notify extension dev server of app assets updates

packages/app/src/cli/models/extensions/extension-instance.ts

@@ -285,7 +285,7 @@ export class ExtensionInstance<TConfiguration extends BaseConfigType = BaseConfi
       return this.specification.devSessionWatchConfig(this)
     }
 
-    return this.specification.experience === 'configuration' ? {paths: []} : undefined
+    return this.isAppConfigExtension ? {paths: []} : undefined
   }
 
   async watchConfigurationPaths() {

packages/app/src/cli/models/extensions/specifications/admin.ts

@@ -7,11 +7,12 @@ const AdminSchema = zod.object({
   admin: zod
     .object({
       static_root: zod.string().optional(),
+      allowed_domains: zod.array(zod.string()).optional(),
     })
     .optional(),
 })
 
-type AdminConfigType = zod.infer<typeof AdminSchema> & BaseConfigType
+export type AdminConfigType = zod.infer<typeof AdminSchema> & BaseConfigType
 
 const adminSpecificationSpec = createExtensionSpecification<AdminConfigType>({
   identifier: 'admin',
@@ -33,6 +34,8 @@ const adminSpecificationSpec = createExtensionSpecification<AdminConfigType>({
       admin: {
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         static_root: (remoteContent as any).admin.static_root,
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        allowed_domains: (remoteContent as any).admin.allowed_domains,
       },
     }
   },

packages/app/src/cli/services/build/steps/include-assets-step.test.ts

@@ -1044,7 +1044,7 @@ describe('executeIncludeAssetsStep', () => {
       )
     })
 
-    test('throws when manifest.json already exists in the output directory', async () => {
+    test('overwrites manifest.json when it already exists in the output directory', async () => {
       // Given — a prior inclusion already copied a manifest.json to the output dir
       const contextWithConfig = {
         ...mockContext,
@@ -1056,8 +1056,7 @@ describe('executeIncludeAssetsStep', () => {
         } as unknown as ExtensionInstance,
       }
 
-      // Source files exist; output manifest.json already exists (simulating conflict);
-      // candidate output paths for tools.json are free so copyConfigKeyEntry succeeds.
+      // Source files exist; output manifest.json already exists
       vi.mocked(fs.fileExists).mockImplementation(async (path) => {
         const pathStr = String(path)
         return pathStr === '/test/output/manifest.json' || pathStr.startsWith('/test/extension/')
@@ -1081,10 +1080,9 @@ describe('executeIncludeAssetsStep', () => {
         },
       }
 
-      // When / Then — throws rather than silently overwriting
-      await expect(executeIncludeAssetsStep(step, contextWithConfig)).rejects.toThrow(
-        `Can't write manifest.json: a file already exists at '/test/output/manifest.json'`,
-      )
+      // When / Then — overwrites existing manifest.json
+      await expect(executeIncludeAssetsStep(step, contextWithConfig)).resolves.not.toThrow()
+      expect(fs.writeFile).toHaveBeenCalledWith('/test/output/manifest.json', expect.any(String))
     })
 
     test('writes an empty manifest when anchor resolves to a non-array value', async () => {

packages/app/src/cli/services/build/steps/include-assets/generate-manifest.ts

@@ -1,6 +1,6 @@
 import {getNestedValue, tokenizePath} from './copy-config-key-entry.js'
 import {joinPath} from '@shopify/cli-kit/node/path'
-import {fileExists, mkdir, writeFile} from '@shopify/cli-kit/node/fs'
+import {mkdir, writeFile} from '@shopify/cli-kit/node/fs'
 import {outputDebug} from '@shopify/cli-kit/node/output'
 import type {BuildContext} from '../../client-steps.js'
 
@@ -20,7 +20,7 @@ interface ConfigKeyManifestEntry {
  * 3. Build root-level entries.
  * 4. Build grouped entries (anchor/groupBy logic) with path strings resolved
  *    via `resolveManifestPaths` using the copy-tracked `pathMap`.
- * 5. Write `outputDir/manifest.json`; throw if the file already exists.
+ * 5. Write `outputDir/manifest.json`, overwriting any existing file.
  *
  * @param pathMap - Map from raw config path values to their output-relative
  *   paths, as recorded during the copy phase by `copyConfigKeyEntry`.
@@ -113,12 +113,6 @@ export async function generateManifestFile(
   }
 
   const manifestPath = joinPath(outputDir, 'manifest.json')
-  if (await fileExists(manifestPath)) {
-    throw new Error(
-      `Can't write manifest.json: a file already exists at '${manifestPath}'. ` +
-        `Remove or rename the conflicting inclusion to avoid overwriting the generated manifest.`,
-    )
-  }
   await mkdir(outputDir)
   await writeFile(manifestPath, JSON.stringify(manifest, null, 2))
   outputDebug(`Generated manifest.json in ${outputDir}\n`, options.stdout)

packages/app/src/cli/services/dev/app-events/file-watcher.ts

@@ -150,7 +150,7 @@ export class FileWatcher {
   private getAllWatchedFiles(): string[] {
     this.extensionWatchedFiles.clear()
 
-    const extensionResults = this.app.nonConfigExtensions.map((extension) => ({
+    const extensionResults = this.app.realExtensions.map((extension) => ({
       extension,
       watchedFiles: extension.watchedFiles(),
     }))

packages/app/src/cli/services/dev/extension.test.ts

@@ -33,7 +33,14 @@ describe('devUIExtensions()', () => {
 
     // eslint-disable-next-line @typescript-eslint/ban-ts-comment
     // @ts-ignore
-    vi.spyOn(store, 'ExtensionsPayloadStore').mockImplementation(() => ({mock: 'payload-store'}))
+    vi.spyOn(store, 'ExtensionsPayloadStore').mockImplementation(
+      () =>
+        ({
+          mock: 'payload-store',
+          updateAdminConfigFromExtensionEvents: vi.fn(),
+          getAppAssets: vi.fn(),
+        }) as unknown as store.ExtensionsPayloadStore,
+    )
     vi.spyOn(server, 'setupHTTPServer').mockReturnValue({
       mock: 'http-server',
       close: serverCloseSpy,
@@ -67,8 +74,9 @@ describe('devUIExtensions()', () => {
     // THEN
     expect(server.setupHTTPServer).toHaveBeenCalledWith({
       devOptions: {...options, websocketURL: 'wss://mock.url/extensions'},
-      payloadStore: {mock: 'payload-store'},
+      payloadStore: expect.objectContaining({mock: 'payload-store'}),
       getExtensions: expect.any(Function),
+      getAppAssets: expect.any(Function),
     })
   })
 
@@ -94,7 +102,7 @@ describe('devUIExtensions()', () => {
     expect(websocket.setupWebsocketConnection).toHaveBeenCalledWith({
       ...options,
       httpServer: expect.objectContaining({mock: 'http-server'}),
-      payloadStore: {mock: 'payload-store'},
+      payloadStore: expect.objectContaining({mock: 'payload-store'}),
       websocketURL: 'wss://mock.url/extensions',
     })
   })

packages/app/src/cli/services/dev/extension.ts

@@ -35,7 +35,8 @@ export interface ExtensionDevOptions {
   buildDirectory?: string
 
   /**
-   * The extension to be built.
+   * All real extensions in the app, including non-previewable ones (e.g., admin config).
+   * Previewable extensions are filtered internally for the UI payload.
    */
   extensions: ExtensionInstance[]
 
@@ -126,14 +127,20 @@ export async function devUIExtensions(options: ExtensionDevOptions): Promise<voi
   const bundlePath = payloadOptions.appWatcher.buildOutputPath
   const payloadStoreRawPayload = await getExtensionsPayloadStoreRawPayload(payloadOptions, bundlePath)
   const payloadStore = new ExtensionsPayloadStore(payloadStoreRawPayload, payloadOptions)
-  let extensions = payloadOptions.extensions
+  let extensions = payloadOptions.extensions.filter((ext) => ext.isPreviewable)
 
   const getExtensions = () => {
     return extensions
   }
 
   outputDebug(`Setting up the UI extensions HTTP server...`, payloadOptions.stdout)
-  const httpServer = setupHTTPServer({devOptions: payloadOptions, payloadStore, getExtensions})
+  const getAppAssets = () => payloadStore.getAppAssets()
+  const httpServer = setupHTTPServer({
+    devOptions: payloadOptions,
+    payloadStore,
+    getExtensions,
+    getAppAssets,
+  })
 
   outputDebug(`Setting up the UI extensions Websocket server...`, payloadOptions.stdout)
   const websocketConnection = setupWebsocketConnection({...payloadOptions, httpServer, payloadStore})
@@ -144,6 +151,11 @@ export async function devUIExtensions(options: ExtensionDevOptions): Promise<voi
       extensions = app.allExtensions.filter((ext) => ext.isPreviewable)
     }
 
+    // Exception for AdminConfig: it's a extension that needs its config extracted at the app level
+    // for the payloed. No other exceptions should be added, if this pattern is needed again we should
+    // generalize it.
+    payloadStore.updateAdminConfigFromExtensionEvents(extensionEvents)
+
     for (const event of extensionEvents) {
       if (!event.extension.isPreviewable) continue
       const status = event.buildResult?.status === 'ok' ? 'success' : 'error'

packages/app/src/cli/services/dev/extension/payload/models.ts

@@ -8,6 +8,13 @@ interface ExtensionsPayloadInterface {
     url: string
     mobileUrl: string
     title: string
+    allowedDomains?: string[]
+    assets?: {
+      [key: string]: {
+        url: string
+        lastUpdated: number
+      }
+    }
   }
   appId?: string
   store: string