extension) {
                         $name = $extension->getId();
 
-                        return 'var module={};'.file_get_contents($this->js).";flarum.extensions['$name']=module.exports";
+                        return 'var module={};'.file_get_contents($this->js).";\nflarum.extensions['$name']=module.exports";
                     });
                 }
             }
diff --git a/framework/core/views/frontend/app.blade.php b/framework/core/views/frontend/app.blade.php
index 1cc8c02d2..4d69331e3 100644
--- a/framework/core/views/frontend/app.blade.php
+++ b/framework/core/views/frontend/app.blade.php
@@ -30,7 +30,7 @@
     @if ($allowJs)
       <script>
         document.getElementById('flarum-loading').style.display = 'block';
-        var flarum={extensions:{}};
+        var flarum = {extensions: {}};
       </script>
 
       @foreach ($jsUrls as $url)
@@ -42,7 +42,9 @@
         @if (! $debug)
         try {
         @endif
-          flarum.core.app.boot(@json($payload));
+          flarum.core.app.load(@json($payload));
+          flarum.core.app.bootExtensions(flarum.extensions);
+          flarum.core.app.boot();
         @if (! $debug)
         } catch (e) {
           window.location += (window.location.search ? '&' : '?') + 'nojs=1';