diff --git a/src/App.ts b/src/App.ts
index 51ea96b7..ab86ac9b 100644
--- a/src/App.ts
+++ b/src/App.ts
@@ -39,7 +39,26 @@ export function createAppPage(derby): typeof Page {
 
 export interface AppOptions {
   appMetadata?: Record<string, string>,
-  scriptHash?: string,
+  /** 
+    * Base URL that the JS bundles are served from, with no trailing slash.
+    * Used by bundler plugins such as derby-webpack and derby-browserify.
+    */
+  scriptBaseUrl?: string,
+  /**
+    * If true, then Derby's <script> tags have the `crossorigin` attribute set by the bundler plugin.
+    */
+  scriptCrossOrigin?: boolean,
+  /**
+    * If set, this is used for auto-refresh in development to determine whether the browser
+    * should auto-refresh due to running different code than the server. Some bundler plugins, 
+    * such as derby-webpack, do their own hot reload and don't use this mechanism.
+    */
+  scriptHash?: string;
+  /**
+    * Base URL for js.map files, if different from scriptBaseUrl.
+    */
+  scriptMapBaseUrl?: string,
+  [key: string]: unknown,
 }
 
 type OnRouteCallback = (this: Page, page: Page, model: Model, params: PageParams, done?: () => void) => void;
diff --git a/src/AppForServer.ts b/src/AppForServer.ts
index e591ee7e..05a8194d 100644
--- a/src/AppForServer.ts
+++ b/src/AppForServer.ts
@@ -8,7 +8,7 @@
 
 import * as racer from 'racer';
 
-import { App } from './App';
+import { App, AppOptions } from './App';
 import { type Derby } from './Derby';
 import { type StyleCompilerOptions } from './files';
 import { PageForServer } from './PageForServer';
@@ -79,7 +79,7 @@ export class AppForServer extends App {
   watchFiles: boolean;
   router: any;
 
-  constructor(derby: Derby, name: string, filename: string, options) {
+  constructor(derby: Derby, name: string, filename: string, options?: AppOptions) {
     super(derby, name, filename, options);
     this._init(options);
   }