diff --git a/.changeset/thin-bikes-tan.md b/.changeset/thin-bikes-tan.md
new file mode 100644
index 00000000000..121b3208d52
--- /dev/null
+++ b/.changeset/thin-bikes-tan.md
@@ -0,0 +1,6 @@
+---
+'@firebase/app': minor
+'firebase': minor
+---
+
+initializeServerApp now supports auto-initialization for Firebase App Hosting.
diff --git a/common/api-review/app.api.md b/common/api-review/app.api.md
index 4e93f1ae87f..c12089c1520 100644
--- a/common/api-review/app.api.md
+++ b/common/api-review/app.api.md
@@ -110,14 +110,20 @@ export function initializeApp(options: FirebaseOptions, config?: FirebaseAppSett
 export function initializeApp(): FirebaseApp;
 
 // @public
-export function initializeServerApp(options: FirebaseOptions | FirebaseApp, config: FirebaseServerAppSettings): FirebaseServerApp;
+export function initializeServerApp(options: FirebaseOptions | FirebaseApp, config?: FirebaseServerAppSettings): FirebaseServerApp;
+
+// @public
+export function initializeServerApp(config?: FirebaseServerAppSettings): FirebaseServerApp;
 
 // @internal (undocumented)
-export function _isFirebaseApp(obj: FirebaseApp | FirebaseOptions): obj is FirebaseApp;
+export function _isFirebaseApp(obj: FirebaseApp | FirebaseOptions | FirebaseAppSettings): obj is FirebaseApp;
 
 // @internal (undocumented)
 export function _isFirebaseServerApp(obj: FirebaseApp | FirebaseServerApp | null | undefined): obj is FirebaseServerApp;
 
+// @internal (undocumented)
+export function _isFirebaseServerAppSettings(obj: FirebaseApp | FirebaseOptions | FirebaseAppSettings): obj is FirebaseServerAppSettings;
+
 // @public
 export function onLog(logCallback: LogCallback | null, options?: LogOptions): void;
 
diff --git a/docs-devsite/app.md b/docs-devsite/app.md
index 9c3b322aaaf..0c9b2d03e4b 100644
--- a/docs-devsite/app.md
+++ b/docs-devsite/app.md
@@ -23,6 +23,8 @@ This package coordinates the communication between the different Firebase compon
 |  <b>function()</b> |
 |  [getApps()](./app.md#getapps) | A (read-only) array of all initialized apps. |
 |  [initializeApp()](./app.md#initializeapp) | Creates and initializes a FirebaseApp instance. |
+|  <b>function(config, ...)</b> |
+|  [initializeServerApp(config)](./app.md#initializeserverapp_e7d0728) | Creates and initializes a [FirebaseServerApp](./app.firebaseserverapp.md#firebaseserverapp_interface) instance. |
 |  <b>function(libraryKeyOrName, ...)</b> |
 |  [registerVersion(libraryKeyOrName, version, variant)](./app.md#registerversion_f673248) | Registers a library's name and version for platform logging purposes. |
 |  <b>function(logCallback, ...)</b> |
@@ -116,6 +118,38 @@ export declare function initializeApp(): FirebaseApp;
 
 [FirebaseApp](./app.firebaseapp.md#firebaseapp_interface)
 
+## function(config, ...)
+
+### initializeServerApp(config) {:#initializeserverapp_e7d0728}
+
+Creates and initializes a [FirebaseServerApp](./app.firebaseserverapp.md#firebaseserverapp_interface) instance.
+
+<b>Signature:</b>
+
+```typescript
+export declare function initializeServerApp(config?: FirebaseServerAppSettings): FirebaseServerApp;
+```
+
+#### Parameters
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  config | [FirebaseServerAppSettings](./app.firebaseserverappsettings.md#firebaseserverappsettings_interface) | Optional <code>FirebaseServerApp</code> settings. |
+
+<b>Returns:</b>
+
+[FirebaseServerApp](./app.firebaseserverapp.md#firebaseserverapp_interface)
+
+The initialized `FirebaseServerApp`<!-- -->.
+
+#### Exceptions
+
+If invoked in an unsupported non-server environment such as a browser.
+
+If [FirebaseServerAppSettings.releaseOnDeref](./app.firebaseserverappsettings.md#firebaseserverappsettingsreleaseonderef) is defined but the runtime doesn't provide Finalization Registry support.
+
+If the `FIREBASE_OPTIONS` enviornment variable does not contain a valid project configuration required for auto-initialization.
+
 ## function(libraryKeyOrName, ...)
 
 ### registerVersion(libraryKeyOrName, version, variant) {:#registerversion_f673248}
@@ -260,6 +294,12 @@ export declare function initializeApp(options: FirebaseOptions, name?: string):
 
 The initialized app.
 
+#### Exceptions
+
+If the optional `name` parameter is malformed or empty.
+
+If a `FirebaseApp` already exists with the same name but with a different configuration.
+
 ### Example 1
 
 
@@ -312,6 +352,12 @@ export declare function initializeApp(options: FirebaseOptions, config?: Firebas
 
 [FirebaseApp](./app.firebaseapp.md#firebaseapp_interface)
 
+#### Exceptions
+
+If [FirebaseAppSettings.name](./app.firebaseappsettings.md#firebaseappsettingsname) is defined but the value is malformed or empty.
+
+If a `FirebaseApp` already exists with the same name but with a different configuration.
+
 ### initializeServerApp(options, config) {:#initializeserverapp_30ab697}
 
 Creates and initializes a [FirebaseServerApp](./app.firebaseserverapp.md#firebaseserverapp_interface) instance.
@@ -323,7 +369,7 @@ See [Add Firebase to your app](https://firebase.google.com/docs/web/setup#add_fi
 <b>Signature:</b>
 
 ```typescript
-export declare function initializeServerApp(options: FirebaseOptions | FirebaseApp, config: FirebaseServerAppSettings): FirebaseServerApp;
+export declare function initializeServerApp(options: FirebaseOptions | FirebaseApp, config?: FirebaseServerAppSettings): FirebaseServerApp;
 ```
 
 #### Parameters
@@ -331,7 +377,7 @@ export declare function initializeServerApp(options: FirebaseOptions | FirebaseA
 |  Parameter | Type | Description |
 |  --- | --- | --- |
 |  options | [FirebaseOptions](./app.firebaseoptions.md#firebaseoptions_interface) \| [FirebaseApp](./app.firebaseapp.md#firebaseapp_interface) | <code>Firebase.AppOptions</code> to configure the app's services, or a a <code>FirebaseApp</code> instance which contains the <code>AppOptions</code> within. |
-|  config | [FirebaseServerAppSettings](./app.firebaseserverappsettings.md#firebaseserverappsettings_interface) | <code>FirebaseServerApp</code> configuration. |
+|  config | [FirebaseServerAppSettings](./app.firebaseserverappsettings.md#firebaseserverappsettings_interface) | Optional <code>FirebaseServerApp</code> settings. |
 
 <b>Returns:</b>
 
@@ -339,6 +385,12 @@ export declare function initializeServerApp(options: FirebaseOptions | FirebaseA
 
 The initialized `FirebaseServerApp`<!-- -->.
 
+#### Exceptions
+
+If invoked in an unsupported non-server environment such as a browser.
+
+If [FirebaseServerAppSettings.releaseOnDeref](./app.firebaseserverappsettings.md#firebaseserverappsettingsreleaseonderef) is defined but the runtime doesn't provide Finalization Registry support.
+
 ### Example
 
 
diff --git a/packages/app/src/api.ts b/packages/app/src/api.ts
index 9cba8ec6f50..6fd50060a6a 100644
--- a/packages/app/src/api.ts
+++ b/packages/app/src/api.ts
@@ -37,6 +37,7 @@ import {
   _apps,
   _components,
   _isFirebaseApp,
+  _isFirebaseServerAppSettings,
   _registerComponent,
   _serverApps
 } from './internal';
@@ -106,6 +107,10 @@ export const SDK_VERSION = version;
  *
  * @returns The initialized app.
  *
+ * @throws If the optional `name` parameter is malformed or empty.
+ *
+ * @throws If a `FirebaseApp` already exists with the same name but with a different configuration.
+ *
  * @public
  */
 export function initializeApp(
@@ -118,6 +123,9 @@ export function initializeApp(
  * @param options - Options to configure the app's services.
  * @param config - FirebaseApp Configuration
  *
+ * @throws If {@link FirebaseAppSettings.name} is defined but the value is malformed or empty.
+ *
+ * @throws If a `FirebaseApp` already exists with the same name but with a different configuration.
  * @public
  */
 export function initializeApp(
@@ -220,41 +228,75 @@ export function initializeApp(
  *
  * @param options - `Firebase.AppOptions` to configure the app's services, or a
  *   a `FirebaseApp` instance which contains the `AppOptions` within.
- * @param config - `FirebaseServerApp` configuration.
+ * @param config - Optional `FirebaseServerApp` settings.
  *
  * @returns The initialized `FirebaseServerApp`.
  *
+ * @throws If invoked in an unsupported non-server environment such as a browser.
+ *
+ * @throws If {@link FirebaseServerAppSettings.releaseOnDeref} is defined but the runtime doesn't
+ *   provide Finalization Registry support.
+ *
  * @public
  */
 export function initializeServerApp(
   options: FirebaseOptions | FirebaseApp,
-  config: FirebaseServerAppSettings
+  config?: FirebaseServerAppSettings
 ): FirebaseServerApp;
 
+/**
+ * Creates and initializes a {@link @firebase/app#FirebaseServerApp} instance.
+ *
+ * @param config - Optional `FirebaseServerApp` settings.
+ *
+ * @returns The initialized `FirebaseServerApp`.
+ *
+ * @throws If invoked in an unsupported non-server environment such as a browser.
+ * @throws If {@link FirebaseServerAppSettings.releaseOnDeref} is defined but the runtime doesn't
+ *   provide Finalization Registry support.
+ * @throws If the `FIREBASE_OPTIONS` enviornment variable does not contain a valid project
+ *   configuration required for auto-initialization.
+ *
+ * @public
+ */
 export function initializeServerApp(
-  _options: FirebaseOptions | FirebaseApp,
-  _serverAppConfig: FirebaseServerAppSettings
+  config?: FirebaseServerAppSettings
+): FirebaseServerApp;
+export function initializeServerApp(
+  _options?: FirebaseApp | FirebaseServerAppSettings | FirebaseOptions,
+  _serverAppConfig: FirebaseServerAppSettings = {}
 ): FirebaseServerApp {
   if (isBrowser() && !isWebWorker()) {
     // FirebaseServerApp isn't designed to be run in browsers.
     throw ERROR_FACTORY.create(AppError.INVALID_SERVER_APP_ENVIRONMENT);
   }
 
-  if (_serverAppConfig.automaticDataCollectionEnabled === undefined) {
-    _serverAppConfig.automaticDataCollectionEnabled = true;
+  let firebaseOptions: FirebaseOptions | undefined;
+  let serverAppSettings: FirebaseServerAppSettings = _serverAppConfig || {};
+
+  if (_options) {
+    if (_isFirebaseApp(_options)) {
+      firebaseOptions = _options.options;
+    } else if (_isFirebaseServerAppSettings(_options)) {
+      serverAppSettings = _options;
+    } else {
+      firebaseOptions = _options;
+    }
   }
 
-  let appOptions: FirebaseOptions;
-  if (_isFirebaseApp(_options)) {
-    appOptions = _options.options;
-  } else {
-    appOptions = _options;
+  if (serverAppSettings.automaticDataCollectionEnabled === undefined) {
+    serverAppSettings.automaticDataCollectionEnabled = true;
+  }
+
+  firebaseOptions ||= getDefaultAppConfig();
+  if (!firebaseOptions) {
+    throw ERROR_FACTORY.create(AppError.NO_OPTIONS);
   }
 
   // Build an app name based on a hash of the configuration options.
   const nameObj = {
-    ..._serverAppConfig,
-    ...appOptions
+    ...serverAppSettings,
+    ...firebaseOptions
   };
 
   // However, Do not mangle the name based on releaseOnDeref, since it will vary between the
@@ -270,7 +312,7 @@ export function initializeServerApp(
     );
   };
 
-  if (_serverAppConfig.releaseOnDeref !== undefined) {
+  if (serverAppSettings.releaseOnDeref !== undefined) {
     if (typeof FinalizationRegistry === 'undefined') {
       throw ERROR_FACTORY.create(
         AppError.FINALIZATION_REGISTRY_NOT_SUPPORTED,
@@ -283,7 +325,7 @@ export function initializeServerApp(
   const existingApp = _serverApps.get(nameString) as FirebaseServerApp;
   if (existingApp) {
     (existingApp as FirebaseServerAppImpl).incRefCount(
-      _serverAppConfig.releaseOnDeref
+      serverAppSettings.releaseOnDeref
     );
     return existingApp;
   }
@@ -294,8 +336,8 @@ export function initializeServerApp(
   }
 
   const newApp = new FirebaseServerAppImpl(
-    appOptions,
-    _serverAppConfig,
+    firebaseOptions,
+    serverAppSettings,
     nameString,
     container
   );
diff --git a/packages/app/src/internal.ts b/packages/app/src/internal.ts
index cbcdcb26501..422c941aba3 100644
--- a/packages/app/src/internal.ts
+++ b/packages/app/src/internal.ts
@@ -17,6 +17,8 @@
 
 import {
   FirebaseApp,
+  FirebaseAppSettings,
+  FirebaseServerAppSettings,
   FirebaseOptions,
   FirebaseServerApp
 } from './public-types';
@@ -147,18 +149,40 @@ export function _removeServiceInstance<T extends Name>(
 
 /**
  *
- * @param obj - an object of type FirebaseApp or FirebaseOptions.
+ * @param obj - an object of type FirebaseApp, FirebaseOptions or FirebaseAppSettings.
  *
  * @returns true if the provide object is of type FirebaseApp.
  *
  * @internal
  */
 export function _isFirebaseApp(
-  obj: FirebaseApp | FirebaseOptions
+  obj: FirebaseApp | FirebaseOptions | FirebaseAppSettings
 ): obj is FirebaseApp {
   return (obj as FirebaseApp).options !== undefined;
 }
 
+/**
+ *
+ * @param obj - an object of type FirebaseApp, FirebaseOptions or FirebaseAppSettings.
+ *
+ * @returns true if the provided object is of type FirebaseServerAppImpl.
+ *
+ * @internal
+ */
+export function _isFirebaseServerAppSettings(
+  obj: FirebaseApp | FirebaseOptions | FirebaseAppSettings
+): obj is FirebaseServerAppSettings {
+  if (_isFirebaseApp(obj)) {
+    return false;
+  }
+  return (
+    'authIdToken' in obj ||
+    'appCheckToken' in obj ||
+    'releaseOnDeref' in obj ||
+    'automaticDataCollectionEnabled' in obj
+  );
+}
+
 /**
  *
  * @param obj - an object of type FirebaseApp.