# SXCHNGE analytics

Shared pure-Dart analytics contract, semantic journey recorder and bounded
in-memory dummy service. No PostHog SDK, network, persistence or logging.

```dart
final analytics = DummyAnalyticsService();
final recorder = JourneyRecorder(analytics);
final operation = recorder.begin(JourneyKind.login, JourneyStep.login);
recorder.finish(operation, simulated: true, terminal: true);
final captured = analytics.events; // immutable snapshot
recorder.dispose();
```

Inject an `AnalyticsService` implementation to replace the sink. Consumers do not
await analytics. See [the auth journey contract](../../../docs/ux/auth-journeys.md)
for schema, metric definitions, simulation rules, privacy, retry/abandonment
semantics, PostHog adapter guidance and measurement limitations.

Run `flutter test` and `flutter analyze` here. The production library imports
only Dart SDK libraries and can be reused by web and mobile.