Axum

Tokio-native web framework built on tower. Routes, extractors, middleware, and shared state.

Routing	Router, method routing, nested routes, fallbacks
Extractors	Json, Path, Query, State, Extension, custom extractors
Middleware	tower::ServiceBuilder, axum::middleware::from_fn
State	Arc<AppState> pattern, Extension vs State
Error handling	IntoResponse, Result<T, AppError>, error extractors