otel_auto_route

OpenTelemetry instrumentation for package:auto_route.

OTelAutoRouterObserver is a real AutoRouterObserver subclass — not just a NavigatorObserver. In a tabbed auto_route app (AutoTabsRouter / AutoTabsScaffold), switching tabs does not push or pop a Navigator route, so a plain NavigatorObserver never fires and every tab switch is a silently lost view. auto_route delivers tab transitions through didInitTabRoute / didChangeTabRoute, which only an AutoRouterObserver receives — this package emits spans for them.

MaterialApp.router(
  routerConfig: _appRouter.config(
    navigatorObservers: () => [OTelAutoRouterObserver()],
  ),
);

navigatorObservers is a factory because every nested router (each AutoRouter, each tabs router) calls it again — returning a new instance per navigator is the supported auto_route pattern; all instances emit through the same tracer.

Span shape

One zero-length span per transition, ended immediately — a view marker, so a trace waterfall reads as a user journey:

Spans carry navigation.route.path and, when present, navigation.previous_route_path; the very first push also carries navigation.is_initial_route = true. Tab spans use the route pattern (so span names stay low-cardinality); tab roots with an empty path fall back to the route name.

Span names and attribute keys are wire-identical to the sibling otel_go_router integration, so a mixed go_router + auto_route codebase produces one uniform trace vocabulary — without either package depending on the other.

Configuration

tracer, spanNameBuilder (stack transitions only), recordArguments (default false — arguments often carry user data), argumentAttributeMaxLength.

Caveats

• The observer calls OTel.tracerProvider().getTracer(...) in its constructor — OTel.initialize() must have already run.

License

Apache 2.0