diff --git a/packages/backend-app-api/api-report.md b/packages/backend-app-api/api-report.md
index 071fd6c1d3..724d3409bf 100644
--- a/packages/backend-app-api/api-report.md
+++ b/packages/backend-app-api/api-report.md
@@ -204,10 +204,17 @@ export const loggerServiceFactory: () => ServiceFactory<
   'plugin'
 >;
 
-// Warning: (ae-forgotten-export) The symbol "MiddlewareFactory_2" needs to be exported by the entry point index.d.ts
-//
 // @public @deprecated (undocumented)
-export const MiddlewareFactory: typeof MiddlewareFactory_2;
+export class MiddlewareFactory {
+  compression(): RequestHandler;
+  cors(): RequestHandler;
+  // Warning: (ae-forgotten-export) The symbol "MiddlewareFactory_2" needs to be exported by the entry point index.d.ts
+  static create(options: MiddlewareFactoryOptions): MiddlewareFactory_2;
+  error(options?: MiddlewareFactoryErrorOptions): ErrorRequestHandler;
+  helmet(): RequestHandler;
+  logging(): RequestHandler;
+  notFound(): RequestHandler;
+}
 
 // Warning: (ae-forgotten-export) The symbol "MiddlewareFactoryErrorOptions_2" needs to be exported by the entry point index.d.ts
 //
diff --git a/packages/backend-app-api/src/http/index.ts b/packages/backend-app-api/src/http/index.ts
index ab1d134688..8fd1b31e75 100644
--- a/packages/backend-app-api/src/http/index.ts
+++ b/packages/backend-app-api/src/http/index.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { ErrorRequestHandler, RequestHandler } from 'express';
 // eslint-disable-next-line @backstage/no-relative-monorepo-imports
 import {
   readHttpServerOptions as _readHttpServerOptions,
@@ -52,7 +53,113 @@ export const readHelmetOptions = _readHelmetOptions;
  * @public
  * @deprecated Please import from `@backstage/backend-defaults/rootHttpRouter` instead.
  */
-export const MiddlewareFactory = _MiddlewareFactory;
+export class MiddlewareFactory {
+  /**
+   * Creates a new {@link MiddlewareFactory}.
+   */
+  static create(options: MiddlewareFactoryOptions) {
+    return _MiddlewareFactory.create(options);
+  }
+
+  private constructor(private readonly impl: _MiddlewareFactory) {}
+
+  /**
+   * Returns a middleware that unconditionally produces a 404 error response.
+   *
+   * @remarks
+   *
+   * Typically you want to place this middleware at the end of the chain, such
+   * that it's the last one attempted after no other routes matched.
+   *
+   * @returns An Express request handler
+   */
+  notFound(): RequestHandler {
+    return this.impl.notFound();
+  }
+
+  /**
+   * Returns the compression middleware.
+   *
+   * @remarks
+   *
+   * The middleware will attempt to compress response bodies for all requests
+   * that traverse through the middleware.
+   */
+  compression(): RequestHandler {
+    return this.impl.compression();
+  }
+
+  /**
+   * Returns a request logging middleware.
+   *
+   * @remarks
+   *
+   * Typically you want to place this middleware at the start of the chain, such
+   * that it always logs requests whether they are "caught" by handlers farther
+   * down or not.
+   *
+   * @returns An Express request handler
+   */
+  logging(): RequestHandler {
+    return this.impl.logging();
+  }
+
+  /**
+   * Returns a middleware that implements the helmet library.
+   *
+   * @remarks
+   *
+   * This middleware applies security policies to incoming requests and outgoing
+   * responses. It is configured using config keys such as `backend.csp`.
+   *
+   * @see {@link https://helmetjs.github.io/}
+   *
+   * @returns An Express request handler
+   */
+  helmet(): RequestHandler {
+    return this.impl.helmet();
+  }
+
+  /**
+   * Returns a middleware that implements the cors library.
+   *
+   * @remarks
+   *
+   * This middleware handles CORS. It is configured using the config key
+   * `backend.cors`.
+   *
+   * @see {@link https://github.com/expressjs/cors}
+   *
+   * @returns An Express request handler
+   */
+  cors(): RequestHandler {
+    return this.impl.cors();
+  }
+
+  /**
+   * Express middleware to handle errors during request processing.
+   *
+   * @remarks
+   *
+   * This is commonly the very last middleware in the chain.
+   *
+   * Its primary purpose is not to do translation of business logic exceptions,
+   * but rather to be a global catch-all for uncaught "fatal" errors that are
+   * expected to result in a 500 error. However, it also does handle some common
+   * error types (such as http-error exceptions, and the well-known error types
+   * in the `@backstage/errors` package) and returns the enclosed status code
+   * accordingly.
+   *
+   * It will also produce a response body with a serialized form of the error,
+   * unless a previous handler already did send a body. See
+   * {@link @backstage/errors#ErrorResponseBody} for the response shape used.
+   *
+   * @returns An Express error request handler
+   */
+  error(options: MiddlewareFactoryErrorOptions = {}): ErrorRequestHandler {
+    return this.impl.error(options);
+  }
+}
 /**
  * @public
  * @deprecated Please import from `@backstage/backend-defaults/rootHttpRouter` instead.
diff --git a/packages/backend-common/api-report.md b/packages/backend-common/api-report.md
index 7915503d7c..de00ef6a5a 100644
--- a/packages/backend-common/api-report.md
+++ b/packages/backend-common/api-report.md
@@ -88,27 +88,27 @@ export type AuthCallbackOptions = {
 // Warning: (ae-forgotten-export) The symbol "AwsS3UrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const AwsS3UrlReader: typeof AwsS3UrlReader_2;
+export class AwsS3UrlReader extends AwsS3UrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "AzureUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const AzureUrlReader: typeof AzureUrlReader_2;
+export class AzureUrlReader extends AzureUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "BitbucketCloudUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const BitbucketCloudUrlReader: typeof BitbucketCloudUrlReader_2;
+export class BitbucketCloudUrlReader extends BitbucketCloudUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "BitbucketServerUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const BitbucketServerUrlReader: typeof BitbucketServerUrlReader_2;
+export class BitbucketServerUrlReader extends BitbucketServerUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "BitbucketUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const BitbucketUrlReader: typeof BitbucketUrlReader_2;
+export class BitbucketUrlReader extends BitbucketUrlReader_2 {}
 
 // @public @deprecated (undocumented)
 export type CacheClient = CacheService;
@@ -122,7 +122,7 @@ export type CacheClientSetOptions = CacheServiceSetOptions;
 // Warning: (ae-forgotten-export) The symbol "CacheManager_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const CacheManager: typeof CacheManager_2;
+export class CacheManager extends CacheManager_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "CacheManagerOptions_2" needs to be exported by the entry point index.d.ts
 //
@@ -242,7 +242,7 @@ export type ErrorHandlerOptions = {
 // Warning: (ae-forgotten-export) The symbol "FetchUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const FetchUrlReader: typeof FetchUrlReader_2;
+export class FetchUrlReader extends FetchUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "FromReadableArrayOptions_2" needs to be exported by the entry point index.d.ts
 //
@@ -252,7 +252,7 @@ export type FromReadableArrayOptions = FromReadableArrayOptions_2;
 // Warning: (ae-forgotten-export) The symbol "GerritUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const GerritUrlReader: typeof GerritUrlReader_2;
+export class GerritUrlReader extends GerritUrlReader_2 {}
 
 // @public @deprecated
 export function getRootLogger(): winston.Logger;
@@ -339,27 +339,38 @@ export class Git {
 // Warning: (ae-forgotten-export) The symbol "GiteaUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const GiteaUrlReader: typeof GiteaUrlReader_2;
+export class GiteaUrlReader extends GiteaUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "GithubUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const GithubUrlReader: typeof GithubUrlReader_2;
+export class GithubUrlReader extends GithubUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "GitlabUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const GitlabUrlReader: typeof GitlabUrlReader_2;
+export class GitlabUrlReader extends GitlabUrlReader_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "HarnessUrlReader_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const HarnessUrlReader: typeof HarnessUrlReader_2;
+export class HarnessUrlReader extends HarnessUrlReader_2 {}
 
-// Warning: (ae-forgotten-export) The symbol "HostDiscovery_2" needs to be exported by the entry point index.d.ts
-//
 // @public @deprecated
-export const HostDiscovery: typeof HostDiscovery_2;
+class HostDiscovery implements DiscoveryService {
+  static fromConfig(
+    config: Config,
+    options?: {
+      basePath?: string;
+    },
+  ): HostDiscovery;
+  // (undocumented)
+  getBaseUrl(pluginId: string): Promise<string>;
+  // (undocumented)
+  getExternalBaseUrl(pluginId: string): Promise<string>;
+}
+export { HostDiscovery };
+export { HostDiscovery as SingleHostDiscovery };
 
 // @public @deprecated (undocumented)
 export const isChildPath: typeof isChildPath_2;
@@ -525,7 +536,7 @@ export type ReadUrlResponse = ReadUrlResponse_2;
 // Warning: (ae-forgotten-export) The symbol "ReadUrlResponseFactory_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const ReadUrlResponseFactory: typeof ReadUrlResponseFactory_2;
+export class ReadUrlResponseFactory extends ReadUrlResponseFactory_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "ReadUrlResponseFactoryFromStreamOptions_2" needs to be exported by the entry point index.d.ts
 //
@@ -626,9 +637,6 @@ export type ServiceBuilder = {
 // @public @deprecated
 export function setRootLogger(newLogger: winston.Logger): void;
 
-// @public @deprecated
-export const SingleHostDiscovery: typeof HostDiscovery_2;
-
 // @public @deprecated
 export type StaticAuthOptions = {
   username?: string;
@@ -664,7 +672,7 @@ export type UrlReaderPredicateTuple = UrlReaderPredicateTuple_2;
 // Warning: (ae-forgotten-export) The symbol "UrlReaders_2" needs to be exported by the entry point index.d.ts
 //
 // @public @deprecated (undocumented)
-export const UrlReaders: typeof UrlReaders_2;
+export class UrlReaders extends UrlReaders_2 {}
 
 // Warning: (ae-forgotten-export) The symbol "UrlReadersOptions_2" needs to be exported by the entry point index.d.ts
 //
diff --git a/packages/backend-common/src/deprecated/index.ts b/packages/backend-common/src/deprecated/index.ts
index ba8b8e7db2..e3e4101d25 100644
--- a/packages/backend-common/src/deprecated/index.ts
+++ b/packages/backend-common/src/deprecated/index.ts
@@ -77,8 +77,6 @@ import type {
 
 import {
   DiscoveryService,
-  LifecycleService,
-  PluginMetadataService,
   CacheService,
   CacheServiceOptions,
   CacheServiceSetOptions,
@@ -97,6 +95,8 @@ import {
   SearchResponse as _SearchResponse,
   SearchResponseFile as _SearchResponseFile,
   UrlReaderService as _UrlReaderService,
+  LifecycleService,
+  PluginMetadataService,
 } from '@backstage/backend-plugin-api';
 
 export * from './hot';
@@ -125,7 +125,45 @@ export type PluginEndpointDiscovery = DiscoveryService;
  * @public
  * @deprecated Please import from `@backstage/backend-defaults/discovery` instead.
  */
-export const HostDiscovery = _HostDiscovery;
+export class HostDiscovery implements DiscoveryService {
+  /**
+   * Creates a new HostDiscovery discovery instance by reading
+   * from the `backend` config section, specifically the `.baseUrl` for
+   * discovering the external URL, and the `.listen` and `.https` config
+   * for the internal one.
+   *
+   * Can be overridden in config by providing a target and corresponding plugins in `discovery.endpoints`.
+   * eg.
+   * ```yaml
+   * discovery:
+   *  endpoints:
+   *    - target: https://internal.example.com/internal-catalog
+   *      plugins: [catalog]
+   *    - target: https://internal.example.com/secure/api/{{pluginId}}
+   *      plugins: [auth, permission]
+   *    - target:
+   *        internal: https://internal.example.com/search
+   *        external: https://example.com/search
+   *      plugins: [search]
+   * ```
+   *
+   * The basePath defaults to `/api`, meaning the default full internal
+   * path for the `catalog` plugin will be `http://localhost:7007/api/catalog`.
+   */
+  static fromConfig(config: Config, options?: { basePath?: string }) {
+    return new HostDiscovery(_HostDiscovery.fromConfig(config, options));
+  }
+
+  private constructor(private readonly impl: _HostDiscovery) {}
+
+  async getBaseUrl(pluginId: string): Promise<string> {
+    return this.impl.getBaseUrl(pluginId);
+  }
+
+  async getExternalBaseUrl(pluginId: string): Promise<string> {
+    return this.impl.getExternalBaseUrl(pluginId);
+  }
+}
 
 /**
  * SingleHostDiscovery is a basic PluginEndpointDiscovery implementation
@@ -138,13 +176,13 @@ export const HostDiscovery = _HostDiscovery;
  * @public
  * @deprecated Use `HostDiscovery` from `@backstage/backend-defaults/discovery` instead
  */
-export const SingleHostDiscovery = _HostDiscovery;
+export { HostDiscovery as SingleHostDiscovery };
 
 /**
  * @public
  * @deprecated Use `CacheManager` from the `@backstage/backend-defaults` package instead
  */
-export const CacheManager = _CacheManager;
+export class CacheManager extends _CacheManager {}
 
 /**
  * @public
@@ -257,79 +295,79 @@ export const isChildPath = _isChildPath;
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const AzureUrlReader = _AzureUrlReader;
+export class AzureUrlReader extends _AzureUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const BitbucketCloudUrlReader = _BitbucketCloudUrlReader;
+export class BitbucketCloudUrlReader extends _BitbucketCloudUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const BitbucketUrlReader = _BitbucketUrlReader;
+export class BitbucketUrlReader extends _BitbucketUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const BitbucketServerUrlReader = _BitbucketServerUrlReader;
+export class BitbucketServerUrlReader extends _BitbucketServerUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const GerritUrlReader = _GerritUrlReader;
+export class GerritUrlReader extends _GerritUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const GithubUrlReader = _GithubUrlReader;
+export class GithubUrlReader extends _GithubUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const GitlabUrlReader = _GitlabUrlReader;
+export class GitlabUrlReader extends _GitlabUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const GiteaUrlReader = _GiteaUrlReader;
+export class GiteaUrlReader extends _GiteaUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const HarnessUrlReader = _HarnessUrlReader;
+export class HarnessUrlReader extends _HarnessUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const AwsS3UrlReader = _AwsS3UrlReader;
+export class AwsS3UrlReader extends _AwsS3UrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const FetchUrlReader = _FetchUrlReader;
+export class FetchUrlReader extends _FetchUrlReader {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const UrlReaders = _UrlReaders;
+export class UrlReaders extends _UrlReaders {}
 
 /**
  * @public
  * @deprecated Import from `@backstage/backend-defaults/urlReader` instead
  */
-export const ReadUrlResponseFactory = _ReadUrlResponseFactory;
+export class ReadUrlResponseFactory extends _ReadUrlResponseFactory {}
 
 /**
  * @public