Add method to determine if player is in OnlineMode

api/src/main/java/com/velocitypowered/api/proxy/Player.java

@@ -65,6 +65,13 @@ public interface Player extends CommandSource, InboundConnection, ChannelMessage
    */
   long getPing();
 
+  /**
+   * Returns the player's connection status.
+   *
+   * @return true if the player is authenticated with Mojang servers
+   */
+  boolean isOnlineMode();
+
   /**
    * Sends a chat message to the player's client.
    *

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -90,6 +90,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
   private PermissionFunction permissionFunction;
   private int tryIndex = 0;
   private long ping = -1;
+  private final boolean onlineMode;
   private @Nullable VelocityServerConnection connectedServer;
   private @Nullable VelocityServerConnection connectionInFlight;
   private @Nullable PlayerSettings settings;
@@ -102,8 +103,8 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
 
   private @MonotonicNonNull List<String> serversToTry = null;
 
-  ConnectedPlayer(VelocityServer server, GameProfile profile,
-      MinecraftConnection connection, @Nullable InetSocketAddress virtualHost) {
+  ConnectedPlayer(VelocityServer server, GameProfile profile, MinecraftConnection connection,
+      @Nullable InetSocketAddress virtualHost, boolean onlineMode) {
     this.server = server;
     if (connection.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       this.tabList = new VelocityTabList(connection);
@@ -116,6 +117,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     this.permissionFunction = PermissionFunction.ALWAYS_UNDEFINED;
     this.connectionPhase = connection.getType().getInitialClientPhase();
     this.knownChannels = CappedSet.create(MAX_PLUGIN_CHANNELS);
+    this.onlineMode = onlineMode;
   }
 
   @Override
@@ -151,6 +153,11 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     this.ping = ping;
   }
 
+  @Override
+  public boolean isOnlineMode() {
+    return onlineMode;
+  }
+
   @Override
   public PlayerSettings getPlayerSettings() {
     return settings == null ? ClientSettingsWrapper.DEFAULT : this.settings;

proxy/src/main/java/com/velocitypowered/proxy/connection/client/LoginSessionHandler.java

@@ -232,7 +232,7 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
       // Initiate a regular connection and move over to it.
       ConnectedPlayer player = new ConnectedPlayer(server, profileEvent.getGameProfile(),
           mcConnection,
-          inbound.getVirtualHost().orElse(null));
+          inbound.getVirtualHost().orElse(null), onlineMode);
       this.connectedPlayer = player;
       if (!server.canRegisterConnection(player)) {
         player.disconnect(VelocityMessages.ALREADY_CONNECTED);