diff --git a/packages/frontend-plugin-api/api-report.md b/packages/frontend-plugin-api/api-report.md
index 2c92f863e8..96c7675c0d 100644
--- a/packages/frontend-plugin-api/api-report.md
+++ b/packages/frontend-plugin-api/api-report.md
@@ -147,20 +147,23 @@ export { AnyApiFactory };
 
 export { AnyApiRef };
 
-// @public (undocumented)
+// @public @deprecated (undocumented)
 export type AnyExtensionDataMap = {
-  [name in string]: ExtensionDataRef<
-    unknown,
-    string,
-    {
-      optional?: true;
-    }
-  >;
+  [name in string]: AnyExtensionDataRef;
 };
 
 // @public (undocumented)
+export type AnyExtensionDataRef = ExtensionDataRef<
+  unknown,
+  string,
+  {
+    optional?: true;
+  }
+>;
+
+// @public @deprecated (undocumented)
 export type AnyExtensionInputMap = {
-  [inputName in string]: ExtensionInput<
+  [inputName in string]: LegacyExtensionInput<
     AnyExtensionDataMap,
     {
       optional: boolean;
@@ -318,16 +321,18 @@ export { configApiRef };
 
 // @public (undocumented)
 export interface ConfigurableExtensionDataRef<
-  TId extends string,
   TData,
+  TId extends string,
   TConfig extends {
     optional?: true;
   } = {},
 > extends ExtensionDataRef<TData, TId, TConfig> {
+  // (undocumented)
+  (t: TData): ExtensionDataValue<TData, TId>;
   // (undocumented)
   optional(): ConfigurableExtensionDataRef<
-    TId,
     TData,
+    TId,
     TData & {
       optional: true;
     }
@@ -351,14 +356,14 @@ export type CoreErrorBoundaryFallbackProps = {
 // @public (undocumented)
 export const coreExtensionData: {
   reactElement: ConfigurableExtensionDataRef<
-    'core.reactElement',
     JSX_2.Element,
+    'core.reactElement',
     {}
   >;
-  routePath: ConfigurableExtensionDataRef<'core.routing.path', string, {}>;
+  routePath: ConfigurableExtensionDataRef<string, 'core.routing.path', {}>;
   routeRef: ConfigurableExtensionDataRef<
-    'core.routing.ref',
     RouteRef<AnyRouteRefParams>,
+    'core.routing.ref',
     {}
   >;
 };
@@ -397,8 +402,8 @@ export function createApiExtension<
 export namespace createApiExtension {
   const // (undocumented)
     factoryDataRef: ConfigurableExtensionDataRef<
-      'core.api.factory',
       AnyApiFactory,
+      'core.api.factory',
       {}
     >;
 }
@@ -455,10 +460,10 @@ export function createAppRootWrapperExtension<
 export namespace createAppRootWrapperExtension {
   const // (undocumented)
     componentDataRef: ConfigurableExtensionDataRef<
-      'app.root.wrapper',
       React_2.ComponentType<{
         children?: React_2.ReactNode;
       }>,
+      'app.root.wrapper',
       {}
     >;
 }
@@ -493,11 +498,11 @@ export function createComponentExtension<
 export namespace createComponentExtension {
   const // (undocumented)
     componentDataRef: ConfigurableExtensionDataRef<
-      'core.component.component',
       {
         ref: ComponentRef;
         impl: ComponentType;
       },
+      'core.component.component',
       {}
     >;
 }
@@ -508,6 +513,50 @@ export function createComponentRef<T extends {} = {}>(options: {
 }): ComponentRef<T>;
 
 // @public (undocumented)
+export function createExtension<
+  UOutput extends AnyExtensionDataRef,
+  TInputs extends {
+    [inputName in string]: ExtensionInput<
+      AnyExtensionDataRef,
+      {
+        optional: boolean;
+        singleton: boolean;
+      }
+    >;
+  },
+  TConfig,
+  TConfigInput,
+  TConfigSchema extends {
+    [key: string]: (zImpl: typeof z) => z.ZodType;
+  },
+  UFactoryOutput extends ExtensionDataValue<any, any>,
+>(
+  options: CreateExtensionOptions<
+    UOutput,
+    TInputs,
+    TConfig,
+    TConfigInput,
+    TConfigSchema,
+    UFactoryOutput
+  >,
+): ExtensionDefinition<
+  TConfig &
+    (string extends keyof TConfigSchema
+      ? {}
+      : {
+          [key in keyof TConfigSchema]: z.infer<ReturnType<TConfigSchema[key]>>;
+        }),
+  TConfigInput &
+    (string extends keyof TConfigSchema
+      ? {}
+      : z.input<
+          z.ZodObject<{
+            [key in keyof TConfigSchema]: ReturnType<TConfigSchema[key]>;
+          }>
+        >)
+>;
+
+// @public @deprecated (undocumented)
 export function createExtension<
   TOutput extends AnyExtensionDataMap,
   TInputs extends AnyExtensionInputMap,
@@ -517,7 +566,7 @@ export function createExtension<
     [key: string]: (zImpl: typeof z) => z.ZodType;
   },
 >(
-  options: CreateExtensionOptions<
+  options: LegacyCreateExtensionOptions<
     TOutput,
     TInputs,
     TConfig,
@@ -624,27 +673,27 @@ export interface CreateExtensionBlueprintOptions<
 // @public @deprecated (undocumented)
 export function createExtensionDataRef<TData>(
   id: string,
-): ConfigurableExtensionDataRef<string, TData>;
+): ConfigurableExtensionDataRef<TData, string>;
 
 // @public (undocumented)
 export function createExtensionDataRef<TData>(): {
   with<TId extends string>(options: {
     id: TId;
-  }): ConfigurableExtensionDataRef<TId, TData>;
+  }): ConfigurableExtensionDataRef<TData, TId>;
 };
 
-// @public (undocumented)
+// @public @deprecated (undocumented)
 export function createExtensionInput<
-  TExtensionData extends AnyExtensionDataMap,
+  TExtensionDataMap extends AnyExtensionDataMap,
   TConfig extends {
     singleton?: boolean;
     optional?: boolean;
   },
 >(
-  extensionData: TExtensionData,
+  extensionData: TExtensionDataMap,
   config?: TConfig,
-): ExtensionInput<
-  TExtensionData,
+): LegacyExtensionInput<
+  TExtensionDataMap,
   {
     singleton: TConfig['singleton'] extends true ? true : false;
     optional: TConfig['optional'] extends true ? true : false;
@@ -652,29 +701,62 @@ export function createExtensionInput<
 >;
 
 // @public (undocumented)
-export interface CreateExtensionOptions<
-  TOutput extends AnyExtensionDataMap,
-  TInputs extends AnyExtensionInputMap,
+export function createExtensionInput<
+  UExtensionData extends ExtensionDataRef<
+    unknown,
+    string,
+    {
+      optional?: true;
+    }
+  >,
+  TConfig extends {
+    singleton?: boolean;
+    optional?: boolean;
+  },
+>(
+  extensionData: Array<UExtensionData>,
+  config?: TConfig,
+): ExtensionInput<
+  UExtensionData,
+  {
+    singleton: TConfig['singleton'] extends true ? true : false;
+    optional: TConfig['optional'] extends true ? true : false;
+  }
+>;
+
+// @public (undocumented)
+export type CreateExtensionOptions<
+  UOutput extends AnyExtensionDataRef,
+  TInputs extends {
+    [inputName in string]: ExtensionInput<
+      AnyExtensionDataRef,
+      {
+        optional: boolean;
+        singleton: boolean;
+      }
+    >;
+  },
   TConfig,
   TConfigInput,
   TConfigSchema extends {
     [key: string]: (zImpl: typeof z) => z.ZodType;
   },
-> {
-  // (undocumented)
+  UFactoryOutput extends ExtensionDataValue<any, any>,
+> = {
+  kind?: string;
+  namespace?: string;
+  name?: string;
   attachTo: {
     id: string;
     input: string;
   };
-  // (undocumented)
+  disabled?: boolean;
+  inputs?: TInputs;
+  output: Array<UOutput>;
+  configSchema?: PortableSchema<TConfig, TConfigInput>;
   config?: {
     schema: TConfigSchema;
   };
-  // @deprecated (undocumented)
-  configSchema?: PortableSchema<TConfig, TConfigInput>;
-  // (undocumented)
-  disabled?: boolean;
-  // (undocumented)
   factory(context: {
     node: AppNode;
     config: TConfig &
@@ -686,18 +768,23 @@ export interface CreateExtensionOptions<
             >;
           });
     inputs: Expand<ResolvedExtensionInputs<TInputs>>;
-  }): Expand<ExtensionDataValues<TOutput>>;
-  // (undocumented)
-  inputs?: TInputs;
-  // (undocumented)
-  kind?: string;
-  // (undocumented)
-  name?: string;
-  // (undocumented)
-  namespace?: string;
-  // (undocumented)
-  output: TOutput;
-}
+  }): Iterable<UFactoryOutput>;
+} & ((
+  UOutput extends any
+    ? UOutput['config']['optional'] extends true
+      ? never
+      : UOutput['id']
+    : never
+) extends infer IRequiredOutputIds
+  ? [IRequiredOutputIds] extends [UFactoryOutput['id']]
+    ? {}
+    : {
+        'Error: The extension factory is missing the following outputs': Exclude<
+          IRequiredOutputIds,
+          UFactoryOutput['id']
+        >;
+      }
+  : never);
 
 // @public (undocumented)
 export function createExtensionOverrides(
@@ -750,12 +837,12 @@ export function createNavItemExtension(options: {
 export namespace createNavItemExtension {
   const // (undocumented)
     targetDataRef: ConfigurableExtensionDataRef<
-      'core.nav-item.target',
       {
         title: string;
         icon: IconComponent_2;
         routeRef: RouteRef<undefined>;
       },
+      'core.nav-item.target',
       {}
     >;
 }
@@ -772,11 +859,11 @@ export function createNavLogoExtension(options: {
 export namespace createNavLogoExtension {
   const // (undocumented)
     logoElementsDataRef: ConfigurableExtensionDataRef<
-      'core.nav-logo.logo-elements',
       {
         logoIcon?: JSX.Element | undefined;
         logoFull?: JSX.Element | undefined;
       },
+      'core.nav-logo.logo-elements',
       {}
     >;
 }
@@ -866,10 +953,10 @@ export function createRouterExtension<
 export namespace createRouterExtension {
   const // (undocumented)
     componentDataRef: ConfigurableExtensionDataRef<
-      'app.router.wrapper',
       React_2.ComponentType<{
         children?: React_2.ReactNode;
       }>,
+      'app.router.wrapper',
       {}
     >;
 }
@@ -903,8 +990,8 @@ export function createSignInPageExtension<
 export namespace createSignInPageExtension {
   const // (undocumented)
     componentDataRef: ConfigurableExtensionDataRef<
-      'core.sign-in-page.component',
       React_2.ComponentType<SignInPageProps>,
+      'core.sign-in-page.component',
       {}
     >;
 }
@@ -927,8 +1014,8 @@ export function createThemeExtension(
 export namespace createThemeExtension {
   const // (undocumented)
     themeDataRef: ConfigurableExtensionDataRef<
-      'core.theme.theme',
       AppTheme,
+      'core.theme.theme',
       {}
     >;
 }
@@ -943,7 +1030,6 @@ export function createTranslationExtension(options: {
 export namespace createTranslationExtension {
   const // (undocumented)
     translationDataRef: ConfigurableExtensionDataRef<
-      'core.translation.translation',
       | TranslationResource<string>
       | TranslationMessages<
           string,
@@ -952,6 +1038,7 @@ export namespace createTranslationExtension {
           },
           boolean
         >,
+      'core.translation.translation',
       {}
     >;
 }
@@ -1083,6 +1170,18 @@ export interface ExtensionBoundaryProps {
   routable?: boolean;
 }
 
+// @public (undocumented)
+export type ExtensionDataContainer<UExtensionData extends AnyExtensionDataRef> =
+  {
+    get<TId extends UExtensionData['id']>(
+      ref: ExtensionDataRef<any, TId, any>,
+    ): UExtensionData extends ExtensionDataRef<infer IData, TId, infer IConfig>
+      ? IConfig['optional'] extends true
+        ? IData | undefined
+        : IData
+      : never;
+  };
+
 // @public (undocumented)
 export type ExtensionDataRef<
   TData,
@@ -1091,13 +1190,20 @@ export type ExtensionDataRef<
     optional?: true;
   } = {},
 > = {
-  id: TId;
-  T: TData;
-  config: TConfig;
-  $$type: '@backstage/ExtensionDataRef';
+  readonly $$type: '@backstage/ExtensionDataRef';
+  readonly id: TId;
+  readonly T: TData;
+  readonly config: TConfig;
 };
 
-// @public
+// @public (undocumented)
+export type ExtensionDataValue<TData, TId extends string> = {
+  readonly $$type: '@backstage/ExtensionDataValue';
+  readonly id: TId;
+  readonly value: TData;
+};
+
+// @public @deprecated
 export type ExtensionDataValues<TExtensionData extends AnyExtensionDataMap> = {
   [DataName in keyof TExtensionData as TExtensionData[DataName]['config'] extends {
     optional: true;
@@ -1135,7 +1241,13 @@ export interface ExtensionDefinition<TConfig, TConfigInput = TConfig> {
 
 // @public (undocumented)
 export interface ExtensionInput<
-  TExtensionData extends AnyExtensionDataMap,
+  TExtensionData extends ExtensionDataRef<
+    unknown,
+    string,
+    {
+      optional?: true;
+    }
+  >,
   TConfig extends {
     singleton: boolean;
     optional: boolean;
@@ -1146,7 +1258,7 @@ export interface ExtensionInput<
   // (undocumented)
   config: TConfig;
   // (undocumented)
-  extensionData: TExtensionData;
+  extensionData: Array<TExtensionData>;
 }
 
 // @public (undocumented)
@@ -1214,10 +1326,10 @@ export const IconBundleBlueprint: ExtensionBlueprint<
   AnyExtensionInputMap,
   {
     icons: ConfigurableExtensionDataRef<
-      'core.icons',
       {
         [x: string]: IconComponent;
       },
+      'core.icons',
       {}
     >;
   },
@@ -1231,10 +1343,10 @@ export const IconBundleBlueprint: ExtensionBlueprint<
   },
   {
     icons: ConfigurableExtensionDataRef<
-      'core.icons',
       {
         [x: string]: IconComponent;
       },
+      'core.icons',
       {}
     >;
   }
@@ -1265,6 +1377,70 @@ export { IdentityApi };
 
 export { identityApiRef };
 
+// @public @deprecated (undocumented)
+export interface LegacyCreateExtensionOptions<
+  TOutput extends AnyExtensionDataMap,
+  TInputs extends AnyExtensionInputMap,
+  TConfig,
+  TConfigInput,
+  TConfigSchema extends {
+    [key: string]: (zImpl: typeof z) => z.ZodType;
+  },
+> {
+  // (undocumented)
+  attachTo: {
+    id: string;
+    input: string;
+  };
+  // (undocumented)
+  config?: {
+    schema: TConfigSchema;
+  };
+  // @deprecated (undocumented)
+  configSchema?: PortableSchema<TConfig, TConfigInput>;
+  // (undocumented)
+  disabled?: boolean;
+  // (undocumented)
+  factory(context: {
+    node: AppNode;
+    config: TConfig &
+      (string extends keyof TConfigSchema
+        ? {}
+        : {
+            [key in keyof TConfigSchema]: z.infer<
+              ReturnType<TConfigSchema[key]>
+            >;
+          });
+    inputs: Expand<ResolvedExtensionInputs<TInputs>>;
+  }): Expand<ExtensionDataValues<TOutput>>;
+  // (undocumented)
+  inputs?: TInputs;
+  // (undocumented)
+  kind?: string;
+  // (undocumented)
+  name?: string;
+  // (undocumented)
+  namespace?: string;
+  // (undocumented)
+  output: TOutput;
+}
+
+// @public @deprecated (undocumented)
+export interface LegacyExtensionInput<
+  TExtensionDataMap extends AnyExtensionDataMap,
+  TConfig extends {
+    singleton: boolean;
+    optional: boolean;
+  },
+> {
+  // (undocumented)
+  $$type: '@backstage/ExtensionInput';
+  // (undocumented)
+  config: TConfig;
+  // (undocumented)
+  extensionData: TExtensionDataMap;
+}
+
 export { microsoftAuthApiRef };
 
 export { OAuthApi };
@@ -1315,25 +1491,30 @@ export { ProfileInfo };
 export { ProfileInfoApi };
 
 // @public
-export type ResolvedExtensionInput<TExtensionData extends AnyExtensionDataMap> =
-  {
-    node: AppNode;
-    output: ExtensionDataValues<TExtensionData>;
-  };
+export type ResolvedExtensionInput<
+  TExtensionInput extends ExtensionInput<any, any>,
+> = TExtensionInput['extensionData'] extends Array<AnyExtensionDataRef>
+  ? {
+      node: AppNode;
+    } & ExtensionDataContainer<TExtensionInput['extensionData'][number]>
+  : TExtensionInput['extensionData'] extends AnyExtensionDataMap
+  ? {
+      node: AppNode;
+      output: ExtensionDataValues<TExtensionInput['extensionData']>;
+    }
+  : never;
 
 // @public
 export type ResolvedExtensionInputs<
   TInputs extends {
-    [name in string]: ExtensionInput<any, any>;
+    [name in string]: ExtensionInput<any, any> | LegacyExtensionInput<any, any>;
   },
 > = {
   [InputName in keyof TInputs]: false extends TInputs[InputName]['config']['singleton']
-    ? Array<Expand<ResolvedExtensionInput<TInputs[InputName]['extensionData']>>>
+    ? Array<Expand<ResolvedExtensionInput<TInputs[InputName]>>>
     : false extends TInputs[InputName]['config']['optional']
-    ? Expand<ResolvedExtensionInput<TInputs[InputName]['extensionData']>>
-    : Expand<
-        ResolvedExtensionInput<TInputs[InputName]['extensionData']> | undefined
-      >;
+    ? Expand<ResolvedExtensionInput<TInputs[InputName]>>
+    : Expand<ResolvedExtensionInput<TInputs[InputName]> | undefined>;
 };
 
 // @public
diff --git a/packages/frontend-plugin-api/src/wiring/index.ts b/packages/frontend-plugin-api/src/wiring/index.ts
index baada41ae8..4b99ba8ebc 100644
--- a/packages/frontend-plugin-api/src/wiring/index.ts
+++ b/packages/frontend-plugin-api/src/wiring/index.ts
@@ -23,6 +23,7 @@ export {
   type ExtensionDataValues,
   type ResolvedExtensionInput,
   type ResolvedExtensionInputs,
+  type LegacyCreateExtensionOptions,
   type AnyExtensionInputMap,
   type AnyExtensionDataMap,
 } from './createExtension';
diff --git a/plugins/catalog-react/api-report-alpha.md b/plugins/catalog-react/api-report-alpha.md
index 1ffa67068f..206c0160e2 100644
--- a/plugins/catalog-react/api-report-alpha.md
+++ b/plugins/catalog-react/api-report-alpha.md
@@ -18,18 +18,18 @@ import { TranslationRef } from '@backstage/core-plugin-api/alpha';
 // @alpha (undocumented)
 export const catalogExtensionData: {
   entityContentTitle: ConfigurableExtensionDataRef<
-    'catalog.entity-content-title',
     string,
+    'catalog.entity-content-title',
     {}
   >;
   entityFilterFunction: ConfigurableExtensionDataRef<
-    'catalog.entity-filter-function',
     (entity: Entity) => boolean,
+    'catalog.entity-filter-function',
     {}
   >;
   entityFilterExpression: ConfigurableExtensionDataRef<
-    'catalog.entity-filter-expression',
     string,
+    'catalog.entity-filter-expression',
     {}
   >;
 };
diff --git a/plugins/home/api-report-alpha.md b/plugins/home/api-report-alpha.md
index 1dd3da96be..eb693a8e6f 100644
--- a/plugins/home/api-report-alpha.md
+++ b/plugins/home/api-report-alpha.md
@@ -12,8 +12,8 @@ export default _default;
 
 // @alpha (undocumented)
 export const titleExtensionDataRef: ConfigurableExtensionDataRef<
-  'title',
   string,
+  'title',
   {}
 >;
 
diff --git a/plugins/search-react/api-report-alpha.md b/plugins/search-react/api-report-alpha.md
index 3da9ac23a4..c6e011fe41 100644
--- a/plugins/search-react/api-report-alpha.md
+++ b/plugins/search-react/api-report-alpha.md
@@ -31,11 +31,11 @@ export function createSearchResultListItemExtension<
 export namespace createSearchResultListItemExtension {
   const // (undocumented)
     itemDataRef: ConfigurableExtensionDataRef<
-      'search.search-result-list-item.item',
       {
         predicate?: SearchResultItemExtensionPredicate | undefined;
         component: SearchResultItemExtensionComponent;
       },
+      'search.search-result-list-item.item',
       {}
     >;
 }