diff --git a/.vscode/extensions.json b/.vscode/extensions.json
index d4c5c72dc..e72a3d0b8 100644
--- a/.vscode/extensions.json
+++ b/.vscode/extensions.json
@@ -8,6 +8,7 @@
     "mesonbuild.mesonbuild",
     "prince781.vala",
     "bodil.blueprint-gtk",
-    "dbaeumer.vscode-eslint"
+    "dbaeumer.vscode-eslint",
+    "ms-python.black-formatter"
   ]
 }
diff --git a/src/IconLibrary/main.js b/src/IconLibrary/main.js
index 60e7c7198..77f1e3899 100644
--- a/src/IconLibrary/main.js
+++ b/src/IconLibrary/main.js
@@ -1,11 +1,12 @@
 import Gtk from "gi://Gtk?version=4.0";
 import Gdk from "gi://Gdk";
-
 import Adw from "gi://Adw";
 import Gio from "gi://Gio";
 
+import { build } from "../../troll/src/builder.js";
+
 import IconWidget from "./IconWidget.js";
-import resource from "./main.blp";
+import resource from "./main.blp" with { type: "uri" };
 
 const toasts = new Set();
 
@@ -21,10 +22,8 @@ export default function IconLibrary() {
     dev_kit_icons,
   );
 
-  const builder = Gtk.Builder.new_from_resource(resource);
-
-  const overlay = builder.get_object("overlay");
-  const search_entry = builder.get_object("search_entry");
+  const { window, overlay, search_entry, flow_box_devkit, flow_box_platform } =
+    build(resource);
 
   function selectIcon(icon_name) {
     clipboard.set(icon_name);
@@ -41,9 +40,6 @@ export default function IconLibrary() {
     overlay.add_toast(toast);
   }
 
-  const flow_box_devkit = builder.get_object("flow_box_devkit");
-  const flow_box_platform = builder.get_object("flow_box_platform");
-
   function filter_func({ icon_name }) {
     return icons[icon_name]?.some((tag) => tag.includes(search_entry.text));
   }
@@ -84,7 +80,6 @@ export default function IconLibrary() {
   populateIconDevKit();
   populatePlatformIcons();
 
-  const window = builder.get_object("window");
   return window;
 }
 
diff --git a/src/Library/Library.blp b/src/Library/Library.blp
index 9c49fb4ae..d4de01568 100644
--- a/src/Library/Library.blp
+++ b/src/Library/Library.blp
@@ -1,7 +1,7 @@
 using Gtk 4.0;
 using Adw 1;
 
-Adw.PreferencesWindow library {
+Adw.PreferencesWindow window {
   hide-on-close: true;
   modal: false;
   title: _("Library");
diff --git a/src/Library/Library.js b/src/Library/Library.js
index 9bcdd34b1..0afe752e4 100644
--- a/src/Library/Library.js
+++ b/src/Library/Library.js
@@ -1,5 +1,4 @@
 import Gio from "gi://Gio";
-import Gtk from "gi://Gtk";
 
 import {
   decode,
@@ -9,17 +8,18 @@ import {
 } from "../util.js";
 import Window from "../window.js";
 
-import resource from "./Library.blp";
+import resource from "./Library.blp" with { type: "uri" };
 import { createSessionFromDemo } from "../sessions.js";
 import EntryRow from "./EntryRow.js";
 
 import illustration from "./library.svg";
 
-export default function Library({ application }) {
-  const builder = Gtk.Builder.new_from_resource(resource);
-  const window = builder.get_object("library");
+import { build } from "../../troll/src/builder.js";
 
-  const picture_illustration = builder.get_object("picture_illustration");
+export default function Library({ application }) {
+  const objects = build(resource);
+  const { window, picture_illustration } = objects;
+  window.application = application;
   picture_illustration.set_resource(illustration);
 
   let last_selected;
@@ -39,7 +39,7 @@ export default function Library({ application }) {
       }).catch(console.error);
     });
 
-    builder.get_object(`library_${demo.category}`).add(widget);
+    objects[`library_${demo.category}`].add(widget);
   });
 
   const action_library = new Gio.SimpleAction({
diff --git a/src/shortcutsWindow.blp b/src/shortcutsWindow.blp
index 67d4bb6d5..bd2bb387f 100644
--- a/src/shortcutsWindow.blp
+++ b/src/shortcutsWindow.blp
@@ -1,6 +1,6 @@
 using Gtk 4.0;
 
-ShortcutsWindow window_shortcuts {
+ShortcutsWindow window {
   hide-on-close: true;
 
   ShortcutsSection {
diff --git a/src/shortcutsWindow.js b/src/shortcutsWindow.js
index d14a27d40..147b7b212 100644
--- a/src/shortcutsWindow.js
+++ b/src/shortcutsWindow.js
@@ -1,23 +1,23 @@
-import Gtk from "gi://Gtk";
 import Gio from "gi://Gio";
 
-import resource from "./shortcutsWindow.blp";
+import resource from "./shortcutsWindow.blp" with { type: "uri" };
+
+import { build } from "../troll/src/builder.js";
 
 export default function ShortcutsWindow({ application }) {
-  let window_shortcuts;
+  let window;
 
   const action_shortcuts = new Gio.SimpleAction({
     name: "shortcuts",
     parameter_type: null,
   });
   action_shortcuts.connect("activate", () => {
-    if (!window_shortcuts) {
-      const builder = Gtk.Builder.new_from_resource(resource);
-      window_shortcuts = builder.get_object("window_shortcuts");
-      window_shortcuts.set_transient_for(application.get_active_window());
-      window_shortcuts.set_application(application);
+    if (!window) {
+      ({ window } = build(resource));
+      window.set_transient_for(application.get_active_window());
+      window.set_application(application);
     }
-    window_shortcuts.present();
+    window.present();
   });
   application.add_action(action_shortcuts);
   application.set_accels_for_action("app.shortcuts", ["<Control>question"]);