Merge remote-tracking branch 'upstream/dev/4.0.0' into update

# Conflicts:
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

.github/workflows/gradle.yml

@@ -6,18 +6,28 @@ on: [push, pull_request]
 
 jobs:
   build:
-    runs-on: ubuntu-24.04
+    runs-on: namespace-profile-linux-default
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@v6
+      uses: namespacelabs/nscloud-checkout-action@v9
       with:
         persist-credentials: false
+    - name: Set up cache
+      uses: namespacelabs/nscloud-cache-action@v1
+      with:
+        cache: gradle
+    - name: Setup gradle build cache
+      run: |
+        nsc cache gradle setup --init-gradle /tmp/init.gradle
     - name: Set up Gradle
-      uses: gradle/actions/setup-gradle@v5
+      uses: gradle/actions/setup-gradle@v6
+      with:
+        cache-disabled: true # namespace handles this
     - name: Set up JDK 21
-      uses: actions/setup-java@v5
+      uses: actions/setup-java@v6
       with:
         java-version: 21
         distribution: 'zulu'
+        cache: "" # namespace handles this
     - name: Build with Gradle
-      run: ./gradlew build
+      run: ./gradlew --init-script=/tmp/init.gradle build

README.md

@@ -40,3 +40,5 @@ page.
 Translations are handled using [Crowdin](https://papermc-io.crowdin.com/velocity).
 If you want to translate a language not available on Crowdin,
 you might want to ask in the [Discord](https://discord.gg/papermc) about it.
+
+[![CI powered by namespace badge](https://papermc.io/assets/misc/namespace-oss-badge.svg?project=velocity)](https://namespace.so/github-actions/?utm_source=oss&utm_campaign=papermc)

api/src/main/java/com/velocitypowered/api/event/connection/PreLoginEvent.java

@@ -73,6 +73,7 @@ public final class PreLoginEvent implements ResultedEvent<PreLoginEvent.PreLogin
 
   /**
    * Returns the UUID of the connecting player.
+   *
    * <p>This value is {@code null} on 1.19.2 and lower,
    * up to 1.20.1 it is optional and from 1.20.2 it will always be available.</p>
    *

api/src/main/java/com/velocitypowered/api/event/player/configuration/PlayerConfigurationEvent.java

@@ -14,6 +14,7 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * This event is executed when a player entered the configuration state and can be configured by Velocity.
+ *
  * <p>Velocity will wait for this event before continuing/ending the configuration state.</p>
  *
  * @param player The player who can be configured.

api/src/main/java/com/velocitypowered/api/event/player/configuration/PlayerEnterConfigurationEvent.java

@@ -15,6 +15,7 @@ import org.jetbrains.annotations.NotNull;
 /**
  * This event is executed when a player is about to enter the configuration state.
  * It is <b>not</b> called for the initial configuration of a player after login.
+ *
  * <p>Velocity will wait for this event before asking the client to enter configuration state.
  * However due to backend server being unable to keep the connection alive during state changes,
  * Velocity will only wait for a maximum of 5 seconds.</p>

api/src/main/java/com/velocitypowered/api/event/player/configuration/PlayerEnteredConfigurationEvent.java

@@ -14,6 +14,7 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * This event is executed when a player has entered the configuration state.
+ *
  * <p>From this moment on, until the {@link PlayerFinishedConfigurationEvent} is executed,
  * the {@linkplain Player#getProtocolState()} method is guaranteed
  * to return {@link ProtocolState#CONFIGURATION}.</p>

api/src/main/java/com/velocitypowered/api/event/player/configuration/PlayerFinishConfigurationEvent.java

@@ -14,6 +14,7 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * This event is executed when a player is about to finish the configuration state.
+ *
  * <p>Velocity will wait for this event before asking the client to finish the configuration state.
  * However due to backend server being unable to keep the connection alive during state changes,
  * Velocity will only wait for a maximum of 5 seconds. If you need to hold a player in configuration

api/src/main/java/com/velocitypowered/api/event/player/configuration/PlayerFinishedConfigurationEvent.java

@@ -14,6 +14,7 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * This event is executed when a player has finished the configuration state.
+ *
  * <p>From this moment on, the {@link Player#getProtocolState()} method
  * will return {@link ProtocolState#PLAY}.</p>
  *

api/src/main/java/com/velocitypowered/api/network/ProtocolState.java

@@ -16,6 +16,7 @@ package com.velocitypowered.api.network;
 public enum ProtocolState {
   /**
    * Initial connection State.
+   *
    * <p>This status can be caused by a {@link HandshakeIntent#STATUS},
    * {@link HandshakeIntent#LOGIN} or {@link HandshakeIntent#TRANSFER} intent.</p>
    * If the intent is LOGIN or TRANSFER, the next state will be {@link #LOGIN},
@@ -24,6 +25,7 @@ public enum ProtocolState {
   HANDSHAKE,
   /**
    * Ping State of a connection.
+   *
    * <p>Connections with the {@link HandshakeIntent#STATUS} intent will pass through this state
    * and be disconnected after it requests the ping from the server
    * and the server responds with the respective ping.</p>
@@ -31,11 +33,13 @@ public enum ProtocolState {
   STATUS,
   /**
    * Authentication State of a connection.
+   *
    * <p>At this moment the player is authenticating with the authentication servers.</p>
    */
   LOGIN,
   /**
    * Configuration State of a connection.
+   *
    * <p>At this point the player allows the server to send information
    * such as resource packs and plugin messages, at the same time the player
    * will send his client brand and the respective plugin messages
@@ -46,6 +50,7 @@ public enum ProtocolState {
   CONFIGURATION,
   /**
    * Game State of a connection.
+   *
    * <p>In this state is where the whole game runs, the server is able to change
    * the player's state to {@link #CONFIGURATION} as needed in versions 1.20.2 and higher.</p>
    */

api/src/main/java/com/velocitypowered/api/network/ProtocolVersion.java

@@ -96,7 +96,8 @@ public enum ProtocolVersion implements Ordered<ProtocolVersion> {
   MINECRAFT_1_21_9(773, "1.21.9", "1.21.10"),
   MINECRAFT_1_21_11(774, "1.21.11"),
   MINECRAFT_26_1(775, "26.1", "26.1.1", "26.1.2"),
-  MINECRAFT_26_2(776, "26.2");
+  MINECRAFT_26_2(776, "26.2"),
+  MINECRAFT_26_3(777, "26.3");
 
   private static final int SNAPSHOT_BIT = 30;
 

api/src/main/java/com/velocitypowered/api/permission/Tristate.java

@@ -15,7 +15,6 @@ import org.checkerframework.checker.nullness.qual.Nullable;
  * Represents three different states of a setting.
  *
  * <p>Possible values:</p>
- * <p></p>
  * <ul>
  * <li>{@link #TRUE} - a positive setting</li>
  * <li>{@link #FALSE} - a negative (negated) setting</li>

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

@@ -315,6 +315,7 @@ public interface Player extends
 
   /**
    * {@inheritDoc}
+   *
    * <p><strong>Note that this method does not send a plugin message to the server the player
    * is connected to.</strong> You should only use this method if you are trying to communicate
    * with a mod that is installed on the player's client.</p>

api/src/main/java/com/velocitypowered/api/proxy/crypto/KeySigned.java

@@ -56,6 +56,7 @@ public interface KeySigned {
    * Validates the signature, expiry temporal and key against the
    * signer public key. Note: This will **not** check for
    * expiry. You can check for expiry with {@link KeySigned#hasExpired()}.
+   *
    * <p>DOES NOT WORK YET FOR MESSAGES AND COMMANDS!</p>
    * Addendum: Does not work for 1.19.1 until the user has authenticated.
    *

api/src/main/java/com/velocitypowered/api/proxy/player/TabListEntry.java

@@ -237,8 +237,11 @@ public interface TabListEntry extends KeyIdentifiable {
 
     /**
      * Sets the {@link IdentifiedKey} of the {@link TabListEntry}.
+     *
      * <p>This only works for players currently <b>not</b> connected to this proxy.</p>
+     *
      * <p>For any player currently connected to this proxy this will be filled automatically.</p>
+     *
      * <p>Will ignore mismatching key revisions data.</p>
      *
      * @param chatSession session to set

gradle.properties

@@ -1,2 +1,2 @@
 group=com.velocitypowered
-version=4.1.0-SNAPSHOT
+version=4.2.1-SNAPSHOT

gradle/libs.versions.toml

@@ -3,12 +3,12 @@ configurate3 = "3.7.3"
 configurate4 = "4.2.0"
 flare = "2.0.1"
 log4j = "2.26.1"
-netty = "4.2.16.Final"
+netty = "4.2.18.Final"
 
 [plugins]
 fill = "io.papermc.fill.gradle:1.0.12"
 shadow = "com.gradleup.shadow:9.6.1"
-spotless = "com.diffplug.spotless:8.9.0"
+spotless = "com.diffplug.spotless:8.10.2"
 
 [libraries]
 adventure-bom = "net.kyori:adventure-bom:5.2.0"
@@ -19,8 +19,8 @@ auto-service-annotations = "com.google.auto.service:auto-service-annotations:1.1
 brigadier = "com.velocitypowered:velocity-brigadier:1.0.0-SNAPSHOT"
 bstats = "org.bstats:bstats-base:3.2.1"
 caffeine = "com.github.ben-manes.caffeine:caffeine:3.2.4"
-checker-qual = "org.checkerframework:checker-qual:4.2.1"
+checker-qual = "org.checkerframework:checker-qual:4.2.3"
-checkstyle = "com.puppycrawl.tools:checkstyle:10.9.3"
+checkstyle = "com.puppycrawl.tools:checkstyle:14.1.0"
 completablefutures = "com.spotify:completable-futures:0.3.6"
 configurate3-hocon = { module = "org.spongepowered:configurate-hocon", version.ref = "configurate3" }
 configurate3-yaml = { module = "org.spongepowered:configurate-yaml", version.ref = "configurate3" }
@@ -32,12 +32,12 @@ disruptor = "com.lmax:disruptor:4.0.0"
 fastutil = "it.unimi.dsi:fastutil:8.5.19"
 flare-core = { module = "space.vectrix.flare:flare", version.ref = "flare" }
 flare-fastutil = { module = "space.vectrix.flare:flare-fastutil", version.ref = "flare" }
-jline = "org.jline:jline-terminal-ffm:4.3.1"
+jline = "org.jline:jline-terminal-jni:4.3.1"
 jopt = "net.sf.jopt-simple:jopt-simple:5.0.4"
-junit = "org.junit.jupiter:junit-jupiter:6.1.2"
+junit = "org.junit.jupiter:junit-jupiter:6.1.3"
 jspecify = "org.jspecify:jspecify:1.0.1"
 kyori-ansi = "net.kyori:ansi:1.1.1"
-guava = "com.google.guava:guava:33.6.0-jre"
+guava = "com.google.guava:guava:33.7.1-jre"
 gson = "com.google.code.gson:gson:2.14.0"
 guice = "com.google.inject:guice:7.0.0"
 lmbda = "org.lanternpowered:lmbda:3.0.0"
@@ -55,9 +55,9 @@ netty-transport-native-epoll = { module = "io.netty:netty-transport-native-epoll
 netty-transport-native-kqueue = { module = "io.netty:netty-transport-native-kqueue", version.ref = "netty" }
 netty-transport-native-iouring = { module = "io.netty:netty-transport-native-io_uring", version.ref = "netty" }
 nightconfig = "com.electronwill.night-config:toml:3.9.0"
-slf4j = "org.slf4j:slf4j-api:2.0.18"
+slf4j = "org.slf4j:slf4j-api:2.0.19"
-snakeyaml = "org.yaml:snakeyaml:2.6"
+snakeyaml = "org.yaml:snakeyaml:2.7"
-spotbugs-annotations = "com.github.spotbugs:spotbugs-annotations:4.10.3"
+spotbugs-annotations = "com.github.spotbugs:spotbugs-annotations:4.10.4"
 terminalconsoleappender = "net.minecrell:terminalconsoleappender:1.3.0"
 
 [bundles]

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -488,23 +488,46 @@ public class VelocityServer implements ProxyServer, ForwardingAudience {
       return false;
     }
 
-    // Re-register servers. If a server is being replaced, make sure to note what players need to
+    // Re-register servers. If a server is being replaced or removed, make sure to note what
-    // move back to a fallback server.
+    // players need to move back to a fallback server.
     Collection<ConnectedPlayer> evacuate = new ArrayList<>();
-    for (Map.Entry<String, String> entry : newConfiguration.getServers().entrySet()) {
+    for (Map.Entry<String, String> entry : configuration.getServers().entrySet()) {
-      ServerInfo newInfo = new ServerInfo(entry.getKey(), AddressUtil.parseAddress(entry.getValue()));
+      if (newConfiguration.getServers().keySet().stream()
-      Optional<RegisteredServer> rs = servers.getServer(entry.getKey());
+          .anyMatch(name -> name.equalsIgnoreCase(entry.getKey()))) {
-      if (rs.isEmpty()) {
+        continue;
-        servers.register(newInfo);
+      }
-      } else if (!rs.get().getServerInfo().equals(newInfo)) {
+
-        for (Player player : rs.get().getPlayersConnected()) {
+      RegisteredServer rs = servers.getServer(entry.getKey()).orElse(null);
+      if (rs == null) {
+        continue;
+      }
+
+      for (Player player : rs.getPlayersConnected()) {
         if (!(player instanceof ConnectedPlayer)) {
-            throw new IllegalStateException("ConnectedPlayer not found for player " + player
+          throw new IllegalStateException("Expected ConnectedPlayer for player " + player
-                + " in server " + rs.get().getServerInfo().getName());
+              + " on server " + rs.getServerInfo().getName() + ", got "
+              + player.getClass().getName());
         }
         evacuate.add((ConnectedPlayer) player);
       }
-        servers.unregister(rs.get().getServerInfo());
+      servers.unregister(rs.getServerInfo());
+    }
+
+    for (Map.Entry<String, String> entry : newConfiguration.getServers().entrySet()) {
+      ServerInfo newInfo = new ServerInfo(entry.getKey(), AddressUtil.parseAddress(entry.getValue()));
+      RegisteredServer rs = servers.getServer(entry.getKey()).orElse(null);
+      if (rs == null) {
+        servers.register(newInfo);
+      } else if (!rs.getServerInfo().equals(newInfo)) {
+        for (Player player : rs.getPlayersConnected()) {
+          if (!(player instanceof ConnectedPlayer)) {
+            throw new IllegalStateException("Expected ConnectedPlayer for player " + player
+                + " on server " + rs.getServerInfo().getName() + ", got "
+                + player.getClass().getName());
+          }
+          evacuate.add((ConnectedPlayer) player);
+        }
+        servers.unregister(rs.getServerInfo());
         servers.register(newInfo);
       }
     }
@@ -653,7 +676,7 @@ public class VelocityServer implements ProxyServer, ForwardingAudience {
   }
 
   /**
-   * Calls {@link #shutdown(boolean, Component)} with the default reason "Proxy shutting down."
+   * Calls {@link #shutdown(boolean, Component)} with the default reason "Proxy shutting down".
    *
    * @param explicitExit whether the user explicitly shut down the proxy
    */

proxy/src/main/java/com/velocitypowered/proxy/config/PingPassthroughMode.java

@@ -16,13 +16,49 @@
  */
 
 package com.velocitypowered.proxy.config;
+import com.electronwill.nightconfig.core.Config;
 
 /**
- * Supported passthrough modes for ping passthrough.
+ * Object to contain all the things that can be toggled for ping passthrough.
+ *
+ * @param version     Whether the version should be passed through.
+ * @param players     Whether the player count should be passed through.
+ * @param description Whether the description should be passed through.
+ * @param favicon     Whether the favicon should be passed through.
+ * @param modinfo     Whether the modinfo should be passed through.
  */
-public enum PingPassthroughMode {
+public record PingPassthroughMode(boolean version, boolean players,
-  DISABLED,
+    boolean description, boolean favicon, boolean modinfo) {
-  MODS,
+  public static final PingPassthroughMode DEFAULT = new PingPassthroughMode();
-  DESCRIPTION,
+  
-  ALL
+  /**
+   * Creates a default PingPassthroughMode.
+   */
+  private PingPassthroughMode() {
+    this(false, false, false, false, false);
+  }
+
+  /**
+   * Returns a PingPassthroughMode from a config section, or the default if the section is null.
+   * Based on the code for PacketLimiterConfig.
+   *
+   * @param config The configuration object to parse.
+   * @return The PingPassthroughMode, or the default if {@code config} is null.
+   */
+  public static PingPassthroughMode fromConfig(Config config) {
+    if (config == null) {
+      return DEFAULT;
+    }
+    return new PingPassthroughMode(
+        config.getOrElse("version", DEFAULT.version()),
+        config.getOrElse("players", DEFAULT.players()),
+        config.getOrElse("description", DEFAULT.description()),
+        config.getOrElse("favicon", DEFAULT.favicon()),
+        config.getOrElse("modinfo", DEFAULT.modinfo()));
+  }
+
+  public boolean enabled() {
+    return this.version || this.players || this.description || this.favicon
+        || this.modinfo;
+  }
 }

proxy/src/main/java/com/velocitypowered/proxy/config/VelocityConfiguration.java

@@ -32,6 +32,7 @@ import com.velocitypowered.proxy.config.migration.KeyAuthenticationMigration;
 import com.velocitypowered.proxy.config.migration.MiniMessageTranslationsMigration;
 import com.velocitypowered.proxy.config.migration.MotdMigration;
 import com.velocitypowered.proxy.config.migration.PacketLimiterMigration;
+import com.velocitypowered.proxy.config.migration.PingPassthroughMigration;
 import com.velocitypowered.proxy.config.migration.TransferIntegrationMigration;
 import com.velocitypowered.proxy.util.AddressUtil;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -79,7 +80,7 @@ public class VelocityConfiguration implements ProxyConfig {
   @Expose
   private boolean onlineModeKickExistingPlayers = false;
   @Expose
-  private PingPassthroughMode pingPassthrough = PingPassthroughMode.DISABLED;
+  private PingPassthroughMode pingPassthrough = PingPassthroughMode.DEFAULT;
   @Expose
   private boolean samplePlayersInPing = false;
   private final Servers servers;
@@ -513,7 +514,8 @@ public class VelocityConfiguration implements ProxyConfig {
           new MotdMigration(),
           new MiniMessageTranslationsMigration(),
           new TransferIntegrationMigration(),
-          new PacketLimiterMigration()
+          new PacketLimiterMigration(),
+          new PingPassthroughMigration(),
       };
 
       for (final ConfigurationMigration migration : migrations) {
@@ -555,9 +557,7 @@ public class VelocityConfiguration implements ProxyConfig {
       final CommentedConfig metricsConfig = config.get("metrics");
       final PlayerInfoForwarding forwardingMode = config.getEnumOrElse(
               "player-info-forwarding-mode", PlayerInfoForwarding.NONE);
-      final PingPassthroughMode pingPassthroughMode = config.getEnumOrElse("ping-passthrough",
+      final PingPassthroughMode pingPassthrough = PingPassthroughMode.fromConfig(config.get("ping-passthrough"));
-              PingPassthroughMode.DISABLED);
-
       final boolean samplePlayersInPing = config.getOrElse("sample-players-in-ping", false);
 
       final String bind = config.getOrElse("bind", "0.0.0.0:25565");
@@ -590,7 +590,7 @@ public class VelocityConfiguration implements ProxyConfig {
               forwardingMode,
               forwardingSecret,
               kickExisting,
-              pingPassthroughMode,
+              pingPassthrough,
               samplePlayersInPing,
               enablePlayerAddressLogging,
               new Servers(serversConfig),

proxy/src/main/java/com/velocitypowered/proxy/config/migration/ConfigurationMigration.java

@@ -30,7 +30,8 @@ public sealed interface ConfigurationMigration
                 MotdMigration,
                 MiniMessageTranslationsMigration,
                 TransferIntegrationMigration,
-                PacketLimiterMigration {
+                PacketLimiterMigration,
+                PingPassthroughMigration {
   boolean shouldMigrate(CommentedFileConfig config);
 
   void migrate(CommentedFileConfig config, Logger logger) throws IOException;

proxy/src/main/java/com/velocitypowered/proxy/config/migration/PingPassthroughMigration.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2024-2026 Velocity Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.velocitypowered.proxy.config.migration;
+
+import com.electronwill.nightconfig.core.file.CommentedFileConfig;
+import java.util.Locale;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * Migrate the old ping passthrough entry to separate config entries.
+ */
+public final class PingPassthroughMigration implements ConfigurationMigration {
+  @Override
+  public boolean shouldMigrate(final CommentedFileConfig config) {
+    return configVersion(config) < 2.9;
+  }
+
+  @Override
+  public void migrate(final CommentedFileConfig config, final Logger logger) {
+    // Get legacy ping passthrough value
+    final String legacyMode = config.getOrElse("ping-passthrough", "DISABLED")
+        .toUpperCase(Locale.ROOT);
+    boolean version = false;
+    boolean players = false;
+    boolean description = false;
+    boolean favicon = false;
+    boolean modinfo = false;
+
+    switch (legacyMode) {
+      case "ALL":
+        version = true;
+        players = true;
+        description = true;
+        favicon = true;
+        modinfo = true;
+        break;
+      case "DESCRIPTION":
+        description = true;
+        modinfo = true;
+        break;
+      case "MODS":
+        modinfo = true;
+        break;
+      default: // DISABLED
+        break;
+    }
+
+    config.removeComment("ping-passthrough");
+    config.remove("ping-passthrough");
+
+    config.setComment("announce-forge",
+        " Announce whether or not your server supports Forge. If you run a modded server, we\n"
+            + " suggest turning this on.\n"
+            + "\n"
+            + " If your network runs one modpack consistently, consider using ping-passthrough.modinfo = true\n"
+            + " instead for a nicer display in the server list.");
+
+    config.set("ping-passthrough.version", version);
+    config.setComment(
+        "ping-passthrough.version",
+        " Should Velocity pass the version number from the backend server when responding to server list ping requests?"
+    );
+
+    config.set("ping-passthrough.players", players);
+    config.setComment(
+        "ping-passthrough.players",
+        " Should Velocity pass the player count from the backend server when responding to server list ping requests?"
+    );
+
+    config.set("ping-passthrough.description", description);
+    config.setComment(
+        "ping-passthrough.description",
+        " Should Velocity pass the description from the backend server when responding to server list ping requests?"
+    );
+
+    config.set("ping-passthrough.favicon", favicon);
+    config.setComment(
+        "ping-passthrough.favicon",
+        " Should Velocity pass the favicon (also known as the server icon) from the backend server when responding to server list ping requests?"
+    );
+
+    config.set("ping-passthrough.modinfo", modinfo);
+    config.setComment(
+        "ping-passthrough.modinfo",
+        " Should Velocity pass the mod list from the backend server when responding to server list ping requests?"
+    );
+
+    config.set("config-version", "2.9");
+  }
+}

proxy/src/main/java/com/velocitypowered/proxy/connection/MinecraftSessionHandler.java

@@ -23,6 +23,7 @@ import com.velocitypowered.proxy.protocol.packet.BossBarPacket;
 import com.velocitypowered.proxy.protocol.packet.BundleDelimiterPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientSettingsPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientboundCookieRequestPacket;
+import com.velocitypowered.proxy.protocol.packet.ClientboundPostEffectsPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientboundSoundEntityPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientboundStopSoundPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientboundStoreCookiePacket;
@@ -404,4 +405,8 @@ public interface MinecraftSessionHandler {
   default boolean handle(ClientboundStopSoundPacket packet) {
     return false;
   }
+
+  default boolean handle(ClientboundPostEffectsPacket packet) {
+    return false;
+  }
 }

proxy/src/main/java/com/velocitypowered/proxy/connection/backend/BackendPlaySessionHandler.java

@@ -57,6 +57,7 @@ import com.velocitypowered.proxy.protocol.packet.ClientSettingsPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientboundCookieRequestPacket;
 import com.velocitypowered.proxy.protocol.packet.ClientboundStoreCookiePacket;
 import com.velocitypowered.proxy.protocol.packet.DisconnectPacket;
+import com.velocitypowered.proxy.protocol.packet.JoinGamePacket;
 import com.velocitypowered.proxy.protocol.packet.KeepAlivePacket;
 import com.velocitypowered.proxy.protocol.packet.LegacyPlayerListItemPacket;
 import com.velocitypowered.proxy.protocol.packet.PluginMessagePacket;
@@ -166,6 +167,13 @@ public class BackendPlaySessionHandler implements MinecraftSessionHandler {
     return false; // forwards on
   }
 
+  @Override
+  public boolean handle(JoinGamePacket packet) {
+    // We receive this if the connection is reconfigured
+    packet.setOnlineMode(serverConn.getPlayer().isOnlineMode());
+    return false; // forward
+  }
+
   @Override
   public boolean handle(ClientSettingsPacket packet) {
     serverConn.ensureConnected().write(packet);

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

@@ -135,6 +135,7 @@ import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
 import net.kyori.adventure.text.minimessage.translation.Argument;
 import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
 import net.kyori.adventure.text.serializer.plain.PlainTextComponentSerializer;
+import net.kyori.adventure.title.Title;
 import net.kyori.adventure.title.Title.Times;
 import net.kyori.adventure.title.TitlePart;
 import net.kyori.adventure.translation.GlobalTranslator;
@@ -486,11 +487,11 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player,
   }
 
   @Override
-  public void showTitle(net.kyori.adventure.title.@NonNull Title title) {
+  public void showTitle(@NonNull Title title) {
     if (this.getProtocolVersion().noLessThan(ProtocolVersion.MINECRAFT_1_8)) {
       GenericTitlePacket timesPkt = GenericTitlePacket.constructTitlePacket(
           GenericTitlePacket.ActionType.SET_TIMES, this.getProtocolVersion());
-      net.kyori.adventure.title.Title.Times times = title.times();
+      Title.Times times = title.times();
       if (times != null) {
         timesPkt.setFadeIn((int) DurationUtils.toTicks(times.fadeIn()));
         timesPkt.setStay((int) DurationUtils.toTicks(times.stay()));

proxy/src/main/java/com/velocitypowered/proxy/connection/player/resourcepack/handler/ModernResourcePackHandler.java

@@ -37,7 +37,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
- * Modern (Minecraft 1.20.3+) ResourcePackHandler
+ * Modern (Minecraft 1.20.3+) ResourcePackHandler.
  */
 public final class ModernResourcePackHandler extends ResourcePackHandler {
   private final ListMultimap<UUID, ResourcePackInfo> outstandingResourcePacks =

proxy/src/main/java/com/velocitypowered/proxy/connection/player/resourcepack/handler/ResourcePackHandler.java

@@ -118,6 +118,7 @@ public abstract sealed class ResourcePackHandler
 
   /**
    * Processes a client response to a sent resource-pack.
+   *
    * <p>Cases in which no action will be taken:</p>
    * <ul>
    *

proxy/src/main/java/com/velocitypowered/proxy/connection/util/ServerListPingHandler.java

@@ -23,6 +23,7 @@ import com.velocitypowered.api.network.ProtocolVersion;
 import com.velocitypowered.api.proxy.server.PingOptions;
 import com.velocitypowered.api.proxy.server.RegisteredServer;
 import com.velocitypowered.api.proxy.server.ServerPing;
+import com.velocitypowered.api.util.Favicon;
 import com.velocitypowered.api.util.ModInfo;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.config.PingPassthroughMode;
@@ -100,60 +101,68 @@ public class ServerListPingHandler {
 
     CompletableFuture<List<ServerPing>> pingResponses = CompletableFutures.successfulAsList(pings,
         (ex) -> fallback);
-    return switch (mode) {
+
-      case ALL -> pingResponses.thenApply(responses -> {
+    // Return early if ping passthrough is not enabled
+    if (!mode.enabled()) {
+      return CompletableFuture.completedFuture(fallback);
+    }
+
+    return pingResponses.thenApply(responses -> {
       // Find the first non-fallback
       for (ServerPing response : responses) {
         if (response == fallback) {
           continue;
         }
 
-          if (response.getDescriptionComponent() == null) {
+        ServerPing.Version version;
-            return response.asBuilder()
+        if (mode.version()) {
-                .description(Component.empty())
+          version = response.getVersion();
-                .build();
+        } else {
+          version = fallback.getVersion();
         }
 
-          return response;
+        ServerPing.Players players;
+        if (mode.players()) {
+          players = response.getPlayers().orElse(null);
+        } else {
+          players = fallback.getPlayers().orElse(null);
         }
-        return fallback;
+
-      });
+        Component description;
-      case MODS -> pingResponses.thenApply(responses -> {
+        if (mode.description()) {
-        // Find the first non-fallback that contains a mod list
+          if (response.getDescriptionComponent() != null) {
-        for (ServerPing response : responses) {
+            description = response.getDescriptionComponent();
-          if (response == fallback) {
+          } else {
-            continue;
+            description = Component.empty();
           }
-          Optional<ModInfo> modInfo = response.getModinfo();
+        } else {
-          if (modInfo.isPresent()) {
+          description = fallback.getDescriptionComponent();
-            return fallback.asBuilder().mods(modInfo.get()).build();
         }
+
+        Favicon favicon;
+        if (mode.favicon()) {
+          favicon = response.getFavicon().orElse(null);
+        } else {
+          favicon = fallback.getFavicon().orElse(null);
         }
-        return fallback;
+
-      });
+        ModInfo modinfo;
-      case DESCRIPTION -> pingResponses.thenApply(responses -> {
+        if (mode.modinfo()) {
-        // Find the first non-fallback. If it includes a modlist, add it too.
+          modinfo = response.getModinfo().orElse(null);
-        for (ServerPing response : responses) {
+        } else {
-          if (response == fallback) {
+          modinfo = fallback.getModinfo().orElse(null);
-            continue;
-          }
-          if (response.getDescriptionComponent() == null) {
-            continue;
         }
 
         return new ServerPing(
-              fallback.getVersion(),
+            version,
-              fallback.getPlayers().orElse(null),
+            players,
-              response.getDescriptionComponent(),
+            description,
-              fallback.getFavicon().orElse(null),
+            favicon,
-              response.getModinfo().orElse(null)
+            modinfo
         );
       }
       return fallback;
     });
-      // Not possible, but covered for completeness.
-      default -> CompletableFuture.completedFuture(fallback);
-    };
   }
 
   /**
@@ -168,7 +177,7 @@ public class ServerListPingHandler {
         ? connection.getProtocolVersion() : ProtocolVersion.MAXIMUM_VERSION;
     PingPassthroughMode passthroughMode = configuration.getPingPassthrough();
 
-    if (passthroughMode == PingPassthroughMode.DISABLED) {
+    if (!passthroughMode.enabled()) {
       return CompletableFuture.completedFuture(constructLocalPing(shownVersion));
     } else {
       String virtualHostStr = connection.getVirtualHost().map(InetSocketAddress::getHostString)

proxy/src/main/java/com/velocitypowered/proxy/event/VelocityEventManager.java

@@ -545,6 +545,36 @@ public class VelocityEventManager implements EventManager {
     }
   }
 
+  private <E> void fire(final @Nullable CompletableFuture<E> future, final E event,
+      final int offset, final boolean currentlyAsync, final HandlerRegistration[] registrations) {
+    for (int i = offset; i < registrations.length; i++) {
+      final HandlerRegistration registration = registrations[i];
+      try {
+        final EventTask eventTask = registration.handler.executeAsync(event);
+        if (eventTask == null) {
+          continue;
+        }
+        final ContinuationTask<E> continuationTask = new ContinuationTask<>(eventTask,
+            registrations, future, event, i, currentlyAsync);
+        if (currentlyAsync || !eventTask.requiresAsync()) {
+          if (continuationTask.execute()) {
+            continue;
+          }
+        } else {
+          registration.plugin.getExecutorService().execute(continuationTask);
+        }
+        // fire will continue in another thread once the async task is
+        // executed and the continuation is resumed
+        return;
+      } catch (final Throwable t) {
+        logHandlerException(registration, t);
+      }
+    }
+    if (future != null) {
+      future.complete(event);
+    }
+  }
+
   private static final int TASK_STATE_DEFAULT = 0;
   private static final int TASK_STATE_EXECUTING = 1;
   private static final int TASK_STATE_CONTINUE_IMMEDIATELY = 2;
@@ -669,36 +699,6 @@ public class VelocityEventManager implements EventManager {
     }
   }
 
-  private <E> void fire(final @Nullable CompletableFuture<E> future, final E event,
-      final int offset, final boolean currentlyAsync, final HandlerRegistration[] registrations) {
-    for (int i = offset; i < registrations.length; i++) {
-      final HandlerRegistration registration = registrations[i];
-      try {
-        final EventTask eventTask = registration.handler.executeAsync(event);
-        if (eventTask == null) {
-          continue;
-        }
-        final ContinuationTask<E> continuationTask = new ContinuationTask<>(eventTask,
-            registrations, future, event, i, currentlyAsync);
-        if (currentlyAsync || !eventTask.requiresAsync()) {
-          if (continuationTask.execute()) {
-            continue;
-          }
-        } else {
-          registration.plugin.getExecutorService().execute(continuationTask);
-        }
-        // fire will continue in another thread once the async task is
-        // executed and the continuation is resumed
-        return;
-      } catch (final Throwable t) {
-        logHandlerException(registration, t);
-      }
-    }
-    if (future != null) {
-      future.complete(event);
-    }
-  }
-
   private static void logHandlerException(
       final HandlerRegistration registration, final Throwable t) {
     final PluginDescription pluginDescription = registration.plugin.getDescription();

proxy/src/main/java/com/velocitypowered/proxy/protocol/ProtocolUtils.java

@@ -143,6 +143,7 @@ public enum ProtocolUtils {
           .build();
 
   public static final int DEFAULT_MAX_STRING_SIZE = 65536; // 64KiB
+  private static final int DEFAULT_MAX_KEY_ARRAY_SIZE = 1024;
   private static final int MAXIMUM_VARINT_SIZE = 5;
   private static final BinaryTagType<? extends BinaryTag>[] BINARY_TAG_TYPES = new BinaryTagType[] {
       BinaryTagTypes.END, BinaryTagTypes.BYTE, BinaryTagTypes.SHORT, BinaryTagTypes.INT,
@@ -349,15 +350,20 @@ public enum ProtocolUtils {
     writeString(buf, key.asMinimalString());
   }
 
+  public static Key[] readKeyArray(ByteBuf buf) {
+    return readKeyArray(buf, DEFAULT_MAX_KEY_ARRAY_SIZE);
+  }
+
   /**
    * Reads a standard Mojang Text namespaced:key array from the buffer.
    *
    * @param buf the buffer to read from
    * @return the decoded key array
    */
-  public static Key[] readKeyArray(ByteBuf buf) {
+  public static Key[] readKeyArray(ByteBuf buf, int cap) {
     int length = readVarInt(buf);
     checkFrame(length >= 0, "Got a negative-length array (%s)", length);
+    checkFrame(length <= cap, "Bad key array size (got %s, maximum is %s)", length, cap);
     checkFrame(buf.isReadable(length),
         "Trying to read an array that is too long (wanted %s, only have %s)", length,
         buf.readableBytes());
@@ -644,7 +650,7 @@ public enum ProtocolUtils {
   private static final int FORGE_MAX_ARRAY_LENGTH = Integer.MAX_VALUE & 0x1FFF9A;
 
   /**
-   * Reads an byte array for legacy version 1.7 from the specified {@code buf}
+   * Reads an byte array for legacy version 1.7 from the specified {@code buf}.
    *
    * @param buf the buffer to read from
    * @return the read byte array
@@ -685,7 +691,7 @@ public enum ProtocolUtils {
   }
 
   /**
-   * Writes an byte array for legacy version 1.7 to the specified {@code buf}
+   * Writes an byte array for legacy version 1.7 to the specified {@code buf}.
    *
    * @param b             array
    * @param buf           buf
@@ -709,7 +715,7 @@ public enum ProtocolUtils {
   }
 
   /**
-   * Writes an {@link ByteBuf} for legacy version 1.7 to the specified {@code buf}
+   * Writes an {@link ByteBuf} for legacy version 1.7 to the specified {@code buf}.
    *
    * @param b             array
    * @param buf           buf

proxy/src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -66,7 +66,6 @@ import com.velocitypowered.proxy.protocol.packet.StatusResponsePacket;
 import com.velocitypowered.proxy.protocol.packet.TabCompleteRequestPacket;
 import com.velocitypowered.proxy.protocol.packet.TabCompleteResponsePacket;
 import com.velocitypowered.proxy.protocol.packet.TransferPacket;
-import com.velocitypowered.proxy.protocol.packet.UpdateTeamsPacket;
 import com.velocitypowered.proxy.protocol.packet.UpsertPlayerInfoPacket;
 import com.velocitypowered.proxy.protocol.packet.chat.ChatAcknowledgementPacket;
 import com.velocitypowered.proxy.protocol.packet.chat.PlayerChatCompletionPacket;
@@ -205,31 +204,44 @@ public enum StateRegistry {
           map(0x06, MINECRAFT_1_20_2, false),
           map(0x07, MINECRAFT_1_20_3, false),
           map(0x09, MINECRAFT_1_20_5, false));
+      clientbound.register(
+          ClientboundPostEffectsPacket.class, ClientboundPostEffectsPacket::new,
+          map(0x0A, MINECRAFT_26_3, false));
       clientbound.register(
           ClientboundStoreCookiePacket.class, ClientboundStoreCookiePacket::new,
-          map(0x0A, MINECRAFT_1_20_5, false));
+          map(0x0A, MINECRAFT_1_20_5, false),
+          map(0x0B, MINECRAFT_26_3, false));
       clientbound.register(TransferPacket.class, TransferPacket::new,
-          map(0x0B, MINECRAFT_1_20_5, false));
+          map(0x0B, MINECRAFT_1_20_5, false),
+          map(0x0C, MINECRAFT_26_3, false));
       clientbound.register(ActiveFeaturesPacket.class, ActiveFeaturesPacket::new,
           map(0x07, MINECRAFT_1_20_2, false),
           map(0x08, MINECRAFT_1_20_3, false),
-          map(0x0C, MINECRAFT_1_20_5, false));
+          map(0x0C, MINECRAFT_1_20_5, false),
+          map(0x0D, MINECRAFT_26_3, false));
       clientbound.register(TagsUpdatePacket.class, TagsUpdatePacket::new,
           map(0x08, MINECRAFT_1_20_2, false),
           map(0x09, MINECRAFT_1_20_3, false),
-          map(0x0D, MINECRAFT_1_20_5, false));
+          map(0x0D, MINECRAFT_1_20_5, false),
+          map(0x0E, MINECRAFT_26_3, false));
       clientbound.register(KnownPacksPacket.class, KnownPacksPacket::new,
-          map(0x0E, MINECRAFT_1_20_5, false));
+          map(0x0E, MINECRAFT_1_20_5, false),
+          map(0x0F, MINECRAFT_26_3, false));
       clientbound.register(ClientboundCustomReportDetailsPacket.class, ClientboundCustomReportDetailsPacket::new,
-          map(0x0F, MINECRAFT_1_21, false));
+          map(0x0F, MINECRAFT_1_21, false),
+          map(0x10, MINECRAFT_26_3, false));
       clientbound.register(ClientboundServerLinksPacket.class, ClientboundServerLinksPacket::new,
-          map(0x10, MINECRAFT_1_21, false));
+          map(0x10, MINECRAFT_1_21, false),
+          map(0x11, MINECRAFT_26_3, false));
       clientbound.register(DialogClearPacket.class, () -> DialogClearPacket.INSTANCE,
-          map(0x11, MINECRAFT_1_21_6, false));
+          map(0x11, MINECRAFT_1_21_6, false),
+          map(0x12, MINECRAFT_26_3, false));
       clientbound.register(DialogShowPacket.class, () -> new DialogShowPacket(this),
-          map(0x12, MINECRAFT_1_21_6, false));
+          map(0x12, MINECRAFT_1_21_6, false),
+          map(0x13, MINECRAFT_26_3, false));
       clientbound.register(CodeOfConductPacket.class, CodeOfConductPacket::new,
-          map(0x13, MINECRAFT_1_21_9, false));
+          map(0x13, MINECRAFT_1_21_9, false),
+          map(0x14, MINECRAFT_26_3, false));
     }
   },
   PLAY {
@@ -381,7 +393,8 @@ public enum StateRegistry {
           map(0x2D, MINECRAFT_1_21_2, false),
           map(0x2F, MINECRAFT_1_21_4, false),
           map(0x30, MINECRAFT_1_21_6, false),
-          map(0x31, MINECRAFT_26_1, false));
+          map(0x31, MINECRAFT_26_1, false),
+          map(0x32, MINECRAFT_26_3, false));
       serverbound.register(
           FinishedUpdatePacket.class, () -> FinishedUpdatePacket.INSTANCE,
           map(0x0B, MINECRAFT_1_20_2, false),
@@ -440,6 +453,9 @@ public enum StateRegistry {
           ClientboundCookieRequestPacket.class, ClientboundCookieRequestPacket::new,
           map(0x16, MINECRAFT_1_20_5, false),
           map(0x15, MINECRAFT_1_21_5, false));
+      clientbound.register(
+          ClientboundPostEffectsPacket.class, ClientboundPostEffectsPacket::new,
+          map(0x53, MINECRAFT_26_3, false));
       clientbound.register(
           ClientboundSoundEntityPacket.class, ClientboundSoundEntityPacket::new,
           map(0x5D, MINECRAFT_1_19_3, true),
@@ -450,7 +466,8 @@ public enum StateRegistry {
           map(0x6E, MINECRAFT_1_21_2, true),
           map(0x6D, MINECRAFT_1_21_5, true),
           map(0x72, MINECRAFT_1_21_9, true),
-          map(0x74, MINECRAFT_26_1, true));
+          map(0x74, MINECRAFT_26_1, true),
+          map(0x76, MINECRAFT_26_3, true));
       clientbound.register(
           ClientboundStopSoundPacket.class, ClientboundStopSoundPacket::new,
           map(0x5F, MINECRAFT_1_19_3, true),
@@ -461,7 +478,8 @@ public enum StateRegistry {
           map(0x71, MINECRAFT_1_21_2, true),
           map(0x70, MINECRAFT_1_21_5, true),
           map(0x75, MINECRAFT_1_21_9, true),
-          map(0x77, MINECRAFT_26_1, true));
+          map(0x77, MINECRAFT_26_1, true),
+          map(0x79, MINECRAFT_26_3, true));
       clientbound.register(
           PluginMessagePacket.class,
           PluginMessagePacket::new,
@@ -519,7 +537,8 @@ public enum StateRegistry {
           map(0x27, MINECRAFT_1_21_2, false),
           map(0x26, MINECRAFT_1_21_5, false),
           map(0x2B, MINECRAFT_1_21_9, false),
-          map(0x2C, MINECRAFT_26_1, false));
+          map(0x2C, MINECRAFT_26_1, false),
+          map(0x2D, MINECRAFT_26_3, false));
       clientbound.register(
           JoinGamePacket.class,
           JoinGamePacket::new,
@@ -540,7 +559,8 @@ public enum StateRegistry {
           map(0x2C, MINECRAFT_1_21_2, false),
           map(0x2B, MINECRAFT_1_21_5, false),
           map(0x30, MINECRAFT_1_21_9, false),
-          map(0x31, MINECRAFT_26_1, false));
+          map(0x31, MINECRAFT_26_1, false),
+          map(0x32, MINECRAFT_26_3, false));
       clientbound.register(
           RespawnPacket.class,
           RespawnPacket::new,
@@ -564,7 +584,8 @@ public enum StateRegistry {
           map(0x4C, MINECRAFT_1_21_2, true),
           map(0x4B, MINECRAFT_1_21_5, true),
           map(0x50, MINECRAFT_1_21_9, true),
-          map(0x52, MINECRAFT_26_1, true));
+          map(0x52, MINECRAFT_26_1, true),
+          map(0x54, MINECRAFT_26_3, true));
       clientbound.register(
           RemoveResourcePackPacket.class,
           RemoveResourcePackPacket::new,
@@ -573,7 +594,8 @@ public enum StateRegistry {
           map(0x4A, MINECRAFT_1_21_2, false),
           map(0x49, MINECRAFT_1_21_5, false),
           map(0x4E, MINECRAFT_1_21_9, false),
-          map(0x50, MINECRAFT_26_1, false));
+          map(0x50, MINECRAFT_26_1, false),
+          map(0x51, MINECRAFT_26_3, false));
       clientbound.register(
           ResourcePackRequestPacket.class,
           ResourcePackRequestPacket::new,
@@ -597,7 +619,8 @@ public enum StateRegistry {
           map(0x4B, MINECRAFT_1_21_2, false),
           map(0x4A, MINECRAFT_1_21_5, false),
           map(0x4F, MINECRAFT_1_21_9, false),
-          map(0x51, MINECRAFT_26_1, false));
+          map(0x51, MINECRAFT_26_1, false),
+          map(0x52, MINECRAFT_26_3, false));
       clientbound.register(
           HeaderAndFooterPacket.class,
           HeaderAndFooterPacket::new,
@@ -622,7 +645,8 @@ public enum StateRegistry {
           map(0x74, MINECRAFT_1_21_2, true),
           map(0x73, MINECRAFT_1_21_5, true),
           map(0x78, MINECRAFT_1_21_9, true),
-          map(0x7A, MINECRAFT_26_1, true));
+          map(0x7A, MINECRAFT_26_1, true),
+          map(0x7D, MINECRAFT_26_3, true));
       clientbound.register(
           LegacyTitlePacket.class,
           LegacyTitlePacket::new,
@@ -646,7 +670,8 @@ public enum StateRegistry {
           map(0x6A, MINECRAFT_1_21_2, true),
           map(0x69, MINECRAFT_1_21_5, true),
           map(0x6E, MINECRAFT_1_21_9, true),
-          map(0x70, MINECRAFT_26_1, true));
+          map(0x70, MINECRAFT_26_1, true),
+          map(0x72, MINECRAFT_26_3, true));
       clientbound.register(
           TitleTextPacket.class,
           TitleTextPacket::new,
@@ -661,7 +686,8 @@ public enum StateRegistry {
           map(0x6C, MINECRAFT_1_21_2, true),
           map(0x6B, MINECRAFT_1_21_5, true),
           map(0x70, MINECRAFT_1_21_9, true),
-          map(0x72, MINECRAFT_26_1, true));
+          map(0x72, MINECRAFT_26_1, true),
+          map(0x74, MINECRAFT_26_3, true));
       clientbound.register(
           TitleActionbarPacket.class,
           TitleActionbarPacket::new,
@@ -676,7 +702,8 @@ public enum StateRegistry {
           map(0x51, MINECRAFT_1_21_2, true),
           map(0x50, MINECRAFT_1_21_5, true),
           map(0x55, MINECRAFT_1_21_9, true),
-          map(0x57, MINECRAFT_26_1, true));
+          map(0x57, MINECRAFT_26_1, true),
+          map(0x59, MINECRAFT_26_3, true));
       clientbound.register(
           TitleTimesPacket.class,
           TitleTimesPacket::new,
@@ -691,7 +718,8 @@ public enum StateRegistry {
           map(0x6D, MINECRAFT_1_21_2, true),
           map(0x6C, MINECRAFT_1_21_5, true),
           map(0x71, MINECRAFT_1_21_9, true),
-          map(0x73, MINECRAFT_26_1, true));
+          map(0x73, MINECRAFT_26_1, true),
+          map(0x75, MINECRAFT_26_3, true));
       clientbound.register(
           TitleClearPacket.class,
           TitleClearPacket::new,
@@ -723,7 +751,8 @@ public enum StateRegistry {
           map(0x3F, MINECRAFT_1_21_2, false),
           map(0x3E, MINECRAFT_1_21_5, false),
           map(0x43, MINECRAFT_1_21_9, false),
-          map(0x45, MINECRAFT_26_1, false));
+          map(0x45, MINECRAFT_26_1, false),
+          map(0x46, MINECRAFT_26_3, false));
       clientbound.register(
           UpsertPlayerInfoPacket.class,
           UpsertPlayerInfoPacket::new,
@@ -734,14 +763,16 @@ public enum StateRegistry {
           map(0x40, MINECRAFT_1_21_2, false),
           map(0x3F, MINECRAFT_1_21_5, false),
           map(0x44, MINECRAFT_1_21_9, false),
-          map(0x46, MINECRAFT_26_1, false));
+          map(0x46, MINECRAFT_26_1, false),
+          map(0x47, MINECRAFT_26_3, false));
       clientbound.register(
           ClientboundStoreCookiePacket.class, ClientboundStoreCookiePacket::new,
           map(0x6B, MINECRAFT_1_20_5, false),
           map(0x72, MINECRAFT_1_21_2, false),
           map(0x71, MINECRAFT_1_21_5, false),
           map(0x76, MINECRAFT_1_21_9, false),
-          map(0x78, MINECRAFT_26_1, false));
+          map(0x78, MINECRAFT_26_1, false),
+          map(0x7A, MINECRAFT_26_3, false));
       clientbound.register(
           SystemChatPacket.class,
           SystemChatPacket::new,
@@ -755,7 +786,8 @@ public enum StateRegistry {
           map(0x73, MINECRAFT_1_21_2, true),
           map(0x72, MINECRAFT_1_21_5, true),
           map(0x77, MINECRAFT_1_21_9, true),
-          map(0x79, MINECRAFT_26_1, true));
+          map(0x79, MINECRAFT_26_1, true),
+          map(0x7C, MINECRAFT_26_3, true));
       clientbound.register(
           PlayerChatCompletionPacket.class,
           PlayerChatCompletionPacket::new,
@@ -778,7 +810,8 @@ public enum StateRegistry {
           map(0x50, MINECRAFT_1_21_2, false),
           map(0x4F, MINECRAFT_1_21_5, false),
           map(0x54, MINECRAFT_1_21_9, false),
-          map(0x56, MINECRAFT_26_1, false));
+          map(0x56, MINECRAFT_26_1, false),
+          map(0x58, MINECRAFT_26_3, false));
       clientbound.register(
           StartUpdatePacket.class,
           () -> StartUpdatePacket.INSTANCE,
@@ -788,7 +821,8 @@ public enum StateRegistry {
           map(0x70, MINECRAFT_1_21_2, false),
           map(0x6F, MINECRAFT_1_21_5, false),
           map(0x74, MINECRAFT_1_21_9, false),
-          map(0x76, MINECRAFT_26_1, false));
+          map(0x76, MINECRAFT_26_1, false),
+          map(0x78, MINECRAFT_26_3, false));
       clientbound.register(
           BundleDelimiterPacket.class,
           () -> BundleDelimiterPacket.INSTANCE,
@@ -799,20 +833,24 @@ public enum StateRegistry {
           map(0x73, MINECRAFT_1_20_5, false),
           map(0x7A, MINECRAFT_1_21_2, false),
           map(0x7F, MINECRAFT_1_21_9, false),
-          map(0x81, MINECRAFT_26_1, false));
+          map(0x81, MINECRAFT_26_1, false),
+          map(0x84, MINECRAFT_26_3, false));
       clientbound.register(
           ClientboundCustomReportDetailsPacket.class,
           ClientboundCustomReportDetailsPacket::new,
           map(0x7A, MINECRAFT_1_21, false),
           map(0x81, MINECRAFT_1_21_2, false),
           map(0x86, MINECRAFT_1_21_9, false),
-          map(0x88, MINECRAFT_26_1, false));
+          map(0x88, MINECRAFT_26_1, false),
+          map(0x8B, MINECRAFT_26_3, false));
       clientbound.register(
           ClientboundServerLinksPacket.class,
           ClientboundServerLinksPacket::new,
           map(0x7B, MINECRAFT_1_21, false),
           map(0x82, MINECRAFT_1_21_2, false),
           map(0x87, MINECRAFT_1_21_9, false),
+          map(0x89, MINECRAFT_26_1, false),
+          map(0x8C, MINECRAFT_26_3, false));
           map(0x89, MINECRAFT_26_1, false));
       clientbound.register(
           UpdateTeamsPacket.class,

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/ClientSettingsPacket.java

@@ -213,7 +213,34 @@ public class ClientSettingsPacket implements MinecraftPacket {
 
   @Override
   public int decodeExpectedMinLength(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
-    return 1 + 0 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1;
+    int minLength = 1 // locale
+            + 1       // viewDistance
+            + 1       // chatVisibility
+            + 1;      // chatColors
+
+    if (version.noGreaterThan(ProtocolVersion.MINECRAFT_1_7_6)) {
+      minLength += 1; // difficulty
+    }
+
+    minLength += 1; // skinParts
+
+    if (version.noLessThan(ProtocolVersion.MINECRAFT_1_9)) {
+      minLength += 1; // mainHand
+
+      if (version.noLessThan(ProtocolVersion.MINECRAFT_1_17)) {
+        minLength += 1; // textFilteringEnabled
+
+        if (version.noLessThan(ProtocolVersion.MINECRAFT_1_18)) {
+          minLength += 1; // clientListingAllowed
+
+          if (version.noLessThan(ProtocolVersion.MINECRAFT_1_21_2)) {
+            minLength += 1; // particleStatus
+          }
+        }
+      }
+    }
+
+    return minLength;
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/ClientboundPostEffectsPacket.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2018-2026 Velocity Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.velocitypowered.proxy.protocol.packet;
+
+import com.velocitypowered.api.network.ProtocolVersion;
+import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
+import com.velocitypowered.proxy.protocol.MinecraftPacket;
+import com.velocitypowered.proxy.protocol.ProtocolUtils;
+import com.velocitypowered.proxy.protocol.ProtocolUtils.Direction;
+import io.netty.buffer.ByteBuf;
+import net.kyori.adventure.key.Key;
+
+public final class ClientboundPostEffectsPacket implements MinecraftPacket {
+
+  private Key[] postEffects;
+
+  public ClientboundPostEffectsPacket() {
+  }
+
+  public ClientboundPostEffectsPacket(Key[] postEffects) {
+    this.postEffects = postEffects;
+  }
+
+  @Override
+  public void decode(ByteBuf buf, Direction direction, ProtocolVersion protocolVersion) {
+    this.postEffects = ProtocolUtils.readKeyArray(buf);
+  }
+
+  @Override
+  public void encode(ByteBuf buf, Direction direction, ProtocolVersion protocolVersion) {
+    ProtocolUtils.writeKeyArray(buf, this.postEffects);
+  }
+
+  @Override
+  public boolean handle(MinecraftSessionHandler handler) {
+    return handler.handle(this);
+  }
+}

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/JoinGamePacket.java

@@ -32,7 +32,7 @@ public class JoinGamePacket implements MinecraftPacket {
 
   private static final BinaryTagIO.Reader JOINGAME_READER = BinaryTagIO.reader(4 * 1024 * 1024);
   private int entityId;
-  private short gamemode;
+  private int gamemode;
   private int dimension;
   private long partialHashedSeed; // 1.15+
   private short difficulty;
@@ -47,7 +47,7 @@ public class JoinGamePacket implements MinecraftPacket {
   private CompoundBinaryTag registry; // 1.16+
   private DimensionInfo dimensionInfo; // 1.16+
   private CompoundBinaryTag currentDimensionData; // 1.16.2+
-  private short previousGamemode; // 1.16+
+  private int previousGamemode; // 1.16+
   private int simulationDistance; // 1.18+
   private @Nullable Pair<String, Long> lastDeathPosition; // 1.19+
   private int portalCooldown; // 1.20+
@@ -63,11 +63,11 @@ public class JoinGamePacket implements MinecraftPacket {
     this.entityId = entityId;
   }
 
-  public short getGamemode() {
+  public int getGamemode() {
     return gamemode;
   }
 
-  public void setGamemode(short gamemode) {
+  public void setGamemode(int gamemode) {
     this.gamemode = gamemode;
   }
 
@@ -131,11 +131,11 @@ public class JoinGamePacket implements MinecraftPacket {
     this.dimensionInfo = dimensionInfo;
   }
 
-  public short getPreviousGamemode() {
+  public int getPreviousGamemode() {
     return previousGamemode;
   }
 
-  public void setPreviousGamemode(short previousGamemode) {
+  public void setPreviousGamemode(int previousGamemode) {
     this.previousGamemode = previousGamemode;
   }
 
@@ -345,8 +345,13 @@ public class JoinGamePacket implements MinecraftPacket {
     String levelName = ProtocolUtils.readString(buf);
     this.partialHashedSeed = buf.readLong();
 
+    if (version.noLessThan(ProtocolVersion.MINECRAFT_26_3)) {
+      this.gamemode = ProtocolUtils.readVarInt(buf);
+      this.previousGamemode = ProtocolUtils.readVarInt(buf); // game mode + 1 or 0
+    } else {
       this.gamemode = buf.readByte();
-    this.previousGamemode = buf.readByte();
+      this.previousGamemode = buf.readByte(); // game mode or -1
+    }
 
     boolean isDebug = buf.readBoolean();
     boolean isFlat = buf.readBoolean();
@@ -498,8 +503,13 @@ public class JoinGamePacket implements MinecraftPacket {
     ProtocolUtils.writeString(buf, dimensionInfo.getLevelName());
     buf.writeLong(partialHashedSeed);
 
-    buf.writeByte(gamemode);
+    if (version.noLessThan(ProtocolVersion.MINECRAFT_26_3)) {
-    buf.writeByte(previousGamemode);
+      ProtocolUtils.writeVarInt(buf, this.gamemode);
+      ProtocolUtils.writeVarInt(buf, this.previousGamemode);
+    } else {
+      buf.writeByte(this.gamemode);
+      buf.writeByte(this.previousGamemode);
+    }
 
     buf.writeBoolean(dimensionInfo.isDebugType());
     buf.writeBoolean(dimensionInfo.isFlat());

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/RespawnPacket.java

@@ -33,11 +33,11 @@ public class RespawnPacket implements MinecraftPacket {
   private int dimension;
   private long partialHashedSeed;
   private short difficulty;
-  private short gamemode;
+  private int gamemode;
   private String levelType = "";
   private byte dataToKeep; // 1.16+
   private DimensionInfo dimensionInfo; // 1.16-1.16.1
-  private short previousGamemode; // 1.16+
+  private int previousGamemode; // 1.16+
   private CompoundBinaryTag currentDimensionData; // 1.16.2+
   private @Nullable Pair<String, Long> lastDeathPosition; // 1.19+
   private int portalCooldown; // 1.20+
@@ -46,9 +46,9 @@ public class RespawnPacket implements MinecraftPacket {
   public RespawnPacket() {
   }
 
-  public RespawnPacket(int dimension, long partialHashedSeed, short difficulty, short gamemode,
+  public RespawnPacket(int dimension, long partialHashedSeed, short difficulty, int gamemode,
                        String levelType, byte dataToKeep, DimensionInfo dimensionInfo,
-                       short previousGamemode, CompoundBinaryTag currentDimensionData,
+                       int previousGamemode, CompoundBinaryTag currentDimensionData,
                        @Nullable Pair<String, Long> lastDeathPosition, int portalCooldown,
                        int seaLevel) {
     this.dimension = dimension;
@@ -97,11 +97,11 @@ public class RespawnPacket implements MinecraftPacket {
     this.difficulty = difficulty;
   }
 
-  public short getGamemode() {
+  public int getGamemode() {
     return gamemode;
   }
 
-  public void setGamemode(short gamemode) {
+  public void setGamemode(int gamemode) {
     this.gamemode = gamemode;
   }
 
@@ -121,11 +121,11 @@ public class RespawnPacket implements MinecraftPacket {
     this.dataToKeep = dataToKeep;
   }
 
-  public short getPreviousGamemode() {
+  public int getPreviousGamemode() {
     return previousGamemode;
   }
 
-  public void setPreviousGamemode(short previousGamemode) {
+  public void setPreviousGamemode(int previousGamemode) {
     this.previousGamemode = previousGamemode;
   }
 
@@ -197,9 +197,17 @@ public class RespawnPacket implements MinecraftPacket {
     if (version.noLessThan(ProtocolVersion.MINECRAFT_1_15)) {
       this.partialHashedSeed = buf.readLong();
     }
+    if (version.noLessThan(ProtocolVersion.MINECRAFT_26_3)) {
+      this.gamemode = ProtocolUtils.readVarInt(buf);
+    } else {
       this.gamemode = buf.readByte();
+    }
     if (version.noLessThan(ProtocolVersion.MINECRAFT_1_16)) {
+      if (version.noLessThan(ProtocolVersion.MINECRAFT_26_3)) {
+        this.previousGamemode = ProtocolUtils.readVarInt(buf);
+      } else {
         this.previousGamemode = buf.readByte();
+      }
       boolean isDebug = buf.readBoolean();
       boolean isFlat = buf.readBoolean();
       this.dimensionInfo = new DimensionInfo(dimensionKey, levelName, isFlat, isDebug, version);
@@ -249,9 +257,17 @@ public class RespawnPacket implements MinecraftPacket {
     if (version.noLessThan(ProtocolVersion.MINECRAFT_1_15)) {
       buf.writeLong(partialHashedSeed);
     }
-    buf.writeByte(gamemode);
+    if (version.noLessThan(ProtocolVersion.MINECRAFT_26_3)) {
+      ProtocolUtils.writeVarInt(buf, this.gamemode);
+    } else {
+      buf.writeByte(this.gamemode);
+    }
     if (version.noLessThan(ProtocolVersion.MINECRAFT_1_16)) {
-      buf.writeByte(previousGamemode);
+      if (version.noLessThan(ProtocolVersion.MINECRAFT_26_3)) {
+        ProtocolUtils.writeVarInt(buf, this.previousGamemode);
+      } else {
+        buf.writeByte(this.previousGamemode);
+      }
       buf.writeBoolean(dimensionInfo.isDebugType());
       buf.writeBoolean(dimensionInfo.isFlat());
       if (version.lessThan(ProtocolVersion.MINECRAFT_1_19_3)) {

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/brigadier/ArgumentPropertyRegistry.java

@@ -25,6 +25,7 @@ import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_20_5;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_21_5;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_21_6;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_26_2;
+import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_26_3;
 import static com.velocitypowered.proxy.protocol.packet.brigadier.ArgumentIdentifier.id;
 import static com.velocitypowered.proxy.protocol.packet.brigadier.ArgumentIdentifier.mapSet;
 import static com.velocitypowered.proxy.protocol.packet.brigadier.DoubleArgumentPropertySerializer.DOUBLE;
@@ -273,16 +274,21 @@ public class ArgumentPropertyRegistry {
     empty(id("minecraft:heightmap", mapSet(MINECRAFT_1_21_6, 51), mapSet(MINECRAFT_1_21_5, 50), mapSet(MINECRAFT_1_20_3, 49),
         mapSet(MINECRAFT_1_19_4, 47))); // 1.19.4
 
-    empty(id("minecraft:uuid", mapSet(MINECRAFT_1_21_6, 56), mapSet(MINECRAFT_1_21_5, 54),mapSet(MINECRAFT_1_20_5, 53), mapSet(MINECRAFT_1_20_3, 48),
+    empty(id("minecraft:uuid", mapSet(MINECRAFT_26_3, 61), mapSet(MINECRAFT_1_21_6, 56), mapSet(MINECRAFT_1_21_5, 54), mapSet(MINECRAFT_1_20_5, 53),
-        mapSet(MINECRAFT_1_19_4, 48), mapSet(MINECRAFT_1_19, 47))); // added in 1.16
+        mapSet(MINECRAFT_1_20_3, 48), mapSet(MINECRAFT_1_19_4, 48), mapSet(MINECRAFT_1_19, 47))); // added in 1.16
 
     empty(id("minecraft:loot_table", mapSet(MINECRAFT_1_21_6, 52), mapSet(MINECRAFT_1_21_5, 51), mapSet(MINECRAFT_1_20_5, 50)));
     empty(id("minecraft:loot_predicate", mapSet(MINECRAFT_1_21_6, 53), mapSet(MINECRAFT_1_21_5, 52), mapSet(MINECRAFT_1_20_5, 51)));
     empty(id("minecraft:loot_modifier", mapSet(MINECRAFT_1_21_6, 54), mapSet(MINECRAFT_1_21_5, 53), mapSet(MINECRAFT_1_20_5, 52)));
 
     empty(id("minecraft:hex_color", mapSet(MINECRAFT_1_21_6, 17))); // added in 1.21.6
-    empty(id("minecraft:dialog", mapSet(MINECRAFT_1_21_6, 55))); // added in 1.21.6
+    empty(id("minecraft:dialog", mapSet(MINECRAFT_26_3, 58), mapSet(MINECRAFT_1_21_6, 55))); // added in 1.21.6
     empty(id("minecraft:team_color", mapSet(MINECRAFT_26_2, 16))); // renamed from color in 26.2
+    empty(id("minecraft:context_float_provider", mapSet(MINECRAFT_26_3, 55))); // added in 26.3
+    empty(id("minecraft:context_int_provider", mapSet(MINECRAFT_26_3, 56))); // added in 26.3
+    empty(id("minecraft:slot_source", mapSet(MINECRAFT_26_3, 57))); // added in 26.3
+    empty(id("minecraft:feature", mapSet(MINECRAFT_26_3, 59))); // added in 26.3
+    empty(id("minecraft:swing_animation", mapSet(MINECRAFT_26_3, 60))); // added in 26.3
 
     // Crossstitch support
     register(id("crossstitch:mod_argument", mapSet(MINECRAFT_1_19, -256)), ModArgumentProperty.class, MOD);

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/GenericTitlePacket.java

@@ -22,10 +22,12 @@ import com.velocitypowered.proxy.protocol.MinecraftPacket;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.chat.ComponentHolder;
 import io.netty.buffer.ByteBuf;
+import org.jetbrains.annotations.NotNull;
 
 public abstract class GenericTitlePacket implements MinecraftPacket {
 
   public enum ActionType {
+
     SET_TITLE(0),
     SET_SUBTITLE(1),
     SET_ACTION_BAR(2),
@@ -45,16 +47,7 @@ public abstract class GenericTitlePacket implements MinecraftPacket {
     }
   }
 
-
+  public abstract @NotNull ActionType getAction();
-  private ActionType action;
-
-  protected void setAction(ActionType action) {
-    this.action = action;
-  }
-
-  public final ActionType getAction() {
-    return action;
-  }
 
   public ComponentHolder getComponent() {
     throw new UnsupportedOperationException("Invalid function for this TitlePacket ActionType");
@@ -88,11 +81,9 @@ public abstract class GenericTitlePacket implements MinecraftPacket {
     throw new UnsupportedOperationException("Invalid function for this TitlePacket ActionType");
   }
 
-
   @Override
-  public final void decode(ByteBuf buf, ProtocolUtils.Direction direction,
+  public final void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
-      ProtocolVersion version) {
+    throw new UnsupportedOperationException("Decode is not implemented");
-    throw new UnsupportedOperationException(); // encode only
   }
 
   /**
@@ -103,21 +94,17 @@ public abstract class GenericTitlePacket implements MinecraftPacket {
    * @return GenericTitlePacket instance that follows the invoker type/version
    */
   public static GenericTitlePacket constructTitlePacket(ActionType type, ProtocolVersion version) {
-    GenericTitlePacket packet = null;
     if (version.noLessThan(ProtocolVersion.MINECRAFT_1_17)) {
-      packet = switch (type) {
+      return switch (type) {
         case SET_ACTION_BAR -> new TitleActionbarPacket();
         case SET_SUBTITLE -> new TitleSubtitlePacket();
         case SET_TIMES -> new TitleTimesPacket();
         case SET_TITLE -> new TitleTextPacket();
-        case HIDE, RESET -> new TitleClearPacket();
+        case HIDE, RESET -> new TitleClearPacket(type);
         default -> throw new IllegalArgumentException("Invalid ActionType");
       };
     } else {
-      packet = new LegacyTitlePacket();
+      return new LegacyTitlePacket(type);
     }
-    packet.setAction(type);
-    return packet;
   }
-
 }

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/LegacyTitlePacket.java

@@ -17,32 +17,44 @@
 
 package com.velocitypowered.proxy.protocol.packet.title;
 
+import com.google.common.base.Preconditions;
 import com.velocitypowered.api.network.ProtocolVersion;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.chat.ComponentHolder;
 import io.netty.buffer.ByteBuf;
-import org.checkerframework.checker.nullness.qual.Nullable;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class LegacyTitlePacket extends GenericTitlePacket {
 
+  private final ActionType action;
+
   private @Nullable ComponentHolder component;
   private int fadeIn;
   private int stay;
   private int fadeOut;
 
+  public LegacyTitlePacket() {
+    throw new UnsupportedOperationException("Decode is not implemented");
+  }
+
+  public LegacyTitlePacket(ActionType action) {
+    this.action = Preconditions.checkNotNull(action, "action");
+  }
+
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
     if (version.lessThan(ProtocolVersion.MINECRAFT_1_11)
-        && getAction() == ActionType.SET_ACTION_BAR) {
+        && this.action == ActionType.SET_ACTION_BAR) {
       throw new IllegalStateException("Action bars are only supported on 1.11 and newer");
     }
-    ProtocolUtils.writeVarInt(buf, getAction().getAction(version));
+    ProtocolUtils.writeVarInt(buf, this.action.getAction(version));
 
-    switch (getAction()) {
+    switch (this.action) {
       case SET_TITLE, SET_SUBTITLE, SET_ACTION_BAR -> {
         if (component == null) {
-          throw new IllegalStateException("No component found for " + getAction());
+          throw new IllegalStateException("No component found for " + this.action);
         }
         component.write(buf);
       }
@@ -52,14 +64,13 @@ public class LegacyTitlePacket extends GenericTitlePacket {
         buf.writeInt(fadeOut);
       }
       case HIDE, RESET -> {}
-      default -> throw new UnsupportedOperationException("Unknown action " + getAction());
+      default -> throw new UnsupportedOperationException("Unknown action " + this.action);
     }
-
   }
 
   @Override
-  public void setAction(ActionType action) {
+  public @NotNull ActionType getAction() {
-    super.setAction(action);
+    return action;
   }
 
   @Override
@@ -105,7 +116,7 @@ public class LegacyTitlePacket extends GenericTitlePacket {
   @Override
   public String toString() {
     return "GenericTitlePacket{"
-        + "action=" + getAction()
+        + "action=" + action
         + ", component='" + component + '\''
         + ", fadeIn=" + fadeIn
         + ", stay=" + stay

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/TitleActionbarPacket.java

@@ -22,13 +22,15 @@ import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.chat.ComponentHolder;
 import io.netty.buffer.ByteBuf;
+import org.jetbrains.annotations.NotNull;
 
 public class TitleActionbarPacket extends GenericTitlePacket {
 
   private ComponentHolder component;
 
-  public TitleActionbarPacket() {
+  @Override
-    setAction(ActionType.SET_ACTION_BAR);
+  public @NotNull ActionType getAction() {
+    return ActionType.SET_ACTION_BAR;
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/TitleClearPacket.java

@@ -21,30 +21,37 @@ import com.velocitypowered.api.network.ProtocolVersion;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import io.netty.buffer.ByteBuf;
+import org.jetbrains.annotations.NotNull;
 
 public class TitleClearPacket extends GenericTitlePacket {
 
+  private final ActionType action;
+
   public TitleClearPacket() {
-    setAction(ActionType.HIDE);
+    this(ActionType.HIDE);
+  }
+
+  public TitleClearPacket(ActionType action) {
+    if (action != ActionType.HIDE && action != ActionType.RESET) {
+      throw new IllegalArgumentException("TitleClearPacket only accepts the HIDE and RESET actions.");
+    }
+    this.action = action;
   }
 
   @Override
-  public void setAction(ActionType action) {
+  public @NotNull ActionType getAction() {
-    if (action != ActionType.HIDE && action != ActionType.RESET) {
+    return action;
-      throw new IllegalArgumentException("TitleClearPacket only accepts CLEAR and RESET actions");
-    }
-    super.setAction(action);
   }
 
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
-    buf.writeBoolean(getAction() == ActionType.RESET);
+    buf.writeBoolean(this.action == ActionType.RESET);
   }
 
   @Override
   public String toString() {
     return "TitleClearPacket{"
-        + ", resetTimes=" + (getAction() == ActionType.RESET)
+        + ", resetTimes=" + (this.action == ActionType.RESET)
         + '}';
   }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/TitleSubtitlePacket.java

@@ -22,13 +22,15 @@ import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.chat.ComponentHolder;
 import io.netty.buffer.ByteBuf;
+import org.jetbrains.annotations.NotNull;
 
 public class TitleSubtitlePacket extends GenericTitlePacket {
 
   private ComponentHolder component;
 
-  public TitleSubtitlePacket() {
+  @Override
-    setAction(ActionType.SET_SUBTITLE);
+  public @NotNull ActionType getAction() {
+    return ActionType.SET_SUBTITLE;
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/TitleTextPacket.java

@@ -22,13 +22,15 @@ import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.chat.ComponentHolder;
 import io.netty.buffer.ByteBuf;
+import org.jetbrains.annotations.NotNull;
 
 public class TitleTextPacket extends GenericTitlePacket {
 
   private ComponentHolder component;
 
-  public TitleTextPacket() {
+  @Override
-    setAction(ActionType.SET_TITLE);
+  public @NotNull ActionType getAction() {
+    return ActionType.SET_TITLE;
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/title/TitleTimesPacket.java

@@ -21,6 +21,7 @@ import com.velocitypowered.api.network.ProtocolVersion;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import io.netty.buffer.ByteBuf;
+import org.jetbrains.annotations.NotNull;
 
 public class TitleTimesPacket extends GenericTitlePacket {
 
@@ -28,8 +29,9 @@ public class TitleTimesPacket extends GenericTitlePacket {
   private int stay;
   private int fadeOut;
 
-  public TitleTimesPacket() {
+  @Override
-    setAction(ActionType.SET_TIMES);
+  public @NotNull ActionType getAction() {
+    return ActionType.SET_TIMES;
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/util/IntervalledCounter.java

@@ -30,40 +30,51 @@ package com.velocitypowered.proxy.util;
  * <p>This class is not thread-safe. If multiple threads access an instance concurrently,
  * external synchronization is required.</p>
  */
-@SuppressWarnings("checkstyle:WhitespaceAfter") // Not our class
 public final class IntervalledCounter {
 
   private static final int INITIAL_SIZE = 8;
 
+  /**
+   * Data points within this many nanoseconds of the newest one are merged into it, bounding the
+   * number of stored data points to roughly {@code interval / COALESCE_INTERVAL}.
+   */
+  private static final long COALESCE_INTERVAL = 1_000_000L; // 1ms
+
   /**
    * Ring buffer holding the timestamp (in nanoseconds) for each data point.
    */
-  protected long[] times;
+  private long[] times;
+
   /**
    * Ring buffer holding the count associated with each timestamp.
    */
-  protected long[] counts;
+  private long[] counts;
+
   /**
    * The sliding window size in nanoseconds. Only entries with time >= (currentTime - interval)
    * are considered part of the window.
    */
-  protected final long interval;
+  private final long interval;
+
   /**
    * Cached lower bound of the window (in nanoseconds) after the last update.
    */
-  protected long minTime;
+  private long minTime;
+
   /**
    * Running sum of all counts currently within the window.
    */
-  protected long sum;
+  private long sum;
+
   /**
    * Head index (inclusive) of the ring buffer.
    */
-  protected int head; // inclusive
+  private int head; // inclusive
+
   /**
    * Tail index (exclusive) of the ring buffer.
    */
-  protected int tail; // exclusive
+  private int tail; // exclusive
 
   /**
    * Creates a new counter with the specified interval.
@@ -131,6 +142,8 @@ public final class IntervalledCounter {
   /**
    * Adds {@code count} units at the specified timestamp, assuming the timestamp is within the
    * current window. If the timestamp is older than {@code minTime}, the value is ignored.
+   * If the timestamp is within {@link #COALESCE_INTERVAL} of the newest stored data point, the
+   * count is merged into that data point instead of creating a new one.
    * This method does not automatically advance the window; callers should invoke
    * {@link #updateCurrentTime()} or {@link #updateCurrentTime(long)} beforehand.
    *
@@ -142,6 +155,15 @@ public final class IntervalledCounter {
     if (currTime - this.minTime < 0) {
       return;
     }
+    if (this.head != this.tail) {
+      final int last = this.tail == 0 ? this.times.length - 1 : this.tail - 1;
+      // guard against overflow by using subtraction
+      if (currTime - this.times[last] < COALESCE_INTERVAL) {
+        this.counts[last] += count;
+        this.sum += count;
+        return;
+      }
+    }
     int nextTail = (this.tail + 1) % this.times.length;
     if (nextTail == this.head) {
       this.resize();

proxy/src/main/resources/default-velocity.toml

@@ -1,5 +1,5 @@
 # Config version. Do not change this
-config-version = "2.8"
+config-version = "2.9"
 
 # What port should the proxy be bound to? By default, we'll bind to all addresses on port 25565.
 bind = "0.0.0.0:25565"
@@ -43,7 +43,7 @@ forwarding-secret-file = "forwarding.secret"
 # Announce whether or not your server supports Forge. If you run a modded server, we
 # suggest turning this on.
 # 
-# If your network runs one modpack consistently, consider using ping-passthrough = "mods"
+# If your network runs one modpack consistently, consider using ping-passthrough.modinfo = true
 # instead for a nicer display in the server list.
 announce-forge = false
 
@@ -51,21 +51,6 @@ announce-forge = false
 # any existing player who is online if a duplicate connection attempt is made.
 kick-existing-players = false
 
-# Should Velocity pass server list ping requests to a backend server?
-# Available options:
-# - "disabled":    No pass-through will be done. The velocity.toml and server-icon.png
-#                  will determine the initial server list ping response.
-# - "mods":        Passes only the mod list from your backend server into the response.
-#                  The first server in your try list (or forced host) with a mod list will be
-#                  used. If no backend servers can be contacted, Velocity won't display any
-#                  mod information.
-# - "description": Uses the description and mod list from the backend server. The first
-#                  server in the try (or forced host) list that responds is used for the
-#                  description and mod list.
-# - "all":         Uses the backend server's response as the proxy response. The Velocity
-#                  configuration is used if no servers could be contacted.
-ping-passthrough = "DISABLED"
-
 # If enabled (default is false), then a sample of the online players on the proxy will be visible
 # when hovering over the player count in the server list.
 # This doesn't have any effect when ping passthrough is set to either "description" or "all".
@@ -74,6 +59,18 @@ sample-players-in-ping = false
 # If not enabled (default is true) player IP addresses will be replaced by <ip address withheld> in logs
 enable-player-address-logging = true
 
+[ping-passthrough]
+# Should Velocity pass the version number from the backend server when responding to server list ping requests?
+version = false
+# Should Velocity pass the player count from the backend server when responding to server list ping requests?
+players = false
+# Should Velocity pass the description from the backend server when responding to server list ping requests?
+description = false
+# Should Velocity pass the favicon (also known as the server icon) from the backend server when responding to server list ping requests?
+favicon = false
+# Should Velocity pass the mod list from the backend server when responding to server list ping requests?
+modinfo = false
+
 [packet-limiter]
 # Size of the moving time window in seconds used to calculate average rates.
 # A larger window tolerates short bursts while still enforcing the configured limits over time.

proxy/src/test/java/com/velocitypowered/proxy/util/IntervalledCounterTest.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2026 Velocity Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.velocitypowered.proxy.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.concurrent.TimeUnit;
+import org.junit.jupiter.api.Test;
+
+class IntervalledCounterTest {
+
+  private static final long INTERVAL = TimeUnit.SECONDS.toNanos(7);
+
+  @Test
+  void sumAndRateTrackAddedCounts() {
+    IntervalledCounter counter = new IntervalledCounter(INTERVAL);
+    long now = 0;
+
+    counter.updateAndAdd(700, now);
+    assertEquals(700, counter.getSum());
+    assertEquals(100.0, counter.getRate(), 1e-9);
+
+    now += TimeUnit.SECONDS.toNanos(1);
+    counter.updateAndAdd(1400, now);
+    assertEquals(2100, counter.getSum());
+    assertEquals(300.0, counter.getRate(), 1e-9);
+  }
+
+  @Test
+  void dataPointsOutsideTheWindowAreEvicted() {
+    IntervalledCounter counter = new IntervalledCounter(INTERVAL);
+    long now = 0;
+
+    counter.updateAndAdd(10, now);
+    now += TimeUnit.SECONDS.toNanos(3);
+    counter.updateAndAdd(20, now);
+    assertEquals(30, counter.getSum());
+    assertEquals(2, counter.totalDataPoints());
+
+    // 7.5s after the first point: only the second point remains
+    now = TimeUnit.MILLISECONDS.toNanos(7500);
+    counter.updateCurrentTime(now);
+    assertEquals(20, counter.getSum());
+    assertEquals(1, counter.totalDataPoints());
+
+    // 10.5s: everything has expired
+    now = TimeUnit.MILLISECONDS.toNanos(10500);
+    counter.updateCurrentTime(now);
+    assertEquals(0, counter.getSum());
+    assertEquals(0, counter.totalDataPoints());
+  }
+
+  @Test
+  void storedDataPointsAreBoundedByTimeNotByCallCount() {
+    IntervalledCounter counter = new IntervalledCounter(INTERVAL);
+
+    // Simulate a flood of tiny (even zero-sized) packets arriving far faster than one per
+    // millisecond for the whole window. Before coalescing was introduced, each call stored a
+    // separate data point, so an attacker could grow the ring buffer without bound while staying
+    // under a bytes-per-second limit.
+    final long stepNanos = 100;
+    final long calls = INTERVAL / stepNanos;
+    long now = 0;
+    for (long i = 0; i < calls; i++) {
+      counter.updateAndAdd(i % 2, now);
+      now += stepNanos;
+    }
+
+    long expectedSum = calls / 2;
+    assertEquals(expectedSum, counter.getSum());
+    // 7s window at 1ms coalescing granularity is ~7000 points; leave some slack.
+    assertTrue(counter.totalDataPoints() <= 7100,
+        "expected at most ~7000 data points, got " + counter.totalDataPoints());
+    assertTrue(counter.totalDataPoints() >= 7000,
+        "expected at least 7000 data points, got " + counter.totalDataPoints());
+  }
+
+  @Test
+  void coalescedDataPointsExpireTogether() {
+    IntervalledCounter counter = new IntervalledCounter(INTERVAL);
+
+    long now = 0;
+    counter.updateAndAdd(5, now);
+    // Within the same 1ms bucket: merged into the previous point
+    counter.updateAndAdd(7, now + 500_000L);
+    assertEquals(12, counter.getSum());
+    assertEquals(1, counter.totalDataPoints());
+
+    // A new bucket starts a new point
+    counter.updateAndAdd(1, now + 1_000_000L);
+    assertEquals(13, counter.getSum());
+    assertEquals(2, counter.totalDataPoints());
+
+    // The merged bucket carries the timestamp of its first point and expires with it
+    counter.updateCurrentTime(now + INTERVAL + 1);
+    assertEquals(1, counter.getSum());
+    assertEquals(1, counter.totalDataPoints());
+  }
+}