feat: restore dual transport (websockets and sse)

server/src/main.rs

@@ -247,6 +247,8 @@ fn run_server(state: Arc<MemoryState>) -> Result<(), Box<dyn std::error::Error>>
                 }))
             }))
             .route("/ws", get(ws_handler))
+            .route("/sse", get(sse_handler))
+            .route("/messages", post(message_handler))
             .route("/health", get(health_handler))
             .route("/gate/verify", get(gate_verify_handler))
             .route("/gate/set", post(gate_set_handler))
@@ -502,6 +504,49 @@ eprintln!("MCP Memory Server running on http://127.0.0.1:3000/sse");
     })
 }
 
+#[derive(serde::Deserialize)]
+struct MsgQuery {
+    session_id: String,
+}
+
+async fn message_handler(
+    State(state): State<Arc<AppState>>,
+    Query(q): Query<MsgQuery>,
+    Json(payload): Json<serde_json::Value>,
+) -> impl axum::response::IntoResponse {
+    let session_id = q.session_id;
+    if let Some(response) = state.handler.handle_request(payload).await {
+        let res_str = serde_json::to_string(&response).unwrap();
+        let tx_opt = state.clients.read().unwrap().get(&session_id).cloned();
+        if let Some(tx) = tx_opt {
+            let _ = tx.send(res_str).await;
+        }
+    }
+    (axum::http::StatusCode::ACCEPTED, "Accepted").into_response()
+}
+
+async fn sse_handler(
+    State(state): State<Arc<AppState>>,
+) -> axum::response::sse::Sse<impl tokio_stream::Stream<Item = Result<axum::response::sse::Event, std::convert::Infallible>>> {
+    let session_id = format!("{}", state.next_id.fetch_add(1, Ordering::SeqCst));
+    let (tx, rx) = mpsc::channel::<String>(100);
+    state.clients.write().unwrap().insert(session_id.clone(), tx.clone());
+
+    let endpoint = format!("/messages?session_id={}", session_id);
+    let _ = tx.send(format!("endpoint|{}", endpoint)).await;
+
+    let rx_stream = tokio_stream::wrappers::ReceiverStream::new(rx);
+    let event_stream = rx_stream.map(|msg| {
+        if let Some(ep) = msg.strip_prefix("endpoint|") {
+            Ok(axum::response::sse::Event::default().event("endpoint").data(ep))
+        } else {
+            Ok(axum::response::sse::Event::default().event("message").data(msg))
+        }
+    });
+
+    axum::response::sse::Sse::new(event_stream).keep_alive(axum::response::sse::KeepAlive::new())
+}
+
 async fn ws_handler(
     ws: WebSocketUpgrade,
     State(state): State<Arc<AppState>>,