Enable standalone app start tracing (SDK 9.28)

.env.example

@@ -6,7 +6,7 @@
 # ========================================
 SENTRY_AUTH_TOKEN=your_auth_token
 SENTRY_DSN=your_dsn
-SENTRY_RELEASE=com.example.empower_flutter@9.25.0+1  # Format: <applicationId>@version+build (matches the build identifier used by Build Distribution)
+SENTRY_RELEASE=com.example.empower_flutter@9.28.0+1  # Format: <applicationId>@version+build (matches the build identifier used by Build Distribution)
 SENTRY_ENVIRONMENT=your_environment
 
 # ========================================

lib/app_start.dart

@@ -0,0 +1,122 @@
+// ignore_for_file: experimental_member_use
+
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:flutter/services.dart';
+import 'package:sentry_flutter/sentry_flutter.dart';
+
+/// Coordinates standalone app-start extension for this demo.
+///
+/// Call [begin] from `appRunner` *before* `runApp` so `extendAppStart`
+/// lands before the first frame. Custom children are parented with
+/// `SentryFlutter.getExtendedAppStartSpanV2()` because the demo uses stream
+/// lifecycle — `getExtendedAppStartSpan()` is the static-lifecycle getter and
+/// returns null here.
+///
+/// The extension stays open through feature-flag hydration, the first-frame
+/// cache write, and the first catalog fetch, then `finishExtendedAppStart()`
+/// releases it. If the catalog never arrives, we still finish before the SDK's
+/// 30s deadline.
+class AppStart {
+  static const _featureFlagCount = 15;
+  static const _catalogTimeout = Duration(seconds: 20);
+
+  static final Completer<void> _catalogReady = Completer<void>();
+  static Future<void>? _extension;
+
+  /// Must run before the first frame. Safe to call only once.
+  static void begin() {
+    if (_extension != null) {
+      return;
+    }
+    SentryFlutter.extendAppStart();
+    _extension = _run();
+    unawaited(_extension!);
+  }
+
+  static Future<void> _run() async {
+    try {
+      await span(
+        'Hydrate feature flags',
+        _hydrateFeatureFlags,
+        op: 'app.init',
+      );
+      await _catalogReady.future.timeout(
+        _catalogTimeout,
+        onTimeout: () {},
+      );
+    } finally {
+      await SentryFlutter.finishExtendedAppStart();
+    }
+  }
+
+  /// Runs [work] as a child of the extended app-start span when one is open.
+  ///
+  /// In stream mode the extension is not the active span, so we must pass it
+  /// as `parentSpan`. The callback then becomes the active span (zone), so
+  /// auto-instrumentation such as `sentry_file` nests under it instead of
+  /// `ui.load`. If the extension has already ended (or never started —
+  /// e.g. web/desktop), [work] runs without opening a stray root span.
+  static Future<T> span<T>(
+    String name,
+    Future<T> Function() work, {
+    String op = 'app.init',
+  }) async {
+    final parent = _extendedParent();
+    if (parent == null) {
+      return work();
+    }
+    return Sentry.startSpan(name, (span) async {
+      span.setAttribute('sentry.op', SentryAttribute.string(op));
+      return work();
+    }, parentSpan: parent);
+  }
+
+  /// Sync counterpart of [span] for first-frame-blocking startup work.
+  static T spanSync<T>(
+    String name,
+    T Function() work, {
+    String op = 'app.init',
+  }) {
+    final parent = _extendedParent();
+    if (parent == null) {
+      return work();
+    }
+    return Sentry.startSpanSync(name, (span) {
+      span.setAttribute('sentry.op', SentryAttribute.string(op));
+      return work();
+    }, parentSpan: parent);
+  }
+
+  static SentrySpanV2? _extendedParent() =>
+      SentryFlutter.getExtendedAppStartSpanV2();
+
+  /// Signals that the first catalog fetch finished (success or failure).
+  static void markCatalogReady() {
+    if (!_catalogReady.isCompleted) {
+      _catalogReady.complete();
+    }
+  }
+
+  static Future<void> _hydrateFeatureFlags() async {
+    final loaded = await Future.wait([
+      for (var i = 1; i <= _featureFlagCount; i++)
+        rootBundle.loadString('assets/config/feature_$i.json'),
+    ]);
+    var enabled = 0;
+    for (final raw in loaded) {
+      final decoded = jsonDecode(raw);
+      if (decoded is Map && decoded['enabled'] == true) {
+        enabled++;
+      }
+    }
+    Sentry.configureScope((scope) {
+      scope.setContexts('feature_flags', {
+        'count': loaded.length,
+        'enabled': enabled,
+      });
+    });
+  }
+}
+

lib/main.dart

@@ -12,6 +12,7 @@ import 'package:flutter_dotenv/flutter_dotenv.dart';
 import 'package:logging/logging.dart';
 import 'backend_config.dart';
 import 'platform/platform_info.dart';
+import 'app_start.dart';
 
 final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
 final log = Logger('EmpowerPlantLogger');
@@ -39,6 +40,9 @@ Future<void> main() async {
   await initSentry(
     appRunner: () {
       log.info('Running app');
+      // Extend before runApp so the first frame cannot close app start.
+      // Custom children + finish live in AppStart (feature flags + catalog).
+      AppStart.begin();
       runApp(
         DefaultAssetBundle(
           bundle: SentryAssetBundle(),

lib/product_list.dart

@@ -13,6 +13,7 @@ import 'platform/platform_info.dart';
 import 'platform/file_io_demo.dart';
 import 'sentry_setup.dart';
 import 'se_config.dart';
+import 'app_start.dart';
 // ignore: depend_on_referenced_packages
 
 class ItemsList extends StatefulWidget {
@@ -31,12 +32,16 @@ class _ItemListState extends State<ItemsList> {
 
   Future<ResponseData> fetchShopItems() async {
     try {
-      // Resolve the products endpoint at request time so the OTLP journey
-      // (which switches BackendConfig.base) targets flask-otlp instead.
-      final response = await client.get(Uri.parse(BackendConfig.products));
-      // Simulate full response processing
-      final data = ResponseData.fromJson((jsonDecode(response.body)));
-      return data;
+      // Nest under the extended app-start span while it's still open so the
+      // first catalog fetch is part of `app.start` (stream mode requires an
+      // explicit parent — see AppStart.span). After the extension ends this
+      // is a no-op wrapper and SentryHttpClient still traces the request.
+      return await AppStart.span('Fetch product catalog', () async {
+        // Resolve the products endpoint at request time so the OTLP journey
+        // (which switches BackendConfig.base) targets flask-otlp instead.
+        final response = await client.get(Uri.parse(BackendConfig.products));
+        return ResponseData.fromJson((jsonDecode(response.body)));
+      }, op: 'http.client');
     } catch (e) {
       rethrow;
     }
@@ -100,6 +105,7 @@ class _ItemListState extends State<ItemsList> {
 
     // Fetch products from API and report TTFD when complete
     shopItems = fetchShopItems().whenComplete(() {
+      AppStart.markCatalogReady();
       // Report TTFD as soon as fetching the shop items is done
       if (mounted) {
         SentryDisplayWidget.of(context).reportFullyDisplayed();
@@ -127,9 +133,15 @@ class _ItemListState extends State<ItemsList> {
 
   // Simulate slow file I/O on main thread (native: real dart:io file via
   // sentry_file; web: equivalent heavy main-thread work — see platform/file_io_demo).
+  // Nested under extended app start so file.write/file.read attach to `app.start`
+  // instead of the home `ui.load` (sentry_file parents to the active zone span).
   void _performFileIO() {
     try {
-      final size = performFileIODemo();
+      final size = AppStart.spanSync(
+        'Warm plant cache',
+        performFileIODemo,
+        op: 'file.io',
+      );
 
       if (kDebugMode) {
         print('File I/O on main thread, size: $size');

lib/sentry_setup.dart

@@ -75,12 +75,12 @@ Future<void> initSentry({required VoidCallback appRunner}) async {
     options.dsn = sentryDsn;
 
     // Release must match exactly with uploaded debug symbols
-    // CRITICAL: This must be in format "appname@version+build" (e.g., "empower_flutter@9.25.0+1")
+    // CRITICAL: This must be in format "appname@version+build" (e.g., "empower_flutter@9.28.0+1")
     options.release = sentryRelease;
     options.environment = sentryEnvironment;
 
     // Set distribution to match build number for better symbol matching
-    options.dist = '1'; // Matches version 9.25.0+1
+    options.dist = '1'; // Matches version 9.28.0+1
 
     // Debug settings (disabled for production to ensure proper symbol resolution)
     // Toggle on via --dart-define=SENTRY_DEBUG=true (or SENTRY_DEBUG=true in .env)
@@ -104,6 +104,14 @@ Future<void> initSentry({required VoidCallback appRunner}) async {
     // the legacy `Sentry.startTransaction` / `startChild` APIs are no-ops here.
     options.traceLifecycle = SentryTraceLifecycle.stream;
 
+    // Standalone app start (experimental since SDK 9.26.0). Reports process
+    // start → first frame as its own `App Start` root (`app.start`) instead of
+    // nesting it under the synthetic initial `ui.load`. Android/iOS only —
+    // other platforms keep the ui.load-attached behavior. Extended past the
+    // first frame in `lib/app_start.dart` via extendAppStart / finishExtendedAppStart.
+    // ignore: experimental_member_use
+    options.enableStandaloneAppStartTracing = true;
+
     // Enable profiling (relative to tracesSampleRate)
     // Required for JSON Decoding, Image Decoding, and Frame Drop detection
     // Profiling is available on iOS, macOS, and Android
@@ -308,6 +316,7 @@ Future<void> initSentry({required VoidCallback appRunner}) async {
         'logs',
         'metrics',
         'distributed_tracing',
+        'standalone_app_start',
       ],
     });
     scope.setContexts('release_info', {

pubspec.lock

@@ -260,10 +260,10 @@ packages:
     dependency: transitive
     description:
       name: matcher
-      sha256: dc0b7dc7651697ea4ff3e69ef44b0407ea32c487a39fff6a4004fa585e901861
+      sha256: "31bd099b47c10cd1aeb55146a2d46ce0277630ecef3f7dae54ad7873f36696cd"
       url: "https://pub.dev"
     source: hosted
-    version: "0.12.19"
+    version: "0.12.20"
   material_color_utilities:
     dependency: transitive
     description:
@@ -276,10 +276,10 @@ packages:
     dependency: transitive
     description:
       name: meta
-      sha256: "1741988757a65eb6b36abe716829688cf01910bbf91c34354ff7ec1c3de2b349"
+      sha256: "307249ce4ff29d58a18e97f6345f539382eb9c9c29ecda628900f31de0443dd9"
       url: "https://pub.dev"
     source: hosted
-    version: "1.18.0"
+    version: "1.19.0"
   mime:
     dependency: transitive
     description:
@@ -372,10 +372,10 @@ packages:
     dependency: transitive
     description:
       name: sentry
-      sha256: a84bf3a83b3ce1c89fce28b9f97659e3826df14a73a256952465aac2c5efdf5a
+      sha256: "5641a2acec1647f6482e472679374ac02070464e8c1d0df946361393ea7681a2"
       url: "https://pub.dev"
     source: hosted
-    version: "9.25.0"
+    version: "9.28.0"
   sentry_dart_plugin:
     dependency: "direct dev"
     description:
@@ -388,34 +388,34 @@ packages:
     dependency: "direct main"
     description:
       name: sentry_dio
-      sha256: "297caacf2ed037d859611d94165f35c34cf0462420aea1ceb1fed8c87a06f1dd"
+      sha256: "8d06e18924922e518b7a318c6c22e1069cd356428fd92c7b113f4eb0ea0d7d82"
       url: "https://pub.dev"
     source: hosted
-    version: "9.25.0"
+    version: "9.28.0"
   sentry_file:
     dependency: "direct main"
     description:
       name: sentry_file
-      sha256: "0e4a36c02901855a383972b210ec33fc97a2619d9e0a4f7562538ed2c8f735f1"
+      sha256: "5f5c1e7748ac0357241cfddd794b24ca9d718ea5e7ae26a080300dd72810dbbd"
       url: "https://pub.dev"
     source: hosted
-    version: "9.25.0"
+    version: "9.28.0"
   sentry_flutter:
     dependency: "direct main"
     description:
       name: sentry_flutter
-      sha256: c85575266d91f57364e9b4cb522835156ec3c5581c78339dc7fae491cd0c6f76
+      sha256: "41df8ab3a30190a05eb44e2c0e739b5ba90eb341de771454ced282295fde8c62"
       url: "https://pub.dev"
     source: hosted
-    version: "9.25.0"
+    version: "9.28.0"
   sentry_logging:
     dependency: "direct main"
     description:
       name: sentry_logging
-      sha256: "7506853de2fe61dd1d814b5266b24360635cd7fc7076c89ea3676f4b4ce2b948"
+      sha256: "189bfbee55ba4dcb1d68bf32dc8bbd25b2cc2732efa40b801ce5ec36cd18c0c4"
       url: "https://pub.dev"
     source: hosted
-    version: "9.25.0"
+    version: "9.28.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -473,10 +473,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: "949a932224383300f01be9221c39180316445ecb8e7547f70a41a35bf421fb9e"
+      sha256: "2a122cbe059f8b610d3a5415f42e255b6c17b1f21eee1d960f31080237fb4f11"
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.11"
+    version: "0.7.12"
   typed_data:
     dependency: transitive
     description:
@@ -561,10 +561,10 @@ packages:
     dependency: transitive
     description:
       name: vector_math
-      sha256: d530bd74fea330e6e364cda7a85019c434070188383e1cd8d9777ee586914c5b
+      sha256: f36f9f3be64c6198714492bb455c11056e33e2f85d9a0b676a48301e44fdcf47
       url: "https://pub.dev"
     source: hosted
-    version: "2.2.0"
+    version: "2.4.2"
   vm_service:
     dependency: transitive
     description:

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: "none" # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 9.25.0+1
+version: 9.28.0+1
 
 environment:
   sdk: ">=3.5.0 <4.0.0"
@@ -36,12 +36,12 @@ dependencies:
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.9
   provider: ^6.1.5
-  sentry_flutter: ^9.25.0
+  sentry_flutter: ^9.28.0
   flutter_dotenv: ^6.0.1
-  sentry_dio: ^9.25.0
+  sentry_dio: ^9.28.0
   dio: ^5.10.0
-  sentry_file: ^9.25.0
-  sentry_logging: ^9.25.0
+  sentry_file: ^9.28.0
+  sentry_logging: ^9.28.0
   logging: ^1.3.0
   # Web View feature (Android/iOS in-app webview; desktop falls back to url_launcher;
   # web uses a dart:ui_web iframe via package:web)