diff --git a/src/extensions/core/clipspace.js b/src/extensions/core/clipspace.js
index e376a02f70..0ec0987b8a 100644
--- a/src/extensions/core/clipspace.js
+++ b/src/extensions/core/clipspace.js
@@ -1,6 +1,6 @@
-import { app } from "../../scripts/app.js";
-import { ComfyDialog, $el } from "../../scripts/ui.js";
-import { ComfyApp } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
+import { ComfyDialog, $el } from "../../scripts/ui";
+import { ComfyApp } from "../../scripts/app";
 
 export class ClipspaceDialog extends ComfyDialog {
 	static items = [];
diff --git a/src/extensions/core/colorPalette.js b/src/extensions/core/colorPalette.js
index 02546782f8..fef2a42709 100644
--- a/src/extensions/core/colorPalette.js
+++ b/src/extensions/core/colorPalette.js
@@ -1,5 +1,5 @@
-import {app} from "../../scripts/app.js";
-import {$el} from "../../scripts/ui.js";
+import {app} from "../../scripts/app";
+import {$el} from "../../scripts/ui";
 
 // Manage color palettes
 
diff --git a/src/extensions/core/contextMenuFilter.js b/src/extensions/core/contextMenuFilter.js
index 0a305391a4..98fd58b8a3 100644
--- a/src/extensions/core/contextMenuFilter.js
+++ b/src/extensions/core/contextMenuFilter.js
@@ -1,4 +1,4 @@
-import {app} from "../../scripts/app.js";
+import {app} from "../../scripts/app";
 
 // Adds filtering to combo context menus
 
diff --git a/src/extensions/core/dynamicPrompts.js b/src/extensions/core/dynamicPrompts.js
index 7417361ba9..f342e1b120 100644
--- a/src/extensions/core/dynamicPrompts.js
+++ b/src/extensions/core/dynamicPrompts.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 // Allows for simple dynamic prompt replacement
 // Inputs in the format {a|b} will have a random value of a or b chosen when the prompt is queued.
diff --git a/src/extensions/core/editAttention.js b/src/extensions/core/editAttention.js
index 6792b23572..fc8da36a1b 100644
--- a/src/extensions/core/editAttention.js
+++ b/src/extensions/core/editAttention.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 // Allows you to edit the attention weight by holding ctrl (or cmd) and using the up/down arrow keys
 
diff --git a/src/extensions/core/groupNode.js b/src/extensions/core/groupNode.js
index 0b0763d1d4..c0a575d9eb 100644
--- a/src/extensions/core/groupNode.js
+++ b/src/extensions/core/groupNode.js
@@ -1,7 +1,7 @@
-import { app } from "../../scripts/app.js";
-import { api } from "../../scripts/api.js";
-import { mergeIfValid } from "./widgetInputs.js";
-import { ManageGroupDialog } from "./groupNodeManage.js";
+import { app } from "../../scripts/app";
+import { api } from "../../scripts/api";
+import { mergeIfValid } from "./widgetInputs";
+import { ManageGroupDialog } from "./groupNodeManage";
 
 const GROUP = Symbol();
 
diff --git a/src/extensions/core/groupNodeManage.js b/src/extensions/core/groupNodeManage.js
index 1ab3383868..02dc81b2d4 100644
--- a/src/extensions/core/groupNodeManage.js
+++ b/src/extensions/core/groupNodeManage.js
@@ -1,7 +1,7 @@
-import { $el, ComfyDialog } from "../../scripts/ui.js";
-import { DraggableList } from "../../scripts/ui/draggableList.js";
-import { addStylesheet } from "../../scripts/utils.js";
-import { GroupNodeConfig, GroupNodeHandler } from "./groupNode.js";
+import { $el, ComfyDialog } from "../../scripts/ui";
+import { DraggableList } from "../../scripts/ui/draggableList";
+import { addStylesheet } from "../../scripts/utils";
+import { GroupNodeConfig, GroupNodeHandler } from "./groupNode";
 
 addStylesheet(import.meta.url);
 
diff --git a/src/extensions/core/groupOptions.js b/src/extensions/core/groupOptions.js
index 5dd21e7301..ec038d0432 100644
--- a/src/extensions/core/groupOptions.js
+++ b/src/extensions/core/groupOptions.js
@@ -1,4 +1,4 @@
-import {app} from "../../scripts/app.js";
+import {app} from "../../scripts/app";
 
 function setNodeMode(node, mode) {
     node.mode = mode;
diff --git a/src/extensions/core/index.js b/src/extensions/core/index.js
new file mode 100644
index 0000000000..c408a97299
--- /dev/null
+++ b/src/extensions/core/index.js
@@ -0,0 +1,23 @@
+import "./clipspace";
+import "./colorPalette";
+import "./contextMenuFilter";
+import "./dynamicPrompts";
+import "./editAttention";
+import "./groupNode";
+import "./groupNodeManage";
+import "./groupOptions";
+import "./invertMenuScrolling";
+import "./keybinds";
+import "./linkRenderMode";
+import "./maskeditor";
+import "./nodeTemplates";
+import "./noteNode";
+import "./rerouteNode";
+import "./saveImageExtraOutput";
+import "./simpleTouchSupport";
+import "./slotDefaults";
+import "./snapToGrid";
+import "./undoRedo";
+import "./uploadImage";
+import "./webcamCapture";
+import "./widgetInputs";
diff --git a/src/extensions/core/invertMenuScrolling.js b/src/extensions/core/invertMenuScrolling.js
index 98a1786ab4..81fb8ed38c 100644
--- a/src/extensions/core/invertMenuScrolling.js
+++ b/src/extensions/core/invertMenuScrolling.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 // Inverts the scrolling of context menus
 
diff --git a/src/extensions/core/keybinds.js b/src/extensions/core/keybinds.js
index ac367c116f..5295cf8d72 100644
--- a/src/extensions/core/keybinds.js
+++ b/src/extensions/core/keybinds.js
@@ -1,4 +1,4 @@
-import {app} from "../../scripts/app.js";
+import {app} from "../../scripts/app";
 
 app.registerExtension({
 	name: "Comfy.Keybinds",
diff --git a/src/extensions/core/linkRenderMode.js b/src/extensions/core/linkRenderMode.js
index fb4df4234e..ca15d16e1a 100644
--- a/src/extensions/core/linkRenderMode.js
+++ b/src/extensions/core/linkRenderMode.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 const id = "Comfy.LinkRenderMode";
 const ext = {
diff --git a/src/extensions/core/maskeditor.js b/src/extensions/core/maskeditor.js
index 36f7496e71..e314910eee 100644
--- a/src/extensions/core/maskeditor.js
+++ b/src/extensions/core/maskeditor.js
@@ -1,8 +1,8 @@
-import { app } from "../../scripts/app.js";
-import { ComfyDialog, $el } from "../../scripts/ui.js";
-import { ComfyApp } from "../../scripts/app.js";
-import { api } from "../../scripts/api.js"
-import { ClipspaceDialog } from "./clipspace.js";
+import { app } from "../../scripts/app";
+import { ComfyDialog, $el } from "../../scripts/ui";
+import { ComfyApp } from "../../scripts/app";
+import { api } from "../../scripts/api";
+import { ClipspaceDialog } from "./clipspace";
 
 // Helper function to convert a data URL to a Blob object
 function dataURLToBlob(dataURL) {
diff --git a/src/extensions/core/nodeTemplates.js b/src/extensions/core/nodeTemplates.js
index 9350ba6549..d0da2c981b 100644
--- a/src/extensions/core/nodeTemplates.js
+++ b/src/extensions/core/nodeTemplates.js
@@ -1,7 +1,7 @@
-import { app } from "../../scripts/app.js";
-import { api } from "../../scripts/api.js";
-import { ComfyDialog, $el } from "../../scripts/ui.js";
-import { GroupNodeConfig, GroupNodeHandler } from "./groupNode.js";
+import { app } from "../../scripts/app";
+import { api } from "../../scripts/api";
+import { ComfyDialog, $el } from "../../scripts/ui";
+import { GroupNodeConfig, GroupNodeHandler } from "./groupNode";
 
 // Adds the ability to save and add multiple nodes as a template
 // To save:
diff --git a/src/extensions/core/noteNode.js b/src/extensions/core/noteNode.js
index 8d89054e9f..c1ba699408 100644
--- a/src/extensions/core/noteNode.js
+++ b/src/extensions/core/noteNode.js
@@ -1,5 +1,5 @@
-import {app} from "../../scripts/app.js";
-import {ComfyWidgets} from "../../scripts/widgets.js";
+import {app} from "../../scripts/app";
+import {ComfyWidgets} from "../../scripts/widgets";
 // Node that add notes to your project
 
 app.registerExtension({
diff --git a/src/extensions/core/rerouteNode.js b/src/extensions/core/rerouteNode.js
index 4feff91e50..bb8666270a 100644
--- a/src/extensions/core/rerouteNode.js
+++ b/src/extensions/core/rerouteNode.js
@@ -1,5 +1,5 @@
-import { app } from "../../scripts/app.js";
-import { mergeIfValid, getWidgetConfig, setWidgetConfig } from "./widgetInputs.js";
+import { app } from "../../scripts/app";
+import { mergeIfValid, getWidgetConfig, setWidgetConfig } from "./widgetInputs";
 
 // Node that allows you to redirect connections for cleaner graphs
 
diff --git a/src/extensions/core/saveImageExtraOutput.js b/src/extensions/core/saveImageExtraOutput.js
index a0506b43b6..5dccd2ac33 100644
--- a/src/extensions/core/saveImageExtraOutput.js
+++ b/src/extensions/core/saveImageExtraOutput.js
@@ -1,5 +1,5 @@
-import { app } from "../../scripts/app.js";
-import { applyTextReplacements } from "../../scripts/utils.js";
+import { app } from "../../scripts/app";
+import { applyTextReplacements } from "../../scripts/utils";
 // Use widget values and dates in output filenames
 
 app.registerExtension({
diff --git a/src/extensions/core/simpleTouchSupport.js b/src/extensions/core/simpleTouchSupport.js
index 041fc2c4ca..451c14d9ce 100644
--- a/src/extensions/core/simpleTouchSupport.js
+++ b/src/extensions/core/simpleTouchSupport.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 let touchZooming;
 let touchCount = 0;
diff --git a/src/extensions/core/slotDefaults.js b/src/extensions/core/slotDefaults.js
index 718d254057..905358cda0 100644
--- a/src/extensions/core/slotDefaults.js
+++ b/src/extensions/core/slotDefaults.js
@@ -1,5 +1,5 @@
-import { app } from "../../scripts/app.js";
-import { ComfyWidgets } from "../../scripts/widgets.js";
+import { app } from "../../scripts/app";
+import { ComfyWidgets } from "../../scripts/widgets";
 // Adds defaults for quickly adding nodes with middle click on the input/output
 
 app.registerExtension({
diff --git a/src/extensions/core/snapToGrid.js b/src/extensions/core/snapToGrid.js
index aac0177484..4ca89ad32c 100644
--- a/src/extensions/core/snapToGrid.js
+++ b/src/extensions/core/snapToGrid.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 // Shift + drag/resize to snap to grid
 
diff --git a/src/extensions/core/undoRedo.js b/src/extensions/core/undoRedo.js
index 900eed2a7c..3bdd6760c4 100644
--- a/src/extensions/core/undoRedo.js
+++ b/src/extensions/core/undoRedo.js
@@ -1,5 +1,5 @@
-import { app } from "../../scripts/app.js";
-import { api } from "../../scripts/api.js"
+import { app } from "../../scripts/app";
+import { api } from "../../scripts/api";
 
 const MAX_HISTORY = 50;
 
diff --git a/src/extensions/core/uploadImage.js b/src/extensions/core/uploadImage.js
index 530c4599e7..7e6186c64a 100644
--- a/src/extensions/core/uploadImage.js
+++ b/src/extensions/core/uploadImage.js
@@ -1,4 +1,4 @@
-import { app } from "../../scripts/app.js";
+import { app } from "../../scripts/app";
 
 // Adds an upload button to the nodes
 
diff --git a/src/extensions/core/webcamCapture.js b/src/extensions/core/webcamCapture.js
index dd5725bd4f..6e60e9b36f 100644
--- a/src/extensions/core/webcamCapture.js
+++ b/src/extensions/core/webcamCapture.js
@@ -1,5 +1,5 @@
-import { app } from "../../scripts/app.js";
-import { api } from "../../scripts/api.js";
+import { app } from "../../scripts/app";
+import { api } from "../../scripts/api";
 
 const WEBCAM_READY = Symbol();
 
diff --git a/src/extensions/core/widgetInputs.js b/src/extensions/core/widgetInputs.js
index f1a1d22cd9..fc705f4678 100644
--- a/src/extensions/core/widgetInputs.js
+++ b/src/extensions/core/widgetInputs.js
@@ -1,6 +1,6 @@
-import { ComfyWidgets, addValueControlWidgets } from "../../scripts/widgets.js";
-import { app } from "../../scripts/app.js";
-import { applyTextReplacements } from "../../scripts/utils.js";
+import { ComfyWidgets, addValueControlWidgets } from "../../scripts/widgets";
+import { app } from "../../scripts/app";
+import { applyTextReplacements } from "../../scripts/utils";
 
 const CONVERTED_TYPE = "converted-widget";
 const VALID_TYPES = ["STRING", "combo", "number", "BOOLEAN"];
diff --git a/src/scripts/app.ts b/src/scripts/app.ts
index e4c5a3b5cf..dbe52858e3 100644
--- a/src/scripts/app.ts
+++ b/src/scripts/app.ts
@@ -1503,14 +1503,19 @@ export class ComfyApp {
 	    const extensions = await api.getExtensions();
 	    this.logging.addEntry("Comfy.App", "debug", { Extensions: extensions });
 
-	    const extensionPromises = extensions.map(async ext => {
+	    const extensionPromises = extensions
+		.filter(extension => !extension.includes("extensions/core"))
+		.map(async ext => {
 	        try {
-	            await import(api.apiURL(ext));
+	            await import(/* @vite-ignore */api.apiURL(ext));
 	        } catch (error) {
 	            console.error("Error loading extension", ext, error);
 	        }
 	    });
 
+		// Need to load core extensions first as some custom extensions
+		// may depend on them.
+		await import("../extensions/core/index.js");
 	    await Promise.all(extensionPromises);
 	}
 
diff --git a/vite.config.mts b/vite.config.mts
index 8aa796bace..ede9783755 100644
--- a/vite.config.mts
+++ b/vite.config.mts
@@ -12,7 +12,8 @@ function comfyAPIPlugin(): Plugin {
 	return {
 		name: 'comfy-api-plugin',
 		transform(code: string, id: string) {
-			if (id.endsWith('.ts')) {
+			// TODO: Remove second condition after all js files are converted to ts
+			if (id.endsWith('.ts') || (id.endsWith('.js') && id.includes("extensions/core"))) {
 				const result = transformExports(code, id);
 
 				if (result.exports.length > 0) {
@@ -87,7 +88,6 @@ export default defineConfig({
 		viteStaticCopy({
 			targets: [
 				{src: "src/lib/*", dest: "lib/"},
-				{src: "src/extensions/*", dest: "extensions/"},
 			],
 		}),
 	],