diff --git a/Streetwriters.Common/Extensions/WampRealmExtensions.cs b/Streetwriters.Common/Extensions/WampRealmExtensions.cs
index 4b86694..0dea9bb 100644
--- a/Streetwriters.Common/Extensions/WampRealmExtensions.cs
+++ b/Streetwriters.Common/Extensions/WampRealmExtensions.cs
@@ -18,6 +18,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 using System;
+using System.Reactive.Disposables;
+using System.Threading;
 using Microsoft.AspNetCore.Builder;
 using Streetwriters.Common.Interfaces;
 using WampSharp.AspNetCore.WebSockets.Server;
@@ -38,5 +40,27 @@ namespace Streetwriters.Common.Extensions
         {
             return realm.Services.GetSubject<T>(topicName).Subscribe<T>(async (message) => await handler.Process(message));
         }
+
+        public static IDisposable SubscribeWithSemaphore<T>(this IWampHostedRealm realm, string topicName, IMessageHandler<T> handler)
+        {
+            var semaphore = new SemaphoreSlim(1, 1);
+            var subscriber = realm.Services.GetSubject<T>(topicName).Subscribe<T>(async (message) =>
+            {
+                await semaphore.WaitAsync();
+                try
+                {
+                    await handler.Process(message);
+                }
+                finally
+                {
+                    semaphore.Release();
+                }
+            });
+            return Disposable.Create(() =>
+            {
+                subscriber.Dispose();
+                semaphore.Dispose();
+            });
+        }
     }
 }
\ No newline at end of file
diff --git a/Streetwriters.Common/Helpers/WampHelper.cs b/Streetwriters.Common/Helpers/WampHelper.cs
index 4d01fa0..b641035 100644
--- a/Streetwriters.Common/Helpers/WampHelper.cs
+++ b/Streetwriters.Common/Helpers/WampHelper.cs
@@ -1,47 +1,55 @@
-/*
-This file is part of the Notesnook Sync Server project (https://notesnook.com/)
-
-Copyright (C) 2023 Streetwriters (Private) Limited
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the Affero GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-Affero GNU General Public License for more details.
-
-You should have received a copy of the Affero GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-using System.Reactive.Subjects;
-using System.Threading.Tasks;
-using Streetwriters.Common.Messages;
-using WampSharp.V2;
-using WampSharp.V2.Client;
-
-namespace Streetwriters.Common.Helpers
-{
-    public class WampHelper
-    {
-        public static async Task<IWampRealmProxy> OpenWampChannelAsync(string server, string realmName)
-        {
-            DefaultWampChannelFactory channelFactory = new();
-
-            IWampChannel channel = channelFactory.CreateJsonChannel(server, realmName);
-
-            await channel.Open();
-
-            return channel.RealmProxy;
-        }
-
-        public static void PublishMessage<T>(IWampRealmProxy realm, string topicName, T message)
-        {
-            var subject = realm.Services.GetSubject<T>(topicName);
-            subject.OnNext(message);
-        }
-    }
+/*
+This file is part of the Notesnook Sync Server project (https://notesnook.com/)
+
+Copyright (C) 2023 Streetwriters (Private) Limited
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the Affero GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+Affero GNU General Public License for more details.
+
+You should have received a copy of the Affero GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+using System.Collections.Generic;
+using System.Reactive.Subjects;
+using System.Threading.Tasks;
+using Streetwriters.Common.Messages;
+using WampSharp.V2;
+using WampSharp.V2.Client;
+
+namespace Streetwriters.Common.Helpers
+{
+    public class WampHelper
+    {
+        public static async Task<IWampRealmProxy> OpenWampChannelAsync(string server, string realmName)
+        {
+            DefaultWampChannelFactory channelFactory = new();
+
+            IWampChannel channel = channelFactory.CreateJsonChannel(server, realmName);
+
+            await channel.Open();
+
+            return channel.RealmProxy;
+        }
+
+        public static void PublishMessage<T>(IWampRealmProxy realm, string topicName, T message)
+        {
+            var subject = realm.Services.GetSubject<T>(topicName);
+            subject.OnNext(message);
+        }
+
+        public static void PublishMessages<T>(IWampRealmProxy realm, string topicName, IEnumerable<T> messages)
+        {
+            var subject = realm.Services.GetSubject<T>(topicName);
+            foreach (var message in messages)
+                subject.OnNext(message);
+        }
+    }
 }
\ No newline at end of file
diff --git a/Streetwriters.Common/WampServers.cs b/Streetwriters.Common/WampServers.cs
index c3269b9..69feedb 100644
--- a/Streetwriters.Common/WampServers.cs
+++ b/Streetwriters.Common/WampServers.cs
@@ -1,126 +1,140 @@
-/*
-This file is part of the Notesnook Sync Server project (https://notesnook.com/)
-
-Copyright (C) 2023 Streetwriters (Private) Limited
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the Affero GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-Affero GNU General Public License for more details.
-
-You should have received a copy of the Affero GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-using System;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Reactive.Subjects;
-using System.Threading.Tasks;
-using Streetwriters.Common.Helpers;
-using Streetwriters.Common.Interfaces;
-using WampSharp.V2.Client;
-
-namespace Streetwriters.Common
-{
-    public class WampServer<T> where T : new()
-    {
-        private readonly ConcurrentDictionary<string, IWampRealmProxy> Channels = new();
-
-        public string Endpoint { get; set; }
-        public string Address { get; set; }
-        public T Topics { get; set; } = new T();
-        public string Realm { get; set; }
-
-        private async Task<IWampRealmProxy> GetChannelAsync(string topic)
-        {
-            if (!Channels.TryGetValue(topic, out IWampRealmProxy channel) || !channel.Monitor.IsConnected)
-            {
-                channel = await WampHelper.OpenWampChannelAsync(Address, Realm);
-                Channels.AddOrUpdate(topic, (key) => channel, (key, old) => channel);
-            }
-            return channel;
-        }
-
-        public async Task<V> GetServiceAsync<V>(string topic) where V : class
-        {
-            var channel = await GetChannelAsync(topic);
-            return channel.Services.GetCalleeProxy<V>();
-        }
-
-        public async Task PublishMessageAsync<V>(string topic, V message)
-        {
-            try
-            {
-                IWampRealmProxy channel = await GetChannelAsync(topic);
-                WampHelper.PublishMessage(channel, topic, message);
-            }
-            catch (Exception ex)
-            {
-                await Slogger<WampServer<T>>.Error(nameof(PublishMessageAsync), ex.ToString());
-                throw ex;
-            }
-        }
-    }
-
-    public class WampServers
-    {
-        public static WampServer<MessengerServerTopics> MessengerServer { get; } = new WampServer<MessengerServerTopics>
-        {
-            Endpoint = "/wamp",
-            Address = $"{Servers.MessengerServer.WS()}/wamp",
-            Realm = "messages",
-        };
-
-        public static WampServer<SubscriptionServerTopics> SubscriptionServer { get; } = new WampServer<SubscriptionServerTopics>
-        {
-            Endpoint = "/wamp",
-            Address = $"{Servers.SubscriptionServer.WS()}/wamp",
-            Realm = "messages",
-        };
-
-        public static WampServer<IdentityServerTopics> IdentityServer { get; } = new WampServer<IdentityServerTopics>
-        {
-            Endpoint = "/wamp",
-            Address = $"{Servers.IdentityServer.WS()}/wamp",
-            Realm = "messages",
-        };
-
-        public static WampServer<NotesnookServerTopics> NotesnookServer { get; } = new WampServer<NotesnookServerTopics>
-        {
-            Endpoint = "/wamp",
-            Address = $"{Servers.NotesnookAPI.WS()}/wamp",
-            Realm = "messages",
-        };
-    }
-
-    public class MessengerServerTopics
-    {
-        public const string SendSSETopic = "co.streetwriters.sse.send";
-    }
-
-    public class SubscriptionServerTopics
-    {
-        public const string UserSubscriptionServiceTopic = "co.streetwriters.subscriptions.subscriptions";
-
-        public const string CreateSubscriptionTopic = "co.streetwriters.subscriptions.create";
+/*
+This file is part of the Notesnook Sync Server project (https://notesnook.com/)
+
+Copyright (C) 2023 Streetwriters (Private) Limited
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the Affero GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+Affero GNU General Public License for more details.
+
+You should have received a copy of the Affero GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Reactive.Subjects;
+using System.Threading.Tasks;
+using Streetwriters.Common.Helpers;
+using Streetwriters.Common.Interfaces;
+using WampSharp.V2.Client;
+
+namespace Streetwriters.Common
+{
+    public class WampServer<T> where T : new()
+    {
+        private readonly ConcurrentDictionary<string, IWampRealmProxy> Channels = new();
+
+        public string Endpoint { get; set; }
+        public string Address { get; set; }
+        public T Topics { get; set; } = new T();
+        public string Realm { get; set; }
+
+        private async Task<IWampRealmProxy> GetChannelAsync(string topic)
+        {
+            if (!Channels.TryGetValue(topic, out IWampRealmProxy channel) || !channel.Monitor.IsConnected)
+            {
+                channel = await WampHelper.OpenWampChannelAsync(Address, Realm);
+                Channels.AddOrUpdate(topic, (key) => channel, (key, old) => channel);
+            }
+            return channel;
+        }
+
+        public async Task<V> GetServiceAsync<V>(string topic) where V : class
+        {
+            var channel = await GetChannelAsync(topic);
+            return channel.Services.GetCalleeProxy<V>();
+        }
+
+        public async Task PublishMessageAsync<V>(string topic, V message)
+        {
+            try
+            {
+                IWampRealmProxy channel = await GetChannelAsync(topic);
+                WampHelper.PublishMessage(channel, topic, message);
+            }
+            catch (Exception ex)
+            {
+                await Slogger<WampServer<T>>.Error(nameof(PublishMessageAsync), ex.ToString());
+                throw ex;
+            }
+        }
+
+        public async Task PublishMessagesAsync<V>(string topic, IEnumerable<V> messages)
+        {
+            try
+            {
+                IWampRealmProxy channel = await GetChannelAsync(topic);
+                WampHelper.PublishMessages(channel, topic, messages);
+            }
+            catch (Exception ex)
+            {
+                await Slogger<WampServer<T>>.Error(nameof(PublishMessagesAsync), ex.ToString());
+                throw ex;
+            }
+        }
+    }
+
+    public class WampServers
+    {
+        public static WampServer<MessengerServerTopics> MessengerServer { get; } = new WampServer<MessengerServerTopics>
+        {
+            Endpoint = "/wamp",
+            Address = $"{Servers.MessengerServer.WS()}/wamp",
+            Realm = "messages",
+        };
+
+        public static WampServer<SubscriptionServerTopics> SubscriptionServer { get; } = new WampServer<SubscriptionServerTopics>
+        {
+            Endpoint = "/wamp",
+            Address = $"{Servers.SubscriptionServer.WS()}/wamp",
+            Realm = "messages",
+        };
+
+        public static WampServer<IdentityServerTopics> IdentityServer { get; } = new WampServer<IdentityServerTopics>
+        {
+            Endpoint = "/wamp",
+            Address = $"{Servers.IdentityServer.WS()}/wamp",
+            Realm = "messages",
+        };
+
+        public static WampServer<NotesnookServerTopics> NotesnookServer { get; } = new WampServer<NotesnookServerTopics>
+        {
+            Endpoint = "/wamp",
+            Address = $"{Servers.NotesnookAPI.WS()}/wamp",
+            Realm = "messages",
+        };
+    }
+
+    public class MessengerServerTopics
+    {
+        public const string SendSSETopic = "co.streetwriters.sse.send";
+    }
+
+    public class SubscriptionServerTopics
+    {
+        public const string UserSubscriptionServiceTopic = "co.streetwriters.subscriptions.subscriptions";
+
+        public const string CreateSubscriptionTopic = "co.streetwriters.subscriptions.create";
         public const string CreateSubscriptionV2Topic = "co.streetwriters.subscriptions.v2.create";
-        public const string DeleteSubscriptionTopic = "co.streetwriters.subscriptions.delete";
-    }
-
-    public class IdentityServerTopics
-    {
-        public const string UserAccountServiceTopic = "co.streetwriters.identity.users";
-        public const string ClearCacheTopic = "co.streetwriters.identity.clear_cache";
-        public const string DeleteUserTopic = "co.streetwriters.identity.delete_user";
-    }
-
-    public class NotesnookServerTopics
-    {
-    }
+        public const string DeleteSubscriptionTopic = "co.streetwriters.subscriptions.delete";
+    }
+
+    public class IdentityServerTopics
+    {
+        public const string UserAccountServiceTopic = "co.streetwriters.identity.users";
+        public const string ClearCacheTopic = "co.streetwriters.identity.clear_cache";
+        public const string DeleteUserTopic = "co.streetwriters.identity.delete_user";
+    }
+
+    public class NotesnookServerTopics
+    {
+    }
 }
\ No newline at end of file