diff --git a/src/axum/app.rs b/src/axum/app.rs
index 64c4ba5..30e8633 100644
--- a/src/axum/app.rs
+++ b/src/axum/app.rs
@@ -44,6 +44,13 @@ impl AppBuilder {
         Self::default()
     }
 
+    pub fn from_router(router: Router) -> Self {
+        Self {
+            router,
+            ..Self::default()
+        }
+    }
+
     pub fn route(mut self, route: Router) -> Self {
         self.router = self.router.merge(route);
         self
@@ -106,6 +113,23 @@ impl AppBuilder {
         self
     }
 
+    /// Creates the app with the given options.
+    /// This method is useful for testing purposes.
+    /// Options used for configuring the listener will be lost.
+    pub fn build(self) -> Router {
+        let mut app = self.router;
+        if let Some(cors) = self.cors {
+            app = app.layer(cors);
+        }
+        app.layer(
+            self.tracing.unwrap_or(
+                TraceLayer::new_for_http()
+                    .make_span_with(trace::DefaultMakeSpan::new().level(Level::INFO))
+                    .on_response(trace::DefaultOnResponse::new().level(Level::INFO)),
+            ),
+        )
+    }
+
     /// Build the app and start the server
     /// # Default Options
     /// - IP == 0.0.0.0
@@ -118,10 +142,10 @@ impl AppBuilder {
         let listener = self.listener().await?;
 
         if self.normalize_path.unwrap_or(true) {
-            let app = NormalizePathLayer::trim_trailing_slash().layer(self.create_app());
+            let app = NormalizePathLayer::trim_trailing_slash().layer(self.build());
             axum::serve(listener, ServiceExt::<Request>::into_make_service(app)).await?;
         } else {
-            let app = self.create_app();
+            let app = self.build();
             axum::serve(listener, app.into_make_service()).await?;
         };
         Ok(())
@@ -132,20 +156,6 @@ impl AppBuilder {
         info!("Initializing server on: {addr}");
         TcpListener::bind(&addr).await
     }
-
-    fn create_app(self) -> Router {
-        let mut app = self.router;
-        if let Some(cors) = self.cors {
-            app = app.layer(cors);
-        }
-        app.layer(
-            self.tracing.unwrap_or(
-                TraceLayer::new_for_http()
-                    .make_span_with(trace::DefaultMakeSpan::new().level(Level::INFO))
-                    .on_response(trace::DefaultOnResponse::new().level(Level::INFO)),
-            ),
-        )
-    }
 }
 
 fn fmt_trace() -> Result<(), String> {
diff --git a/src/axum/router.rs b/src/axum/router.rs
index 0f3e108..d45cfb0 100644
--- a/src/axum/router.rs
+++ b/src/axum/router.rs
@@ -29,12 +29,28 @@ macro_rules! router {
             $body
         }
     };
+    ($body:expr; $state:ident: $($bound:tt),*) => {
+        pub fn router<$state: $($bound+)* 'static>() -> axum::Router<$state> {
+            $body
+        }
+    };
+    ($body:expr; $generic:ident: $($bound:tt),* -> $state:ty) => {
+        pub fn router<$generic: $($bound+)* 'static>() -> axum::Router<$state<$generic>> {
+            $body
+        }
+    };
     ($route:expr, $router:expr) => {
         router!(axum::Router::new().nest($route, $router));
     };
     ($route:expr, $router:expr, $state:ty) => {
         router!(axum::Router::new().nest($route, $router); $state);
     };
+    ($route:expr, $router:expr, $state:ident: $($bound:tt),*) => {
+        router!(axum::Router::new().nest($route, $router); $state: $($bound),*);
+    };
+      ($route:expr, $router:expr, $generic:ident: $($bound:tt),* -> $state:ty) => {
+        router!(axum::Router::new().nest($route, $router); $generic: $($bound),* -> $state);
+    };
     ($($method:ident $route:expr => $func:expr),* $(,)?) => {
         router!($crate::routes!($($method $route => $func),*));
     };
@@ -112,6 +128,18 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_nested_router_with_generic_state() {
+        router!(
+            "/simplify",
+            routes!(
+                get "/:exp" => || async {},
+                get "/table/:exp" => |_state: State<T>| async {}
+            ),
+            T: Clone, Send, Sync
+        );
+    }
+
     #[test]
     fn test_routes() {
         let _router: Router = routes!(