From c22ba3f2a126706127b7af2a64f83fbb45b6cc87 Mon Sep 17 00:00:00 2001
From: Jhin Lee <leehack@gmail.com>
Date: Mon, 1 Jun 2026 02:47:31 -0400
Subject: [PATCH] Reject stateless legacy task status notifications

---
 lib/src/client/client.dart    |  1 +
 lib/src/server/server.dart    |  1 +
 test/mcp_2026_07_28_test.dart | 26 ++++++++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/lib/src/client/client.dart b/lib/src/client/client.dart
index 0c0fdc9a..35defaf5 100644
--- a/lib/src/client/client.dart
+++ b/lib/src/client/client.dart
@@ -122,6 +122,7 @@ const Set<String> _statelessRemovedRequestMethods = {
 const Set<String> _statelessRemovedNotificationMethods = {
   Method.notificationsInitialized,
   Method.notificationsRootsListChanged,
+  Method.notificationsTasksStatus,
 };
 
 /// An MCP client implementation built on top of a pluggable [Transport].
diff --git a/lib/src/server/server.dart b/lib/src/server/server.dart
index e5da1fdb..d5a1f52d 100644
--- a/lib/src/server/server.dart
+++ b/lib/src/server/server.dart
@@ -76,6 +76,7 @@ class Server extends Protocol {
   static const Set<String> _statelessRemovedNotificationMethods = {
     Method.notificationsInitialized,
     Method.notificationsRootsListChanged,
+    Method.notificationsTasksStatus,
   };
 
   static const Set<String> _inputRequiredResultMethods = {
diff --git a/test/mcp_2026_07_28_test.dart b/test/mcp_2026_07_28_test.dart
index ac69cfe4..5b82dbef 100644
--- a/test/mcp_2026_07_28_test.dart
+++ b/test/mcp_2026_07_28_test.dart
@@ -1541,6 +1541,18 @@ void main() {
             resultParams: const TaskResultRequest(taskId: 'task-1'),
             meta: taskExtensionMeta,
           ),
+        )
+        ..receive(
+          JsonRpcTaskStatusNotification(
+            statusParams: const TaskStatusNotification(
+              taskId: 'task-1',
+              status: TaskStatus.working,
+              ttl: null,
+              createdAt: '2026-07-28T00:00:00Z',
+              lastUpdatedAt: '2026-07-28T00:00:00Z',
+            ),
+            meta: taskExtensionMeta,
+          ),
         );
       await _pump();
 
@@ -2623,6 +2635,20 @@ void main() {
           method: Method.notificationsRootsListChanged,
           call: client.sendRootsListChanged,
         ),
+        (
+          method: Method.notificationsTasksStatus,
+          call: () => client.notification(
+                JsonRpcTaskStatusNotification(
+                  statusParams: const TaskStatusNotification(
+                    taskId: 'task-1',
+                    status: TaskStatus.working,
+                    ttl: null,
+                    createdAt: '2026-07-28T00:00:00Z',
+                    lastUpdatedAt: '2026-07-28T00:00:00Z',
+                  ),
+                ),
+              ),
+        ),
       ];
 
       for (final scenario in removedNotifications) {