diff --git a/MareSynchronosServer/MareSynchronos.API/BannedUserDto.cs b/MareSynchronosServer/MareSynchronos.API/BannedUserDto.cs
index 2d5fc0a..0f58c5c 100644
--- a/MareSynchronosServer/MareSynchronos.API/BannedUserDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/BannedUserDto.cs
@@ -1,12 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MareSynchronos.API
+namespace MareSynchronos.API
 {
-    public class BannedUserDto
+    public record BannedUserDto
     {
         public string CharacterHash { get; set; }
         public string Reason { get; set; }
diff --git a/MareSynchronosServer/MareSynchronos.API/CharacterCacheDto.cs b/MareSynchronosServer/MareSynchronos.API/CharacterCacheDto.cs
index 7b22427..2873c32 100644
--- a/MareSynchronosServer/MareSynchronos.API/CharacterCacheDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/CharacterCacheDto.cs
@@ -1,13 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using Newtonsoft.Json;
+using System.Collections.Generic;
 
 namespace MareSynchronos.API
 {
-    public class CharacterCacheDto
+    public record CharacterCacheDto
     {
         public List<FileReplacementDto> FileReplacements { get; set; } = new();
         public string GlamourerData { get; set; }
@@ -15,10 +10,4 @@ namespace MareSynchronos.API
         public string Hash { get; set; }
         public int JobId { get; set; }
     }
-
-    public class FileReplacementDto
-    {
-        public string[] GamePaths { get; set; } = Array.Empty<string>();
-        public string Hash { get; set; }
-    }
 }
diff --git a/MareSynchronosServer/MareSynchronos.API/ClientPairDto.cs b/MareSynchronosServer/MareSynchronos.API/ClientPairDto.cs
index dfa657f..598727f 100644
--- a/MareSynchronosServer/MareSynchronos.API/ClientPairDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/ClientPairDto.cs
@@ -1,6 +1,6 @@
 namespace MareSynchronos.API
 {
-    public class ClientPairDto
+    public record ClientPairDto
     {
         public string OtherUID { get; set; }
         public bool IsPaused { get; set; }
diff --git a/MareSynchronosServer/MareSynchronos.API/DownloadFileDto.cs b/MareSynchronosServer/MareSynchronos.API/DownloadFileDto.cs
index a515b8a..483c2cc 100644
--- a/MareSynchronosServer/MareSynchronos.API/DownloadFileDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/DownloadFileDto.cs
@@ -1,12 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MareSynchronos.API
+namespace MareSynchronos.API
 {
-    public class DownloadFileDto
+    public record DownloadFileDto : ITransferFileDto
     {
         public bool FileExists { get; set; } = true;
         public string Hash { get; set; } = string.Empty;
diff --git a/MareSynchronosServer/MareSynchronos.API/FileReplacementDto.cs b/MareSynchronosServer/MareSynchronos.API/FileReplacementDto.cs
new file mode 100644
index 0000000..57aa2cb
--- /dev/null
+++ b/MareSynchronosServer/MareSynchronos.API/FileReplacementDto.cs
@@ -0,0 +1,10 @@
+using System;
+
+namespace MareSynchronos.API
+{
+    public record FileReplacementDto
+    {
+        public string[] GamePaths { get; set; } = Array.Empty<string>();
+        public string Hash { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MareSynchronosServer/MareSynchronos.API/ForbiddenUploadsDto.cs b/MareSynchronosServer/MareSynchronos.API/ForbiddenUploadsDto.cs
index 50d5f42..d5bfa5c 100644
--- a/MareSynchronosServer/MareSynchronos.API/ForbiddenUploadsDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/ForbiddenUploadsDto.cs
@@ -1,12 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MareSynchronos.API
+namespace MareSynchronos.API
 {
-    public class ForbiddenFileDto
+    public record ForbiddenFileDto
     {
         public string Hash { get; set; }
         public string ForbiddenBy { get; set; }
diff --git a/MareSynchronosServer/MareSynchronos.API/ITransferFileDto.cs b/MareSynchronosServer/MareSynchronos.API/ITransferFileDto.cs
new file mode 100644
index 0000000..4ff8561
--- /dev/null
+++ b/MareSynchronosServer/MareSynchronos.API/ITransferFileDto.cs
@@ -0,0 +1,9 @@
+namespace MareSynchronos.API
+{
+    public interface ITransferFileDto
+    {
+        string Hash { get; set; }
+        bool IsForbidden { get; set; }
+        string ForbiddenBy { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MareSynchronosServer/MareSynchronos.API/LoggedInUserDto.cs b/MareSynchronosServer/MareSynchronos.API/LoggedInUserDto.cs
index 4644c0f..11323f1 100644
--- a/MareSynchronosServer/MareSynchronos.API/LoggedInUserDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/LoggedInUserDto.cs
@@ -1,12 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MareSynchronos.API
+namespace MareSynchronos.API
 {
-    public class LoggedInUserDto
+    public record LoggedInUserDto
     {
         public bool IsAdmin { get; set; }
         public bool IsModerator { get; set; }
diff --git a/MareSynchronosServer/MareSynchronos.API/OnlineUserDto.cs b/MareSynchronosServer/MareSynchronos.API/OnlineUserDto.cs
index 37dc325..78da994 100644
--- a/MareSynchronosServer/MareSynchronos.API/OnlineUserDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/OnlineUserDto.cs
@@ -1,12 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MareSynchronos.API
+namespace MareSynchronos.API
 {
-    public class OnlineUserDto
+    public record OnlineUserDto
     {
         public string UID { get; set; }
         public string CharacterNameHash { get; set; }
diff --git a/MareSynchronosServer/MareSynchronos.API/UploadFileDto.cs b/MareSynchronosServer/MareSynchronos.API/UploadFileDto.cs
index 01fb490..07ad783 100644
--- a/MareSynchronosServer/MareSynchronos.API/UploadFileDto.cs
+++ b/MareSynchronosServer/MareSynchronos.API/UploadFileDto.cs
@@ -1,12 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MareSynchronos.API
+namespace MareSynchronos.API
 {
-    public class UploadFileDto
+    public record UploadFileDto : ITransferFileDto
     {
         public string Hash { get; set; } = string.Empty;
         public bool IsForbidden { get; set; } = false;
diff --git a/MareSynchronosServer/MareSynchronosServer/Authentication/SecretKeyAuthenticationHandler.cs b/MareSynchronosServer/MareSynchronosServer/Authentication/SecretKeyAuthenticationHandler.cs
index ff03a58..f379dce 100644
--- a/MareSynchronosServer/MareSynchronosServer/Authentication/SecretKeyAuthenticationHandler.cs
+++ b/MareSynchronosServer/MareSynchronosServer/Authentication/SecretKeyAuthenticationHandler.cs
@@ -45,9 +45,16 @@ namespace MareSynchronosServer.Authentication
                 return AuthenticateResult.Fail("Failed Authorization");
             }
 
-            user.CharacterIdentification = charNameHeader;
-            _mareDbContext.Users.Update(user);
-            await _mareDbContext.SaveChangesAsync();
+            if (user.CharacterIdentification != charNameHeader)
+            {
+                try
+                {
+                    user.CharacterIdentification = charNameHeader;
+                    _mareDbContext.Users.Update(user);
+                    await _mareDbContext.SaveChangesAsync();
+                }
+                catch (DbUpdateConcurrencyException) { }
+            }
 
             var claims = new List<Claim> {
                 new Claim(ClaimTypes.Name, user.CharacterIdentification),
diff --git a/MareSynchronosServer/MareSynchronosServer/Hubs/ConnectionHub.cs b/MareSynchronosServer/MareSynchronosServer/Hubs/ConnectionHub.cs
index 675e1c9..7cf3e9a 100644
--- a/MareSynchronosServer/MareSynchronosServer/Hubs/ConnectionHub.cs
+++ b/MareSynchronosServer/MareSynchronosServer/Hubs/ConnectionHub.cs
@@ -17,10 +17,11 @@ namespace MareSynchronosServer.Hubs
         public async Task<LoggedInUserDto> Heartbeat()
         {
             var userId = Context.User!.Claims.SingleOrDefault(c => c.Type == ClaimTypes.NameIdentifier)?.Value;
-            Logger.LogInformation("Heartbeat from " + (userId ?? "Unknown user"));
+            
 
             if (userId != null)
             {
+                Logger.LogInformation("Heartbeat from " + userId);
                 var user = (await DbContext.Users.SingleAsync(u => u.UID == userId));
                 return new LoggedInUserDto
                 {
diff --git a/MareSynchronosServer/MareSynchronosServer/Hubs/UserHub.cs b/MareSynchronosServer/MareSynchronosServer/Hubs/UserHub.cs
index 296a83b..56985ea 100644
--- a/MareSynchronosServer/MareSynchronosServer/Hubs/UserHub.cs
+++ b/MareSynchronosServer/MareSynchronosServer/Hubs/UserHub.cs
@@ -45,6 +45,13 @@ namespace MareSynchronosServer.Hubs
                 user.UID = uid;
                 hasValidUid = true;
             }
+
+            // make the first registered user on the service to admin
+            if (!await DbContext.Users.AnyAsync())
+            {
+                user.IsAdmin = true;
+            }
+
             DbContext.Users.Add(user);
 
             Logger.LogInformation("User registered: " + user.UID);
@@ -89,6 +96,28 @@ namespace MareSynchronosServer.Hubs
             }
         }
 
+        [Authorize(AuthenticationSchemes = SecretKeyAuthenticationHandler.AuthScheme)]
+        public async Task PushCharacterDataToVisibleClients(CharacterCacheDto characterCache, List<string> visibleCharacterIds)
+        {
+            Logger.LogInformation("User " + AuthenticatedUserId + " pushing character data to visible clients");
+
+            var uid = AuthenticatedUserId;
+            var entriesHavingThisUser = DbContext.ClientPairs
+                .Include(w => w.User)
+                .Include(w => w.OtherUser)
+                .Where(w => w.OtherUser.UID == uid && !w.IsPaused
+                    && visibleCharacterIds.Contains(w.User.CharacterIdentification)).ToList();
+
+            foreach (var pair in entriesHavingThisUser)
+            {
+                var ownEntry = DbContext.ClientPairs.SingleOrDefault(w =>
+                    w.User.UID == uid && w.OtherUser.UID == pair.User.UID);
+                if (ownEntry == null || ownEntry.IsPaused) continue;
+                await Clients.User(pair.User.UID).SendAsync("ReceiveCharacterData", characterCache,
+                    pair.OtherUser.CharacterIdentification);
+            }
+        }
+
         [Authorize(AuthenticationSchemes = SecretKeyAuthenticationHandler.AuthScheme)]
         public async Task PushCharacterData(CharacterCacheDto characterCache, List<string> visibleCharacterIds)
         {
@@ -152,7 +181,7 @@ namespace MareSynchronosServer.Hubs
             await Clients.Users(otherEntries.Select(e => e.User.UID)).SendAsync("AddOnlinePairedPlayer", ownUser.CharacterIdentification);
             await Clients.All.SendAsync("UsersOnline",
                 await DbContext.Users.CountAsync(u => !string.IsNullOrEmpty(u.CharacterIdentification)));
-            return otherEntries.Select(e => e.User.CharacterIdentification).ToList();
+            return otherEntries.Select(e => e.User.CharacterIdentification).Distinct().ToList();
         }
 
         [Authorize(AuthenticationSchemes = SecretKeyAuthenticationHandler.AuthScheme)]
@@ -340,11 +369,6 @@ namespace MareSynchronosServer.Hubs
             {
                 Logger.LogInformation("Disconnect from " + AuthenticatedUserId);
 
-                var outdatedCharacterData = DbContext.CharacterData.Where(v => v.UserId == user.UID);
-                DbContext.RemoveRange(outdatedCharacterData);
-                user.CharacterIdentification = null;
-                await DbContext.SaveChangesAsync();
-
                 var otherUsers = DbContext.ClientPairs
                     .Include(u => u.User)
                     .Include(u => u.OtherUser)
@@ -354,6 +378,12 @@ namespace MareSynchronosServer.Hubs
                 var otherEntries = DbContext.ClientPairs.Include(u => u.User)
                     .Where(u => otherUsers.Any(e => e == u.User) && u.OtherUser == user && !u.IsPaused).ToList();
                 await Clients.Users(otherEntries.Select(e => e.User.UID)).SendAsync("RemoveOnlinePairedPlayer", user.CharacterIdentification);
+
+                var outdatedCharacterData = DbContext.CharacterData.Where(v => v.UserId == user.UID);
+                DbContext.RemoveRange(outdatedCharacterData);
+                user.CharacterIdentification = null;
+                await DbContext.SaveChangesAsync();
+
                 await Clients.All.SendAsync("UsersOnline",
                     await DbContext.Users.CountAsync(u => !string.IsNullOrEmpty(u.CharacterIdentification)));
             }