Talaria

Instrumentation is an adapter. It is constructed in the bootstrap, next to the composition root, and it stays out of Note, SaveNoteUseCase, and the note tile.

lib/bootstrap/talaria_monitoring.dart starts the client only when a key is present. The sample reads TALARIA_API_KEY from --dart-define. An empty or blank value leaves the SDK off. shouldInit trims the key first.

bootstrap is the entrypoint. WidgetsFlutterBinding.ensureInitialized and runApp share one zone. Flutter reports a zone mismatch when the binding is created outside the zone that later calls runApp.

static Future<void> bootstrap(Future<void> Function() startApp) {
  if (!shouldInit(apiKey)) {
    WidgetsFlutterBinding.ensureInitialized();
    return startApp();
  }

  final started = Completer<void>();
  runZonedGuarded(() async {
    WidgetsFlutterBinding.ensureInitialized();
    await init();
    await startApp();
    if (!started.isCompleted) started.complete();
  }, (Object error, StackTrace stack) {
    final client = Talaria.getClient();
    if (client != null) {
      client.captureException(
        error,
        stackTrace: stack,
        context: const CaptureContext(
          mechanism: ExceptionMechanism(type: 'zone', handled: false),
        ),
      );
    }
    if (!started.isCompleted) started.completeError(error, stack);
  });
  return started.future;
}

init calls TalariaFlutter.init and installs talariaErrorWidgetBuilder. Zone errors use mechanism type zone.

lib/main.dart passes NotesMonitoring.httpClient() into the provider scope. With a key, that is Talaria.wrapHttpClient, so later HTTP calls carry the trace header. Without a key, it is a plain http.Client.

setSignedInUser sets the user, opts in, and identifies. clearSignedInUser opts out, clears the user, and resets analytics so the next account is a new visitor. Both return immediately when no client exists.

Beamer reports the screen. The notes location builds a ScreenReporter, which calls setScreen with the path and title. The same path and title twice in a row is one screen.

lib/notes_app.dart wraps the routed child:

builder: (context, child) {
  return TalariaScreenCapture(child: child ?? const SizedBox.shrink());
},

TalariaScreenCapture records taps, scroll depth, and an on-request snapshot. It belongs at the top of the tree, around the child MaterialApp.router builds.

test/unit/monitoring_test.dart checks the empty key and the no-client returns. The tests page lists it with the others.

The package is talaria_flutter, already in this example's pubspec.yaml. Pass the key when you want the SDK on:

flutter run --dart-define=TALARIA_API_KEY=your_key

That is the end of this track. The chooser links the other two layouts.