Update to Minecraft 26.3 (#3681)

* Update to Minecraft 26.3

- Bump the server dependency, latest version and plugin api-version to 26.3
- Add the configuration POST_EFFECTS packet and shift the following ids
- Add the CHANGE_DESTROY_DIRECTION player dig type
- Stop resolving the legacy particle enum on 1.13+, the 26.3 particle packet has an unrelated enum
- Read optional message signatures in getMessageSignatures
- Cache parameterized structure modifiers separately from the raw field type
- Add WrappedVecDelta and WrappedPositionPath for the new entity movement packets
- Update tests for the 26.3 server classes

* Change default class type from null to void.class

.github/CONTRIBUTING.md

@@ -6,15 +6,20 @@ development, so keep changes focused and preserve existing behavior unless a bre
 
 ## Building ProtocolLib
 
-Use the Gradle wrapper from the repository root. The build uses the Java 25 toolchain and resolves the current Spigot
-server dependency from the CodeMC repository.
+Use the Gradle wrapper from the repository root. The root project builds the platform-neutral library published to
+Maven. The `paper` module compiles and tests it against Paper's development bundle and produces the primary plugin,
+`build/libs/ProtocolLib.jar`. The `spigot` compatibility module produces `build/libs/ProtocolLib-Spigot.jar`.
 
 ```shell
 ./gradlew test
 ./gradlew build shadowJar
 ```
 
-`shadowJar` produces `build/libs/ProtocolLib.jar` with the required Byte Buddy classes included.
+`shadowJar` builds both plugin distributions with the required Byte Buddy classes included. Neither platform provider
+nor plugin descriptor is included in the Maven core artifact.
+
+ProtocolLib uses the Java 25 toolchain to compile against the current server, but production classes target Java 17 for
+compatibility with older supported servers.
 
 ## Updating ProtocolLib for a Minecraft Release
 
@@ -23,7 +28,7 @@ server classes. The server packet classes and codecs are authoritative when docu
 
 ### 1. Update version metadata
 
-- Update `mcVersion` in `build.gradle.kts`.
+- Update `mcVersion` in `gradle.properties`.
 - Add the release to `MinecraftVersion` and update `MinecraftVersion.LATEST`.
 - Update `ProtocolLibrary.MAXIMUM_MINECRAFT_VERSION` and `ProtocolLibrary.MINECRAFT_LAST_RELEASE_DATE`.
 - Update `MinecraftProtocolVersion` if the release changed the protocol number.
@@ -44,6 +49,7 @@ serverbound and clientbound packet classes and codecs against every protocol pha
 
 - Inspect changed fields, constructors, records, nested classes, and stream codecs instead of relying only on class names.
 - Prefer structural or type-based reflection where names are unstable.
+- Treat the current server API shape as primary and use older supported shapes only as narrow compatibility fallbacks.
 - Put version checks at the narrowest compatibility boundary and leave the older path unchanged.
 - If an NMS concept was removed, report it as unsupported or absent rather than treating a different class as equivalent.
 - Preserve packet fields that are unrelated to the value being changed.
@@ -54,7 +60,7 @@ serverbound and clientbound packet classes and codecs against every protocol pha
 ### 4. Add regression coverage
 
 - Initialize the test environment with `BukkitInitialization` when tests access CraftBukkit or NMS classes.
-- Exercise the actual packet structure supplied by the current Spigot dependency.
+- Exercise the actual packet structure supplied by the current Paper dependency.
 - Cover both sides of a version guard when feasible.
 - Re-enable previously disabled tests when the underlying incompatibility is fixed.
 - Run targeted tests while developing, followed by `./gradlew test`.

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: '21'
+          java-version: '25'
           cache: 'gradle'
 
       - name: Run gradle build lifecycle
@@ -27,4 +27,6 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: ProtocolLib
-          path: build/libs/ProtocolLib.jar
+          path: |
+            build/libs/ProtocolLib.jar
+            build/libs/ProtocolLib-Spigot.jar

.github/workflows/dev-build.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: '21'
+          java-version: '25'
           cache: 'gradle'
 
       - name: Run gradle build lifecycle
@@ -27,7 +27,9 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: ProtocolLib
-          path: build/libs/ProtocolLib.jar
+          path: |
+            build/libs/ProtocolLib.jar
+            build/libs/ProtocolLib-Spigot.jar
 
       - name: Create or update GitHub pre-release
         env:
@@ -41,3 +43,4 @@ jobs:
           NEW_NOTES="$RELEASE_NOTES"$'\n'"* [$SHORT_HASH] $COMMIT_MSG"
           gh release edit dev-build --notes "$NEW_NOTES" --repo ${{ github.repository }}
           gh release upload dev-build build/libs/ProtocolLib.jar#ProtocolLib.jar --clobber --repo ${{ github.repository }}
+          gh release upload dev-build build/libs/ProtocolLib-Spigot.jar#ProtocolLib-Spigot.jar --clobber --repo ${{ github.repository }}

AGENTS.md

@@ -7,6 +7,7 @@ definitions, reflection, or public wrappers.
 
 - The main project uses the Gradle wrapper. Do not use `TinyProtocol/pom.xml` to build ProtocolLib.
 - The Java toolchain and current Spigot dependency are defined in `build.gradle.kts`.
+- Keep the Java 25 build toolchain separate from the Java 17 production bytecode target.
 - Production code is under `src/main/java`; JUnit tests and NMS test initialization are under `src/test/java`.
 - Keep changes focused. Do not combine protocol fixes with unrelated cleanup or formatting.
 - Preserve public API and binary compatibility unless the task explicitly requires a breaking change.
@@ -59,6 +60,7 @@ renamed packet can abort registration of later packets in the same registry.
 ## Version Compatibility
 
 - Put version checks at the narrowest affected boundary.
+- Treat the current supported server API shape as the primary path. Use older supported shapes only as narrow fallbacks.
 - Keep the pre-change code path intact whenever possible.
 - Use named `MinecraftVersion` constants with `atOrAbove()` instead of scattered version strings.
 - A public method should keep the same signature and broad contract across versions.

Readme.md

@@ -14,16 +14,19 @@ lead to more subtle bugs.
 
 * [Spigot Page](https://spigotmc.org/resources/protocollib.1997/)
 * [Releases](https://github.com/dmulloy2/ProtocolLib/releases)
-* [Dev Build](https://github.com/dmulloy2/ProtocolLib/releases/tag/dev-build)
-* [JavaDoc](https://dmulloy2.net/ProtocolLib/javadoc/)
+* [Dev Builds](https://ci.dmulloy2.net/job/ProtocolLib/)
+* [JavaDoc](https://ci.dmulloy2.net/job/ProtocolLib/javadoc/index.html)
 * [Protocol Wiki](https://minecraft.wiki/w/Minecraft_Wiki:Projects/wiki.vg_merge/Protocol)
 
+`ProtocolLib.jar` is the primary Paper plugin. Spigot servers must use the compatibility artifact,
+`ProtocolLib-Spigot.jar`. The Maven artifact is the platform-neutral library shared by both distributions.
+
 ### Compilation
 
 ProtocolLib is built with [Gradle](https://gradle.org/). If you have it installed, just run
 `./gradlew build` in the root project folder. Other gradle targets you may be interested in 
 include `clean`, `test`, and `shadowJar`. `shadowJar` will create a jar with all dependencies
-(ByteBuddy) included.
+(ByteBuddy) included for both Paper and Spigot.
 
 ### A new API
 
@@ -66,6 +69,48 @@ dependencies {
 }
 ```
 
+#### Snapshot builds
+
+Snapshot builds are available for testing changes before the next release. To use `5.5.0-SNAPSHOT`,
+add the [public repository](https://repo.dmulloy2.net/repository/public/) and update your dependency version.
+
+For Maven:
+
+```xml
+<repositories>
+  <repository>
+    <id>dmulloy2-public</id>
+    <url>https://repo.dmulloy2.net/repository/public/</url>
+  </repository>
+</repositories>
+
+<dependencies>
+  <dependency>
+    <groupId>net.dmulloy2</groupId>
+    <artifactId>ProtocolLib</artifactId>
+    <version>5.5.0-SNAPSHOT</version>
+    <scope>provided</scope>
+  </dependency>
+</dependencies>
+```
+
+For Gradle:
+
+```gradle
+repositories {
+    mavenCentral()
+    maven {
+        url = uri('https://repo.dmulloy2.net/repository/public/')
+    }
+}
+
+dependencies {
+    compileOnly 'net.dmulloy2:ProtocolLib:5.5.0-SNAPSHOT'
+}
+```
+
+#### Accessing the API
+
 Then get a reference to ProtocolManager in onLoad() or onEnable() and you're good to go.
 
 ````java
@@ -92,25 +137,26 @@ protocolManager.addPacketListener(new PacketAdapter(
 });
 ````
 
-It's also possible to read and modify the content of these packets. For instance, you can create a global
-censor by listening for Packet3Chat events:
+It's also possible to read and modify the content of packets, including the ones sent by a client. For
+instance, you can censor the text players write on signs by listening for `UPDATE_SIGN` packets:
 
 ````java
-// Censor
+// Censor signs
 protocolManager.addPacketListener(new PacketAdapter(
     this,
     ListenerPriority.NORMAL,
-    PacketType.Play.Client.CHAT
+    PacketType.Play.Client.UPDATE_SIGN
 ) {
     @Override
     public void onPacketReceiving(PacketEvent event) {
         PacketContainer packet = event.getPacket();
-        String message = packet.getStrings().read(0);
+        String[] lines = packet.getStringArrays().read(0);
 
-        if (message.contains("shit") || message.contains("damn")) {
-            event.setCancelled(true);
-            event.getPlayer().sendMessage("Bad manners!");
+        for (int i = 0; i < lines.length; i++) {
+            lines[i] = lines[i].replace("shit", "****").replace("damn", "****");
         }
+
+        packet.getStringArrays().write(0, lines);
     }
 });
 ````

build.gradle.kts

@@ -1,10 +1,7 @@
-import org.gradle.api.tasks.testing.logging.TestExceptionFormat
-
 plugins {
     `java-library`
     `maven-publish`
     signing
-    id("com.gradleup.shadow") version "9.4.0"
     id("io.github.patrick.remapper") version "1.4.3"
     id("com.vanniktech.maven.publish") version "0.36.0"
 }
@@ -12,7 +9,7 @@ plugins {
 group = "net.dmulloy2"
 description = "Provides access to the Minecraft protocol"
 
-val mcVersion = "26.2"
+val mcVersion: String by project
 val isSnapshot = version.toString().endsWith("-SNAPSHOT")
 val isJitPack = System.getenv("JITPACK")?.equals("true", ignoreCase = true) ?: false
 val commitHash = System.getenv("COMMIT_SHA") ?: ""
@@ -46,83 +43,51 @@ repositories {
 dependencies {
     implementation("net.bytebuddy:byte-buddy:1.18.2")
     compileOnly("org.spigotmc:spigot-api:${mcVersion}-R0.1-SNAPSHOT")
-    compileOnly("org.spigotmc:spigot:${mcVersion}-R0.1-SNAPSHOT")//:remapped-mojang")
+    compileOnly("org.spigotmc:spigot:${mcVersion}-R0.1-SNAPSHOT")
     compileOnly("io.netty:netty-all:4.2.8.Final")
     compileOnly("net.kyori:adventure-text-serializer-gson:4.25.0")
     compileOnly("com.googlecode.json-simple:json-simple:1.1.1")
-
-    testImplementation("org.junit.jupiter:junit-jupiter-engine:6.0.1")
-    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:6.0.1")
-    testRuntimeOnly("org.junit.platform:junit-platform-launcher:6.0.1")
-    testImplementation("org.mockito:mockito-core:5.21.0")
-    testImplementation("io.netty:netty-common:4.2.8.Final")
-    testImplementation("io.netty:netty-transport:4.2.8.Final")
-    testImplementation("org.spigotmc:spigot:${mcVersion}-R0.1-SNAPSHOT")//:remapped-mojang")
-    testImplementation("net.kyori:adventure-text-serializer-gson:4.25.0")
-    testImplementation("net.kyori:adventure-text-serializer-plain:4.25.0")
+    compileOnly("commons-lang:commons-lang:2.6")
 }
 
 java {
-    // sourceCompatibility = JavaVersion.VERSION_25
-    // targetCompatibility = JavaVersion.VERSION_25
-
     toolchain {
         languageVersion.set(JavaLanguageVersion.of(25))
     }
 }
 
-tasks {
-    processResources {
-        val fullVersion = if (isSnapshot && isCI) "${version}-${commitHash.take(7)}" else version
-
-        eachFile {
-            expand("version" to fullVersion)
-        }
-    }
-
+sourceSets {
     test {
-        useJUnitPlatform()
-        testLogging {
-            exceptionFormat = TestExceptionFormat.FULL
-        }
+        java.setSrcDirs(emptyList<String>())
+        resources.setSrcDirs(emptyList<String>())
+    }
+}
+
+tasks {
+    test {
+        dependsOn(":paper:test")
     }
 
-    shadowJar {
-        dependencies {
-            include(dependency("net.bytebuddy:byte-buddy:.*"))
-        }
-        relocate("net.bytebuddy", "com.comphenix.net.bytebuddy")
-
-        manifest {
-            attributes(
-                "paperweight-mappings-namespace" to "mojang"
-            )
-        }
-
-        archiveFileName = "ProtocolLib.jar"
+    check {
+        dependsOn(":paper:check", ":spigot:check")
     }
 
-    /*remap {
-        dependsOn("shadowJar")
-
-        inputTask.set(getByName<ShadowJar>("shadowJar"))
-        version.set(mcVersion)
-        action.set(RemapTask.Action.MOJANG_TO_SPIGOT)
-    }
-
-    assemble {
-        dependsOn("remap")
-    }*/
-
     javadoc {
         options.encoding = "UTF-8"
     }
 
     compileJava {
         options.encoding = "UTF-8"
+        options.release.set(17)
     }
 }
 
+tasks.register("shadowJar") {
+    group = "build"
+    description = "Builds the Paper and Spigot plugin distributions."
+    dependsOn(":paper:shadowJar", ":spigot:shadowJar")
+}
+
 mavenPublishing {
     publishToMavenCentral()
     if (!isSnapshot && !isJitPack) {

gradle.properties

@@ -1,4 +1,5 @@
 version=5.5.0-SNAPSHOT
+mcVersion=26.3
 mavenCentralUsername=
 mavenCentralPassword=
 signing.keyId=

paper/build.gradle.kts

@@ -0,0 +1,104 @@
+import org.gradle.api.attributes.java.TargetJvmVersion
+import org.gradle.api.tasks.testing.logging.TestExceptionFormat
+
+plugins {
+    `java-library`
+    id("com.gradleup.shadow") version "9.4.0"
+    id("io.papermc.paperweight.userdev") version "2.0.0-beta.21"
+}
+
+group = "net.dmulloy2"
+version = rootProject.version
+
+val mcVersion: String by project
+val isSnapshot = version.toString().endsWith("-SNAPSHOT")
+val commitHash = System.getenv("COMMIT_SHA") ?: ""
+val isCI = commitHash.isNotEmpty()
+
+repositories {
+    mavenLocal()
+    mavenCentral()
+    maven("https://repo.papermc.io/repository/maven-public/")
+    maven("https://repo.codemc.io/repository/nms/")
+    maven("https://hub.spigotmc.org/nexus/content/groups/public/")
+    maven("https://libraries.minecraft.net/") {
+        metadataSources {
+            mavenPom()
+            artifact()
+            ignoreGradleMetadataRedirection()
+        }
+    }
+}
+
+dependencies {
+    implementation(project(":"))
+    paperweight.paperDevBundle("$mcVersion.build.+")
+
+    compileOnly("io.netty:netty-all:4.2.8.Final")
+    compileOnly("net.kyori:adventure-text-serializer-gson:4.25.0")
+    compileOnly("commons-lang:commons-lang:2.6")
+
+    testImplementation("org.junit.jupiter:junit-jupiter-engine:6.0.1")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:6.0.1")
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher:6.0.1")
+    testImplementation("org.mockito:mockito-core:5.21.0")
+    testImplementation("io.netty:netty-common:4.2.8.Final")
+    testImplementation("io.netty:netty-transport:4.2.8.Final")
+    testImplementation("net.kyori:adventure-text-serializer-gson:4.25.0")
+    testImplementation("net.kyori:adventure-text-serializer-plain:4.25.0")
+    testImplementation("commons-lang:commons-lang:2.6")
+}
+
+paperweight.reobfArtifactConfiguration =
+    io.papermc.paperweight.userdev.ReobfArtifactConfiguration.MOJANG_PRODUCTION
+
+configurations.matching { it.name == "compileClasspath" || it.name == "runtimeClasspath" || it.name == "testCompileClasspath" || it.name == "testRuntimeClasspath" }.configureEach {
+    attributes {
+        attribute(TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE, 25)
+    }
+}
+
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(25))
+    }
+}
+
+sourceSets {
+    test {
+        java.srcDir(rootProject.file("src/test/java"))
+        resources.srcDir(rootProject.file("src/test/resources"))
+    }
+}
+
+tasks {
+    processResources {
+        val fullVersion = if (isSnapshot && isCI) "${version}-${commitHash.take(7)}" else version
+
+        eachFile {
+            expand("version" to fullVersion)
+        }
+    }
+
+    test {
+        useJUnitPlatform()
+        testLogging {
+            exceptionFormat = TestExceptionFormat.FULL
+        }
+    }
+
+    compileJava {
+        options.release.set(17)
+    }
+
+    shadowJar {
+        relocate("net.bytebuddy", "com.comphenix.net.bytebuddy")
+
+        manifest {
+            attributes("paperweight-mappings-namespace" to "mojang")
+        }
+
+        destinationDirectory.set(rootProject.layout.buildDirectory.dir("libs"))
+        archiveFileName.set("ProtocolLib.jar")
+    }
+}

paper/src/main/java/com/comphenix/protocol/paper/PaperPlatformProvider.java

@@ -0,0 +1,105 @@
+package com.comphenix.protocol.paper;
+
+import java.util.List;
+import java.util.function.Consumer;
+
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+
+import com.comphenix.protocol.ProtocolLib;
+import com.comphenix.protocol.internal.PlatformProvider;
+
+import io.netty.channel.Channel;
+import io.papermc.paper.command.brigadier.BasicCommand;
+import io.papermc.paper.command.brigadier.CommandSourceStack;
+import io.papermc.paper.network.ChannelInitializeListenerHolder;
+import net.kyori.adventure.key.Key;
+
+public final class PaperPlatformProvider implements PlatformProvider {
+
+    public static final Key CHANNEL_INITIALIZER_KEY = Key.key("protocollib", "channel-initializer");
+
+    @Override
+    public boolean hasEarlyChannelInitialization() {
+        return true;
+    }
+
+    @Override
+    public Runnable registerChannelInitializer(Consumer<Channel> channelInitializer) {
+        ChannelInitializeListenerHolder.addListener(CHANNEL_INITIALIZER_KEY, channelInitializer::accept);
+        return () -> ChannelInitializeListenerHolder.removeListener(CHANNEL_INITIALIZER_KEY);
+    }
+
+    @Override
+    public void registerCommand(ProtocolLib plugin, String name, CommandExecutor executor) {
+        CommandMetadata metadata = getMetadata(name);
+        Command command = new RegisteredCommand(name, metadata);
+
+        plugin.registerCommand(
+                name,
+                metadata.description(),
+                metadata.aliases(),
+                new RegisteredBasicCommand(name, metadata, command, executor));
+    }
+
+    private static CommandMetadata getMetadata(String name) {
+        return switch (name) {
+            case "protocol" -> new CommandMetadata(
+                    "Performs administrative tasks regarding ProtocolLib.",
+                    "/<command> config|check|update|timings|listeners|version|dump",
+                    "protocol.admin",
+                    List.of());
+            case "packet" -> new CommandMetadata(
+                    "Add or remove a simple packet listener.",
+                    "/<command> add|remove|names client|server [ID start]-[ID stop] [detailed]",
+                    "protocol.admin",
+                    List.of());
+            case "filter" -> new CommandMetadata(
+                    "Add or remove programmable filters to the packet listeners.",
+                    "/<command> add|remove name [ID start]-[ID stop]",
+                    "protocol.admin",
+                    List.of("packet_filter"));
+            case "packetlog" -> new CommandMetadata(
+                    "Logs hex representations of packets to a file or console",
+                    "/<command> <protocol> <sender> <packet> [location]",
+                    "protocol.admin",
+                    List.of());
+            default -> throw new IllegalArgumentException("Unknown ProtocolLib command " + name);
+        };
+    }
+
+    private record CommandMetadata(String description, String usage, String permission, List<String> aliases) {
+    }
+
+    private record RegisteredBasicCommand(
+            String name,
+            CommandMetadata metadata,
+            Command command,
+            CommandExecutor executor) implements BasicCommand {
+
+        @Override
+        public void execute(CommandSourceStack source, String[] arguments) {
+            if (!this.executor.onCommand(source.getSender(), this.command, this.name, arguments)) {
+                source.getSender().sendMessage(this.metadata.usage().replace("<command>", this.name));
+            }
+        }
+
+        @Override
+        public String permission() {
+            return this.metadata.permission();
+        }
+    }
+
+    private static final class RegisteredCommand extends Command {
+
+        private RegisteredCommand(String name, CommandMetadata metadata) {
+            super(name, metadata.description(), metadata.usage(), metadata.aliases());
+        }
+
+        @Override
+        public boolean execute(CommandSender sender, String commandLabel, String[] args) {
+            throw new UnsupportedOperationException();
+        }
+    }
+}

paper/src/main/resources/META-INF/services/com.comphenix.protocol.internal.PlatformProvider

@@ -0,0 +1 @@
+com.comphenix.protocol.paper.PaperPlatformProvider

paper/src/main/resources/paper-plugin.yml

@@ -0,0 +1,22 @@
+name: ProtocolLib
+version: ${version}
+description: Provides read/write access to the Minecraft protocol.
+authors: [dmulloy2]
+
+main: com.comphenix.protocol.ProtocolLib
+load: STARTUP
+api-version: "26.3"
+folia-supported: true
+
+permissions:
+  protocol.*:
+    description: Gives access to everything.
+    children:
+      protocol.admin: true
+      protocol.info: true
+  protocol.admin:
+    description: Able to initiate the update process and configure debug mode.
+    default: op
+  protocol.info:
+    description: Can read update notifications and error reports.
+    default: op

settings.gradle

@@ -3,3 +3,5 @@
  */
 
 rootProject.name = 'ProtocolLib'
+
+include 'paper', 'spigot'

spigot/build.gradle.kts

@@ -0,0 +1,79 @@
+import org.gradle.api.attributes.java.TargetJvmVersion
+
+plugins {
+    `java-library`
+    id("com.gradleup.shadow") version "9.4.0"
+}
+
+group = "net.dmulloy2"
+version = rootProject.version
+
+val mcVersion: String by project
+
+repositories {
+    mavenLocal()
+    mavenCentral()
+    maven("https://repo.codemc.io/repository/nms/")
+    maven("https://hub.spigotmc.org/nexus/content/groups/public/")
+    maven("https://libraries.minecraft.net/") {
+        metadataSources {
+            mavenPom()
+            artifact()
+            ignoreGradleMetadataRedirection()
+        }
+    }
+}
+
+dependencies {
+    implementation(project(":"))
+    compileOnly("org.spigotmc:spigot-api:${mcVersion}-R0.1-SNAPSHOT")
+    compileOnly("org.spigotmc:spigot:${mcVersion}-R0.1-SNAPSHOT")
+    compileOnly("io.netty:netty-all:4.2.8.Final")
+    compileOnly("net.kyori:adventure-text-serializer-gson:4.25.0")
+    compileOnly("com.googlecode.json-simple:json-simple:1.1.1")
+
+    testImplementation("org.junit.jupiter:junit-jupiter-engine:6.0.1")
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher:6.0.1")
+    testImplementation("org.mockito:mockito-core:5.21.0")
+    testImplementation("io.netty:netty-transport:4.2.8.Final")
+    testImplementation("org.spigotmc:spigot:${mcVersion}-R0.1-SNAPSHOT")
+}
+
+configurations.matching { it.name == "compileClasspath" || it.name == "runtimeClasspath" || it.name == "testCompileClasspath" || it.name == "testRuntimeClasspath" }.configureEach {
+    attributes {
+        attribute(TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE, 25)
+    }
+}
+
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(25))
+    }
+}
+
+tasks {
+    processResources {
+        eachFile {
+            expand("version" to project.version)
+        }
+    }
+
+    test {
+        useJUnitPlatform()
+    }
+
+    compileJava {
+        options.release.set(17)
+    }
+
+    shadowJar {
+        relocate("net.bytebuddy", "com.comphenix.net.bytebuddy")
+
+        manifest {
+            attributes("paperweight-mappings-namespace" to "mojang")
+        }
+
+        destinationDirectory.set(rootProject.layout.buildDirectory.dir("libs"))
+        archiveFileName.set("ProtocolLib-Spigot.jar")
+    }
+}

spigot/src/main/java/com/comphenix/protocol/spigot/SpigotPlatformProvider.java

@@ -0,0 +1,34 @@
+package com.comphenix.protocol.spigot;
+
+import java.util.function.Consumer;
+
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.PluginCommand;
+
+import com.comphenix.protocol.ProtocolLib;
+import com.comphenix.protocol.internal.PlatformProvider;
+
+import io.netty.channel.Channel;
+
+public final class SpigotPlatformProvider implements PlatformProvider {
+
+    @Override
+    public boolean hasEarlyChannelInitialization() {
+        return false;
+    }
+
+    @Override
+    public Runnable registerChannelInitializer(Consumer<Channel> channelInitializer) {
+        throw new UnsupportedOperationException("Early channel initialization is unavailable");
+    }
+
+    @Override
+    public void registerCommand(ProtocolLib plugin, String name, CommandExecutor executor) {
+        PluginCommand command = plugin.getCommand(name);
+        if (command == null) {
+            throw new IllegalStateException("plugin.yml might be corrupt.");
+        }
+
+        command.setExecutor(executor);
+    }
+}

spigot/src/main/resources/META-INF/services/com.comphenix.protocol.internal.PlatformProvider

@@ -0,0 +1 @@
+com.comphenix.protocol.spigot.SpigotPlatformProvider

spigot/src/main/resources/plugin.yml

@@ -1,7 +1,7 @@
 name: ProtocolLib
 version: ${version}
 description: Provides read/write access to the Minecraft protocol.
-authors: [dmulloy2, comphenix]
+authors: [dmulloy2]
 
 main: com.comphenix.protocol.ProtocolLib
 load: STARTUP
@@ -44,4 +44,4 @@ permissions:
     default: op
   protocol.info:
     description: Can read update notifications and error reports.
-    default: op
+    default: op

spigot/src/test/java/com/comphenix/protocol/PlatformCommandRegistrarTest.java

@@ -0,0 +1,26 @@
+package com.comphenix.protocol;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.PluginCommand;
+import org.junit.jupiter.api.Test;
+
+import com.comphenix.protocol.spigot.SpigotPlatformProvider;
+
+class PlatformCommandRegistrarTest {
+
+    @Test
+    void registersLegacyExecutorFromPluginDescriptor() {
+        ProtocolLib plugin = mock(ProtocolLib.class);
+        CommandExecutor executor = mock(CommandExecutor.class);
+        PluginCommand command = mock(PluginCommand.class);
+        when(plugin.getCommand("protocol")).thenReturn(command);
+
+        new SpigotPlatformProvider().registerCommand(plugin, "protocol", executor);
+
+        verify(command).setExecutor(executor);
+    }
+}

spigot/src/test/java/com/comphenix/protocol/injector/netty/manager/PlatformChannelInitializerTest.java

@@ -0,0 +1,17 @@
+package com.comphenix.protocol.injector.netty.manager;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+
+import org.junit.jupiter.api.Test;
+
+import com.comphenix.protocol.internal.PlatformProvider;
+class PlatformChannelInitializerTest {
+
+    @Test
+    void reportsPaperInitializerUnavailable() {
+        PlatformProvider provider = PlatformProvider.get();
+        assertInstanceOf(com.comphenix.protocol.spigot.SpigotPlatformProvider.class, provider);
+        assertFalse(provider.hasEarlyChannelInitialization());
+    }
+}

src/main/java/com/comphenix/protocol/CommandProtocol.java

@@ -120,25 +120,9 @@ class CommandProtocol extends CommandBase {
             return;
         }
 
-        // Perform on an async thread
-        Runnable notify = new Runnable() {
-            @Override
-            public void run() {
-                if (command) {
-                    sender.sendMessage(ChatColor.YELLOW + "[ProtocolLib] " + updater.getResult());
-                    String remoteVersion = updater.getRemoteVersion();
-                    if (remoteVersion != null) {
-                        sender.sendMessage(ChatColor.YELLOW + "Remote version: " + remoteVersion);
-                        sender.sendMessage(ChatColor.YELLOW + "Current version: " + plugin.getDescription().getVersion());
-                    }
-                } else if (updater.shouldNotify() || config.isDebug()) {
-                    sender.sendMessage(ChatColor.YELLOW + "[ProtocolLib] " + updater.getResult());
-                }
-
-                updater.removeListener(this);
-                updateFinished();
-            }
-        };
+        // Top-level class instead of anonymous inner class so that PaperPluginClassLoader
+        // can resolve the .class entry when BukkitScheduler dispatches it on the main thread.
+        Runnable notify = new UpdateNotifyRunnable(sender, command, updater, config, plugin, this);
         updater.start(type);
         updater.addListener(notify);
     }

src/main/java/com/comphenix/protocol/PacketType.java

@@ -144,110 +144,113 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
             public static final PacketType ENTITY_STATUS =                new PacketType(PROTOCOL, SENDER, 0x22, "EntityEvent", "EntityStatus", "SPacketEntityStatus");
             public static final PacketType ENTITY_POSITION_SYNC =         new PacketType(PROTOCOL, SENDER, 0x23, "EntityPositionSync");
             public static final PacketType EXPLOSION =                    new PacketType(PROTOCOL, SENDER, 0x24, "Explode", "Explosion", "SPacketExplosion");
-            public static final PacketType UNLOAD_CHUNK =                 new PacketType(PROTOCOL, SENDER, 0x25, "ForgetLevelChunk", "UnloadChunk", "SPacketUnloadChunk");
-            public static final PacketType GAME_STATE_CHANGE =            new PacketType(PROTOCOL, SENDER, 0x26, "GameEvent", "GameStateChange", "SPacketChangeGameState");
-            public static final PacketType GAME_RULE_VALUES =             new PacketType(PROTOCOL, SENDER, 0x27, "GameRuleValues");
-            public static final PacketType GAME_TEST_HIGHLIGHT_POS =      new PacketType(PROTOCOL, SENDER, 0x28, "GameTestHighlightPos");
-            public static final PacketType OPEN_WINDOW_HORSE =            new PacketType(PROTOCOL, SENDER, 0x29, "MountScreenOpen", "HorseScreenOpen", "OpenWindowHorse");
-            public static final PacketType HURT_ANIMATION =               new PacketType(PROTOCOL, SENDER, 0x2A, "HurtAnimation", "ClientboundHurtAnimationPacket");
-            public static final PacketType INITIALIZE_BORDER =            new PacketType(PROTOCOL, SENDER, 0x2B, "InitializeBorder");
-            public static final PacketType KEEP_ALIVE =                   new PacketType(PROTOCOL, SENDER, 0x2C, "KeepAlive", "SPacketKeepAlive");
-            public static final PacketType MAP_CHUNK =                    new PacketType(PROTOCOL, SENDER, 0x2D, "LevelChunkWithLight", "MapChunk", "SPacketChunkData");
-            public static final PacketType WORLD_EVENT =                  new PacketType(PROTOCOL, SENDER, 0x2E, "LevelEvent", "WorldEvent", "SPacketEffect");
-            public static final PacketType WORLD_PARTICLES =              new PacketType(PROTOCOL, SENDER, 0x2F, "LevelParticles", "WorldParticles", "SPacketParticles");
-            public static final PacketType LIGHT_UPDATE =                 new PacketType(PROTOCOL, SENDER, 0x30, "LightUpdate");
-            public static final PacketType LOGIN =                        new PacketType(PROTOCOL, SENDER, 0x31, "Login", "SPacketJoinGame");
-            public static final PacketType LOW_DISK_SPACE_WARNING =       new PacketType(PROTOCOL, SENDER, 0x32, "LowDiskSpaceWarning");
-            public static final PacketType MAP =                          new PacketType(PROTOCOL, SENDER, 0x33, "MapItemData", "Map", "SPacketMaps");
-            public static final PacketType OPEN_WINDOW_MERCHANT =         new PacketType(PROTOCOL, SENDER, 0x34, "MerchantOffers", "OpenWindowMerchant");
-            public static final PacketType REL_ENTITY_MOVE =              new PacketType(PROTOCOL, SENDER, 0x35, "net.minecraft.network.protocol.game.ClientboundMoveEntityPacket$Pos", "Entity$RelEntityMove", "Entity$PacketPlayOutRelEntityMove");
-            public static final PacketType REL_ENTITY_MOVE_LOOK =         new PacketType(PROTOCOL, SENDER, 0x36, "net.minecraft.network.protocol.game.ClientboundMoveEntityPacket$PosRot", "Entity$RelEntityMoveLook", "Entity$PacketPlayOutRelEntityMoveLook");
-            public static final PacketType MOVE_MINECART =                new PacketType(PROTOCOL, SENDER, 0x37, "MoveMinecart");
-            public static final PacketType ENTITY_LOOK =                  new PacketType(PROTOCOL, SENDER, 0x38, "net.minecraft.network.protocol.game.ClientboundMoveEntityPacket$Rot", "Entity$EntityLook", "Entity$PacketPlayOutEntityLook");
-            public static final PacketType VEHICLE_MOVE =                 new PacketType(PROTOCOL, SENDER, 0x39, "MoveVehicle", "VehicleMove", "SPacketMoveVehicle");
-            public static final PacketType OPEN_BOOK =                    new PacketType(PROTOCOL, SENDER, 0x3A, "OpenBook");
-            public static final PacketType OPEN_WINDOW =                  new PacketType(PROTOCOL, SENDER, 0x3B, "OpenScreen", "OpenWindow", "SPacketOpenWindow");
-            public static final PacketType OPEN_SIGN_EDITOR =             new PacketType(PROTOCOL, SENDER, 0x3C, "OpenSignEditor", "SPacketSignEditorOpen");
-            public static final PacketType PING =                         new PacketType(PROTOCOL, SENDER, 0x3D, "Ping");
-            public static final PacketType PONG_RESPONSE =                new PacketType(PROTOCOL, SENDER, 0x3E, "PongResponse");
-            public static final PacketType AUTO_RECIPE =                  new PacketType(PROTOCOL, SENDER, 0x3F, "PlaceGhostRecipe", "AutoRecipe", "SPacketPlaceGhostRecipe");
-            public static final PacketType ABILITIES =                    new PacketType(PROTOCOL, SENDER, 0x40, "PlayerAbilities", "Abilities", "SPacketPlayerAbilities");
-            public static final PacketType CHAT =                         new PacketType(PROTOCOL, SENDER, 0x41, "PlayerChat", "Chat", "SPacketChat");
-            public static final PacketType PLAYER_COMBAT_END =            new PacketType(PROTOCOL, SENDER, 0x42, "PlayerCombatEnd");
-            public static final PacketType PLAYER_COMBAT_ENTER =          new PacketType(PROTOCOL, SENDER, 0x43, "PlayerCombatEnter");
-            public static final PacketType PLAYER_COMBAT_KILL =           new PacketType(PROTOCOL, SENDER, 0x44, "PlayerCombatKill");
-            public static final PacketType PLAYER_INFO_REMOVE =           new PacketType(PROTOCOL, SENDER, 0x45, "PlayerInfoRemove");
-            public static final PacketType PLAYER_INFO =                  new PacketType(PROTOCOL, SENDER, 0x46, "PlayerInfoUpdate", "PlayerInfo");
-            public static final PacketType LOOK_AT =                      new PacketType(PROTOCOL, SENDER, 0x47, "PlayerLookAt", "LookAt", "SPacketPlayerPosLook");
-            public static final PacketType POSITION =                     new PacketType(PROTOCOL, SENDER, 0x48, "PlayerPosition", "Position");
-            public static final PacketType PLAYER_ROTATION =              new PacketType(PROTOCOL, SENDER, 0x49, "PlayerRotation");
-            public static final PacketType RECIPE_BOOK_ADD =              new PacketType(PROTOCOL, SENDER, 0x4A, "RecipeBookAdd");
-            public static final PacketType RECIPE_BOOK_REMOVE =           new PacketType(PROTOCOL, SENDER, 0x4B, "RecipeBookRemove");
-            public static final PacketType RECIPE_BOOK_SETTINGS =         new PacketType(PROTOCOL, SENDER, 0x4C, "RecipeBookSettings");
-            public static final PacketType ENTITY_DESTROY =               new PacketType(PROTOCOL, SENDER, 0x4D, "RemoveEntities", "EntityDestroy", "SPacketDestroyEntities");
-            public static final PacketType REMOVE_ENTITY_EFFECT =         new PacketType(PROTOCOL, SENDER, 0x4E, "RemoveMobEffect", "RemoveEntityEffect", "SPacketRemoveEntityEffect");
-            public static final PacketType RESET_SCORE =                  new PacketType(PROTOCOL, SENDER, 0x4F, "ResetScore", "ResetScorePacket");
-            public static final PacketType REMOVE_RESOURCE_PACK =         new PacketType(PROTOCOL, SENDER, 0x50, "ResourcePackPop", "ResourcePackPopPacket");
-            public static final PacketType ADD_RESOURCE_PACK =            new PacketType(PROTOCOL, SENDER, 0x51, "ResourcePackPush", "ResourcePackPushPacket");
-            public static final PacketType RESPAWN =                      new PacketType(PROTOCOL, SENDER, 0x52, "Respawn", "SPacketRespawn");
-            public static final PacketType ENTITY_HEAD_ROTATION =         new PacketType(PROTOCOL, SENDER, 0x53, "RotateHead", "EntityHeadRotation", "SPacketEntityHeadLook");
-            public static final PacketType MULTI_BLOCK_CHANGE =           new PacketType(PROTOCOL, SENDER, 0x54, "SectionBlocksUpdate", "MultiBlockChange", "SPacketMultiBlockChange");
-            public static final PacketType SELECT_ADVANCEMENT_TAB =       new PacketType(PROTOCOL, SENDER, 0x55, "SelectAdvancementsTab", "SelectAdvancementTab", "SPacketSelectAdvancementsTab");
-            public static final PacketType SERVER_DATA =                  new PacketType(PROTOCOL, SENDER, 0x56, "ServerData");
-            public static final PacketType SET_ACTION_BAR_TEXT =          new PacketType(PROTOCOL, SENDER, 0x57, "SetActionBarText");
-            public static final PacketType SET_BORDER_CENTER =            new PacketType(PROTOCOL, SENDER, 0x58, "SetBorderCenter");
-            public static final PacketType SET_BORDER_LERP_SIZE =         new PacketType(PROTOCOL, SENDER, 0x59, "SetBorderLerpSize");
-            public static final PacketType SET_BORDER_SIZE =              new PacketType(PROTOCOL, SENDER, 0x5A, "SetBorderSize");
-            public static final PacketType SET_BORDER_WARNING_DELAY =     new PacketType(PROTOCOL, SENDER, 0x5B, "SetBorderWarningDelay");
-            public static final PacketType SET_BORDER_WARNING_DISTANCE =  new PacketType(PROTOCOL, SENDER, 0x5C, "SetBorderWarningDistance");
-            public static final PacketType CAMERA =                       new PacketType(PROTOCOL, SENDER, 0x5D, "SetCamera", "Camera", "SPacketCamera");
-            public static final PacketType VIEW_CENTRE =                  new PacketType(PROTOCOL, SENDER, 0x5E, "SetChunkCacheCenter", "ViewCentre");
-            public static final PacketType VIEW_DISTANCE =                new PacketType(PROTOCOL, SENDER, 0x5F, "SetChunkCacheRadius", "ViewDistance");
-            public static final PacketType SET_CURSOR_ITEM =              new PacketType(PROTOCOL, SENDER, 0x60, "SetCursorItem");
-            public static final PacketType SPAWN_POSITION =               new PacketType(PROTOCOL, SENDER, 0x61, "SetDefaultSpawnPosition", "SpawnPosition", "SPacketSpawnPosition");
-            public static final PacketType SCOREBOARD_DISPLAY_OBJECTIVE = new PacketType(PROTOCOL, SENDER, 0x62, "SetDisplayObjective", "ScoreboardDisplayObjective", "SPacketDisplayObjective");
-            public static final PacketType ENTITY_METADATA =              new PacketType(PROTOCOL, SENDER, 0x63, "SetEntityData", "EntityMetadata", "SPacketEntityMetadata");
-            public static final PacketType ATTACH_ENTITY =                new PacketType(PROTOCOL, SENDER, 0x64, "SetEntityLink", "AttachEntity", "SPacketEntityAttach");
-            public static final PacketType ENTITY_VELOCITY =              new PacketType(PROTOCOL, SENDER, 0x65, "SetEntityMotion", "EntityVelocity", "SPacketEntityVelocity");
-            public static final PacketType ENTITY_EQUIPMENT =             new PacketType(PROTOCOL, SENDER, 0x66, "SetEquipment", "EntityEquipment", "SPacketEntityEquipment");
-            public static final PacketType EXPERIENCE =                   new PacketType(PROTOCOL, SENDER, 0x67, "SetExperience", "Experience", "SPacketSetExperience");
-            public static final PacketType UPDATE_HEALTH =                new PacketType(PROTOCOL, SENDER, 0x68, "SetHealth", "UpdateHealth", "SPacketUpdateHealth");
-            public static final PacketType HELD_ITEM_SLOT =               new PacketType(PROTOCOL, SENDER, 0x69, "SetHeldSlot", "SetCarriedItem", "HeldItemSlot", "SPacketHeldItemChange");
-            public static final PacketType SCOREBOARD_OBJECTIVE =         new PacketType(PROTOCOL, SENDER, 0x6A, "SetObjective", "ScoreboardObjective", "SPacketScoreboardObjective");
-            public static final PacketType MOUNT =                        new PacketType(PROTOCOL, SENDER, 0x6B, "SetPassengers", "Mount", "SPacketSetPassengers");
-            public static final PacketType SET_PLAYER_INVENTORY =         new PacketType(PROTOCOL, SENDER, 0x6C, "SetPlayerInventory");
-            public static final PacketType SCOREBOARD_TEAM =              new PacketType(PROTOCOL, SENDER, 0x6D, "SetPlayerTeam", "ScoreboardTeam", "SPacketTeams");
-            public static final PacketType SCOREBOARD_SCORE =             new PacketType(PROTOCOL, SENDER, 0x6E, "SetScore", "ScoreboardScore", "SPacketUpdateScore");
-            public static final PacketType UPDATE_SIMULATION_DISTANCE =   new PacketType(PROTOCOL, SENDER, 0x6F, "SetSimulationDistance");
-            public static final PacketType SET_SUBTITLE_TEXT =            new PacketType(PROTOCOL, SENDER, 0x70, "SetSubtitleText");
-            public static final PacketType UPDATE_TIME =                  new PacketType(PROTOCOL, SENDER, 0x71, "SetTime", "UpdateTime", "SPacketTimeUpdate");
-            public static final PacketType SET_TITLE_TEXT =               new PacketType(PROTOCOL, SENDER, 0x72, "SetTitleText");
-            public static final PacketType SET_TITLES_ANIMATION =         new PacketType(PROTOCOL, SENDER, 0x73, "SetTitlesAnimation");
-            public static final PacketType ENTITY_SOUND =                 new PacketType(PROTOCOL, SENDER, 0x74, "SoundEntity", "EntitySound", "SPacketSoundEffect");
-            public static final PacketType NAMED_SOUND_EFFECT =           new PacketType(PROTOCOL, SENDER, 0x75, "Sound", "NamedSoundEffect");
-            public static final PacketType START_CONFIGURATION =          new PacketType(PROTOCOL, SENDER, 0x76, "StartConfiguration");
-            public static final PacketType STOP_SOUND =                   new PacketType(PROTOCOL, SENDER, 0x77, "StopSound");
-            public static final PacketType STORE_COOKIE =                 new PacketType(PROTOCOL, SENDER, 0x78, "StoreCookie");
-            public static final PacketType SYSTEM_CHAT =                  new PacketType(PROTOCOL, SENDER, 0x79, "SystemChat");
-            public static final PacketType PLAYER_LIST_HEADER_FOOTER =    new PacketType(PROTOCOL, SENDER, 0x7A, "TabList", "PlayerListHeaderFooter", "SPacketPlayerListHeaderFooter");
-            public static final PacketType NBT_QUERY =                    new PacketType(PROTOCOL, SENDER, 0x7B, "TagQuery", "NBTQuery");
-            public static final PacketType COLLECT =                      new PacketType(PROTOCOL, SENDER, 0x7C, "TakeItemEntity", "Collect", "SPacketCollectItem");
-            public static final PacketType ENTITY_TELEPORT =              new PacketType(PROTOCOL, SENDER, 0x7D, "TeleportEntity", "EntityTeleport", "SPacketEntityTeleport");
-            public static final PacketType TEST_INSTANCE_BLOCK_STATUS =   new PacketType(PROTOCOL, SENDER, 0x7E, "ClientboundTestInstanceBlockStatus");
-            public static final PacketType TICKING_STATE =                new PacketType(PROTOCOL, SENDER, 0x7F, "TickingState", "TickingStatePacket");
-            public static final PacketType TICKING_STEP_STATE =           new PacketType(PROTOCOL, SENDER, 0x80, "TickingStep", "TickingStepPacket");
-            public static final PacketType TRANSFER =                     new PacketType(PROTOCOL, SENDER, 0x81, "Transfer");
-            public static final PacketType ADVANCEMENTS =                 new PacketType(PROTOCOL, SENDER, 0x82, "UpdateAdvancements", "Advancements", "SPacketAdvancementInfo");
-            public static final PacketType UPDATE_ATTRIBUTES =            new PacketType(PROTOCOL, SENDER, 0x83, "UpdateAttributes", "SPacketEntityProperties");
-            public static final PacketType ENTITY_EFFECT =                new PacketType(PROTOCOL, SENDER, 0x84, "UpdateMobEffect", "EntityEffect", "SPacketEntityEffect");
-            public static final PacketType RECIPE_UPDATE =                new PacketType(PROTOCOL, SENDER, 0x85, "UpdateRecipes", "RecipeUpdate");
-            public static final PacketType TAGS =                         new PacketType(PROTOCOL, SENDER, 0x86, "UpdateTags", "Tags");
-            public static final PacketType PROJECTILE_POWER =             new PacketType(PROTOCOL, SENDER, 0x87, "ProjectilePower");
-            public static final PacketType REPORT_DETAILS =               new PacketType(PROTOCOL, SENDER, 0x88, "CustomReportDetails");
-            public static final PacketType SERVER_LINKS =                 new PacketType(PROTOCOL, SENDER, 0x89, "ServerLinks");
-            public static final PacketType TRACKED_WAYPOINT =             new PacketType(PROTOCOL, SENDER, 0x8A, "TrackedWaypoint");
-            public static final PacketType CLEAR_DIALOG =                 new PacketType(PROTOCOL, SENDER, 0x8B, "ClearDialog");
-            public static final PacketType SHOW_DIALOG =                  new PacketType(PROTOCOL, SENDER, 0x8C, "ShowDialog");
+            public static final PacketType ADD_TRANSIENT_BLOCK =          new PacketType(PROTOCOL, SENDER, 0x25, MinecraftVersion.v26_3, "AddTransientBlock");
+            public static final PacketType UNLOAD_CHUNK =                 new PacketType(PROTOCOL, SENDER, 0x26, MinecraftVersion.v26_3, "ForgetLevelChunk", "UnloadChunk", "SPacketUnloadChunk");
+            public static final PacketType GAME_STATE_CHANGE =            new PacketType(PROTOCOL, SENDER, 0x27, MinecraftVersion.v26_3, "GameEvent", "GameStateChange", "SPacketChangeGameState");
+            public static final PacketType GAME_RULE_VALUES =             new PacketType(PROTOCOL, SENDER, 0x28, MinecraftVersion.v26_3, "GameRuleValues");
+            public static final PacketType GAME_TEST_HIGHLIGHT_POS =      new PacketType(PROTOCOL, SENDER, 0x29, MinecraftVersion.v26_3, "GameTestHighlightPos");
+            public static final PacketType OPEN_WINDOW_HORSE =            new PacketType(PROTOCOL, SENDER, 0x2A, MinecraftVersion.v26_3, "MountScreenOpen", "HorseScreenOpen", "OpenWindowHorse");
+            public static final PacketType HURT_ANIMATION =               new PacketType(PROTOCOL, SENDER, 0x2B, MinecraftVersion.v26_3, "HurtAnimation", "ClientboundHurtAnimationPacket");
+            public static final PacketType INITIALIZE_BORDER =            new PacketType(PROTOCOL, SENDER, 0x2C, MinecraftVersion.v26_3, "InitializeBorder");
+            public static final PacketType KEEP_ALIVE =                   new PacketType(PROTOCOL, SENDER, 0x2D, MinecraftVersion.v26_3, "KeepAlive", "SPacketKeepAlive");
+            public static final PacketType MAP_CHUNK =                    new PacketType(PROTOCOL, SENDER, 0x2E, MinecraftVersion.v26_3, "LevelChunkWithLight", "MapChunk", "SPacketChunkData");
+            public static final PacketType WORLD_EVENT =                  new PacketType(PROTOCOL, SENDER, 0x2F, MinecraftVersion.v26_3, "LevelEvent", "WorldEvent", "SPacketEffect");
+            public static final PacketType WORLD_PARTICLES =              new PacketType(PROTOCOL, SENDER, 0x30, MinecraftVersion.v26_3, "LevelParticles", "WorldParticles", "SPacketParticles");
+            public static final PacketType LIGHT_UPDATE =                 new PacketType(PROTOCOL, SENDER, 0x31, MinecraftVersion.v26_3, "LightUpdate");
+            public static final PacketType LOGIN =                        new PacketType(PROTOCOL, SENDER, 0x32, MinecraftVersion.v26_3, "Login", "SPacketJoinGame");
+            public static final PacketType LOW_DISK_SPACE_WARNING =       new PacketType(PROTOCOL, SENDER, 0x33, MinecraftVersion.v26_3, "LowDiskSpaceWarning");
+            public static final PacketType MAP =                          new PacketType(PROTOCOL, SENDER, 0x34, MinecraftVersion.v26_3, "MapItemData", "Map", "SPacketMaps");
+            public static final PacketType OPEN_WINDOW_MERCHANT =         new PacketType(PROTOCOL, SENDER, 0x35, MinecraftVersion.v26_3, "MerchantOffers", "OpenWindowMerchant");
+            public static final PacketType REL_ENTITY_MOVE =              new PacketType(PROTOCOL, SENDER, 0x36, MinecraftVersion.v26_3, "net.minecraft.network.protocol.game.ClientboundMoveEntityPacket$Pos", "Entity$RelEntityMove", "Entity$PacketPlayOutRelEntityMove");
+            public static final PacketType REL_ENTITY_MOVE_LOOK =         new PacketType(PROTOCOL, SENDER, 0x37, MinecraftVersion.v26_3, "net.minecraft.network.protocol.game.ClientboundMoveEntityPacket$PosRot", "Entity$RelEntityMoveLook", "Entity$PacketPlayOutRelEntityMoveLook");
+            public static final PacketType MOVE_MINECART =                new PacketType(PROTOCOL, SENDER, 0x38, MinecraftVersion.v26_3, "MoveMinecart");
+            public static final PacketType ENTITY_LOOK =                  new PacketType(PROTOCOL, SENDER, 0x39, MinecraftVersion.v26_3, "net.minecraft.network.protocol.game.ClientboundMoveEntityPacket$Rot", "Entity$EntityLook", "Entity$PacketPlayOutEntityLook");
+            public static final PacketType VEHICLE_MOVE =                 new PacketType(PROTOCOL, SENDER, 0x3A, MinecraftVersion.v26_3, "MoveVehicle", "VehicleMove", "SPacketMoveVehicle");
+            public static final PacketType OPEN_BOOK =                    new PacketType(PROTOCOL, SENDER, 0x3B, MinecraftVersion.v26_3, "OpenBook");
+            public static final PacketType OPEN_WINDOW =                  new PacketType(PROTOCOL, SENDER, 0x3C, MinecraftVersion.v26_3, "OpenScreen", "OpenWindow", "SPacketOpenWindow");
+            public static final PacketType OPEN_SIGN_EDITOR =             new PacketType(PROTOCOL, SENDER, 0x3D, MinecraftVersion.v26_3, "OpenSignEditor", "SPacketSignEditorOpen");
+            public static final PacketType PING =                         new PacketType(PROTOCOL, SENDER, 0x3E, MinecraftVersion.v26_3, "Ping");
+            public static final PacketType PONG_RESPONSE =                new PacketType(PROTOCOL, SENDER, 0x3F, MinecraftVersion.v26_3, "PongResponse");
+            public static final PacketType AUTO_RECIPE =                  new PacketType(PROTOCOL, SENDER, 0x40, MinecraftVersion.v26_3, "PlaceGhostRecipe", "AutoRecipe", "SPacketPlaceGhostRecipe");
+            public static final PacketType ABILITIES =                    new PacketType(PROTOCOL, SENDER, 0x41, MinecraftVersion.v26_3, "PlayerAbilities", "Abilities", "SPacketPlayerAbilities");
+            public static final PacketType CHAT =                         new PacketType(PROTOCOL, SENDER, 0x42, MinecraftVersion.v26_3, "PlayerChat", "Chat", "SPacketChat");
+            public static final PacketType PLAYER_COMBAT_END =            new PacketType(PROTOCOL, SENDER, 0x43, MinecraftVersion.v26_3, "PlayerCombatEnd");
+            public static final PacketType PLAYER_COMBAT_ENTER =          new PacketType(PROTOCOL, SENDER, 0x44, MinecraftVersion.v26_3, "PlayerCombatEnter");
+            public static final PacketType PLAYER_COMBAT_KILL =           new PacketType(PROTOCOL, SENDER, 0x45, MinecraftVersion.v26_3, "PlayerCombatKill");
+            public static final PacketType PLAYER_INFO_REMOVE =           new PacketType(PROTOCOL, SENDER, 0x46, MinecraftVersion.v26_3, "PlayerInfoRemove");
+            public static final PacketType PLAYER_INFO =                  new PacketType(PROTOCOL, SENDER, 0x47, MinecraftVersion.v26_3, "PlayerInfoUpdate", "PlayerInfo");
+            public static final PacketType LOOK_AT =                      new PacketType(PROTOCOL, SENDER, 0x48, MinecraftVersion.v26_3, "PlayerLookAt", "LookAt", "SPacketPlayerPosLook");
+            public static final PacketType POSITION =                     new PacketType(PROTOCOL, SENDER, 0x49, MinecraftVersion.v26_3, "PlayerPosition", "Position");
+            public static final PacketType PLAYER_ROTATION =              new PacketType(PROTOCOL, SENDER, 0x4A, MinecraftVersion.v26_3, "PlayerRotation");
+            public static final PacketType RECIPE_BOOK_ADD =              new PacketType(PROTOCOL, SENDER, 0x4B, MinecraftVersion.v26_3, "RecipeBookAdd");
+            public static final PacketType RECIPE_BOOK_REMOVE =           new PacketType(PROTOCOL, SENDER, 0x4C, MinecraftVersion.v26_3, "RecipeBookRemove");
+            public static final PacketType RECIPE_BOOK_SETTINGS =         new PacketType(PROTOCOL, SENDER, 0x4D, MinecraftVersion.v26_3, "RecipeBookSettings");
+            public static final PacketType ENTITY_DESTROY =               new PacketType(PROTOCOL, SENDER, 0x4E, MinecraftVersion.v26_3, "RemoveEntities", "EntityDestroy", "SPacketDestroyEntities");
+            public static final PacketType REMOVE_ENTITY_EFFECT =         new PacketType(PROTOCOL, SENDER, 0x4F, MinecraftVersion.v26_3, "RemoveMobEffect", "RemoveEntityEffect", "SPacketRemoveEntityEffect");
+            public static final PacketType RESET_SCORE =                  new PacketType(PROTOCOL, SENDER, 0x50, MinecraftVersion.v26_3, "ResetScore", "ResetScorePacket");
+            public static final PacketType REMOVE_RESOURCE_PACK =         new PacketType(PROTOCOL, SENDER, 0x51, MinecraftVersion.v26_3, "ResourcePackPop", "ResourcePackPopPacket");
+            public static final PacketType ADD_RESOURCE_PACK =            new PacketType(PROTOCOL, SENDER, 0x52, MinecraftVersion.v26_3, "ResourcePackPush", "ResourcePackPushPacket");
+            public static final PacketType POST_EFFECTS =                 new PacketType(PROTOCOL, SENDER, 0x53, MinecraftVersion.v26_3, "PostEffects");
+            public static final PacketType RESPAWN =                      new PacketType(PROTOCOL, SENDER, 0x54, MinecraftVersion.v26_3, "Respawn", "SPacketRespawn");
+            public static final PacketType ENTITY_HEAD_ROTATION =         new PacketType(PROTOCOL, SENDER, 0x55, MinecraftVersion.v26_3, "RotateHead", "EntityHeadRotation", "SPacketEntityHeadLook");
+            public static final PacketType MULTI_BLOCK_CHANGE =           new PacketType(PROTOCOL, SENDER, 0x56, MinecraftVersion.v26_3, "SectionBlocksUpdate", "MultiBlockChange", "SPacketMultiBlockChange");
+            public static final PacketType SELECT_ADVANCEMENT_TAB =       new PacketType(PROTOCOL, SENDER, 0x57, MinecraftVersion.v26_3, "SelectAdvancementsTab", "SelectAdvancementTab", "SPacketSelectAdvancementsTab");
+            public static final PacketType SERVER_DATA =                  new PacketType(PROTOCOL, SENDER, 0x58, MinecraftVersion.v26_3, "ServerData");
+            public static final PacketType SET_ACTION_BAR_TEXT =          new PacketType(PROTOCOL, SENDER, 0x59, MinecraftVersion.v26_3, "SetActionBarText");
+            public static final PacketType SET_BORDER_CENTER =            new PacketType(PROTOCOL, SENDER, 0x5A, MinecraftVersion.v26_3, "SetBorderCenter");
+            public static final PacketType SET_BORDER_LERP_SIZE =         new PacketType(PROTOCOL, SENDER, 0x5B, MinecraftVersion.v26_3, "SetBorderLerpSize");
+            public static final PacketType SET_BORDER_SIZE =              new PacketType(PROTOCOL, SENDER, 0x5C, MinecraftVersion.v26_3, "SetBorderSize");
+            public static final PacketType SET_BORDER_WARNING_DELAY =     new PacketType(PROTOCOL, SENDER, 0x5D, MinecraftVersion.v26_3, "SetBorderWarningDelay");
+            public static final PacketType SET_BORDER_WARNING_DISTANCE =  new PacketType(PROTOCOL, SENDER, 0x5E, MinecraftVersion.v26_3, "SetBorderWarningDistance");
+            public static final PacketType CAMERA =                       new PacketType(PROTOCOL, SENDER, 0x5F, MinecraftVersion.v26_3, "SetCamera", "Camera", "SPacketCamera");
+            public static final PacketType VIEW_CENTRE =                  new PacketType(PROTOCOL, SENDER, 0x60, MinecraftVersion.v26_3, "SetChunkCacheCenter", "ViewCentre");
+            public static final PacketType VIEW_DISTANCE =                new PacketType(PROTOCOL, SENDER, 0x61, MinecraftVersion.v26_3, "SetChunkCacheRadius", "ViewDistance");
+            public static final PacketType SET_CURSOR_ITEM =              new PacketType(PROTOCOL, SENDER, 0x62, MinecraftVersion.v26_3, "SetCursorItem");
+            public static final PacketType SPAWN_POSITION =               new PacketType(PROTOCOL, SENDER, 0x63, MinecraftVersion.v26_3, "SetDefaultSpawnPosition", "SpawnPosition", "SPacketSpawnPosition");
+            public static final PacketType SCOREBOARD_DISPLAY_OBJECTIVE = new PacketType(PROTOCOL, SENDER, 0x64, MinecraftVersion.v26_3, "SetDisplayObjective", "ScoreboardDisplayObjective", "SPacketDisplayObjective");
+            public static final PacketType ENTITY_METADATA =              new PacketType(PROTOCOL, SENDER, 0x65, MinecraftVersion.v26_3, "SetEntityData", "EntityMetadata", "SPacketEntityMetadata");
+            public static final PacketType ATTACH_ENTITY =                new PacketType(PROTOCOL, SENDER, 0x66, MinecraftVersion.v26_3, "SetEntityLink", "AttachEntity", "SPacketEntityAttach");
+            public static final PacketType ENTITY_VELOCITY =              new PacketType(PROTOCOL, SENDER, 0x67, MinecraftVersion.v26_3, "SetEntityMotion", "EntityVelocity", "SPacketEntityVelocity");
+            public static final PacketType ENTITY_EQUIPMENT =             new PacketType(PROTOCOL, SENDER, 0x68, MinecraftVersion.v26_3, "SetEquipment", "EntityEquipment", "SPacketEntityEquipment");
+            public static final PacketType EXPERIENCE =                   new PacketType(PROTOCOL, SENDER, 0x69, MinecraftVersion.v26_3, "SetExperience", "Experience", "SPacketSetExperience");
+            public static final PacketType UPDATE_HEALTH =                new PacketType(PROTOCOL, SENDER, 0x6A, MinecraftVersion.v26_3, "SetHealth", "UpdateHealth", "SPacketUpdateHealth");
+            public static final PacketType HELD_ITEM_SLOT =               new PacketType(PROTOCOL, SENDER, 0x6B, MinecraftVersion.v26_3, "SetHeldSlot", "SetCarriedItem", "HeldItemSlot", "SPacketHeldItemChange");
+            public static final PacketType SCOREBOARD_OBJECTIVE =         new PacketType(PROTOCOL, SENDER, 0x6C, MinecraftVersion.v26_3, "SetObjective", "ScoreboardObjective", "SPacketScoreboardObjective");
+            public static final PacketType MOUNT =                        new PacketType(PROTOCOL, SENDER, 0x6D, MinecraftVersion.v26_3, "SetPassengers", "Mount", "SPacketSetPassengers");
+            public static final PacketType SET_PLAYER_INVENTORY =         new PacketType(PROTOCOL, SENDER, 0x6E, MinecraftVersion.v26_3, "SetPlayerInventory");
+            public static final PacketType SCOREBOARD_TEAM =              new PacketType(PROTOCOL, SENDER, 0x6F, MinecraftVersion.v26_3, "SetPlayerTeam", "ScoreboardTeam", "SPacketTeams");
+            public static final PacketType SCOREBOARD_SCORE =             new PacketType(PROTOCOL, SENDER, 0x70, MinecraftVersion.v26_3, "SetScore", "ScoreboardScore", "SPacketUpdateScore");
+            public static final PacketType UPDATE_SIMULATION_DISTANCE =   new PacketType(PROTOCOL, SENDER, 0x71, MinecraftVersion.v26_3, "SetSimulationDistance");
+            public static final PacketType SET_SUBTITLE_TEXT =            new PacketType(PROTOCOL, SENDER, 0x72, MinecraftVersion.v26_3, "SetSubtitleText");
+            public static final PacketType UPDATE_TIME =                  new PacketType(PROTOCOL, SENDER, 0x73, MinecraftVersion.v26_3, "SetTime", "UpdateTime", "SPacketTimeUpdate");
+            public static final PacketType SET_TITLE_TEXT =               new PacketType(PROTOCOL, SENDER, 0x74, MinecraftVersion.v26_3, "SetTitleText");
+            public static final PacketType SET_TITLES_ANIMATION =         new PacketType(PROTOCOL, SENDER, 0x75, MinecraftVersion.v26_3, "SetTitlesAnimation");
+            public static final PacketType ENTITY_SOUND =                 new PacketType(PROTOCOL, SENDER, 0x76, MinecraftVersion.v26_3, "SoundEntity", "EntitySound", "SPacketSoundEffect");
+            public static final PacketType NAMED_SOUND_EFFECT =           new PacketType(PROTOCOL, SENDER, 0x77, MinecraftVersion.v26_3, "Sound", "NamedSoundEffect");
+            public static final PacketType START_CONFIGURATION =          new PacketType(PROTOCOL, SENDER, 0x78, MinecraftVersion.v26_3, "StartConfiguration");
+            public static final PacketType STOP_SOUND =                   new PacketType(PROTOCOL, SENDER, 0x79, MinecraftVersion.v26_3, "StopSound");
+            public static final PacketType STORE_COOKIE =                 new PacketType(PROTOCOL, SENDER, 0x7A, MinecraftVersion.v26_3, "StoreCookie");
+            public static final PacketType SWING_ANIMATION =              new PacketType(PROTOCOL, SENDER, 0x7B, MinecraftVersion.v26_3, "SwingAnimation");
+            public static final PacketType SYSTEM_CHAT =                  new PacketType(PROTOCOL, SENDER, 0x7C, MinecraftVersion.v26_3, "SystemChat");
+            public static final PacketType PLAYER_LIST_HEADER_FOOTER =    new PacketType(PROTOCOL, SENDER, 0x7D, MinecraftVersion.v26_3, "TabList", "PlayerListHeaderFooter", "SPacketPlayerListHeaderFooter");
+            public static final PacketType NBT_QUERY =                    new PacketType(PROTOCOL, SENDER, 0x7E, MinecraftVersion.v26_3, "TagQuery", "NBTQuery");
+            public static final PacketType COLLECT =                      new PacketType(PROTOCOL, SENDER, 0x7F, MinecraftVersion.v26_3, "TakeItemEntity", "Collect", "SPacketCollectItem");
+            public static final PacketType ENTITY_TELEPORT =              new PacketType(PROTOCOL, SENDER, 0x80, MinecraftVersion.v26_3, "TeleportEntity", "EntityTeleport", "SPacketEntityTeleport");
+            public static final PacketType TEST_INSTANCE_BLOCK_STATUS =   new PacketType(PROTOCOL, SENDER, 0x81, MinecraftVersion.v26_3, "ClientboundTestInstanceBlockStatus");
+            public static final PacketType TICKING_STATE =                new PacketType(PROTOCOL, SENDER, 0x82, MinecraftVersion.v26_3, "TickingState", "TickingStatePacket");
+            public static final PacketType TICKING_STEP_STATE =           new PacketType(PROTOCOL, SENDER, 0x83, MinecraftVersion.v26_3, "TickingStep", "TickingStepPacket");
+            public static final PacketType TRANSFER =                     new PacketType(PROTOCOL, SENDER, 0x84, MinecraftVersion.v26_3, "Transfer");
+            public static final PacketType ADVANCEMENTS =                 new PacketType(PROTOCOL, SENDER, 0x85, MinecraftVersion.v26_3, "UpdateAdvancements", "Advancements", "SPacketAdvancementInfo");
+            public static final PacketType UPDATE_ATTRIBUTES =            new PacketType(PROTOCOL, SENDER, 0x86, MinecraftVersion.v26_3, "UpdateAttributes", "SPacketEntityProperties");
+            public static final PacketType ENTITY_EFFECT =                new PacketType(PROTOCOL, SENDER, 0x87, MinecraftVersion.v26_3, "UpdateMobEffect", "EntityEffect", "SPacketEntityEffect");
+            public static final PacketType RECIPE_UPDATE =                new PacketType(PROTOCOL, SENDER, 0x88, MinecraftVersion.v26_3, "UpdateRecipes", "RecipeUpdate");
+            public static final PacketType TAGS =                         new PacketType(PROTOCOL, SENDER, 0x89, MinecraftVersion.v26_3, "UpdateTags", "Tags");
+            public static final PacketType PROJECTILE_POWER =             new PacketType(PROTOCOL, SENDER, 0x8A, MinecraftVersion.v26_3, "ProjectilePower");
+            public static final PacketType REPORT_DETAILS =               new PacketType(PROTOCOL, SENDER, 0x8B, MinecraftVersion.v26_3, "CustomReportDetails");
+            public static final PacketType SERVER_LINKS =                 new PacketType(PROTOCOL, SENDER, 0x8C, MinecraftVersion.v26_3, "ServerLinks");
+            public static final PacketType TRACKED_WAYPOINT =             new PacketType(PROTOCOL, SENDER, 0x8D, MinecraftVersion.v26_3, "TrackedWaypoint");
+            public static final PacketType CLEAR_DIALOG =                 new PacketType(PROTOCOL, SENDER, 0x8E, MinecraftVersion.v26_3, "ClearDialog");
+            public static final PacketType SHOW_DIALOG =                  new PacketType(PROTOCOL, SENDER, 0x8F, MinecraftVersion.v26_3, "ShowDialog");
 
             /**
              * @deprecated Removed in 1.9
@@ -490,24 +493,24 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
             public static final PacketType STEER_VEHICLE =                new PacketType(PROTOCOL, SENDER, 0x2B, "PlayerInput", "SteerVehicle", "CPacketInput");
             public static final PacketType PLAYER_LOADED =                new PacketType(PROTOCOL, SENDER, 0x2C, "PlayerLoaded");
             public static final PacketType PONG =                         new PacketType(PROTOCOL, SENDER, 0x2D, "Pong");
-            public static final PacketType RECIPE_SETTINGS =              new PacketType(PROTOCOL, SENDER, 0x2E, "RecipeBookChangeSettings", "RecipeSettings");
-            public static final PacketType RECIPE_DISPLAYED =             new PacketType(PROTOCOL, SENDER, 0x2F, "RecipeBookSeenRecipe", "RecipeDisplayed", "CPacketRecipeInfo");
-            public static final PacketType ITEM_NAME =                    new PacketType(PROTOCOL, SENDER, 0x30, "RenameItem", "ItemName");
-            public static final PacketType RESOURCE_PACK_STATUS =         new PacketType(PROTOCOL, SENDER, 0x31, "ResourcePack", "ResourcePackStatus", "CPacketResourcePackStatus");
-            public static final PacketType ADVANCEMENTS =                 new PacketType(PROTOCOL, SENDER, 0x32, "SeenAdvancements", "Advancements", "CPacketSeenAdvancements");
-            public static final PacketType TR_SEL =                       new PacketType(PROTOCOL, SENDER, 0x33, "SelectTrade", "TrSel");
-            public static final PacketType BEACON =                       new PacketType(PROTOCOL, SENDER, 0x34, "SetBeacon", "Beacon");
-            public static final PacketType HELD_ITEM_SLOT =               new PacketType(PROTOCOL, SENDER, 0x35, "SetCarriedItem", "HeldItemSlot", "CPacketHeldItemChange");
-            public static final PacketType SET_COMMAND_BLOCK =            new PacketType(PROTOCOL, SENDER, 0x36, "SetCommandBlock");
-            public static final PacketType SET_COMMAND_MINECART =         new PacketType(PROTOCOL, SENDER, 0x37, "SetCommandMinecart");
-            public static final PacketType SET_CREATIVE_SLOT =            new PacketType(PROTOCOL, SENDER, 0x38, "SetCreativeModeSlot", "SetCreativeSlot", "CPacketCreativeInventoryAction");
-            public static final PacketType SET_GAME_RULE =                new PacketType(PROTOCOL, SENDER, 0x39, "SetGameRule");
-            public static final PacketType SET_JIGSAW =                   new PacketType(PROTOCOL, SENDER, 0x3A, "SetJigsawBlock", "SetJigsaw");
-            public static final PacketType STRUCT =                       new PacketType(PROTOCOL, SENDER, 0x3B, "SetStructureBlock", "Struct");
-            public static final PacketType SET_TEST_BLOCK =               new PacketType(PROTOCOL, SENDER, 0x3C, "SetTestBlock");
-            public static final PacketType UPDATE_SIGN =                  new PacketType(PROTOCOL, SENDER, 0x3D, "SignUpdate", "UpdateSign", "CPacketUpdateSign");
-            public static final PacketType SPECTATE_ENTITY =              new PacketType(PROTOCOL, SENDER, 0x3E, "SpectatorAction", "SpectateEntity");
-            public static final PacketType ARM_ANIMATION =                new PacketType(PROTOCOL, SENDER, 0x3F, "Swing", "ArmAnimation", "CPacketAnimation");
+            public static final PacketType PUNCH =                        new PacketType(PROTOCOL, SENDER, 0x2E, MinecraftVersion.v26_3, "Punch");
+            public static final PacketType RECIPE_SETTINGS =              new PacketType(PROTOCOL, SENDER, 0x2F, MinecraftVersion.v26_3, "RecipeBookChangeSettings", "RecipeSettings");
+            public static final PacketType RECIPE_DISPLAYED =             new PacketType(PROTOCOL, SENDER, 0x30, MinecraftVersion.v26_3, "RecipeBookSeenRecipe", "RecipeDisplayed", "CPacketRecipeInfo");
+            public static final PacketType ITEM_NAME =                    new PacketType(PROTOCOL, SENDER, 0x31, MinecraftVersion.v26_3, "RenameItem", "ItemName");
+            public static final PacketType RESOURCE_PACK_STATUS =         new PacketType(PROTOCOL, SENDER, 0x32, MinecraftVersion.v26_3, "ResourcePack", "ResourcePackStatus", "CPacketResourcePackStatus");
+            public static final PacketType ADVANCEMENTS =                 new PacketType(PROTOCOL, SENDER, 0x33, MinecraftVersion.v26_3, "SeenAdvancements", "Advancements", "CPacketSeenAdvancements");
+            public static final PacketType TR_SEL =                       new PacketType(PROTOCOL, SENDER, 0x34, MinecraftVersion.v26_3, "SelectTrade", "TrSel");
+            public static final PacketType BEACON =                       new PacketType(PROTOCOL, SENDER, 0x35, MinecraftVersion.v26_3, "SetBeacon", "Beacon");
+            public static final PacketType HELD_ITEM_SLOT =               new PacketType(PROTOCOL, SENDER, 0x36, MinecraftVersion.v26_3, "SetCarriedItem", "HeldItemSlot", "CPacketHeldItemChange");
+            public static final PacketType SET_COMMAND_BLOCK =            new PacketType(PROTOCOL, SENDER, 0x37, MinecraftVersion.v26_3, "SetCommandBlock");
+            public static final PacketType SET_COMMAND_MINECART =         new PacketType(PROTOCOL, SENDER, 0x38, MinecraftVersion.v26_3, "SetCommandMinecart");
+            public static final PacketType SET_CREATIVE_SLOT =            new PacketType(PROTOCOL, SENDER, 0x39, MinecraftVersion.v26_3, "SetCreativeModeSlot", "SetCreativeSlot", "CPacketCreativeInventoryAction");
+            public static final PacketType SET_GAME_RULE =                new PacketType(PROTOCOL, SENDER, 0x3A, MinecraftVersion.v26_3, "SetGameRule");
+            public static final PacketType SET_JIGSAW =                   new PacketType(PROTOCOL, SENDER, 0x3B, MinecraftVersion.v26_3, "SetJigsawBlock", "SetJigsaw");
+            public static final PacketType STRUCT =                       new PacketType(PROTOCOL, SENDER, 0x3C, MinecraftVersion.v26_3, "SetStructureBlock", "Struct");
+            public static final PacketType SET_TEST_BLOCK =               new PacketType(PROTOCOL, SENDER, 0x3D, MinecraftVersion.v26_3, "SetTestBlock");
+            public static final PacketType UPDATE_SIGN =                  new PacketType(PROTOCOL, SENDER, 0x3E, MinecraftVersion.v26_3, "SignUpdate", "UpdateSign", "CPacketUpdateSign");
+            public static final PacketType SPECTATE_ENTITY =              new PacketType(PROTOCOL, SENDER, 0x3F, MinecraftVersion.v26_3, "SpectatorAction", "SpectateEntity");
             public static final PacketType SPECTATE =                     new PacketType(PROTOCOL, SENDER, 0x40, "TeleportToEntity", "Spectate", "CPacketSpectate");
             public static final PacketType TEST_INSTANCE_BLOCK_ACTION =   new PacketType(PROTOCOL, SENDER, 0x41, "TestInstanceBlockAction");
             public static final PacketType USE_ITEM_ON =                  new PacketType(PROTOCOL, SENDER, 0x42, "UseItemOn", "BlockPlace", "CPacketPlayerTryUseItemOnBlock");
@@ -538,6 +541,12 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
             @Deprecated
             public static final PacketType DEBUG_SAMPLE_SUBSCRIPTION =    new PacketType(PROTOCOL, SENDER, 0x16, "DebugSampleSubscription");
 
+            /**
+             * @deprecated Removed in 26.3
+             */
+            @Deprecated
+            public static final PacketType ARM_ANIMATION =                new PacketType(PROTOCOL, SENDER, 252, "Swing", "ArmAnimation", "CPacketAnimation");
+
             /**
              * @deprecated Renamed to USE_ITEM_ON
              */
@@ -719,16 +728,17 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
             public static final PacketType REGISTRY_DATA =                new PacketType(PROTOCOL, SENDER, 0x07, "RegistryData");
             public static final PacketType REMOVE_RESOURCE_PACK =         new PacketType(PROTOCOL, SENDER, 0x08, "ResourcePackPop");
             public static final PacketType ADD_RESOURCE_PACK =            new PacketType(PROTOCOL, SENDER, 0x09, "ResourcePackPush");
-            public static final PacketType STORE_COOKIE =                 new PacketType(PROTOCOL, SENDER, 0x0A, "StoreCookie");
-            public static final PacketType TRANSFER =                     new PacketType(PROTOCOL, SENDER, 0x0B, "Transfer");
-            public static final PacketType UPDATE_ENABLED_FEATURES =      new PacketType(PROTOCOL, SENDER, 0x0C, "UpdateEnabledFeatures");
-            public static final PacketType UPDATE_TAGS =                  new PacketType(PROTOCOL, SENDER, 0x0D, "UpdateTags");
-            public static final PacketType SELECT_KNOWN_PACKS =           new PacketType(PROTOCOL, SENDER, 0x0E, "ClientboundSelectKnownPacks");
-            public static final PacketType REPORT_DETAILS =               new PacketType(PROTOCOL, SENDER, 0x0F, "CustomReportDetails");
-            public static final PacketType SERVER_LINKS =                 new PacketType(PROTOCOL, SENDER, 0x10, "ServerLinks");
-            public static final PacketType CLEAR_DIALOG =                 new PacketType(PROTOCOL, SENDER, 0x11, "ClearDialog");
-            public static final PacketType SHOW_DIALOG =                  new PacketType(PROTOCOL, SENDER, 0x12, "ShowDialog");
-            public static final PacketType CODE_OF_CONDUCT =              new PacketType(PROTOCOL, SENDER, 0x13, "CodeOfConduct");
+            public static final PacketType POST_EFFECTS =                 new PacketType(PROTOCOL, SENDER, 0x0A, "PostEffects");
+            public static final PacketType STORE_COOKIE =                 new PacketType(PROTOCOL, SENDER, 0x0B, "StoreCookie");
+            public static final PacketType TRANSFER =                     new PacketType(PROTOCOL, SENDER, 0x0C, "Transfer");
+            public static final PacketType UPDATE_ENABLED_FEATURES =      new PacketType(PROTOCOL, SENDER, 0x0D, "UpdateEnabledFeatures");
+            public static final PacketType UPDATE_TAGS =                  new PacketType(PROTOCOL, SENDER, 0x0E, "UpdateTags");
+            public static final PacketType SELECT_KNOWN_PACKS =           new PacketType(PROTOCOL, SENDER, 0x0F, "ClientboundSelectKnownPacks");
+            public static final PacketType REPORT_DETAILS =               new PacketType(PROTOCOL, SENDER, 0x10, "CustomReportDetails");
+            public static final PacketType SERVER_LINKS =                 new PacketType(PROTOCOL, SENDER, 0x11, "ServerLinks");
+            public static final PacketType CLEAR_DIALOG =                 new PacketType(PROTOCOL, SENDER, 0x12, "ClearDialog");
+            public static final PacketType SHOW_DIALOG =                  new PacketType(PROTOCOL, SENDER, 0x13, "ShowDialog");
+            public static final PacketType CODE_OF_CONDUCT =              new PacketType(PROTOCOL, SENDER, 0x14, "CodeOfConduct");
 
             /**
              * @deprecated Removed in 1.20.4: replaced with new packets for removing and sending resource packs

src/main/java/com/comphenix/protocol/ProtocolLib.java

@@ -49,10 +49,11 @@ import java.util.logging.Logger;
 
 import org.bukkit.Server;
 import org.bukkit.command.CommandExecutor;
-import org.bukkit.command.PluginCommand;
 import org.bukkit.plugin.PluginManager;
 import org.bukkit.plugin.java.JavaPlugin;
 
+import com.comphenix.protocol.internal.PlatformProvider;
+
 /**
  * The main entry point for ProtocolLib.
  *
@@ -444,14 +445,7 @@ public class ProtocolLib extends JavaPlugin {
                 return;
             }
 
-            PluginCommand command = this.getCommand(name);
-
-            // Try to load the command
-            if (command != null) {
-                command.setExecutor(executor);
-            } else {
-                throw new RuntimeException("plugin.yml might be corrupt.");
-            }
+            PlatformProvider.get().registerCommand(this, name, executor);
         } catch (RuntimeException e) {
             reporter.reportWarning(this,
                     Report.newBuilder(REPORT_CANNOT_REGISTER_COMMAND).messageParam(name, e.getMessage()).error(e));

src/main/java/com/comphenix/protocol/ProtocolLibrary.java

@@ -35,12 +35,12 @@ public class ProtocolLibrary {
     /**
      * The maximum version ProtocolLib has been tested with.
      */
-    public static final String MAXIMUM_MINECRAFT_VERSION = "26.2";
+    public static final String MAXIMUM_MINECRAFT_VERSION = "26.3";
 
     /**
-     * The date (with ISO 8601 or YYYY-MM-DD) when the most recent version (26.2) was released.
+     * The date (with ISO 8601 or YYYY-MM-DD) when the most recent version (26.3) was released.
      */
-    public static final String MINECRAFT_LAST_RELEASE_DATE = "2026-06-16";
+    public static final String MINECRAFT_LAST_RELEASE_DATE = "2026-09-15";
 
     private static Plugin plugin;
     private static ProtocolConfig config;

src/main/java/com/comphenix/protocol/UpdateNotifyRunnable.java

@@ -0,0 +1,69 @@
+/**
+ *  ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
+ *  Copyright (C) 2012 Kristian S. Stangeland
+ *
+ *  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 2 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ *  02111-1307 USA
+ */
+package com.comphenix.protocol;
+
+import org.bukkit.ChatColor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.plugin.Plugin;
+
+import com.comphenix.protocol.updater.Updater;
+
+/**
+ * Callback invoked on the main thread after an asynchronous update check completes.
+ * <p>
+ * Extracted as a top-level class (instead of an anonymous inner class) so that
+ * {@code PaperPluginClassLoader} can always resolve its {@code .class} entry when
+ * {@link org.bukkit.scheduler.BukkitScheduler#runTask} dispatches it back onto the
+ * main server thread — the same pattern used by {@code SpigotUpdateRunnable}.
+ */
+final class UpdateNotifyRunnable implements Runnable {
+
+    private final CommandSender sender;
+    private final boolean command;
+    private final Updater updater;
+    private final ProtocolConfig config;
+    private final Plugin plugin;
+    private final CommandProtocol owner;
+
+    UpdateNotifyRunnable(CommandSender sender, boolean command,
+                         Updater updater, ProtocolConfig config,
+                         Plugin plugin, CommandProtocol owner) {
+        this.sender = sender;
+        this.command = command;
+        this.updater = updater;
+        this.config = config;
+        this.plugin = plugin;
+        this.owner = owner;
+    }
+
+    @Override
+    public void run() {
+        if (command) {
+            sender.sendMessage(ChatColor.YELLOW + "[ProtocolLib] " + updater.getResult());
+            String remoteVersion = updater.getRemoteVersion();
+            if (remoteVersion != null) {
+                sender.sendMessage(ChatColor.YELLOW + "Remote version: " + remoteVersion);
+                sender.sendMessage(ChatColor.YELLOW + "Current version: " + plugin.getDescription().getVersion());
+            }
+        } else if (updater.shouldNotify() || config.isDebug()) {
+            sender.sendMessage(ChatColor.YELLOW + "[ProtocolLib] " + updater.getResult());
+        }
+
+        updater.removeListener(this);
+        owner.updateFinished();
+    }
+}

src/main/java/com/comphenix/protocol/async/AsyncFilterManager.java

@@ -309,12 +309,10 @@ public class AsyncFilterManager implements AsynchronousManager {
 
         asyncMarker.setQueuedSendingIndex(asyncMarker.getNewSendingIndex());
 
-        // The player is only be null when they're logged out,
-        // so this should be a pretty safe check
-        Player player = syncPacket.getPlayer();
-        if (player != null) {
+        PacketSendingQueue sendingQueue = getSendingQueue(syncPacket);
+        if (sendingQueue != null) {
             // Start the process
-            getSendingQueue(syncPacket).enqueue(newEvent);
+            sendingQueue.enqueue(newEvent);
 
             // We know this is occurring on the main thread, so pass TRUE
             getProcessingQueue(syncPacket).enqueue(newEvent, true);
@@ -323,12 +321,12 @@ public class AsyncFilterManager implements AsynchronousManager {
 
     @Override
     public Set<PacketType> getReceivingTypes() {
-        return serverProcessingQueue.keySet();
+        return clientProcessingQueue.keySet();
     }
 
     @Override
     public Set<PacketType> getSendingTypes() {
-        return clientProcessingQueue.keySet();
+        return serverProcessingQueue.keySet();
     }
     
     /**

src/main/java/com/comphenix/protocol/async/PlayerSendingHandler.java

@@ -134,14 +134,18 @@ class PlayerSendingHandler {
      * @return The server or client sending queue the packet belongs to.
      */
     public PacketSendingQueue getSendingQueue(PacketEvent packet, boolean createNew) {
-        QueueContainer queues = playerSendingQueues.get(packet.getPlayer());
+        Player player = packet.getPlayer();
+        if (player == null)
+            return null;
+
+        QueueContainer queues = playerSendingQueues.get(player);
         
         // Safe concurrent initialization
         if (queues == null && createNew) {
             final QueueContainer newContainer = new QueueContainer();
 
             // Attempt to map the queue
-            queues = playerSendingQueues.putIfAbsent(packet.getPlayer(), newContainer);
+            queues = playerSendingQueues.putIfAbsent(player, newContainer);
             
             if (queues == null) {
                 queues = newContainer;

src/main/java/com/comphenix/protocol/collections/IntegerMap.java

@@ -58,6 +58,8 @@ public class IntegerMap<T> {
      * @return The old associated value, or NULL.
      */
     public T remove(int key) {
+        if (key < 0 || key >= array.length) return null;
+
         T old = array[key];
         array[key] = null;
 

src/main/java/com/comphenix/protocol/concurrency/ConcurrentPlayerMap.java

@@ -190,7 +190,8 @@ public class ConcurrentPlayerMap<TValue> extends AbstractMap<Player, TValue> imp
         Preconditions.checkNotNull(player, "player cannot be null");
 
         Object key = keyMethod.apply(player);
-        
+        Preconditions.checkState(key != null, "Unable to derive a key for the player.");
+
         keyLookup.put(key, player);
         return key;
     }

src/main/java/com/comphenix/protocol/events/AbstractStructure.java

@@ -56,6 +56,7 @@ import com.comphenix.protocol.wrappers.WrappedMessageSignature;
 import com.comphenix.protocol.wrappers.WrappedNumberFormat;
 import com.comphenix.protocol.wrappers.WrappedParticle;
 import com.comphenix.protocol.wrappers.WrappedPositionMoveRotation;
+import com.comphenix.protocol.wrappers.WrappedPositionPath;
 import com.comphenix.protocol.wrappers.WrappedProfilePublicKey;
 import com.comphenix.protocol.wrappers.WrappedProfilePublicKey.WrappedProfileKeyData;
 import com.comphenix.protocol.wrappers.WrappedRegistrable;
@@ -65,6 +66,7 @@ import com.comphenix.protocol.wrappers.WrappedSaltedSignature;
 import com.comphenix.protocol.wrappers.WrappedServerPing;
 import com.comphenix.protocol.wrappers.WrappedStatistic;
 import com.comphenix.protocol.wrappers.WrappedTeamParameters;
+import com.comphenix.protocol.wrappers.WrappedVecDelta;
 import com.comphenix.protocol.wrappers.WrappedWatchableObject;
 import com.comphenix.protocol.wrappers.nbt.NbtBase;
 import com.comphenix.protocol.wrappers.nbt.NbtCompound;
@@ -1164,9 +1166,35 @@ public abstract class AbstractStructure {
     }
 
     /**
+     * Since 26.3 the signature fields are optional, an absent signature is read and written as {@code null}.
+     *
      * @return read/writer structure direct access to unsalted signature data for example in chat message (since 1.19.3)
      */
     public StructureModifier<WrappedMessageSignature> getMessageSignatures() {
+        if (MinecraftVersion.v26_3.atOrAbove()) {
+            EquivalentConverter<WrappedMessageSignature> converter = BukkitConverters.getWrappedMessageSignatureConverter();
+            return structureModifier.withParamType(
+                    Optional.class,
+                    new EquivalentConverter<WrappedMessageSignature>() {
+                        @Override
+                        public Object getGeneric(WrappedMessageSignature specific) {
+                            return Optional.ofNullable(converter.getGeneric(specific));
+                        }
+
+                        @Override
+                        public WrappedMessageSignature getSpecific(Object generic) {
+                            return generic == null ? null : ((Optional<?>) generic).map(converter::getSpecific).orElse(null);
+                        }
+
+                        @Override
+                        public Class<WrappedMessageSignature> getSpecificType() {
+                            return WrappedMessageSignature.class;
+                        }
+                    },
+                    MinecraftReflection.getMessageSignatureClass()
+            );
+        }
+
         return structureModifier.withType(
                 MinecraftReflection.getMessageSignatureClass(),
                 BukkitConverters.getWrappedMessageSignatureConverter()
@@ -1299,7 +1327,7 @@ public abstract class AbstractStructure {
     /**
      * Retrieve a read/write structure for {@link WrappedPositionMoveRotation} (available since Minecraft 1.21.2).
      * <p>
-     * This is used in packets such as {@code ENTITY_TELEPORT} and {@code ENTITY_POSITION_SYNC}.
+     * This is used in packets such as {@code ENTITY_TELEPORT} and {@code ENTITY_POSITION_SYNC} (before 26.3).
      *
      * @return A modifier for PositionMoveRotation fields.
      */
@@ -1310,6 +1338,34 @@ public abstract class AbstractStructure {
         );
     }
 
+    /**
+     * Retrieve a read/write structure for {@link WrappedVecDelta} (available since Minecraft 26.3).
+     * <p>
+     * This is used in {@code REL_ENTITY_MOVE} and {@code REL_ENTITY_MOVE_LOOK}.
+     *
+     * @return A modifier for VecDelta fields.
+     */
+    public StructureModifier<WrappedVecDelta> getVecDeltas() {
+        return structureModifier.withType(
+                MinecraftReflection.getVecDeltaClass().orElse(void.class),
+                WrappedVecDelta.getConverter()
+        );
+    }
+
+    /**
+     * Retrieve a read/write structure for {@link WrappedPositionPath} (available since Minecraft 26.3).
+     * <p>
+     * This is used in {@code ENTITY_POSITION_SYNC}.
+     *
+     * @return A modifier for PositionPath fields.
+     */
+    public StructureModifier<WrappedPositionPath> getPositionPaths() {
+        return structureModifier.withType(
+                MinecraftReflection.getPositionPathClass().orElse(void.class),
+                WrappedPositionPath.getConverter()
+        );
+    }
+
     /**
      * Represents an equivalent converter for ItemStack arrays.
      * @author Kristian

src/main/java/com/comphenix/protocol/events/PacketEvent.java

@@ -391,6 +391,8 @@ public class PacketEvent extends EventObject implements Cancellable {
      *     <li>getPlayer</li>
      *     <li>getAddress</li>
      *     <li>getServer</li>
+     *     <li>getName, after the login start packet</li>
+     *     <li>getUniqueId, when supplied by the login protocol</li>
      *     <li>chat</li>
      *     <li>sendMessage</li>
      *     <li>kickPlayer</li>

src/main/java/com/comphenix/protocol/events/SerializedOfflinePlayer.java

@@ -22,8 +22,10 @@ import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Date;
@@ -68,7 +70,7 @@ import org.jetbrains.annotations.Nullable;
  *
  * @author Kristian
  */
-class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
+class SerializedOfflinePlayer implements Serializable {
 
     /**
      * Generated by Eclipse.
@@ -122,22 +124,18 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
         }
     }
 
-    @Override
     public boolean isOp() {
         return operator;
     }
 
-    @Override
     public void setOp(boolean operator) {
         this.operator = operator;
     }
 
-    @Override
     public Map<String, Object> serialize() {
         throw new UnsupportedOperationException();
     }
 
-    @Override
     public Location getBedSpawnLocation() {
         return bedSpawnLocation;
     }
@@ -152,12 +150,10 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
         return lastSeen;
     }
 
-    @Override
     public Location getRespawnLocation() {
         return null;
     }
 
-    @Override
     public Location getLocation() {
         return null;
     }
@@ -221,42 +217,34 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
     public void setStatistic(Statistic statistic, EntityType entityType, int i) {
     }
 
-    @Override
     public Location getLastDeathLocation() {
         return null;
     }
 
-    @Override
     public long getFirstPlayed() {
         return firstPlayed;
     }
 
-    @Override
     public long getLastPlayed() {
         return lastPlayed;
     }
 
-    @Override
     public UUID getUniqueId() {
         return uuid;
     }
 
-    @Override
     public @NotNull PlayerProfile getPlayerProfile() {
         return null;
     }
 
-    @Override
     public String getName() {
         return name;
     }
 
-    @Override
     public boolean hasPlayedBefore() {
         return playedBefore;
     }
 
-    @Override
     public boolean isBanned() {
         return banned;
     }
@@ -283,17 +271,14 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
         this.banned = banned;
     }
 
-    @Override
     public boolean isOnline() {
         return online;
     }
 
-    @Override
     public boolean isWhitelisted() {
         return whitelisted;
     }
 
-    @Override
     public void setWhitelisted(boolean whitelisted) {
         this.whitelisted = whitelisted;
     }
@@ -330,7 +315,6 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
         }
     }
 
-    @Override
     public Player getPlayer() {
         try {
             // Try to get the real player underneath
@@ -349,7 +333,7 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
      */
     public Player getProxyPlayer() {
         try {
-            return (Player) proxyPlayerConstructor.newInstance(this);
+            return (Player) proxyPlayerConstructor.newInstance(this.createOfflinePlayerProxy());
         } catch (IllegalAccessException e) {
             throw new RuntimeException("Cannot access reflection.", e);
         } catch (InstantiationException e) {
@@ -359,6 +343,38 @@ class SerializedOfflinePlayer implements OfflinePlayer, Serializable {
         }
     }
 
+    private OfflinePlayer createOfflinePlayerProxy() {
+        return (OfflinePlayer) Proxy.newProxyInstance(
+                OfflinePlayer.class.getClassLoader(),
+                new Class<?>[]{OfflinePlayer.class},
+                (proxy, method, arguments) -> {
+                    if (method.getDeclaringClass() == Object.class) {
+                        return switch (method.getName()) {
+                            case "equals" -> proxy == arguments[0];
+                            case "hashCode" -> System.identityHashCode(proxy);
+                            case "toString" -> "SerializedOfflinePlayer[" + this.name + "]";
+                            default -> throw new UnsupportedOperationException("Unsupported Object method " + method);
+                        };
+                    }
+
+                    try {
+                        Method target = SerializedOfflinePlayer.class.getMethod(
+                                method.getName(),
+                                method.getParameterTypes());
+                        return target.invoke(this, arguments);
+                    } catch (NoSuchMethodException exception) {
+                        if (method.isDefault()) {
+                            return InvocationHandler.invokeDefault(proxy, method, arguments);
+                        }
+                        throw new UnsupportedOperationException(
+                                "The method " + method.getName() + " is not supported for offline players.",
+                                exception);
+                    } catch (InvocationTargetException exception) {
+                        throw exception.getCause();
+                    }
+                });
+    }
+
     private static Constructor<? extends Player> setupProxyPlayerConstructor() {
         final Method[] offlinePlayerMethods = OfflinePlayer.class.getMethods();
         final String[] methodNames = new String[offlinePlayerMethods.length];

src/main/java/com/comphenix/protocol/injector/PacketFilterManager.java

@@ -426,14 +426,20 @@ public class PacketFilterManager implements ListenerManager, InternalManager {
             this.injected = true;
             this.networkManagerInjector.inject();
 
+            // Paper disables reconfiguration when any PlayerLoginEvent listener is registered.
+            if (!this.networkManagerInjector.isUsingPaperChannelInitializer()) {
+                manager.registerEvents(new Listener() {
+
+                    @EventHandler(priority = EventPriority.LOWEST)
+                    public void handleLogin(PlayerLoginEvent event) {
+                        networkManagerInjector.getInjector(event.getPlayer()).inject();
+                    }
+                }, plugin);
+            }
+
             // all listeners we need, this is a bit messy, but it makes the job correctly
             manager.registerEvents(new Listener() {
 
-                @EventHandler(priority = EventPriority.LOWEST)
-                public void handleLogin(PlayerLoginEvent event) {
-                	networkManagerInjector.getInjector(event.getPlayer()).inject();
-                }
-
                 @EventHandler(priority = EventPriority.LOWEST)
                 public void handleJoin(PlayerJoinEvent event) {
                 	networkManagerInjector.getInjector(event.getPlayer()).inject();

src/main/java/com/comphenix/protocol/injector/StructureCache.java

@@ -35,6 +35,7 @@ import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
+import com.comphenix.protocol.reflect.cloning.ImmutableDetector;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
 import com.comphenix.protocol.reflect.instances.DefaultInstances;
@@ -82,15 +83,26 @@ public class StructureCache {
         return newInstance(packetClass);
     }
 
+    // determineBestCreator can re-enter this cache (legacy 1.8 packet registry), which
+    // ConcurrentHashMap.computeIfAbsent rejects on Java 9+, so use get/put instead.
+    private static Optional<Supplier<Object>> creatorFor(Class<?> clazz) {
+        Optional<Supplier<Object>> creator = CACHED_INSTANCE_CREATORS.get(clazz);
+        if (creator == null) {
+            creator = Optional.ofNullable(determineBestCreator(clazz));
+            Optional<Supplier<Object>> existing = CACHED_INSTANCE_CREATORS.putIfAbsent(clazz, creator);
+            if (existing != null) {
+                creator = existing;
+            }
+        }
+        return creator;
+    }
+
     public static boolean canCreateInstance(Class<?> clazz) {
-        Optional<Supplier<Object>> creator = CACHED_INSTANCE_CREATORS.computeIfAbsent(clazz, x ->
-            Optional.ofNullable(determineBestCreator(clazz)));
-        return creator.isPresent();
+        return creatorFor(clazz).isPresent();
     }
 
     public static Object newInstance(Class<?> clazz) {
-        Optional<Supplier<Object>> creator = CACHED_INSTANCE_CREATORS.computeIfAbsent(clazz, x ->
-            Optional.ofNullable(determineBestCreator(clazz)));
+        Optional<Supplier<Object>> creator = creatorFor(clazz);
         if (!creator.isPresent()) {
             throw new IllegalArgumentException("Cannot create instance of " + clazz);
         }
@@ -98,15 +110,21 @@ public class StructureCache {
     }
 
     static Supplier<Object> determineBestCreator(Class<?> clazz) {
-        // certain packets are singletons which can't really be created
-        if (MinecraftReflection.isPacketClass(clazz)) {
+        boolean packetClass = MinecraftReflection.isPacketClass(clazz);
+        boolean immutableClass = ImmutableDetector.isImmutable(clazz);
+
+        // Certain packets are singletons which can't really be created. Immutable classes may also expose multiple
+        // constant instances as an enum replacement, which should be reused instead of invoking their constructors.
+        if (packetClass || immutableClass) {
             FuzzyReflection fuzzy = FuzzyReflection.fromClass(clazz, false);
             List<Field> singletons = fuzzy.getFieldList(FuzzyFieldContract.newBuilder()
                 .typeExact(clazz)
                 .requireModifier(Modifier.STATIC)
                 .requireModifier(Modifier.PUBLIC)
                 .build());
-            if (singletons.size() == 1) {
+
+            // Preserve the existing packet singleton behavior.
+            if (packetClass && singletons.size() == 1) {
                 FieldAccessor accessor = Accessors.getFieldAccessor(singletons.get(0));
                 try {
                     accessor.get(null);
@@ -114,6 +132,23 @@ public class StructureCache {
                 } catch (Exception ignored) {
                 }
             }
+
+            if (immutableClass) {
+                for (Field singleton : singletons) {
+                    if (!Modifier.isFinal(singleton.getModifiers())) {
+                        continue;
+                    }
+
+                    FieldAccessor accessor = Accessors.getFieldAccessor(singleton);
+                    try {
+                        Object instance = accessor.get(null);
+                        if (instance != null) {
+                            return () -> instance;
+                        }
+                    } catch (Exception ignored) {
+                    }
+                }
+            }
         }
 
         try {
@@ -124,7 +159,10 @@ public class StructureCache {
         } catch (Exception ignored) {
         }
 
-        WrappedStreamCodec streamCodec = PacketRegistry.getStreamCodec(clazz);
+        // stream codecs only exist on 1.20.5+; on legacy versions asking the registry re-enters its own
+        // initialization (createOldRegister builds StructureModifiers, which land back here)
+        WrappedStreamCodec streamCodec = MinecraftVersion.v1_20_5.atOrAbove()
+            ? PacketRegistry.getStreamCodec(clazz) : null;
 
         // use the new stream codec for versions above 1.20.5 if possible
         if (streamCodec != null && tryInitTrickDataSerializer()) {

src/main/java/com/comphenix/protocol/injector/collection/OutboundPacketListenerSet.java

@@ -13,6 +13,7 @@ import com.comphenix.protocol.events.ListeningWhitelist;
 import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.events.PacketEvent;
 import com.comphenix.protocol.events.PacketListener;
+import com.comphenix.protocol.wrappers.Converters;
 
 public class OutboundPacketListenerSet extends PacketListenerSet {
 
@@ -31,36 +32,42 @@ public class OutboundPacketListenerSet extends PacketListenerSet {
 
         if (event.getPacketType() == PacketType.Play.Server.BUNDLE && !event.isCancelled()) {
             // unpack the bundle and invoke for each packet in the bundle
-            Iterable<PacketContainer> packets = event.getPacket().getPacketBundles().read(0);
-            List<PacketContainer> outPackets = new ArrayList<>();
-            for (PacketContainer subPacket : packets) {
-                // ignore null packets as the will throw an error in the packet encoder
-                if (subPacket == null) {
-                    continue;
+            List<PacketContainer> packets = Converters.toList(event.getPacket().getPacketBundles().read(0));
+            // lazily allocated when the first packet is removed or replaced
+            List<PacketContainer> outPackets = null;
+            for (int index = 0; index < packets.size(); index++) {
+                PacketContainer subPacket = packets.get(index);
+                PacketContainer packet = null;
+
+                if (subPacket != null) {
+                    PacketEvent subPacketEvent = PacketEvent.fromServer(this, subPacket, event.getNetworkMarker(),
+                            event.getPlayer(), event.isFiltered(), event);
+                    super.invoke(subPacketEvent, priorityFilter);
+
+                    if (!subPacketEvent.isCancelled()) {
+                        PacketContainer result = subPacketEvent.getPacket();
+                        if (result != null && result.getHandle() != null) {
+                            packet = result;
+                        }
+                    }
                 }
 
-                PacketEvent subPacketEvent = PacketEvent.fromServer(this, subPacket, event.getNetworkMarker(),
-                        event.getPlayer());
-                super.invoke(subPacketEvent, priorityFilter);
-
-                
-                // if the packet has been cancelled, the packet will not be add to the bundle
-                if (subPacketEvent.isCancelled()) {
-                    continue;
+                boolean changed = packet == null || packet.getHandle() != subPacket.getHandle();
+                if (outPackets == null && changed) {
+                    outPackets = new ArrayList<>(packets.size());
+                    outPackets.addAll(packets.subList(0, index));
                 }
-
-                PacketContainer packet = subPacketEvent.getPacket();
-                if (packet == null || packet.getHandle() == null) {
-                    // super.invoke() should prevent us from getting new null packet so we just ignore it here
-                    continue;
-                } else {
+                if (outPackets != null && packet != null) {
                     outPackets.add(packet);
                 }
             }
 
-            if (!event.isReadOnly()) {
-                if (packets.iterator().hasNext()) {
-                    event.getPacket().getPacketBundles().write(0, outPackets);
+            if (!event.isReadOnly() && outPackets != null) {
+                if (!outPackets.isEmpty()) {
+                    // the original bundle may be shared between multiple recipients
+                    PacketContainer bundle = event.getPacket().shallowClone();
+                    bundle.getPacketBundles().write(0, outPackets);
+                    event.setPacket(bundle);
                 } else {
                     // cancel entire packet if each individual packet has been cancelled
                     event.setCancelled(true);

src/main/java/com/comphenix/protocol/injector/netty/Injector.java

@@ -1,6 +1,7 @@
 package com.comphenix.protocol.injector.netty;
 
 import java.net.SocketAddress;
+import java.util.UUID;
 
 import org.bukkit.entity.Player;
 
@@ -67,6 +68,24 @@ public interface Injector {
      */
     Player getPlayer();
 
+    /**
+     * Retrieve the player name captured during login.
+     *
+     * @return The player name, or NULL if it is not known yet.
+     */
+    default String getPlayerName() {
+        return null;
+    }
+
+    /**
+     * Retrieve the player UUID captured during login.
+     *
+     * @return The player UUID, or NULL if it is not available.
+     */
+    default UUID getPlayerUniqueId() {
+        return null;
+    }
+
     /**
      * Set the current player instance.
      *

src/main/java/com/comphenix/protocol/injector/netty/WirePacket.java

@@ -19,10 +19,13 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.events.PacketContainer;
+import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.accessors.MethodAccessor;
 import com.comphenix.protocol.utility.MinecraftMethods;
 import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.utility.MinecraftVersion;
 import com.comphenix.protocol.utility.StreamSerializer;
+import com.comphenix.protocol.wrappers.CustomPacketPayloadWrapper;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.util.ReferenceCountUtil;
@@ -81,6 +84,11 @@ public class WirePacket {
     public static byte[] bytesFromPacket(PacketContainer packet) {
         checkNotNull(packet, "packet cannot be null!");
 
+        // packets are written by their stream codec since 1.20.5
+        if (MinecraftVersion.v1_20_5.atOrAbove()) {
+            return bytesFromStreamCodec(packet);
+        }
+
         ByteBuf buffer = PacketContainer.createPacketBuffer();
         ByteBuf store = PacketContainer.createPacketBuffer();
 
@@ -107,6 +115,44 @@ public class WirePacket {
         return bytes;
     }
 
+    private static byte[] bytesFromStreamCodec(PacketContainer packet) {
+        // Spigot keeps the data of unknown custom payloads in a buffer and the codec reads from it,
+        // so the reader index is restored to keep the packet writable after this call
+        ByteBuf payloadData = getCustomPayloadData(packet);
+        int readerIndex = payloadData != null ? payloadData.readerIndex() : 0;
+
+        try {
+            ByteBuf buffer = (ByteBuf) packet.serializeToBuffer();
+            return StreamSerializer.getDefault().getBytesAndRelease(buffer);
+        } finally {
+            if (payloadData != null) {
+                payloadData.readerIndex(readerIndex);
+            }
+        }
+    }
+
+    private static ByteBuf getCustomPayloadData(PacketContainer packet) {
+        PacketType type = packet.getType();
+        if (type != PacketType.Play.Server.CUSTOM_PAYLOAD
+                && type != PacketType.Play.Client.CUSTOM_PAYLOAD
+                && type != PacketType.Configuration.Server.CUSTOM_PAYLOAD
+                && type != PacketType.Configuration.Client.CUSTOM_PAYLOAD) {
+            return null;
+        }
+
+        Object payload = packet.getModifier()
+                .withType(CustomPacketPayloadWrapper.getCustomPacketPayloadClass())
+                .readSafely(0);
+        if (payload == null) {
+            return null;
+        }
+
+        StructureModifier<ByteBuf> buffers = new StructureModifier<>(payload.getClass())
+                .withTarget(payload)
+                .withType(ByteBuf.class);
+        return buffers.readSafely(0);
+    }
+
     /**
      * Creates a WirePacket from an existing Minecraft packet
      *
@@ -118,6 +164,10 @@ public class WirePacket {
         checkNotNull(packet, "packet cannot be null!");
         checkArgument(MinecraftReflection.isPacketClass(packet), "packet must be a Minecraft packet");
 
+        if (MinecraftVersion.v1_20_5.atOrAbove()) {
+            return fromPacket(PacketContainer.fromPacket(packet));
+        }
+
         ByteBuf buffer = PacketContainer.createPacketBuffer();
 
         MethodAccessor write = MinecraftMethods.getPacketWriteByteBufMethod();

src/main/java/com/comphenix/protocol/injector/netty/channel/EmptyInjector.java

@@ -1,6 +1,7 @@
 package com.comphenix.protocol.injector.netty.channel;
 
 import java.net.SocketAddress;
+import java.util.UUID;
 
 import org.bukkit.entity.Player;
 
@@ -67,6 +68,16 @@ final class EmptyInjector implements Injector {
         return this.player;
     }
 
+    @Override
+    public String getPlayerName() {
+        return this.player != null ? this.player.getName() : null;
+    }
+
+    @Override
+    public UUID getPlayerUniqueId() {
+        return this.player != null ? this.player.getUniqueId() : null;
+    }
+
     @Override
     public void setPlayer(Player player) {
         this.player = player;

src/main/java/com/comphenix/protocol/injector/netty/channel/NettyChannelInjector.java

@@ -4,7 +4,9 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.net.SocketAddress;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
+import java.util.UUID;
 import java.util.WeakHashMap;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
@@ -31,6 +33,7 @@ import com.comphenix.protocol.injector.netty.WirePacket;
 import com.comphenix.protocol.injector.packet.PacketRegistry;
 import com.comphenix.protocol.injector.temporary.TemporaryPlayer;
 import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
@@ -100,6 +103,7 @@ public class NettyChannelInjector implements Injector {
 
     // information about the player belonging to this injector
     private String playerName;
+    private UUID playerUniqueId;
     private Player player;
 
     // lazy initialized fields, if we don't need them we don't bother about them
@@ -115,6 +119,10 @@ public class NettyChannelInjector implements Injector {
     ) {
         // bukkit stuff
         this.player = player;
+        if (player != null && !(player instanceof TemporaryPlayer)) {
+            this.playerName = player.getName();
+            this.playerUniqueId = player.getUniqueId();
+        }
 
         // protocol lib stuff
         this.errorReporter = errorReporter;
@@ -361,12 +369,23 @@ public class NettyChannelInjector implements Injector {
         return this.player;
     }
 
+    @Override
+    public String getPlayerName() {
+        return this.playerName;
+    }
+
+    @Override
+    public UUID getPlayerUniqueId() {
+        return this.playerUniqueId;
+    }
+
     @Override
     public void setPlayer(Player player) {
         this.injectionFactory.invalidate(this.player, this.playerName);
 
         this.player = player;
         this.playerName = player.getName();
+        this.playerUniqueId = player.getUniqueId();
 
         this.injectionFactory.cacheInjector(player, this);
         this.injectionFactory.cacheInjector(player.getName(), this);
@@ -421,14 +440,19 @@ public class NettyChannelInjector implements Injector {
         // process login packets for the player name
         if (packet.getType() == PacketType.Login.Client.START) {
             String username;
+            UUID uniqueId;
             if (MinecraftVersion.WILD_UPDATE.atOrAbove()) {
                 // 1.19 replaced the gameprofile with username and uuid field
                 username = packet.getStrings().readSafely(0);
+                uniqueId = readLoginUniqueId(packet);
             } else {
                 WrappedGameProfile profile = packet.getGameProfiles().readSafely(0);
                 username = profile != null ? profile.getName() : null;
+                uniqueId = profile != null ? profile.getUUID() : null;
             }
 
+            this.playerUniqueId = uniqueId;
+
             if (username != null) {
                 this.playerName = username;
                 this.injectionFactory.cacheInjector(username, this);
@@ -443,6 +467,22 @@ public class NettyChannelInjector implements Injector {
         }
     }
 
+    private static UUID readLoginUniqueId(PacketContainer packet) {
+        UUID uniqueId = packet.getUUIDs().readSafely(0);
+        if (uniqueId != null) {
+            return uniqueId;
+        }
+
+        StructureModifier<Optional> optionals = packet.getModifier().withType(Optional.class);
+        for (int i = 0; i < optionals.size(); i++) {
+            Optional<?> optional = optionals.readSafely(i);
+            if (optional != null && optional.orElse(null) instanceof UUID optionalUniqueId) {
+                return optionalUniqueId;
+            }
+        }
+        return null;
+    }
+
     private void processInboundInternal(ChannelHandlerContext ctx, PacketContainer packetContainer) {
         if (this.listenerManager.hasMainThreadListener(packetContainer.getType()) && !Bukkit.isPrimaryThread()) {
             // not on the main thread but we are required to be reschedule the packet on the
@@ -516,15 +556,16 @@ public class NettyChannelInjector implements Injector {
             return action;
         }
 
+        PacketContainer packetContainer = new PacketContainer(packetType, packet);
+
         // ensure that we are on the main thread if we need to
-        if (this.listenerManager.hasMainThreadListener(packetType) && !Bukkit.isPrimaryThread()) {
+        if (!Bukkit.isPrimaryThread() && hasMainThreadListener(this.listenerManager, protocol, packetContainer)) {
             // not on the main thread but we are required to be - re-schedule the packet on the main thread
-            ProtocolLibrary.getScheduler().runTask(() -> this.sendClientboundPacket(packet, null, true));
+            ProtocolLibrary.getScheduler().runTask(() -> this.sendClientboundPacket(packet, marker, true));
             return null;
         }
 
         // create event and invoke listeners
-        PacketContainer packetContainer = new PacketContainer(packetType, packet);
         PacketEvent event = PacketEvent.fromServer(this, packetContainer, marker, this.player);
         this.listenerManager.invokeOutboundPacketListeners(event);
 
@@ -554,6 +595,44 @@ public class NettyChannelInjector implements Injector {
         return null;
     }
 
+    /**
+     * Checks if a listener that must be called on the main thread is going to be invoked for the given outbound packet.
+     * The packets inside a bundle are posted to their listeners together with the bundle, so their listeners count for
+     * the bundle as well.
+     *
+     * @param listenerManager the listener manager holding the registered listeners.
+     * @param protocol        the current outbound protocol of the connection.
+     * @param packet          the outbound packet.
+     * @return true if the packet must be processed on the main thread, false otherwise.
+     */
+    static boolean hasMainThreadListener(ListenerManager listenerManager, Protocol protocol, PacketContainer packet) {
+        if (listenerManager.hasMainThreadListener(packet.getType())) {
+            return true;
+        }
+
+        if (packet.getType() != PacketType.Play.Server.BUNDLE) {
+            return false;
+        }
+
+        Iterable<?> subPackets = packet.getModifier().<Iterable<?>>withType(Iterable.class).readSafely(0);
+        if (subPackets == null) {
+            return false;
+        }
+
+        for (Object subPacket : subPackets) {
+            if (subPacket == null) {
+                continue;
+            }
+
+            PacketType subPacketType = PacketRegistry.getPacketType(protocol, subPacket.getClass());
+            if (subPacketType != null && listenerManager.hasMainThreadListener(subPacketType)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     @SuppressWarnings("unchecked")
     private <T> T proxyAction(T action, PacketEvent event, NetworkMarker marker) {
         // hack - we only know that the given action is either a runnable or callable, but we need to work out which thing

src/main/java/com/comphenix/protocol/injector/netty/manager/NetworkManagerInjector.java

@@ -15,6 +15,7 @@ import com.comphenix.protocol.error.ErrorReporter;
 import com.comphenix.protocol.injector.ListenerManager;
 import com.comphenix.protocol.injector.netty.Injector;
 import com.comphenix.protocol.injector.netty.channel.InjectionFactory;
+import com.comphenix.protocol.internal.PlatformProvider;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
@@ -23,7 +24,9 @@ import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.wrappers.Pair;
 
+import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandler;
 
 public class NetworkManagerInjector {
 
@@ -36,7 +39,9 @@ public class NetworkManagerInjector {
     private final InjectionFactory injectionFactory;
 
     // netty handler
+    private final InjectionChannelInboundHandler injectionHandler;
     private final InjectionChannelInitializer pipelineInjectorHandler;
+    private Runnable paperChannelInitializerCleanup;
 
     // status of this injector
     private boolean closed = false;
@@ -47,22 +52,35 @@ public class NetworkManagerInjector {
         this.injectionFactory = new InjectionFactory(plugin, reporter, listenerManager);
 
         // hooking netty handlers
-        InjectionChannelInboundHandler injectionHandler = new InjectionChannelInboundHandler(
+        this.injectionHandler = new InjectionChannelInboundHandler(
                 this.errorReporter,
                 this.injectionFactory);
-        this.pipelineInjectorHandler = new InjectionChannelInitializer(INBOUND_INJECT_HANDLER_NAME, injectionHandler);
+        this.pipelineInjectorHandler = new InjectionChannelInitializer(
+                INBOUND_INJECT_HANDLER_NAME,
+                this.injectionHandler);
     }
 
     public Injector getInjector(Player player) {
     	return this.injectionFactory.fromPlayer(player);
     }
 
+    public boolean isUsingPaperChannelInitializer() {
+        return this.paperChannelInitializerCleanup != null;
+    }
+
     @SuppressWarnings("unchecked")
     public void inject() {
         if (this.closed || this.injected) {
             return;
         }
 
+        PlatformProvider platformProvider = PlatformProvider.get();
+        if (platformProvider.hasEarlyChannelInitialization()) {
+            this.paperChannelInitializerCleanup = platformProvider.registerChannelInitializer(this::injectChannel);
+            this.injected = true;
+            return;
+        }
+
         // get all "server connections" defined in the minecraft server class
         FuzzyReflection server = FuzzyReflection.fromClass(MinecraftReflection.getMinecraftServerClass());
         List<Method> serverConnectionGetter = server.getMethodList(FuzzyMethodContract.newBuilder()
@@ -125,6 +143,23 @@ public class NetworkManagerInjector {
         this.injected = true;
     }
 
+    private void injectChannel(Channel channel) {
+        addInjectionHandler(channel, MinecraftReflection.getNetworkManagerClass(), this.injectionHandler);
+    }
+
+    static void addInjectionHandler(Channel channel, Class<?> networkManagerClass, ChannelHandler injectionHandler) {
+        for (String handlerName : channel.pipeline().names()) {
+            ChannelHandler handler = channel.pipeline().get(handlerName);
+            if (networkManagerClass.isInstance(handler)) {
+                channel.pipeline().addBefore(handlerName, INBOUND_INJECT_HANDLER_NAME, injectionHandler);
+                return;
+            }
+        }
+
+        // Preserve the existing behavior for forks with an unexpected pipeline layout.
+        channel.pipeline().addLast(INBOUND_INJECT_HANDLER_NAME, injectionHandler);
+    }
+
     public void close() {
         if (this.closed || !this.injected) {
             return;
@@ -153,6 +188,13 @@ public class NetworkManagerInjector {
 
         // clear up
         this.overriddenLists.clear();
-        this.injectionFactory.close();
+        try {
+            if (this.paperChannelInitializerCleanup != null) {
+                this.paperChannelInitializerCleanup.run();
+            }
+        } finally {
+            this.paperChannelInitializerCleanup = null;
+            this.injectionFactory.close();
+        }
     }
 }

src/main/java/com/comphenix/protocol/injector/temporary/TemporaryPlayerFactory.java

@@ -19,6 +19,7 @@ package com.comphenix.protocol.injector.temporary;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
+import java.util.UUID;
 
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
@@ -132,7 +133,16 @@ public class TemporaryPlayerFactory {
                 if (methodName.equals("isOnline")) {
                     return injector.isConnected();
                 } else if (methodName.equals("getName")) {
+                    String playerName = injector.getPlayerName();
+                    if (playerName != null) {
+                        return playerName;
+                    }
                     return "UNKNOWN[" + injector.getAddress() + "]";
+                } else if (methodName.equals("getUniqueId")) {
+                    UUID playerUniqueId = injector.getPlayerUniqueId();
+                    if (playerUniqueId != null) {
+                        return playerUniqueId;
+                    }
                 }
 
                 // Ignore all other methods
@@ -184,14 +194,16 @@ public class TemporaryPlayerFactory {
      *   <li>getPlayer()</li>
      *   <li>getAddress()</li>
      *   <li>getServer()</li>
+     *   <li>getName()</li>
+     *   <li>getUniqueId(), when supplied by the login protocol</li>
      *   <li>chat(String)</li>
      *   <li>sendMessage(String)</li>
      *   <li>sendMessage(String[])</li>
      *   <li>kickPlayer(String)</li>
      * </ul>
      * <p>
-     * Note that a temporary player has not yet been assigned a name, and thus cannot be
-     * uniquely identified. Use the address instead.
+     * Before the login start packet is received, the player has no profile information
+     * and can only be identified by its address.
      *
      * @return A temporary player instance.
      */

src/main/java/com/comphenix/protocol/internal/PlatformProvider.java

@@ -0,0 +1,35 @@
+package com.comphenix.protocol.internal;
+
+import java.util.ServiceLoader;
+import java.util.function.Consumer;
+
+import org.bukkit.command.CommandExecutor;
+
+import com.comphenix.protocol.ProtocolLib;
+
+import io.netty.channel.Channel;
+
+public interface PlatformProvider {
+
+    static PlatformProvider get() {
+        return Holder.INSTANCE;
+    }
+
+    boolean hasEarlyChannelInitialization();
+
+    Runnable registerChannelInitializer(Consumer<Channel> channelInitializer);
+
+    void registerCommand(ProtocolLib plugin, String name, CommandExecutor executor);
+
+    final class Holder {
+
+        private static final PlatformProvider INSTANCE = ServiceLoader.load(
+                        PlatformProvider.class,
+                        PlatformProvider.class.getClassLoader())
+                .findFirst()
+                .orElseThrow(() -> new IllegalStateException("No ProtocolLib platform provider is available"));
+
+        private Holder() {
+        }
+    }
+}

src/main/java/com/comphenix/protocol/reflect/StructureModifier.java

@@ -90,6 +90,8 @@ public class StructureModifier<T> {
     protected Map<FieldAccessor, Integer> defaultFields;
     // Cache of previous types
     protected Map<Class<?>, StructureModifier<?>> subtypeCache;
+    // Cache of previous parameterized types
+    private Map<List<Type>, StructureModifier<?>> paramTypeCache = new HashMap<>();
 
     // Whether or subclasses should handle conversion
     protected boolean customConvertHandling;
@@ -201,6 +203,7 @@ public class StructureModifier<T> {
                 other.defaultFields,
                 other.converter,
                 other.subtypeCache);
+        this.paramTypeCache = other.paramTypeCache;
     }
 
     /**
@@ -531,8 +534,18 @@ public class StructureModifier<T> {
             return (StructureModifier<R>) NO_OP_MODIFIER;
         }
 
+        // parameterized lookups must not share a cache entry with the raw field type
+        List<Type> paramTypeKey = null;
+        if (paramTypes.length > 0) {
+            paramTypeKey = new ArrayList<>(paramTypes.length + 1);
+            paramTypeKey.add(fieldType);
+            paramTypeKey.addAll(Arrays.asList(paramTypes));
+        }
+
         // Do we need to update the cache?
-        StructureModifier<R> result = (StructureModifier<R>) this.subtypeCache.get(fieldType);
+        StructureModifier<R> result = (StructureModifier<R>) (paramTypeKey == null
+                ? this.subtypeCache.get(fieldType)
+                : this.paramTypeCache.get(paramTypeKey));
         if (result == null) {
             List<FieldAccessor> fields = new ArrayList<>();
             Map<FieldAccessor, Integer> defaults = new HashMap<>();
@@ -571,7 +584,11 @@ public class StructureModifier<T> {
 
             // Cache structure modifiers
             result = this.withFieldType(fieldType, fields, defaults);
-            this.subtypeCache.put(fieldType, result);
+            if (paramTypeKey == null) {
+                this.subtypeCache.put(fieldType, result);
+            } else {
+                this.paramTypeCache.put(paramTypeKey, result);
+            }
         }
 
         // Add the target too

src/main/java/com/comphenix/protocol/reflect/cloning/ImmutableDetector.java

@@ -63,6 +63,7 @@ public class ImmutableDetector implements Cloner {
         add(MinecraftReflection::getBlockClass);
         add(MinecraftReflection::getItemClass);
         add(MinecraftReflection::getSoundEffectClass);
+        add(MinecraftReflection::getWorldTypeClass);
 
         if (MinecraftVersion.AQUATIC_UPDATE.atOrAbove()) {
             add(MinecraftReflection::getFluidTypeClass);

src/main/java/com/comphenix/protocol/updater/SpigotUpdateRunnable.java

@@ -0,0 +1,58 @@
+/**
+ * ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
+ * Copyright (C) 2015 dmulloy2
+ * <p>
+ * 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 2 of
+ * the License, or (at your option) any later version.
+ * <p>
+ * 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.
+ * <p>
+ * You should have received a copy of the GNU General Public License along with this program;
+ * if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA
+ */
+package com.comphenix.protocol.updater;
+
+import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.error.Report;
+
+/**
+ * Update check worker (top-level class so the runtime always loads a single {@code .class} entry).
+ */
+final class SpigotUpdateRunnable implements Runnable {
+
+    private final SpigotUpdater updater;
+
+    SpigotUpdateRunnable(SpigotUpdater updater) {
+        this.updater = updater;
+    }
+
+    @Override
+    public void run() {
+        try {
+            String version = this.updater.getSpigotVersion();
+            this.updater.setRemoteVersion(version);
+
+            if (this.updater.versionCheck(version)) {
+                this.updater.result = Updater.UpdateResult.SPIGOT_UPDATE_AVAILABLE;
+            } else {
+                this.updater.result = Updater.UpdateResult.NO_UPDATE;
+            }
+        } catch (Throwable ex) {
+            if (ProtocolLibrary.getConfig().isDebug()) {
+                ProtocolLibrary.getErrorReporter().reportDetailed(
+                        this.updater,
+                        Report.newBuilder(Updater.REPORT_CANNOT_UPDATE_PLUGIN).error(ex).callerParam(this));
+            }
+
+            ProtocolLibrary.disableUpdates();
+        } finally {
+            for (Runnable listener : this.updater.listeners) {
+                ProtocolLibrary.getScheduler().runTask(listener);
+            }
+        }
+    }
+}

src/main/java/com/comphenix/protocol/updater/SpigotUpdater.java

@@ -16,8 +16,6 @@
  */
 package com.comphenix.protocol.updater;
 
-import com.comphenix.protocol.ProtocolLibrary;
-import com.comphenix.protocol.error.Report;
 import com.comphenix.protocol.utility.Closer;
 import org.bukkit.plugin.Plugin;
 
@@ -44,7 +42,7 @@ public final class SpigotUpdater extends Updater {
         waitForThread();
 
         this.type = type;
-        this.thread = new Thread(new SpigotUpdateRunnable());
+        this.thread = new Thread(new SpigotUpdateRunnable(this));
         this.thread.start();
     }
 
@@ -54,36 +52,8 @@ public final class SpigotUpdater extends Updater {
         return String.format(result.toString(), remoteVersion, plugin.getDescription().getVersion(), RESOURCE_URL);
     }
 
-    private class SpigotUpdateRunnable implements Runnable {
-
-        @Override
-        public void run() {
-            try {
-                String version = getSpigotVersion();
-                remoteVersion = version;
-
-                if (versionCheck(version)) {
-                    result = UpdateResult.SPIGOT_UPDATE_AVAILABLE;
-                } else {
-                    result = UpdateResult.NO_UPDATE;
-                }
-            } catch (Throwable ex) {
-                if (ProtocolLibrary.getConfig().isDebug()) {
-                    ProtocolLibrary.getErrorReporter().reportDetailed(
-                            SpigotUpdater.this, Report.newBuilder(REPORT_CANNOT_UPDATE_PLUGIN).error(ex).callerParam(this));
-                } else {
-                    // People don't care
-                    // plugin.getLogger().log(Level.WARNING, "Failed to check for updates: " + ex);
-                }
-
-                ProtocolLibrary.disableUpdates();
-            } finally {
-                // Invoke the listeners on the main thread
-                for (Runnable listener : listeners) {
-                    ProtocolLibrary.getScheduler().runTask(listener);
-                }
-            }
-        }
+    void setRemoteVersion(String remoteVersion) {
+        this.remoteVersion = remoteVersion;
     }
 
     private static final String RESOURCE_URL = "https://www.spigotmc.org/resources/protocollib.1997/";

src/main/java/com/comphenix/protocol/utility/MinecraftMethods.java

@@ -57,21 +57,25 @@ public final class MinecraftMethods {
     }
     
     public static Function<ByteBuf, Object> getFriendlyBufBufConstructor() {
-    	if (friendlyBufBufConstructor == null) {
-    		Optional<Class<?>> registryByteBuf = MinecraftReflection.getRegistryFriendlyByteBufClass();
-    		
-    		if (registryByteBuf.isPresent()) {
-    			ConstructorAccessor accessor = Accessors.getConstructorAccessor(FuzzyReflection.fromClass(registryByteBuf.get()).getConstructor(FuzzyMethodContract.newBuilder()
-    					.parameterDerivedOf(ByteBuf.class)
-    					.parameterDerivedOf(MinecraftReflection.getRegistryAccessClass())
-    					.build()));
-    			friendlyBufBufConstructor = (byteBuf) -> accessor.invoke(byteBuf, MinecraftRegistryAccess.get());
-    		} else {
-    			ConstructorAccessor accessor = Accessors.getConstructorAccessor(MinecraftReflection.getPacketDataSerializerClass(), ByteBuf.class);
-    			friendlyBufBufConstructor = (byteBuf) -> accessor.invoke(byteBuf);
-    		}
-    	}
-    	return friendlyBufBufConstructor;
+        if (friendlyBufBufConstructor == null) {
+            Optional<Class<?>> registryByteBuf = MinecraftReflection.getRegistryFriendlyByteBufClass();
+
+            if (registryByteBuf.isPresent()) {
+                ConstructorAccessor accessor = Accessors.getConstructorAccessor(
+                        FuzzyReflection.fromClass(registryByteBuf.get()).getConstructor(
+                                FuzzyMethodContract.newBuilder()
+                                        .parameterExactType(ByteBuf.class, 0)
+                                        .parameterExactType(MinecraftReflection.getRegistryAccessClass(), 1)
+                                        .build()));
+                friendlyBufBufConstructor = byteBuf -> accessor.invoke(byteBuf, MinecraftRegistryAccess.get());
+            } else {
+                ConstructorAccessor accessor = Accessors.getConstructorAccessor(
+                        MinecraftReflection.getPacketDataSerializerClass(),
+                        ByteBuf.class);
+                friendlyBufBufConstructor = byteBuf -> accessor.invoke(byteBuf);
+            }
+        }
+        return friendlyBufBufConstructor;
     }
 
     /**

src/main/java/com/comphenix/protocol/utility/MinecraftProtocolVersion.java

@@ -101,6 +101,7 @@ public final class MinecraftProtocolVersion {
 
         map.put(new MinecraftVersion(26, 1, 0), 775);
         map.put(new MinecraftVersion(26, 2, 0), 776);
+        map.put(new MinecraftVersion(26, 3, 0), 777);
         return map;
     }
 

src/main/java/com/comphenix/protocol/utility/MinecraftReflection.java

@@ -928,6 +928,10 @@ public final class MinecraftReflection {
         return getMinecraftClass("world.effect.MobEffectList", "MobEffectList", "world.effect.MobEffect", "world.effect.MobEffects");
     }
 
+    public static Class<?> getDamageTypeClass() {
+        return getMinecraftClass("world.damagesource.DamageType");
+    }
+
     public static Class<?> getSoundEffectClass() {
         return getNullableNMS("sounds.SoundEffect", "sounds.SoundEvent", "SoundEffect", "sounds.SoundEvents");
     }
@@ -1426,8 +1430,13 @@ public final class MinecraftReflection {
             try {
                 Method asMirrorMethod = getCraftItemStackClass().getMethod("asCraftMirror", getItemStackClass());
                 asCraftMirror = Accessors.getMethodAccessor(asMirrorMethod);
-            } catch (ReflectiveOperationException ex) {
-                throw new RuntimeException("Failed to obtain CraftItemStack.asCraftMirror", ex);
+            } catch (ReflectiveOperationException ex1) {
+                try {
+                    Method asMirrorMethod = getCraftItemStackClass().getMethod("asBukkitMirror", getItemStackClass());
+                    asCraftMirror = Accessors.getMethodAccessor(asMirrorMethod);
+                } catch (ReflectiveOperationException ex2) {
+                    throw new RuntimeException("Failed to obtain CraftItemStack.asCraftMirror", ex2);
+                }
             }
         }
 
@@ -1933,4 +1942,22 @@ public final class MinecraftReflection {
     public static Class<?> getPositionMoveRotationClass() {
         return getMinecraftClass("world.entity.PositionMoveRotation");
     }
+
+    /**
+     * Retrieves the VecDelta class (since 26.3).
+     *
+     * @return The VecDelta class.
+     */
+    public static Optional<Class<?>> getVecDeltaClass() {
+        return getOptionalNMS("network.protocol.game.VecDelta");
+    }
+
+    /**
+     * Retrieves the PositionPath class (since 26.3).
+     *
+     * @return The PositionPath class.
+     */
+    public static Optional<Class<?>> getPositionPathClass() {
+        return getOptionalNMS("world.entity.PositionPath");
+    }
 }

src/main/java/com/comphenix/protocol/utility/MinecraftVersion.java

@@ -36,6 +36,11 @@ import org.bukkit.Server;
  * @author Kristian
  */
 public final class MinecraftVersion implements Comparable<MinecraftVersion>, Serializable {
+    /**
+     * Version 26.3 - wilderness bound
+     */
+    public static final MinecraftVersion v26_3 = new MinecraftVersion("26.3");
+
     /**
      * Version 26.2 - chaos cubed
      */
@@ -194,7 +199,7 @@ public final class MinecraftVersion implements Comparable<MinecraftVersion>, Ser
     /**
      * The latest release version of minecraft.
      */
-    public static final MinecraftVersion LATEST = v26_2;
+    public static final MinecraftVersion LATEST = v26_3;
 
     // used when serializing
     private static final long serialVersionUID = -8695133558996459770L;

src/main/java/com/comphenix/protocol/utility/StreamSerializer.java

@@ -326,15 +326,9 @@ public class StreamSerializer {
 
     public byte[] getBytesAndRelease(ByteBuf buf) {
         try {
-            if (buf.hasArray()) {
-                // heap buffer, we can access the array directly
-                return buf.array();
-            } else {
-                // direct buffer, we need to copy the bytes into an array
-                byte[] bytes = new byte[buf.readableBytes()];
-                buf.readBytes(bytes);
-                return bytes;
-            }
+            byte[] bytes = new byte[buf.readableBytes()];
+            buf.getBytes(buf.readerIndex(), bytes);
+            return bytes;
         } finally {
             ReferenceCountUtil.safeRelease(buf);
         }

src/main/java/com/comphenix/protocol/wrappers/BukkitConverters.java

@@ -1436,6 +1436,142 @@ public class BukkitConverters {
         });
     }
 
+    // Lazily-resolved CraftDamageType reflection. volatile + DCL keeps the publish safe
+    // and avoids re-running fuzzy lookups in concurrent injection paths.
+    private static volatile MethodAccessor damageTypeToNms = null;
+    private static volatile MethodAccessor damageTypeFromNms = null;
+    private static volatile MethodAccessor damageTypeHolderValue = null;
+    private static boolean damageTypeToNmsReturnsHolder;
+    private static boolean damageTypeFromNmsAcceptsHolder;
+    private static final Map<Object, Object> damageTypeHolders = new ConcurrentHashMap<>();
+
+    private static FuzzyReflection craftDamageTypeFuzzy() {
+        return FuzzyReflection.fromClass(getCraftBukkitClass("damage.CraftDamageType"), false);
+    }
+
+    private static MethodAccessor resolveDamageTypeToNms() {
+        MethodAccessor accessor = damageTypeToNms;
+        if (accessor != null) return accessor;
+        synchronized (BukkitConverters.class) {
+            accessor = damageTypeToNms;
+            if (accessor != null) return accessor;
+            try {
+                accessor = Accessors.getMethodAccessor(craftDamageTypeFuzzy().getMethod(FuzzyMethodContract.newBuilder()
+                        .parameterExactArray(org.bukkit.damage.DamageType.class)
+                        .returnTypeExact(MinecraftReflection.getDamageTypeClass())
+                        .requireModifier(Modifier.STATIC)
+                        .build()));
+            } catch (IllegalArgumentException exception) {
+                accessor = Accessors.getMethodAccessor(craftDamageTypeFuzzy().getMethod(FuzzyMethodContract.newBuilder()
+                        .parameterExactArray(org.bukkit.damage.DamageType.class)
+                        .returnTypeExact(MinecraftReflection.getHolderClass())
+                        .requireModifier(Modifier.STATIC)
+                        .build()));
+                damageTypeToNmsReturnsHolder = true;
+            }
+            damageTypeToNms = accessor;
+            return accessor;
+        }
+    }
+
+    private static MethodAccessor resolveDamageTypeFromNms() {
+        MethodAccessor accessor = damageTypeFromNms;
+        if (accessor != null) return accessor;
+        synchronized (BukkitConverters.class) {
+            accessor = damageTypeFromNms;
+            if (accessor != null) return accessor;
+            try {
+                accessor = Accessors.getMethodAccessor(craftDamageTypeFuzzy().getMethod(FuzzyMethodContract.newBuilder()
+                        .parameterExactArray(MinecraftReflection.getDamageTypeClass())
+                        .returnTypeExact(org.bukkit.damage.DamageType.class)
+                        .requireModifier(Modifier.STATIC)
+                        .build()));
+            } catch (IllegalArgumentException exception) {
+                accessor = Accessors.getMethodAccessor(craftDamageTypeFuzzy().getMethod(FuzzyMethodContract.newBuilder()
+                        .parameterExactArray(MinecraftReflection.getHolderClass())
+                        .returnTypeExact(org.bukkit.damage.DamageType.class)
+                        .requireModifier(Modifier.STATIC)
+                        .build()));
+                damageTypeFromNmsAcceptsHolder = true;
+            }
+            damageTypeFromNms = accessor;
+            return accessor;
+        }
+    }
+
+    private static Object getHolderValue(Object holder) {
+        MethodAccessor accessor = damageTypeHolderValue;
+        if (accessor == null) {
+            synchronized (BukkitConverters.class) {
+                accessor = damageTypeHolderValue;
+                if (accessor == null) {
+                    accessor = Accessors.getMethodAccessor(
+                            FuzzyReflection.fromClass(MinecraftReflection.getHolderClass(), false)
+                                    .getMethod(FuzzyMethodContract.newBuilder()
+                                            .parameterCount(0)
+                                            .banModifier(Modifier.STATIC)
+                                            .returnTypeExact(Object.class)
+                                            .build()));
+                    damageTypeHolderValue = accessor;
+                }
+            }
+        }
+        return accessor.invoke(holder);
+    }
+
+    private static Object getDamageTypeHolder(Object generic) {
+        Object holder = damageTypeHolders.get(generic);
+        if (holder != null) {
+            return holder;
+        }
+
+        MethodAccessor accessor = resolveDamageTypeToNms();
+        if (!damageTypeToNmsReturnsHolder) {
+            throw new IllegalStateException("CraftDamageType accepts holders but does not produce them");
+        }
+
+        for (org.bukkit.damage.DamageType damageType : org.bukkit.Registry.DAMAGE_TYPE) {
+            Object candidate = accessor.invoke(null, damageType);
+            Object candidateValue = getHolderValue(candidate);
+            damageTypeHolders.putIfAbsent(candidateValue, candidate);
+            if (Objects.equal(candidateValue, generic)) {
+                return candidate;
+            }
+        }
+
+        throw new IllegalArgumentException("Unable to resolve a holder for damage type " + generic);
+    }
+
+    public static EquivalentConverter<org.bukkit.damage.DamageType> getDamageTypeConverter() {
+        return ignoreNull(new EquivalentConverter<org.bukkit.damage.DamageType>() {
+
+            @Override
+            public Class<org.bukkit.damage.DamageType> getSpecificType() {
+                return org.bukkit.damage.DamageType.class;
+            }
+
+            @Override
+            public Object getGeneric(org.bukkit.damage.DamageType specific) {
+                Object generic = resolveDamageTypeToNms().invoke(null, specific);
+                if (damageTypeToNmsReturnsHolder) {
+                    Object value = getHolderValue(generic);
+                    damageTypeHolders.putIfAbsent(value, generic);
+                    return value;
+                }
+                return generic;
+            }
+
+            @Override
+            public org.bukkit.damage.DamageType getSpecific(Object generic) {
+                MethodAccessor accessor = resolveDamageTypeFromNms();
+                if (damageTypeFromNmsAcceptsHolder) {
+                    generic = getDamageTypeHolder(generic);
+                }
+                return (org.bukkit.damage.DamageType) accessor.invoke(null, generic);
+            }
+        });
+    }
+
     private static Class<?> dimensionManager;
     private static FauxEnumConverter<Dimension> dimensionConverter;
     private static FauxEnumConverter<DimensionImpl> dimensionImplConverter;

src/main/java/com/comphenix/protocol/wrappers/CustomPacketPayloadWrapper.java

@@ -18,6 +18,8 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
 
 import net.bytebuddy.ByteBuddy;
 import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
@@ -33,8 +35,8 @@ import net.bytebuddy.matcher.ElementMatchers;
  * by default. Constructing a new wrapper instance will give out a handle to a completely new implemented type, that
  * allows to set a key and some kind of data of any choice.
  * <p>
- * Note that constructing this class from a generic handle is only possible for the spigot-specific UnknownPayload type.
- * All other payloads should be accessed via a structure modifier directly.
+ * Constructing this class from a generic handle requires either retained raw byte data, such as {@code DiscardedPayload},
+ * or a writable serialization method on the concrete payload type.
  *
  * @author Pasqual Koschmieder
  */
@@ -46,7 +48,16 @@ public final class CustomPacketPayloadWrapper {
     private static final ConstructorAccessor PAYLOAD_WRAPPER_CONSTRUCTOR;
 
     private static final MethodAccessor GET_ID_PAYLOAD_METHOD;
+    private static final MethodAccessor GET_ID_HOLDER_PAYLOAD_METHOD;
+    private static final MethodAccessor GET_ID_PAYLOAD_HOLDER_METHOD;
     private static final MethodAccessor SERIALIZE_PAYLOAD_METHOD;
+    private static final Class<?> PAYLOAD_SERIALIZER_CLASS;
+    private static final ConcurrentHashMap<Class<?>, Optional<MethodAccessor>> SERIALIZE_PAYLOAD_METHODS =
+            new ConcurrentHashMap<>();
+
+    /** True when running on the nested-ID API where DiscardedPayload is used instead of the ByteBuddy proxy. */
+    private static final boolean USE_DISCARDED_PAYLOAD;
+    private static final boolean DISCARDED_PAYLOAD_USES_BYTE_ARRAY;
 
     private static final EquivalentConverter<CustomPacketPayloadWrapper> CONVERTER;
 
@@ -55,22 +66,73 @@ public final class CustomPacketPayloadWrapper {
             MINECRAFT_KEY_CLASS = MinecraftReflection.getMinecraftKeyClass();
             CUSTOM_PACKET_PAYLOAD_CLASS = MinecraftReflection.getMinecraftClass("network.protocol.common.custom.CustomPacketPayload");
 
-            Method getPayloadId = FuzzyReflection.fromClass(CUSTOM_PACKET_PAYLOAD_CLASS).getMethod(FuzzyMethodContract.newBuilder()
-                    .banModifier(Modifier.STATIC)
-                    .returnTypeExact(MINECRAFT_KEY_CLASS)
-                    .parameterCount(0)
-                    .build());
-            GET_ID_PAYLOAD_METHOD = Accessors.getMethodAccessor(getPayloadId);
+            Method getPayloadId = null;
+            Method getPayloadIdHolder = null;
+            Method getPayloadIdFromHolder = null;
+            boolean useDiscardedPayload = false;
+            try {
+                getPayloadId = FuzzyReflection.fromClass(CUSTOM_PACKET_PAYLOAD_CLASS).getMethod(FuzzyMethodContract.newBuilder()
+                        .banModifier(Modifier.STATIC)
+                        .returnTypeExact(MINECRAFT_KEY_CLASS)
+                        .parameterCount(0)
+                        .build());
+            } catch (IllegalArgumentException ignored) {
+                // Paper 26: the payload exposes its identifier through one intermediate record.
+                Method[] accessors = findChainedIdAccessors(CUSTOM_PACKET_PAYLOAD_CLASS, MINECRAFT_KEY_CLASS);
+                getPayloadIdHolder = accessors[0];
+                getPayloadIdFromHolder = accessors[1];
+                useDiscardedPayload = true;
+            }
+            GET_ID_PAYLOAD_METHOD = getPayloadId != null ? Accessors.getMethodAccessor(getPayloadId) : null;
+            GET_ID_HOLDER_PAYLOAD_METHOD = getPayloadIdHolder != null
+                    ? Accessors.getMethodAccessor(getPayloadIdHolder) : null;
+            GET_ID_PAYLOAD_HOLDER_METHOD = getPayloadIdFromHolder != null
+                    ? Accessors.getMethodAccessor(getPayloadIdFromHolder) : null;
+            USE_DISCARDED_PAYLOAD = useDiscardedPayload;
 
-            Method serializePayloadData = FuzzyReflection.fromClass(CUSTOM_PACKET_PAYLOAD_CLASS).getMethod(FuzzyMethodContract.newBuilder()
-                    .banModifier(Modifier.STATIC)
-                    .returnTypeVoid()
-                    .parameterCount(1)
-                    .parameterDerivedOf(ByteBuf.class, 0)
-                    .build());
-            SERIALIZE_PAYLOAD_METHOD = Accessors.getMethodAccessor(serializePayloadData);
+            Method serializePayloadData = null;
+            try {
+                serializePayloadData = FuzzyReflection.fromClass(CUSTOM_PACKET_PAYLOAD_CLASS).getMethod(FuzzyMethodContract.newBuilder()
+                        .banModifier(Modifier.STATIC)
+                        .returnTypeVoid()
+                        .parameterCount(1)
+                        .parameterDerivedOf(ByteBuf.class, 0)
+                        .build());
+            } catch (IllegalArgumentException ignored) {
+                // Paper 26 declares the write method on each concrete payload instead.
+            }
+            SERIALIZE_PAYLOAD_METHOD = serializePayloadData != null
+                    ? Accessors.getMethodAccessor(serializePayloadData) : null;
+            if (serializePayloadData == null) {
+                ByteBuf buffer = Unpooled.buffer();
+                try {
+                    PAYLOAD_SERIALIZER_CLASS = MinecraftReflection.getPacketDataSerializer(buffer).getClass();
+                } finally {
+                    if (buffer.refCnt() > 0) {
+                        buffer.release();
+                    }
+                }
+            } else {
+                PAYLOAD_SERIALIZER_CLASS = null;
+            }
 
-            Constructor<?> payloadWrapperConstructor = makePayloadWrapper();
+            Constructor<?> payloadWrapperConstructor;
+            boolean discardedPayloadUsesByteArray = false;
+            if (useDiscardedPayload) {
+                Class<?> discardedPayloadClass = MinecraftReflection.getMinecraftClass(
+                        "network.protocol.common.custom.DiscardedPayload");
+                try {
+                    payloadWrapperConstructor = discardedPayloadClass.getConstructor(
+                            MINECRAFT_KEY_CLASS, byte[].class);
+                    discardedPayloadUsesByteArray = true;
+                } catch (NoSuchMethodException exception) {
+                    payloadWrapperConstructor = discardedPayloadClass.getConstructor(
+                            MINECRAFT_KEY_CLASS, ByteBuf.class);
+                }
+            } else {
+                payloadWrapperConstructor = makePayloadWrapper();
+            }
+            DISCARDED_PAYLOAD_USES_BYTE_ARRAY = discardedPayloadUsesByteArray;
             PAYLOAD_WRAPPER_CONSTRUCTOR = Accessors.getConstructorAccessor(payloadWrapperConstructor);
 
             CONVERTER = new EquivalentConverter<CustomPacketPayloadWrapper>() {
@@ -94,6 +156,41 @@ public final class CustomPacketPayloadWrapper {
         }
     }
 
+    private static Method[] findChainedIdAccessors(Class<?> payloadClass, Class<?> keyClass) {
+        Method payloadAccessor = null;
+        Method keyAccessor = null;
+        FuzzyMethodContract keyAccessorContract = FuzzyMethodContract.newBuilder()
+                .banModifier(Modifier.STATIC)
+                .returnTypeExact(keyClass)
+                .parameterCount(0)
+                .build();
+
+        for (Method candidate : payloadClass.getMethods()) {
+            if (Modifier.isStatic(candidate.getModifiers()) || candidate.getParameterCount() != 0) {
+                continue;
+            }
+
+            Method candidateKeyAccessor;
+            try {
+                candidateKeyAccessor = FuzzyReflection.fromClass(candidate.getReturnType(), true)
+                        .getMethod(keyAccessorContract);
+            } catch (IllegalArgumentException ignored) {
+                continue;
+            }
+
+            if (payloadAccessor != null) {
+                throw new IllegalArgumentException("Multiple CustomPacketPayload identifier accessors found");
+            }
+            payloadAccessor = candidate;
+            keyAccessor = candidateKeyAccessor;
+        }
+
+        if (payloadAccessor == null) {
+            throw new IllegalArgumentException("Unable to find a CustomPacketPayload identifier accessor");
+        }
+        return new Method[]{payloadAccessor, keyAccessor};
+    }
+
     private static Constructor<?> makePayloadWrapper() throws Exception {
         return new ByteBuddy()
                 .subclass(Object.class)
@@ -116,6 +213,64 @@ public final class CustomPacketPayloadWrapper {
                 .getConstructor(MinecraftReflection.getMinecraftKeyClass(), byte[].class);
     }
 
+    private static Optional<MethodAccessor> findSerializePayloadMethod(Class<?> payloadClass) {
+        Method serializeMethod = null;
+        for (Method candidate : FuzzyReflection.fromClass(payloadClass, true).getMethods()) {
+            if (Modifier.isStatic(candidate.getModifiers())
+                    || candidate.getReturnType() != void.class
+                    || candidate.getParameterCount() != 1) {
+                continue;
+            }
+
+            Class<?> parameterClass = candidate.getParameterTypes()[0];
+            if (parameterClass == Object.class || !parameterClass.isAssignableFrom(PAYLOAD_SERIALIZER_CLASS)) {
+                continue;
+            }
+            if (serializeMethod != null) {
+                throw new IllegalArgumentException("Multiple CustomPacketPayload serialization methods found on "
+                        + payloadClass.getName());
+            }
+            serializeMethod = candidate;
+        }
+
+        if (serializeMethod == null) {
+            return Optional.empty();
+        }
+        serializeMethod.setAccessible(true);
+        return Optional.of(Accessors.getMethodAccessor(serializeMethod));
+    }
+
+    private static MethodAccessor getSerializePayloadMethod(Object payload) {
+        if (SERIALIZE_PAYLOAD_METHOD != null) {
+            return SERIALIZE_PAYLOAD_METHOD;
+        }
+        return SERIALIZE_PAYLOAD_METHODS
+                .computeIfAbsent(payload.getClass(), CustomPacketPayloadWrapper::findSerializePayloadMethod)
+                .orElse(null);
+    }
+
+    private static byte[] serializePayload(Object payload) {
+        MethodAccessor serializeMethod = getSerializePayloadMethod(payload);
+        if (serializeMethod == null) {
+            throw new UnsupportedOperationException(
+                    "Cannot extract raw custom payload bytes from " + payload.getClass().getName()
+                            + ": payload has no byte array, ByteBuf, or serialization method");
+        }
+
+        ByteBuf buffer = Unpooled.buffer();
+        try {
+            Object serializer = MinecraftReflection.getPacketDataSerializer(buffer);
+            serializeMethod.invoke(payload, serializer);
+            byte[] result = new byte[buffer.readableBytes()];
+            buffer.getBytes(buffer.readerIndex(), result);
+            return result;
+        } finally {
+            if (buffer.refCnt() > 0) {
+                buffer.release();
+            }
+        }
+    }
+
     // ====== api methods ======
 
     /**
@@ -171,29 +326,39 @@ public final class CustomPacketPayloadWrapper {
      * @return a wrapper holding the minecraft key and payload of the given custom payload instance.
      */
     public static CustomPacketPayloadWrapper fromUnknownPayload(Object payload) {
-        Object messageId = GET_ID_PAYLOAD_METHOD.invoke(payload);
-        MinecraftKey id = MinecraftKey.getConverter().getSpecific(messageId);
+        MinecraftKey id = getPayloadId(payload);
 
         // we read and retain the underlying buffer in case the class uses a buffer to store the data
         // this way, when passing the packet to further handling, the buffer is not released and can be re-used
         StructureModifier<Object> modifier = new StructureModifier<>(payload.getClass()).withTarget(payload);
-        byte[] messagePayload = modifier.withType(ByteBuf.class).optionRead(0)
-                .map(buffer -> {
-                    ByteBuf buf = (ByteBuf) buffer;
-                    byte[] data = StreamSerializer.getDefault().getBytesAndRelease(buf.markReaderIndex().retain());
-                    buf.resetReaderIndex();
-                    return data;
-                })
-                .orElseGet(() -> {
-                    ByteBuf buffer = Unpooled.buffer();
-                    Object serializer = MinecraftReflection.getPacketDataSerializer(buffer);
-                    SERIALIZE_PAYLOAD_METHOD.invoke(payload, serializer);
-                    return StreamSerializer.getDefault().getBytesAndRelease(buffer);
-                });
+        byte[] messagePayload = (byte[]) modifier.withType(byte[].class).readSafely(0);
+        if (messagePayload != null) {
+            messagePayload = messagePayload.clone();
+        } else {
+            messagePayload = modifier.withType(ByteBuf.class).optionRead(0)
+                    .map(buffer -> {
+                        ByteBuf buf = (ByteBuf) buffer;
+                        byte[] data = StreamSerializer.getDefault().getBytesAndRelease(buf.markReaderIndex().retain());
+                        buf.resetReaderIndex();
+                        return data;
+                    })
+                    .orElseGet(() -> serializePayload(payload));
+        }
 
         return new CustomPacketPayloadWrapper(messagePayload, id);
     }
 
+    private static MinecraftKey getPayloadId(Object payload) {
+        Object messageId;
+        if (GET_ID_PAYLOAD_METHOD != null) {
+            messageId = GET_ID_PAYLOAD_METHOD.invoke(payload);
+        } else {
+            Object idHolder = GET_ID_HOLDER_PAYLOAD_METHOD.invoke(payload);
+            messageId = GET_ID_PAYLOAD_HOLDER_METHOD.invoke(idHolder);
+        }
+        return MinecraftKey.getConverter().getSpecific(messageId);
+    }
+
     /**
      * Get the generic id of the wrapped message id.
      *
@@ -230,6 +395,13 @@ public final class CustomPacketPayloadWrapper {
      * @return a new payload wrapper instance using the provided message id and payload.
      */
     public Object newHandle() {
+        if (USE_DISCARDED_PAYLOAD) {
+            if (DISCARDED_PAYLOAD_USES_BYTE_ARRAY) {
+                return PAYLOAD_WRAPPER_CONSTRUCTOR.invoke(this.getGenericId(), this.payload);
+            }
+            ByteBuf buf = Unpooled.copiedBuffer(this.payload);
+            return PAYLOAD_WRAPPER_CONSTRUCTOR.invoke(this.getGenericId(), buf);
+        }
         return PAYLOAD_WRAPPER_CONSTRUCTOR.invoke(this.getGenericId(), this.payload);
     }
 

src/main/java/com/comphenix/protocol/wrappers/EnumWrappers.java

@@ -187,7 +187,8 @@ public abstract class EnumWrappers {
         DROP_ITEM,
         RELEASE_USE_ITEM,
         SWAP_HELD_ITEMS("SWAP_ITEM_WITH_OFFHAND"),
-        STAB;
+        STAB,
+        CHANGE_DESTROY_DIRECTION;
 
         final String[] aliases;
         PlayerDigType(String... aliases) {
@@ -803,7 +804,10 @@ public abstract class EnumWrappers {
             PLAYER_DIG_TYPE_CLASS = getEnum(PacketType.Play.Client.BLOCK_DIG.getPacketClass(), 1);
             PLAYER_ACTION_CLASS = getEnum(PacketType.Play.Client.ENTITY_ACTION.getPacketClass(), 0);
             SCOREBOARD_ACTION_CLASS = getEnum(PacketType.Play.Server.SCOREBOARD_SCORE.getPacketClass(), 0);
-            PARTICLE_CLASS = getEnum(PacketType.Play.Server.WORLD_PARTICLES.getPacketClass(), 0);
+            // the particle enum was removed in 1.13, later packets may contain unrelated enums
+            if (!MinecraftVersion.AQUATIC_UPDATE.atOrAbove()) {
+                PARTICLE_CLASS = getEnum(PacketType.Play.Server.WORLD_PARTICLES.getPacketClass(), 0);
+            }
 
             PLAYER_INFO_ACTION_CLASS = getEnum(PacketType.Play.Server.PLAYER_INFO.getPacketClass(), 0);
             if (PLAYER_INFO_ACTION_CLASS == null) {

src/main/java/com/comphenix/protocol/wrappers/LegacyDataWatcher.java

@@ -105,17 +105,22 @@ public class LegacyDataWatcher extends AbstractWrapper implements IDataWatcher {
      */
     @Deprecated
     public LegacyDataWatcher(List<WrappedWatchableObject> objects) {
-        this(newHandle(fakeEntity(), objects));
+        this(newHandle(fakeEntity()));
+
+        for (WrappedWatchableObject object : objects) {
+            WrappedDataWatcherObject watcherObject = MinecraftReflection.watcherObjectExists()
+                    ? object.getWatcherObject()
+                    : WrappedDataWatcherObject.fromIndex(object.getIndex());
+            setObject(watcherObject, object, false);
+        }
     }
 
-    private static Object newHandle(Object entity, List<WrappedWatchableObject> objects) {
+    private static Object newHandle(Object entity) {
         if (constructor == null) {
-            constructor = Accessors.getConstructorAccessor(HANDLE_TYPE, MinecraftReflection.getEntityClass(),
-                MinecraftReflection.getArrayClass(MinecraftReflection.getDataWatcherItemClass()));
+            constructor = Accessors.getConstructorAccessor(HANDLE_TYPE, MinecraftReflection.getEntityClass());
         }
 
-        Object[] genericItems = new Object[0];// (Object[]) ITEMS_CONVERTER.getGeneric(objects);
-        return constructor.invoke(entity, genericItems);
+        return constructor.invoke(entity);
     }
 
     private static Object fakeEntity() {

src/main/java/com/comphenix/protocol/wrappers/WrappedGameProfile.java

@@ -41,23 +41,16 @@ public class WrappedGameProfile extends AbstractWrapper {
     private static final FieldAccessor GET_UUID_STRING = Accessors.getFieldAccessorOrNull(
             GAME_PROFILE, "id", String.class);
 
-    private static MethodAccessor GET_ID;
-    private static MethodAccessor GET_NAME;
-    private static MethodAccessor GET_PROPERTIES;
-    private static MethodAccessor IS_COMPLETE;
+    private static final MethodAccessor GET_ID = findMethodAccessor(GAME_PROFILE, "id", "getId");
+    private static final MethodAccessor GET_NAME = findMethodAccessor(GAME_PROFILE, "name", "getName");
+    private static final MethodAccessor GET_PROPERTIES = findMethodAccessor(
+            GAME_PROFILE, "properties", "getProperties");
+    private static final MethodAccessor IS_COMPLETE = findMethodAccessor(
+            GAME_PROFILE, "complete", "isComplete");
 
-    static {
-        GET_ID = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "getId");
-        if (GET_ID == null) {
-            GET_ID = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "id");
-            GET_NAME = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "name");
-            GET_PROPERTIES = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "properties");
-            IS_COMPLETE = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "complete");
-        } else {
-            GET_NAME = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "getName");
-            GET_PROPERTIES = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "getProperties");
-            IS_COMPLETE = Accessors.getMethodAccessorOrNull(GAME_PROFILE, "isComplete");
-        }
+    static MethodAccessor findMethodAccessor(Class<?> type, String methodName, String fallbackName) {
+        MethodAccessor accessor = Accessors.getMethodAccessorOrNull(type, methodName);
+        return accessor != null ? accessor : Accessors.getMethodAccessorOrNull(type, fallbackName);
     }
 
     // Fetching game profile

src/main/java/com/comphenix/protocol/wrappers/WrappedLevelChunkData.java

@@ -3,8 +3,11 @@ package com.comphenix.protocol.wrappers;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.BitSet;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
+import java.util.function.Function;
 
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import org.jetbrains.annotations.Nullable;
@@ -49,11 +52,19 @@ public final class WrappedLevelChunkData {
         static {
             FuzzyReflection reflection = FuzzyReflection.fromClass(HANDLE_TYPE, true);
 
-            LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR = Accessors.getConstructorAccessor(reflection.getConstructor(FuzzyMethodContract.newBuilder()
-            		.parameterDerivedOf(MinecraftReflection.getPacketDataSerializerClass())
-            		.parameterExactType(int.class)
-            		.parameterExactType(int.class)
-            		.build()));
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR = Accessors.getConstructorAccessor(reflection.getConstructor(FuzzyMethodContract.newBuilder()
+                        .parameterExactType(Map.class)
+                        .parameterExactType(byte[].class)
+                        .parameterExactType(List.class)
+                        .build()));
+            } else {
+                LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR = Accessors.getConstructorAccessor(reflection.getConstructor(FuzzyMethodContract.newBuilder()
+                        .parameterDerivedOf(MinecraftReflection.getPacketDataSerializerClass())
+                        .parameterExactType(int.class)
+                        .parameterExactType(int.class)
+                        .build()));
+            }
             BLOCK_ENTITIES_DATA_ACCESSOR = Accessors.getFieldAccessor(reflection.getField(FuzzyFieldContract.newBuilder()
                     .typeExact(List.class)
                     .build()));
@@ -180,7 +191,12 @@ public final class WrappedLevelChunkData {
          */
         @Deprecated
         public static ChunkData fromValues(NbtCompound heightmapsTag, byte[] buffer, List<BlockEntityInfo> blockEntityInfo) {
-            ChunkData data = new ChunkData(LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR.invoke(StructureCache.newNullDataSerializer(), 0, 0));
+            ChunkData data;
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                data = new ChunkData(LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR.invoke(Collections.emptyMap(), new byte[0], Collections.emptyList()));
+            } else {
+                data = new ChunkData(LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR.invoke(StructureCache.newNullDataSerializer(), 0, 0));
+            }
 
             data.setHeightmapsTag(heightmapsTag);
             data.setBuffer(buffer);
@@ -198,7 +214,12 @@ public final class WrappedLevelChunkData {
          * @return a newly created wrapper
          */
         public static ChunkData fromValues(Map<EnumWrappers.HeightmapType, long[]> heightmaps, byte[] buffer, List<BlockEntityInfo> blockEntityInfo) {
-            ChunkData data = new ChunkData(LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR.invoke(StructureCache.newNullDataSerializer(), 0, 0));
+            ChunkData data;
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                data = new ChunkData(LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR.invoke(Collections.emptyMap(), new byte[0], Collections.emptyList()));
+            } else {
+                data = new ChunkData(LEVEL_CHUNK_PACKET_DATA_CONSTRUCTOR.invoke(StructureCache.newNullDataSerializer(), 0, 0));
+            }
 
             data.setHeightmaps(heightmaps);
             data.setBuffer(buffer);
@@ -433,18 +454,29 @@ public final class WrappedLevelChunkData {
 
         static {
             FuzzyReflection reflection = FuzzyReflection.fromClass(HANDLE_TYPE, true);
-            List<Field> posFields = reflection.getFieldList(FuzzyFieldContract.newBuilder().typeExact(int.class).build());
 
-            BLOCK_ENTITY_INFO_CONSTRUCTOR = Accessors.getConstructorAccessor(HANDLE_TYPE, int.class, int.class,
-                    MinecraftReflection.getBlockEntityTypeClass(), MinecraftReflection.getNBTCompoundClass());
-            PACKED_XZ_ACCESSOR = Accessors.getFieldAccessor(posFields.get(0));
-            Y_ACCESSOR = Accessors.getFieldAccessor(posFields.get(1));
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                BLOCK_ENTITY_INFO_CONSTRUCTOR = Accessors.getConstructorAccessor(HANDLE_TYPE, byte.class, short.class,
+                        MinecraftReflection.getBlockEntityTypeClass(), Optional.class);
+                PACKED_XZ_ACCESSOR = new IntegerFieldAccessor(Accessors.getFieldAccessor(HANDLE_TYPE, byte.class, true), Number::byteValue);
+                Y_ACCESSOR = new IntegerFieldAccessor(Accessors.getFieldAccessor(HANDLE_TYPE, short.class, true), Number::shortValue);
+                TAG_ACCESSOR = Accessors.getFieldAccessor(reflection.getField(FuzzyFieldContract.newBuilder()
+                    .typeExact(Optional.class)
+                    .build()));
+            } else {
+                List<Field> posFields = reflection.getFieldList(FuzzyFieldContract.newBuilder().typeExact(int.class).build());
+
+                BLOCK_ENTITY_INFO_CONSTRUCTOR = Accessors.getConstructorAccessor(HANDLE_TYPE, int.class, int.class,
+                        MinecraftReflection.getBlockEntityTypeClass(), MinecraftReflection.getNBTCompoundClass());
+                PACKED_XZ_ACCESSOR = Accessors.getFieldAccessor(posFields.get(0));
+                Y_ACCESSOR = Accessors.getFieldAccessor(posFields.get(1));
+                TAG_ACCESSOR = Accessors.getFieldAccessor(reflection.getField(FuzzyFieldContract.newBuilder()
+                    .typeExact(MinecraftReflection.getNBTCompoundClass())
+                    .build()));
+            }
             TYPE_ACCESSOR = Accessors.getFieldAccessor(reflection.getField(FuzzyFieldContract.newBuilder()
                     .typeExact(MinecraftReflection.getBlockEntityTypeClass())
                     .build()));
-            TAG_ACCESSOR = Accessors.getFieldAccessor(reflection.getField(FuzzyFieldContract.newBuilder()
-                    .typeExact(MinecraftReflection.getNBTCompoundClass())
-                    .build()));
         }
 
         public BlockEntityInfo(Object handle) {
@@ -533,6 +565,9 @@ public final class WrappedLevelChunkData {
         @Nullable
         public NbtCompound getAdditionalData() {
             Object tagHandle = TAG_ACCESSOR.get(handle);
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                tagHandle = ((Optional<Object>) tagHandle).orElse(null);
+            }
 
             return tagHandle == null ? null : NbtFactory.fromNMSCompound(tagHandle);
         }
@@ -543,7 +578,11 @@ public final class WrappedLevelChunkData {
          * @param additionalData the additional data for this block entity, can be {@code null}
          */
         public void setAdditionalData(@Nullable NbtCompound additionalData) {
-            TAG_ACCESSOR.set(handle, additionalData == null ? null : NbtFactory.fromBase(additionalData).getHandle());
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                TAG_ACCESSOR.set(handle, Optional.ofNullable(additionalData).map(data -> NbtFactory.fromBase(data).getHandle()));
+            } else {
+                TAG_ACCESSOR.set(handle, additionalData == null ? null : NbtFactory.fromBase(additionalData).getHandle());
+            }
         }
 
         /**
@@ -568,12 +607,46 @@ public final class WrappedLevelChunkData {
          * @param additionalData An NBT-Tag containing additional information. Can be {@code null}.
          */
         public static BlockEntityInfo fromValues(int sectionX, int sectionZ, int y, MinecraftKey typeKey, @Nullable NbtCompound additionalData) {
-            return new BlockEntityInfo(BLOCK_ENTITY_INFO_CONSTRUCTOR.invoke(
+            if (MinecraftVersion.v26_3.atOrAbove()) {
+                return new BlockEntityInfo(BLOCK_ENTITY_INFO_CONSTRUCTOR.invoke(
+                    (byte) (sectionX << 4 | sectionZ),
+                    (short) y,
+                    REGISTRY.get(typeKey),
+                    Optional.ofNullable(additionalData).map(data -> NbtFactory.fromBase(data).getHandle())
+                ));
+            } else {
+                return new BlockEntityInfo(BLOCK_ENTITY_INFO_CONSTRUCTOR.invoke(
                     sectionX << 4 | sectionZ,
                     y,
                     REGISTRY.get(typeKey),
                     additionalData == null ? null : NbtFactory.fromBase(additionalData).getHandle()
-            ));
+                ));
+            }
+        }
+    }
+
+    private final static class IntegerFieldAccessor implements FieldAccessor {
+        private final FieldAccessor inner;
+        private final Function<Number, Object> toType;
+
+        public IntegerFieldAccessor(FieldAccessor inner, Function<Number, Object> toType) {
+            this.inner = inner;
+            this.toType = toType;
+        }
+
+        @Override
+        public Object get(Object instance) {
+            return ((Number) this.inner.get(instance)).intValue();
+        }
+
+        @Override
+        public void set(Object instance, Object value) {
+            this.inner.set(instance, this.toType.apply((Integer) value));
+        }
+
+        @Override
+        public Field getField() {
+            return this.inner.getField();
         }
     }
 }

src/main/java/com/comphenix/protocol/wrappers/WrappedParticle.java

@@ -27,6 +27,15 @@ public class WrappedParticle<T> {
     private static MethodAccessor toNMS;
     private static MethodAccessor toCraftData;
 
+    private static final class ItemStackTemplateAccessor {
+        private static final Class<?> TYPE = MinecraftReflection.getMinecraftClass("world.item.ItemStackTemplate");
+        private static final MethodAccessor CREATE_ITEM_STACK = Accessors.getMethodAccessor(
+                FuzzyReflection.fromClass(TYPE).getMethod(FuzzyMethodContract.newBuilder()
+                        .returnTypeExact(MinecraftReflection.getItemStackClass())
+                        .parameterCount(0)
+                        .build()));
+    }
+
     private static void ensureMethods() {
         if (toBukkit != null && toNMS != null) {
             return;
@@ -176,6 +185,15 @@ public class WrappedParticle<T> {
     }
 
     private static Object getItem(Object handle) {
+        if (MinecraftVersion.v26_1.atOrAbove()) {
+            Object template = new StructureModifier<>(handle.getClass())
+                    .withTarget(handle)
+                    .withType(ItemStackTemplateAccessor.TYPE)
+                    .read(0);
+            Object itemStack = ItemStackTemplateAccessor.CREATE_ITEM_STACK.invoke(template);
+            return BukkitConverters.getItemStackConverter().getSpecific(itemStack);
+        }
+
         return new StructureModifier<>(handle.getClass())
                 .withTarget(handle)
                 .withType(MinecraftReflection.getItemStackClass(), BukkitConverters.getItemStackConverter())

src/main/java/com/comphenix/protocol/wrappers/WrappedPositionPath.java

@@ -0,0 +1,207 @@
+package com.comphenix.protocol.wrappers;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.ParameterizedType;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import com.comphenix.protocol.reflect.EquivalentConverter;
+import com.comphenix.protocol.reflect.StructureModifier;
+import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
+import com.comphenix.protocol.utility.MinecraftReflection;
+
+import com.google.common.base.Preconditions;
+import org.bukkit.util.Vector;
+
+/**
+ * Wrapper around the NMS {@code PositionPath} type, introduced in Minecraft 26.3.
+ * <p>
+ * Used by {@code ENTITY_POSITION_SYNC} to store the entity position. A path is either linear (a single position) or
+ * stepped (several positions reached at given ticks).
+ * <pre>{@code
+ * packet.getPositionPaths().write(0, WrappedPositionPath.linear(new Vector(x, y, z)));
+ * }</pre>
+ */
+public final class WrappedPositionPath extends AbstractWrapper {
+
+    private static Class<?> STEPPED_CLASS;
+
+    private static ConstructorAccessor LINEAR_CONSTRUCTOR;
+    private static ConstructorAccessor STEPPED_CONSTRUCTOR;
+    private static ConstructorAccessor STEP_CONSTRUCTOR;
+
+    private static StructureModifier<Object> LINEAR_MODIFIER;
+    private static StructureModifier<Object> STEPPED_MODIFIER;
+    private static StructureModifier<Object> STEP_MODIFIER;
+
+    private static volatile boolean initialized;
+
+    private WrappedPositionPath(Object handle) {
+        super(getPositionPathClass());
+        setHandle(handle);
+    }
+
+    private static Class<?> getPositionPathClass() {
+        return MinecraftReflection.getPositionPathClass()
+                .orElseThrow(() -> new UnsupportedOperationException("PositionPath requires Minecraft 26.3 or newer"));
+    }
+
+    private static void initialize() {
+        if (initialized) {
+            return;
+        }
+
+        Class<?> pathClass = getPositionPathClass();
+        Class<?> vec3Class = MinecraftReflection.getVec3DClass();
+        Class<?> linearClass = null;
+        Class<?> stepClass = null;
+
+        for (Class<?> nested : pathClass.getDeclaredClasses()) {
+            if (!pathClass.isAssignableFrom(nested)) {
+                continue;
+            }
+
+            Field steps = getListField(nested);
+            if (steps != null) {
+                STEPPED_CLASS = nested;
+                stepClass = (Class<?>) ((ParameterizedType) steps.getGenericType()).getActualTypeArguments()[0];
+            } else {
+                linearClass = nested;
+            }
+        }
+
+        Preconditions.checkState(linearClass != null && STEPPED_CLASS != null, "Unable to find PositionPath implementations");
+
+        LINEAR_CONSTRUCTOR = Accessors.getConstructorAccessor(linearClass, vec3Class);
+        STEPPED_CONSTRUCTOR = Accessors.getConstructorAccessor(STEPPED_CLASS, List.class);
+        STEP_CONSTRUCTOR = Accessors.getConstructorAccessor(stepClass, vec3Class, int.class);
+
+        LINEAR_MODIFIER = new StructureModifier<>(linearClass);
+        STEPPED_MODIFIER = new StructureModifier<>(STEPPED_CLASS);
+        STEP_MODIFIER = new StructureModifier<>(stepClass);
+        initialized = true;
+    }
+
+    private static Field getListField(Class<?> clazz) {
+        for (Field field : clazz.getDeclaredFields()) {
+            if (List.class.equals(field.getType())) {
+                return field;
+            }
+        }
+        return null;
+    }
+
+    public static WrappedPositionPath fromHandle(Object handle) {
+        return new WrappedPositionPath(handle);
+    }
+
+    /**
+     * Creates a linear path.
+     *
+     * @param position - the absolute position.
+     * @return the path.
+     */
+    public static WrappedPositionPath linear(Vector position) {
+        Preconditions.checkNotNull(position, "position cannot be NULL");
+        initialize();
+        return new WrappedPositionPath(LINEAR_CONSTRUCTOR.invoke(BukkitConverters.getVectorConverter().getGeneric(position)));
+    }
+
+    /**
+     * Creates a stepped path ending at the position of the last step.
+     *
+     * @param steps - the steps in order, must not be empty.
+     * @return the path.
+     */
+    public static WrappedPositionPath stepped(List<Step> steps) {
+        Preconditions.checkArgument(steps != null && !steps.isEmpty(), "steps cannot be empty");
+        initialize();
+
+        EquivalentConverter<Vector> vectorConverter = BukkitConverters.getVectorConverter();
+        List<Object> handles = new ArrayList<>(steps.size());
+        for (Step step : steps) {
+            handles.add(STEP_CONSTRUCTOR.invoke(vectorConverter.getGeneric(step.getPosition()), step.getTickOffset()));
+        }
+
+        return new WrappedPositionPath(STEPPED_CONSTRUCTOR.invoke(Collections.unmodifiableList(handles)));
+    }
+
+    public boolean isStepped() {
+        initialize();
+        return STEPPED_CLASS.isInstance(handle);
+    }
+
+    /**
+     * @return the final position of the path.
+     */
+    public Vector getEndPosition() {
+        StructureModifier<Object> modifier = isStepped() ? STEPPED_MODIFIER : LINEAR_MODIFIER;
+        return modifier.withTarget(handle)
+                .withType(MinecraftReflection.getVec3DClass(), BukkitConverters.getVectorConverter())
+                .read(0);
+    }
+
+    /**
+     * @return the steps of a stepped path.
+     * @throws IllegalStateException if the path is linear.
+     */
+    public List<Step> getSteps() {
+        Preconditions.checkState(isStepped(), "Linear paths have no steps");
+
+        List<?> handles = STEPPED_MODIFIER.withTarget(handle).<List<?>>withType(List.class).read(0);
+        List<Step> steps = new ArrayList<>(handles.size());
+        for (Object stepHandle : handles) {
+            StructureModifier<Object> step = STEP_MODIFIER.withTarget(stepHandle);
+            Vector position = step.withType(MinecraftReflection.getVec3DClass(), BukkitConverters.getVectorConverter()).read(0);
+            steps.add(new Step(position, step.<Integer>withType(int.class).read(0)));
+        }
+
+        return Collections.unmodifiableList(steps);
+    }
+
+    public static EquivalentConverter<WrappedPositionPath> getConverter() {
+        return Converters.ignoreNull(Converters.handle(AbstractWrapper::getHandle,
+                WrappedPositionPath::fromHandle, WrappedPositionPath.class));
+    }
+
+    public static final class Step {
+
+        private final Vector position;
+        private final int tickOffset;
+
+        public Step(Vector position, int tickOffset) {
+            this.position = Preconditions.checkNotNull(position, "position cannot be NULL").clone();
+            this.tickOffset = tickOffset;
+        }
+
+        public Vector getPosition() {
+            return position.clone();
+        }
+
+        public int getTickOffset() {
+            return tickOffset;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) return true;
+            if (!(obj instanceof Step)) return false;
+
+            Step that = (Step) obj;
+            return tickOffset == that.tickOffset && position.equals(that.position);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(position, tickOffset);
+        }
+
+        @Override
+        public String toString() {
+            return "Step[position=" + position + ", tickOffset=" + tickOffset + "]";
+        }
+    }
+}

src/main/java/com/comphenix/protocol/wrappers/WrappedStatistic.java

@@ -16,15 +16,26 @@ import com.comphenix.protocol.utility.MinecraftReflection;
 public class WrappedStatistic extends AbstractWrapper {
     private static final Class<?> STATISTIC = MinecraftReflection.getStatisticClass();
     private static final Class<?> STATISTIC_LIST = MinecraftReflection.getStatisticListClass();
-
+    private static final FieldAccessor GET_NAME_FIELD;
+    private static final MethodAccessor GET_NAME_METHOD;
 
     static {
+        FieldAccessor[] nameFields = Accessors.getFieldAccessorArray(STATISTIC, String.class, true);
+        if (nameFields.length > 0) {
+            GET_NAME_FIELD = nameFields[0];
+            GET_NAME_METHOD = null;
+        } else {
+            GET_NAME_FIELD = null;
+            GET_NAME_METHOD = Accessors.getMethodAccessor(
+                    FuzzyReflection.fromClass(STATISTIC.getSuperclass(), true)
+                            .getMethodByReturnTypeAndParameters("getName", String.class));
+        }
+
         try {
             FIND_STATISTICS = Accessors.getMethodAccessor(
                     FuzzyReflection.fromClass(STATISTIC_LIST).getMethodByReturnTypeAndParameters(
                             "findStatistic", STATISTIC, new Class<?>[]{String.class}));
             MAP_ACCESSOR = Accessors.getFieldAccessor(STATISTIC_LIST, Map.class, true);
-            GET_NAME = Accessors.getFieldAccessor(STATISTIC, String.class, true);
         } catch (Exception ex) {
             // TODO - find an alternative
         }
@@ -32,7 +43,6 @@ public class WrappedStatistic extends AbstractWrapper {
 
     private static MethodAccessor FIND_STATISTICS;
     private static FieldAccessor MAP_ACCESSOR;
-    private static FieldAccessor GET_NAME;
     
     private final String name;
     
@@ -40,7 +50,9 @@ public class WrappedStatistic extends AbstractWrapper {
         super(STATISTIC);
         setHandle(handle);
         
-        this.name = (String) GET_NAME.get(handle);
+        this.name = GET_NAME_FIELD != null
+                ? (String) GET_NAME_FIELD.get(handle)
+                : (String) GET_NAME_METHOD.invoke(handle);
     }
     
     /**

src/main/java/com/comphenix/protocol/wrappers/WrappedVecDelta.java

@@ -0,0 +1,237 @@
+package com.comphenix.protocol.wrappers;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.ParameterizedType;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import com.comphenix.protocol.reflect.EquivalentConverter;
+import com.comphenix.protocol.reflect.StructureModifier;
+import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
+import com.comphenix.protocol.utility.MinecraftReflection;
+
+import com.google.common.base.Preconditions;
+
+/**
+ * Wrapper around the NMS {@code VecDelta} type, introduced in Minecraft 26.3.
+ * <p>
+ * Used by {@code REL_ENTITY_MOVE} and {@code REL_ENTITY_MOVE_LOOK} to store the position change. A delta is either
+ * linear (a single offset) or stepped (several offsets reached at given ticks). Offsets use the same encoding as the
+ * short fields of older versions.
+ * <pre>{@code
+ * packet.getVecDeltas().write(0, WrappedVecDelta.linear(deltaX, deltaY, deltaZ));
+ * }</pre>
+ */
+public final class WrappedVecDelta extends AbstractWrapper {
+
+    private static Class<?> STEPPED_CLASS;
+
+    private static ConstructorAccessor LINEAR_CONSTRUCTOR;
+    private static ConstructorAccessor STEPPED_CONSTRUCTOR;
+    private static ConstructorAccessor STEP_CONSTRUCTOR;
+
+    private static StructureModifier<Object> LINEAR_MODIFIER;
+    private static StructureModifier<Object> STEPPED_MODIFIER;
+    private static StructureModifier<Object> STEP_MODIFIER;
+
+    private static volatile boolean initialized;
+
+    private WrappedVecDelta(Object handle) {
+        super(getVecDeltaClass());
+        setHandle(handle);
+    }
+
+    private static Class<?> getVecDeltaClass() {
+        return MinecraftReflection.getVecDeltaClass()
+                .orElseThrow(() -> new UnsupportedOperationException("VecDelta requires Minecraft 26.3 or newer"));
+    }
+
+    private static void initialize() {
+        if (initialized) {
+            return;
+        }
+
+        Class<?> vecDeltaClass = getVecDeltaClass();
+        Class<?> linearClass = null;
+        Class<?> stepClass = null;
+
+        for (Class<?> nested : vecDeltaClass.getDeclaredClasses()) {
+            if (!vecDeltaClass.isAssignableFrom(nested)) {
+                continue;
+            }
+
+            Field steps = getListField(nested);
+            if (steps != null) {
+                STEPPED_CLASS = nested;
+                stepClass = (Class<?>) ((ParameterizedType) steps.getGenericType()).getActualTypeArguments()[0];
+            } else {
+                linearClass = nested;
+            }
+        }
+
+        Preconditions.checkState(linearClass != null && STEPPED_CLASS != null, "Unable to find VecDelta implementations");
+
+        LINEAR_CONSTRUCTOR = Accessors.getConstructorAccessor(linearClass, short.class, short.class, short.class);
+        STEPPED_CONSTRUCTOR = Accessors.getConstructorAccessor(STEPPED_CLASS, List.class);
+        STEP_CONSTRUCTOR = Accessors.getConstructorAccessor(stepClass, short.class, short.class, short.class, int.class);
+
+        LINEAR_MODIFIER = new StructureModifier<>(linearClass);
+        STEPPED_MODIFIER = new StructureModifier<>(STEPPED_CLASS);
+        STEP_MODIFIER = new StructureModifier<>(stepClass);
+        initialized = true;
+    }
+
+    private static Field getListField(Class<?> clazz) {
+        for (Field field : clazz.getDeclaredFields()) {
+            if (List.class.equals(field.getType())) {
+                return field;
+            }
+        }
+        return null;
+    }
+
+    public static WrappedVecDelta fromHandle(Object handle) {
+        return new WrappedVecDelta(handle);
+    }
+
+    /**
+     * Creates a linear delta.
+     *
+     * @param deltaX - the encoded x offset.
+     * @param deltaY - the encoded y offset.
+     * @param deltaZ - the encoded z offset.
+     * @return the delta.
+     */
+    public static WrappedVecDelta linear(short deltaX, short deltaY, short deltaZ) {
+        initialize();
+        return new WrappedVecDelta(LINEAR_CONSTRUCTOR.invoke(deltaX, deltaY, deltaZ));
+    }
+
+    /**
+     * Creates a stepped delta.
+     *
+     * @param steps - the steps in order, must not be empty.
+     * @return the delta.
+     */
+    public static WrappedVecDelta stepped(List<Step> steps) {
+        Preconditions.checkArgument(steps != null && !steps.isEmpty(), "steps cannot be empty");
+        initialize();
+
+        List<Object> handles = new ArrayList<>(steps.size());
+        for (Step step : steps) {
+            handles.add(STEP_CONSTRUCTOR.invoke(step.getDeltaX(), step.getDeltaY(), step.getDeltaZ(), step.getTicks()));
+        }
+
+        return new WrappedVecDelta(STEPPED_CONSTRUCTOR.invoke(Collections.unmodifiableList(handles)));
+    }
+
+    public boolean isStepped() {
+        initialize();
+        return STEPPED_CLASS.isInstance(handle);
+    }
+
+    /**
+     * @return the encoded x offset of a linear delta.
+     * @throws IllegalStateException if the delta is stepped.
+     */
+    public short getDeltaX() {
+        return readLinear(0);
+    }
+
+    /**
+     * @return the encoded y offset of a linear delta.
+     * @throws IllegalStateException if the delta is stepped.
+     */
+    public short getDeltaY() {
+        return readLinear(1);
+    }
+
+    /**
+     * @return the encoded z offset of a linear delta.
+     * @throws IllegalStateException if the delta is stepped.
+     */
+    public short getDeltaZ() {
+        return readLinear(2);
+    }
+
+    private short readLinear(int index) {
+        Preconditions.checkState(!isStepped(), "Stepped deltas have no single offset");
+        return LINEAR_MODIFIER.withTarget(handle).<Short>withType(short.class).read(index);
+    }
+
+    /**
+     * @return the steps of a stepped delta.
+     * @throws IllegalStateException if the delta is linear.
+     */
+    public List<Step> getSteps() {
+        Preconditions.checkState(isStepped(), "Linear deltas have no steps");
+
+        List<?> handles = STEPPED_MODIFIER.withTarget(handle).<List<?>>withType(List.class).read(0);
+        List<Step> steps = new ArrayList<>(handles.size());
+        for (Object stepHandle : handles) {
+            StructureModifier<Object> step = STEP_MODIFIER.withTarget(stepHandle);
+            StructureModifier<Short> shorts = step.withType(short.class);
+            steps.add(new Step(shorts.read(0), shorts.read(1), shorts.read(2), step.<Integer>withType(int.class).read(0)));
+        }
+
+        return Collections.unmodifiableList(steps);
+    }
+
+    public static EquivalentConverter<WrappedVecDelta> getConverter() {
+        return Converters.ignoreNull(Converters.handle(AbstractWrapper::getHandle,
+                WrappedVecDelta::fromHandle, WrappedVecDelta.class));
+    }
+
+    public static final class Step {
+
+        private final short deltaX;
+        private final short deltaY;
+        private final short deltaZ;
+        private final int ticks;
+
+        public Step(short deltaX, short deltaY, short deltaZ, int ticks) {
+            this.deltaX = deltaX;
+            this.deltaY = deltaY;
+            this.deltaZ = deltaZ;
+            this.ticks = ticks;
+        }
+
+        public short getDeltaX() {
+            return deltaX;
+        }
+
+        public short getDeltaY() {
+            return deltaY;
+        }
+
+        public short getDeltaZ() {
+            return deltaZ;
+        }
+
+        public int getTicks() {
+            return ticks;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) return true;
+            if (!(obj instanceof Step)) return false;
+
+            Step that = (Step) obj;
+            return deltaX == that.deltaX && deltaY == that.deltaY && deltaZ == that.deltaZ && ticks == that.ticks;
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(deltaX, deltaY, deltaZ, ticks);
+        }
+
+        @Override
+        public String toString() {
+            return "Step[deltaX=" + deltaX + ", deltaY=" + deltaY + ", deltaZ=" + deltaZ + ", ticks=" + ticks + "]";
+        }
+    }
+}

src/test/java/com/comphenix/protocol/BukkitInitialization.java

@@ -3,16 +3,19 @@ package com.comphenix.protocol;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
-import java.util.concurrent.Executors;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
 import com.comphenix.protocol.utility.MinecraftReflectionTestUtil;
 
 import com.google.common.base.Preconditions;
 import com.google.common.util.concurrent.MoreExecutors;
+import io.papermc.paper.configuration.GlobalConfiguration;
+import io.papermc.paper.configuration.WorldConfiguration;
+import io.papermc.paper.registry.PaperRegistryAccess;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
 import net.minecraft.SharedConstants;
 import net.minecraft.commands.Commands;
 import net.minecraft.core.HolderLookup;
@@ -23,12 +26,12 @@ import net.minecraft.core.registries.Registries;
 import net.minecraft.resources.RegistryDataLoader;
 import net.minecraft.resources.Identifier;
 import net.minecraft.server.Bootstrap;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.RegistryLayer;
 import net.minecraft.server.ReloadableServerResources;
 import net.minecraft.server.dedicated.DedicatedServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.packs.PackType;
-import net.minecraft.server.packs.repository.Pack;
 import net.minecraft.server.packs.repository.PackRepository;
 import net.minecraft.server.packs.repository.ServerPacksSource;
 import net.minecraft.server.packs.resources.MultiPackResourceManager;
@@ -37,10 +40,13 @@ import net.minecraft.server.permissions.LevelBasedPermissionSet;
 import net.minecraft.server.permissions.PermissionSet;
 import net.minecraft.tags.TagKey;
 import net.minecraft.tags.TagLoader;
+import net.minecraft.util.Util;
 import net.minecraft.world.entity.EntityType;
 import net.minecraft.world.flag.FeatureFlags;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.enchantment.Enchantments;
+import net.minecraft.world.level.DataPackConfig;
+import net.minecraft.world.level.WorldDataConfiguration;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.material.Fluid;
 import org.apache.logging.log4j.LogManager;
@@ -126,30 +132,69 @@ public class BukkitInitialization {
             // Minecraft Data Init
             SharedConstants.tryDetectVersion(); // .tryDetectVersion()
             Bootstrap.bootStrap(); // .bootStrap()
+            Bootstrap.validate();
 
             PackRepository repo = ServerPacksSource.createVanillaTrustedRepository();
-            repo.reload();
+            MinecraftServer.configurePackRepository(
+                    repo,
+                    new WorldDataConfiguration(
+                            new DataPackConfig(
+                                    FeatureFlags.REGISTRY.toNames(FeatureFlags.REGISTRY.allFlags())
+                                            .stream()
+                                            .map(Identifier::getPath)
+                                            .toList(),
+                                    List.of()),
+                            FeatureFlags.REGISTRY.allFlags()),
+                    true,
+                    false);
 
             ResourceManager resourceManager = new MultiPackResourceManager(
                 PackType.SERVER_DATA,
-                repo.getAvailablePacks().stream().map(Pack::open).collect(Collectors.toList())
+                repo.openAllSelected()
             );
 
             LayeredRegistryAccess<RegistryLayer> layeredAccess1 = RegistryLayer.createRegistryAccess();
             List<net.minecraft.core.Registry.PendingTags<?>> tags = TagLoader.loadTagsForExistingRegistries(resourceManager, layeredAccess1.getLayer(RegistryLayer.STATIC));
-            RegistryAccess.Frozen access1 = layeredAccess1.getAccessForLoading(RegistryLayer.WORLDGEN);
+            RegistryAccess.Frozen access1 = layeredAccess1.getAccessForLoading(RegistryLayer.WORLD);
             List<HolderLookup.RegistryLookup<?>> list1 = TagLoader.buildUpdatedLookups(access1, tags);
 
             RegistryAccess.Frozen access2;
 
             try {
-                access2 = RegistryDataLoader.load(resourceManager, list1, RegistryDataLoader.WORLDGEN_REGISTRIES, Executors.newSingleThreadExecutor()).get();
+                access2 = RegistryDataLoader.load(
+                        resourceManager,
+                        list1,
+                        RegistryDataLoader.WORLD_REGISTRIES,
+                        Util.backgroundExecutor()).get();
             } catch (Exception ex) {
                 throw new RuntimeException(ex);
             }
-            
-            LayeredRegistryAccess<RegistryLayer> layeredAccess2 = layeredAccess1.replaceFrom(RegistryLayer.WORLDGEN, access2);
+
+            LayeredRegistryAccess<RegistryLayer> layeredAccess2 =
+                    layeredAccess1.replaceFrom(RegistryLayer.WORLD, access2);
+            List<HolderLookup.RegistryLookup<?>> dimensionLookups =
+                    Stream.concat(list1.stream(), access2.listRegistries()).toList();
+            RegistryAccess.Frozen dimensions = RegistryDataLoader.load(
+                    resourceManager,
+                    dimensionLookups,
+                    RegistryDataLoader.DIMENSION_REGISTRIES,
+                    Util.backgroundExecutor()).join();
+            layeredAccess2 = layeredAccess2.replaceFrom(RegistryLayer.DIMENSIONS, dimensions);
+
+            try {
+                Class.forName(Registry.class.getName());
+            } catch (ClassNotFoundException exception) {
+                throw new RuntimeException(exception);
+            }
+
             RegistryAccess.Frozen registryCustom = layeredAccess2.compositeAccess().freeze();
+            PaperRegistryAccess paperRegistryAccess = PaperRegistryAccess.instance();
+            GlobalConfiguration globalConfiguration = new GlobalConfiguration();
+            globalConfiguration.collisions = globalConfiguration.new Collisions();
+            Accessors.getMethodAccessor(
+                    GlobalConfiguration.class,
+                    "set",
+                    GlobalConfiguration.class).invoke(null, globalConfiguration);
 
             ReloadableServerResources dataPackResources = ReloadableServerResources.loadResources(
                 resourceManager,
@@ -177,6 +222,13 @@ public class BukkitInitialization {
             DedicatedServer mockedGameServer = mock(DedicatedServer.class);
 
             when(mockedGameServer.registryAccess()).thenReturn(registryCustom);
+            try {
+                FieldAccessor serverInstance = Accessors.getFieldAccessor(
+                        MinecraftServer.class.getDeclaredField("SERVER"));
+                serverInstance.set(null, mockedGameServer);
+            } catch (NoSuchFieldException exception) {
+                throw new RuntimeException(exception);
+            }
 
             when(mockedServer.getLogger()).thenReturn(java.util.logging.Logger.getLogger("Minecraft"));
             when(mockedServer.getName()).thenReturn("Mock Server");
@@ -193,7 +245,7 @@ public class BukkitInitialization {
             });
             when(mockedServer.getRegistry(any())).thenAnswer(invocation -> {
                 Class<Keyed> registryType = invocation.getArgument(0);
-                Object registry = CraftRegistry.createRegistry(registryType, registryCustom);
+                Object registry = paperRegistryAccess.getRegistry(registryType);
 
                 if (registry == null) {
                     System.err.println("WARN: Missing registry for " + registryType);
@@ -245,6 +297,18 @@ public class BukkitInitialization {
 
             ServerLevel nmsWorld = mock(ServerLevel.class);
             SpigotWorldConfig mockWorldConfig = mock(SpigotWorldConfig.class);
+            ConstructorAccessor worldConfigurationConstructor = Accessors.getConstructorAccessor(
+                    WorldConfiguration.class,
+                    SpigotWorldConfig.class,
+                    Identifier.class);
+            WorldConfiguration worldConfiguration = (WorldConfiguration) worldConfigurationConstructor.invoke(
+                    mockWorldConfig,
+                    Identifier.parse("minecraft:test"));
+            worldConfiguration.entities = worldConfiguration.new Entities();
+            worldConfiguration.entities.spawning =
+                    worldConfiguration.entities.new Spawning();
+            worldConfiguration.entities.spawning.despawnTime = new Reference2ObjectOpenHashMap<>();
+            when(nmsWorld.paperConfig()).thenReturn(worldConfiguration);
 
             try {
                 FieldAccessor spigotConfig = Accessors.getFieldAccessor(nmsWorld.getClass().getField("spigotConfig"));
@@ -311,5 +375,35 @@ public class BukkitInitialization {
             List<T> empty = Collections.emptyList();
             return empty.stream();
         }
+
+        @Override
+        public Stream<NamespacedKey> keyStream() {
+            return Stream.empty();
+        }
+
+        @Override
+        public NamespacedKey getKey(T value) {
+            return null;
+        }
+
+        @Override
+        public boolean hasTag(io.papermc.paper.registry.tag.TagKey<T> key) {
+            return false;
+        }
+
+        @Override
+        public io.papermc.paper.registry.tag.Tag<T> getTag(io.papermc.paper.registry.tag.TagKey<T> key) {
+            return null;
+        }
+
+        @Override
+        public java.util.Collection<io.papermc.paper.registry.tag.Tag<T>> getTags() {
+            return Collections.emptyList();
+        }
+
+        @Override
+        public int size() {
+            return 0;
+        }
     }
 }

src/test/java/com/comphenix/protocol/PacketTypeTest.java

@@ -16,6 +16,7 @@ package com.comphenix.protocol;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -35,6 +36,8 @@ import com.comphenix.protocol.injector.packet.PacketRegistry;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.wrappers.WrappedChatComponent;
 
+import net.minecraft.network.protocol.common.ClientboundPostEffectsPacket;
+import net.minecraft.network.protocol.common.ClientboundStoreCookiePacket;
 import net.minecraft.network.protocol.login.ServerboundHelloPacket;
 
 /**
@@ -254,6 +257,27 @@ public class PacketTypeTest {
             assertEquals(type, roundTrip);
         }
     }
+
+    @Test
+    public void testMinecraft263PacketMappings() {
+        assertEquals(0x25, PacketType.Play.Server.ADD_TRANSIENT_BLOCK.getCurrentId());
+        assertEquals(0x26, PacketType.Play.Server.UNLOAD_CHUNK.getCurrentId());
+        assertNotEquals(PacketType.Play.Server.ADD_TRANSIENT_BLOCK, PacketType.Play.Server.UNLOAD_CHUNK);
+
+        assertEquals(0x53, PacketType.Play.Server.POST_EFFECTS.getCurrentId());
+        assertEquals(0x7B, PacketType.Play.Server.SWING_ANIMATION.getCurrentId());
+        assertEquals(0x2E, PacketType.Play.Client.PUNCH.getCurrentId());
+        assertNotEquals(PacketType.Play.Client.PUNCH, PacketType.Play.Client.RECIPE_SETTINGS);
+    }
+
+    @Test
+    public void testMinecraft263ConfigurationPacketMappings() {
+        assertEquals(0x0A, PacketType.Configuration.Server.POST_EFFECTS.getCurrentId());
+        assertEquals(ClientboundPostEffectsPacket.class, PacketType.Configuration.Server.POST_EFFECTS.getPacketClass());
+        assertEquals(0x0B, PacketType.Configuration.Server.STORE_COOKIE.getCurrentId());
+        assertEquals(ClientboundStoreCookiePacket.class, PacketType.Configuration.Server.STORE_COOKIE.getPacketClass());
+        assertEquals(0x14, PacketType.Configuration.Server.CODE_OF_CONDUCT.getCurrentId());
+    }
     
     @Test
     public void testPacketCodec() {

src/test/java/com/comphenix/protocol/PlatformCommandRegistrarTest.java

@@ -0,0 +1,54 @@
+package com.comphenix.protocol;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.List;
+
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+import com.comphenix.protocol.paper.PaperPlatformProvider;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+
+import io.papermc.paper.command.brigadier.BasicCommand;
+import io.papermc.paper.command.brigadier.CommandSourceStack;
+
+class PlatformCommandRegistrarTest {
+
+    @Test
+    void registersLegacyExecutorAsPaperCommand() throws CommandSyntaxException {
+        ProtocolLib plugin = mock(ProtocolLib.class);
+        CommandExecutor executor = mock(CommandExecutor.class);
+        ArgumentCaptor<BasicCommand> commandCaptor = ArgumentCaptor.forClass(BasicCommand.class);
+
+        new PaperPlatformProvider().registerCommand(plugin, "filter", executor);
+
+        verify(plugin).registerCommand(
+                eq("filter"),
+                eq("Add or remove programmable filters to the packet listeners."),
+                eq(List.of("packet_filter")),
+                commandCaptor.capture());
+
+        CommandSourceStack source = mock(CommandSourceStack.class);
+        CommandSender sender = mock(CommandSender.class);
+        when(source.getSender()).thenReturn(sender);
+
+        ArgumentCaptor<Command> legacyCommand = ArgumentCaptor.forClass(Command.class);
+        String[] arguments = {"add"};
+        when(executor.onCommand(eq(sender), legacyCommand.capture(), eq("filter"), eq(arguments)))
+                .thenReturn(false);
+
+        commandCaptor.getValue().execute(source, arguments);
+
+        assertEquals("filter", legacyCommand.getValue().getName());
+        assertEquals("protocol.admin", commandCaptor.getValue().permission());
+        verify(sender).sendMessage("/filter add|remove name [ID start]-[ID stop]");
+    }
+}

src/test/java/com/comphenix/protocol/async/AsyncFilterManagerTest.java

@@ -0,0 +1,36 @@
+package com.comphenix.protocol.async;
+
+import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.ProtocolManager;
+import com.comphenix.protocol.error.ErrorReporter;
+import com.comphenix.protocol.events.PacketAdapter;
+import com.comphenix.protocol.scheduler.ProtocolScheduler;
+
+import org.bukkit.plugin.Plugin;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+
+class AsyncFilterManagerTest {
+
+    @BeforeAll
+    static void initializeBukkit() {
+        BukkitInitialization.initializeAll();
+    }
+
+    @Test
+    void testSendingTypesUseServerProcessingQueue() {
+        AsyncFilterManager manager = new AsyncFilterManager(
+                mock(ErrorReporter.class), mock(ProtocolScheduler.class));
+        manager.setManager(mock(ProtocolManager.class));
+        manager.registerAsyncHandler(new PacketAdapter(
+                mock(Plugin.class), PacketType.Play.Server.SYSTEM_CHAT) { }, false);
+
+        assertTrue(manager.getSendingTypes().contains(PacketType.Play.Server.SYSTEM_CHAT));
+        assertFalse(manager.getReceivingTypes().contains(PacketType.Play.Server.SYSTEM_CHAT));
+    }
+}

src/test/java/com/comphenix/protocol/collections/IntegerMapTest.java

@@ -5,6 +5,7 @@ import com.comphenix.protocol.utility.IntegerMath;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 class IntegerMapTest {
     @Test
@@ -21,4 +22,15 @@ class IntegerMapTest {
         }
         assertEquals(map.size(), 512);
     }
-}
+
+    @Test
+    public void testRemoveOutsideBounds() {
+        IntegerMap<Boolean> map = new IntegerMap<>();
+        map.put(0, true);
+
+        assertNull(map.remove(-1));
+        assertEquals(1, map.size());
+        assertNull(map.remove(8));
+        assertEquals(1, map.size());
+    }
+}

src/test/java/com/comphenix/protocol/concurrency/ConcurrentPlayerMapTest.java

@@ -0,0 +1,20 @@
+package com.comphenix.protocol.concurrency;
+
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+
+class ConcurrentPlayerMapTest {
+
+    @Test
+    void testPutIfAbsentWithUnavailableAddress() {
+        ConcurrentPlayerMap<Object> map = ConcurrentPlayerMap.usingAddress();
+        Player player = mock(Player.class);
+
+        assertThrows(IllegalStateException.class, () -> map.putIfAbsent(player, new Object()));
+        assertTrue(map.isEmpty());
+    }
+}

src/test/java/com/comphenix/protocol/events/PacketContainerTest.java

@@ -23,6 +23,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertInstanceOf;
 import static org.junit.jupiter.api.Assertions.assertNotSame;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -41,6 +42,8 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ThreadLocalRandom;
 
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import net.minecraft.network.protocol.game.ClientboundAddEntityPacket;
 import org.apache.commons.lang.SerializationUtils;
 import org.bukkit.ChatColor;
@@ -70,6 +73,7 @@ import com.comphenix.protocol.utility.MinecraftMethods;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.wrappers.BlockPosition;
 import com.comphenix.protocol.wrappers.BukkitConverters;
+import com.comphenix.protocol.wrappers.Converters;
 import com.comphenix.protocol.wrappers.ComponentConverter;
 import com.comphenix.protocol.wrappers.CustomPacketPayloadWrapper;
 import com.comphenix.protocol.wrappers.EnumWrappers;
@@ -101,6 +105,10 @@ import net.md_5.bungee.api.chat.ComponentBuilder;
 import net.md_5.bungee.api.chat.HoverEvent;
 import net.md_5.bungee.api.chat.hover.content.Text;
 import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.protocol.common.custom.BrandPayload;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
+import net.minecraft.network.protocol.common.custom.DiscardedPayload;
 import net.minecraft.network.protocol.game.ClientboundGameEventPacket;
 import net.minecraft.network.protocol.game.ClientboundUpdateAttributesPacket;
 import net.minecraft.network.protocol.game.ClientboundUpdateAttributesPacket.AttributeSnapshot;
@@ -177,8 +185,8 @@ public class PacketContainerTest {
 
     @Test
     public void testGetShorts() {
-        PacketContainer itemData = new PacketContainer(PacketType.Play.Server.REL_ENTITY_MOVE);
-        this.testPrimitive(itemData.getShorts(), 0, (short) 0, (short) 1);
+        PacketContainer creativeSlot = new PacketContainer(PacketType.Play.Client.SET_CREATIVE_SLOT);
+        this.testPrimitive(creativeSlot.getShorts(), 0, (short) 0, (short) 1);
     }
 
     @Test
@@ -423,6 +431,64 @@ public class PacketContainerTest {
         Assertions.assertNotSame(payload, cloned);
     }
 
+    @Test
+    public void testCustomPayloadConcreteSerialization() {
+        BrandPayload payload = new BrandPayload("Hello World!");
+
+        CustomPacketPayloadWrapper wrapper = CustomPacketPayloadWrapper.fromUnknownPayload(payload);
+
+        assertEquals(BrandPayload.TYPE.id().toString(), wrapper.getId().getFullKey());
+        FriendlyByteBuf buffer = new FriendlyByteBuf(Unpooled.wrappedBuffer(wrapper.getPayload()));
+        try {
+            assertEquals("Hello World!", buffer.readUtf());
+            assertEquals(0, buffer.readableBytes());
+        } finally {
+            buffer.release();
+        }
+    }
+
+    @Test
+    public void testCustomPayloadSerializationFailureReleasesBuffer() {
+        FailingPayload payload = new FailingPayload();
+
+        assertThrows(RuntimeException.class, () -> CustomPacketPayloadWrapper.fromUnknownPayload(payload));
+
+        assertEquals(0, payload.buffer.refCnt());
+    }
+
+    @Test
+    public void testCustomPayloadCreatesDiscardedPayload() {
+        byte[] data = {0x00, 0x01, 0x05, 0x07};
+        com.comphenix.protocol.wrappers.MinecraftKey id =
+                new com.comphenix.protocol.wrappers.MinecraftKey("protocollib", "test");
+        CustomPacketPayloadWrapper wrapper = new CustomPacketPayloadWrapper(data, id);
+
+        Object handle = wrapper.newHandle();
+
+        assertInstanceOf(DiscardedPayload.class, handle);
+        CustomPacketPayloadWrapper converted = CustomPacketPayloadWrapper.fromUnknownPayload(handle);
+        assertEquals(id, converted.getId());
+        assertArrayEquals(data, converted.getPayload());
+    }
+
+    private static final class FailingPayload implements CustomPacketPayload {
+        private static final Type<FailingPayload> TYPE =
+                new Type<>(Identifier.fromNamespaceAndPath("protocollib", "failing"));
+
+        private ByteBuf buffer;
+
+        @SuppressWarnings("unused")
+        private void write(FriendlyByteBuf buffer) {
+            this.buffer = buffer;
+            throw new IllegalStateException("expected failure");
+        }
+
+        @Override
+        public Type<FailingPayload> type() {
+            return TYPE;
+        }
+    }
+
 	/*
     @Test
     public void testUnknownPayloadDeserialize() {
@@ -878,6 +944,32 @@ public class PacketContainerTest {
         assertArrayEquals(signature, read.getBytes());
     }
 
+    @Test
+    public void testAbsentChatMessageSignature() {
+        PacketContainer chatPacket = new PacketContainer(PacketType.Play.Client.CHAT);
+        StructureModifier<WrappedMessageSignature> signatures = chatPacket.getMessageSignatures();
+
+        signatures.write(0, new WrappedMessageSignature(new byte[256]));
+        signatures.write(0, null);
+
+        assertNull(signatures.read(0));
+        assertEquals(Optional.empty(), chatPacket.getModifier().withType(Optional.class).read(0));
+    }
+
+    @Test
+    public void testMessageSignaturesDoNotShadowOptionals() {
+        PacketContainer chatPacket = new PacketContainer(PacketType.Play.Server.CHAT);
+        byte[] signature = new byte[256];
+        signature[0] = 42;
+
+        assertEquals(1, chatPacket.getMessageSignatures().size());
+        assertEquals(2, chatPacket.getOptionals(Converters.passthrough(Object.class)).size());
+        assertEquals(1, chatPacket.getMessageSignatures().size());
+
+        chatPacket.getMessageSignatures().write(0, new WrappedMessageSignature(signature));
+        assertArrayEquals(signature, chatPacket.getMessageSignatures().read(0).getBytes());
+    }
+
     private void assertPacketsEqualAndSerializable(PacketContainer constructed, PacketContainer cloned) {
         StructureModifier<Object> firstMod = constructed.getModifier(), secondMod = cloned.getModifier();
         assertEquals(firstMod.size(), secondMod.size());

src/test/java/com/comphenix/protocol/injector/StructureCacheTests.java

@@ -1,10 +1,16 @@
 package com.comphenix.protocol.injector;
 
+import java.math.BigInteger;
+import java.util.concurrent.atomic.AtomicBoolean;
+
 import com.comphenix.protocol.BukkitInitialization;
 
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertNotSame;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class StructureCacheTests {
@@ -23,4 +29,42 @@ public class StructureCacheTests {
 			assertTrue(ex.getMessage().contains("Cannot inject already loaded type"));
 		}
 	}
+
+	@Test
+	public void testReusesImmutableConstant() {
+		assertSame(BigInteger.ZERO, StructureCache.newInstance(BigInteger.class));
+	}
+
+	@Test
+	public void testDoesNotReuseMutableStaticInstance() {
+		assertNotSame(MutableStaticInstance.INSTANCE, StructureCache.newInstance(MutableStaticInstance.class));
+	}
+
+	@Test
+	public void testCreatorLookupCanReenterCache() {
+		assertTrue(StructureCache.canCreateInstance(ReentrantConstructor.class));
+		assertNull(ReentrantConstructor.failure);
+	}
+
+	private static final class ReentrantConstructor {
+		private static final AtomicBoolean ENTERED = new AtomicBoolean();
+		private static volatile RuntimeException failure;
+
+		private ReentrantConstructor() {
+			if (ENTERED.compareAndSet(false, true)) {
+				try {
+					StructureCache.canCreateInstance(ReentrantConstructor.class);
+				} catch (RuntimeException ex) {
+					failure = ex;
+				}
+			}
+		}
+	}
+
+	private static final class MutableStaticInstance {
+		public static final MutableStaticInstance INSTANCE = new MutableStaticInstance();
+
+		private MutableStaticInstance() {
+		}
+	}
 }

src/test/java/com/comphenix/protocol/injector/WirePacketTest.java

@@ -10,8 +10,22 @@ import com.comphenix.protocol.BukkitInitialization;
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.injector.netty.WirePacket;
+import com.comphenix.protocol.wrappers.CustomPacketPayloadWrapper;
+import com.comphenix.protocol.wrappers.MinecraftKey;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.Unpooled;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.protocol.common.ServerboundKeepAlivePacket;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
+import net.minecraft.network.protocol.game.ClientboundOpenBookPacket;
+import net.minecraft.world.InteractionHand;
+import org.bukkit.Material;
+import org.bukkit.craftbukkit.CraftRegistry;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
+import org.bukkit.inventory.ItemStack;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
@@ -52,6 +66,65 @@ public class WirePacketTest {
         assertEquals(failures, new ArrayList<>());
     }
 
+    @Test
+    public void testBytesFromClientboundPacket() {
+        ClientboundOpenBookPacket handle = new ClientboundOpenBookPacket(InteractionHand.OFF_HAND);
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.OPEN_BOOK, handle);
+
+        assertArrayEquals(new byte[] {1}, WirePacket.bytesFromPacket(packet));
+    }
+
+    @Test
+    public void testBytesFromServerboundPacket() {
+        ServerboundKeepAlivePacket handle = new ServerboundKeepAlivePacket(0x0102030405060708L);
+        PacketContainer packet = new PacketContainer(PacketType.Play.Client.KEEP_ALIVE, handle);
+
+        assertArrayEquals(new byte[] {1, 2, 3, 4, 5, 6, 7, 8}, WirePacket.bytesFromPacket(packet));
+    }
+
+    @Test
+    public void testBytesFromPacketWithItemStack() {
+        ClientboundContainerSetSlotPacket handle = new ClientboundContainerSetSlotPacket(1, 2, 3,
+                CraftItemStack.asNMSCopy(new ItemStack(Material.GOLDEN_SHOVEL)));
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.SET_SLOT, handle);
+
+        // the item stack can only be written to a buffer which knows the registries
+        RegistryFriendlyByteBuf expected = new RegistryFriendlyByteBuf(Unpooled.buffer(),
+                CraftRegistry.getMinecraftRegistry());
+        ClientboundContainerSetSlotPacket.STREAM_CODEC.encode(expected, handle);
+
+        assertArrayEquals(ByteBufUtil.getBytes(expected), WirePacket.bytesFromPacket(packet));
+    }
+
+    @Test
+    public void testFromPacketHandle() {
+        ClientboundOpenBookPacket handle = new ClientboundOpenBookPacket(InteractionHand.MAIN_HAND);
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.OPEN_BOOK, handle);
+
+        WirePacket wire = WirePacket.fromPacket(handle);
+
+        assertEquals(PacketType.Play.Server.OPEN_BOOK.getCurrentId(), wire.getId());
+        assertArrayEquals(new byte[] {0}, wire.getBytes());
+        assertEquals(WirePacket.fromPacket(packet), wire);
+    }
+
+    @Test
+    public void testBytesFromCustomPayloadPacket() {
+        byte[] data = {0x00, 0x01, 0x05, 0x07};
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.CUSTOM_PAYLOAD);
+        packet.getCustomPacketPayloads().write(0,
+                new CustomPacketPayloadWrapper(data, new MinecraftKey("protocollib", "test")));
+
+        FriendlyByteBuf expected = new FriendlyByteBuf(Unpooled.buffer());
+        expected.writeUtf("protocollib:test");
+        expected.writeBytes(data);
+
+        assertArrayEquals(ByteBufUtil.getBytes(expected), WirePacket.bytesFromPacket(packet));
+        // the packet has to stay writable, it is still sent after it was logged
+        assertArrayEquals(ByteBufUtil.getBytes(expected), WirePacket.bytesFromPacket(packet));
+        assertArrayEquals(data, packet.getCustomPacketPayloads().read(0).getPayload());
+    }
+
     @Test
     public void testSerialization() {
         int id = 42;

src/test/java/com/comphenix/protocol/injector/collection/OutboundPacketListenerSetTest.java

@@ -0,0 +1,150 @@
+package com.comphenix.protocol.injector.collection;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Consumer;
+
+import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.error.ErrorReporter;
+import com.comphenix.protocol.events.PacketAdapter;
+import com.comphenix.protocol.events.PacketContainer;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.wrappers.Converters;
+
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotSame;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+
+public class OutboundPacketListenerSetTest {
+
+    @BeforeAll
+    public static void beforeClass() {
+        BukkitInitialization.initializeAll();
+    }
+
+    @Test
+    public void testCancelledSubPacketsCancelBundle() {
+        OutboundPacketListenerSet listenerSet = createListenerSet(event -> event.setCancelled(true));
+        PacketEvent bundleEvent = createBundleEvent();
+
+        listenerSet.invoke(bundleEvent);
+
+        assertTrue(bundleEvent.isCancelled());
+    }
+
+    @Test
+    public void testSubPacketEventReferencesBundle() {
+        AtomicReference<PacketEvent> subPacketEvent = new AtomicReference<>();
+        OutboundPacketListenerSet listenerSet = createListenerSet(subPacketEvent::set);
+        PacketEvent bundleEvent = createBundleEvent();
+
+        listenerSet.invoke(bundleEvent);
+
+        assertSame(bundleEvent, subPacketEvent.get().getBundle());
+    }
+
+    @Test
+    public void testUnchangedBundleIsNotCopied() {
+        OutboundPacketListenerSet listenerSet = createListenerSet(event -> { });
+        PacketEvent bundleEvent = createBundleEvent();
+        PacketContainer bundle = bundleEvent.getPacket();
+        Object packets = getRawPackets(bundle);
+
+        listenerSet.invoke(bundleEvent);
+
+        assertSame(bundle, bundleEvent.getPacket());
+        assertSame(packets, getRawPackets(bundleEvent.getPacket()));
+    }
+
+    @Test
+    public void testCancelledSubPacketDoesNotModifySharedBundle() {
+        PacketContainer cancelled = new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer retained = new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer sharedBundle = createBundle(cancelled, retained);
+        PacketEvent modifiedEvent = createBundleEvent(sharedBundle);
+        PacketEvent sharedEvent = createBundleEvent(PacketContainer.fromPacket(sharedBundle.getHandle()));
+        Object sharedPackets = getRawPackets(sharedBundle);
+
+        OutboundPacketListenerSet listenerSet = createListenerSet(event -> {
+            if (event.getPacket().getHandle() == cancelled.getHandle()) {
+                event.setCancelled(true);
+            }
+        });
+        listenerSet.invoke(modifiedEvent);
+
+        assertNotSame(sharedBundle.getHandle(), modifiedEvent.getPacket().getHandle());
+        assertSame(sharedBundle.getHandle(), sharedEvent.getPacket().getHandle());
+        assertSame(sharedPackets, getRawPackets(sharedEvent.getPacket()));
+        assertPacketHandles(modifiedEvent.getPacket(), retained);
+        assertPacketHandles(sharedEvent.getPacket(), cancelled, retained);
+    }
+
+    @Test
+    public void testReplacedSubPacketDoesNotModifySharedBundle() {
+        PacketContainer replaced = new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer retained = new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer replacement = new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer sharedBundle = createBundle(replaced, retained);
+        PacketEvent modifiedEvent = createBundleEvent(sharedBundle);
+        PacketEvent sharedEvent = createBundleEvent(PacketContainer.fromPacket(sharedBundle.getHandle()));
+        Object sharedPackets = getRawPackets(sharedBundle);
+
+        OutboundPacketListenerSet listenerSet = createListenerSet(event -> {
+            if (event.getPacket().getHandle() == replaced.getHandle()) {
+                event.setPacket(replacement);
+            }
+        });
+        listenerSet.invoke(modifiedEvent);
+
+        assertNotSame(sharedBundle.getHandle(), modifiedEvent.getPacket().getHandle());
+        assertSame(sharedBundle.getHandle(), sharedEvent.getPacket().getHandle());
+        assertSame(sharedPackets, getRawPackets(sharedEvent.getPacket()));
+        assertPacketHandles(modifiedEvent.getPacket(), replacement, retained);
+        assertPacketHandles(sharedEvent.getPacket(), replaced, retained);
+    }
+
+    private static OutboundPacketListenerSet createListenerSet(Consumer<PacketEvent> callback) {
+        OutboundPacketListenerSet listenerSet = new OutboundPacketListenerSet(null, mock(ErrorReporter.class));
+        listenerSet.addListener(new PacketAdapter(mock(Plugin.class), PacketType.Play.Server.SYSTEM_CHAT) {
+            @Override
+            public void onPacketSending(PacketEvent event) {
+                callback.accept(event);
+            }
+        });
+        return listenerSet;
+    }
+
+    private static PacketEvent createBundleEvent() {
+        return createBundleEvent(createBundle(new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT)));
+    }
+
+    private static PacketEvent createBundleEvent(PacketContainer bundle) {
+        return PacketEvent.fromServer(OutboundPacketListenerSetTest.class, bundle, mock(Player.class));
+    }
+
+    private static PacketContainer createBundle(PacketContainer... packets) {
+        PacketContainer bundle = new PacketContainer(PacketType.Play.Server.BUNDLE);
+        bundle.getPacketBundles().write(0, List.of(packets));
+        return bundle;
+    }
+
+    private static Object getRawPackets(PacketContainer bundle) {
+        return bundle.getModifier().withType(Iterable.class).read(0);
+    }
+
+    private static void assertPacketHandles(PacketContainer bundle, PacketContainer... expected) {
+        List<PacketContainer> packets = Converters.toList(bundle.getPacketBundles().read(0));
+        assertEquals(expected.length, packets.size());
+        for (int index = 0; index < expected.length; index++) {
+            assertSame(expected[index].getHandle(), packets.get(index).getHandle());
+        }
+    }
+}

src/test/java/com/comphenix/protocol/injector/netty/channel/NettyChannelInjectorTest.java

@@ -0,0 +1,170 @@
+package com.comphenix.protocol.injector.netty.channel;
+
+import java.lang.reflect.Field;
+import java.util.List;
+
+import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.PacketType.Protocol;
+import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.error.ErrorReporter;
+import com.comphenix.protocol.events.ConnectionSide;
+import com.comphenix.protocol.events.NetworkMarker;
+import com.comphenix.protocol.events.PacketContainer;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.events.PacketPostListener;
+import com.comphenix.protocol.injector.ListenerManager;
+import com.comphenix.protocol.scheduler.ProtocolScheduler;
+
+import io.netty.channel.Channel;
+import io.netty.channel.embedded.EmbeddedChannel;
+import net.minecraft.network.protocol.Packet;
+import org.bukkit.Bukkit;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.MockedConstruction;
+import org.mockito.MockedStatic;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.CALLS_REAL_METHODS;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockConstruction;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class NettyChannelInjectorTest {
+
+    @BeforeAll
+    public static void beforeClass() {
+        BukkitInitialization.initializeAll();
+    }
+
+    @Test
+    public void testBundleNeedsMainThreadForSubPacketListener() {
+        ListenerManager listenerManager = createListenerManager(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer bundle = createBundle(
+                new PacketContainer(PacketType.Play.Server.KEEP_ALIVE),
+                new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT));
+
+        assertTrue(NettyChannelInjector.hasMainThreadListener(listenerManager, Protocol.PLAY, bundle));
+    }
+
+    @Test
+    public void testBundleNeedsMainThreadForBundleListener() {
+        ListenerManager listenerManager = createListenerManager(PacketType.Play.Server.BUNDLE);
+        PacketContainer bundle = createBundle(new PacketContainer(PacketType.Play.Server.KEEP_ALIVE));
+
+        assertTrue(NettyChannelInjector.hasMainThreadListener(listenerManager, Protocol.PLAY, bundle));
+    }
+
+    @Test
+    public void testBundleWithoutListenedSubPacketsStaysOffMainThread() {
+        ListenerManager listenerManager = createListenerManager(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer bundle = createBundle(
+                new PacketContainer(PacketType.Play.Server.KEEP_ALIVE),
+                new PacketContainer(PacketType.Play.Server.KEEP_ALIVE));
+
+        assertFalse(NettyChannelInjector.hasMainThreadListener(listenerManager, Protocol.PLAY, bundle));
+    }
+
+    @Test
+    public void testSinglePacketOnlyChecksItsOwnType() {
+        ListenerManager listenerManager = createListenerManager(PacketType.Play.Server.SYSTEM_CHAT);
+
+        assertTrue(NettyChannelInjector.hasMainThreadListener(listenerManager, Protocol.PLAY,
+                new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT)));
+        assertFalse(NettyChannelInjector.hasMainThreadListener(listenerManager, Protocol.PLAY,
+                new PacketContainer(PacketType.Play.Server.KEEP_ALIVE)));
+    }
+
+    @Test
+    public void testRescheduledBundleKeepsNetworkMarker() throws Exception {
+        ListenerManager listenerManager = createListenerManager(PacketType.Play.Server.SYSTEM_CHAT);
+        PacketContainer bundle = createBundle(
+                new PacketContainer(PacketType.Play.Server.KEEP_ALIVE),
+                new PacketContainer(PacketType.Play.Server.SYSTEM_CHAT));
+        SendAction action = new SendAction((Packet<?>) bundle.getHandle());
+
+        NetworkMarker marker = new NetworkMarker(ConnectionSide.SERVER_SIDE, PacketType.Play.Server.BUNDLE);
+        PacketPostListener postListener = mock(PacketPostListener.class);
+        marker.addPostListener(postListener);
+
+        // the real Connection can't be loaded in tests, so the injector gets a stand-in and a mocked invoker
+        NettyChannelInjector injector;
+        try (MockedConstruction<PacketListenerInvoker> ignored = mockConstruction(PacketListenerInvoker.class)) {
+            injector = spy(new NettyChannelInjector(null, new FakeNetworkManager(), new EmbeddedChannel(),
+                    listenerManager, mock(InjectionFactory.class), mock(ErrorReporter.class)));
+        }
+        doReturn(Protocol.PLAY).when(injector).getCurrentProtocol(PacketType.Sender.SERVER);
+        Field injected = NettyChannelInjector.class.getDeclaredField("injected");
+        injected.setAccessible(true);
+        injected.setBoolean(injector, true);
+
+        ProtocolScheduler scheduler = mock(ProtocolScheduler.class);
+        try (MockedStatic<ProtocolLibrary> protocolLibrary = mockStatic(ProtocolLibrary.class, CALLS_REAL_METHODS)) {
+            protocolLibrary.when(ProtocolLibrary::getScheduler).thenReturn(scheduler);
+
+            // a plugin sends the bundle with a marker off the main thread
+            when(Bukkit.getServer().isPrimaryThread()).thenReturn(false);
+            injector.sendClientboundPacket(action.packet, marker, true);
+            assertNull(injector.processOutbound(action));
+
+            ArgumentCaptor<Runnable> rescheduled = ArgumentCaptor.forClass(Runnable.class);
+            verify(scheduler).runTask(rescheduled.capture());
+            verify(listenerManager, never()).invokeOutboundPacketListeners(any());
+
+            // the rescheduled send runs on the main thread and is written again
+            when(Bukkit.getServer().isPrimaryThread()).thenReturn(true);
+            rescheduled.getValue().run();
+            Runnable sent = injector.processOutbound(action);
+            assertNotNull(sent);
+            sent.run();
+        } finally {
+            when(Bukkit.getServer().isPrimaryThread()).thenReturn(true);
+        }
+
+        assertTrue(action.ran);
+        verify(postListener).onPostEvent(any(PacketEvent.class));
+    }
+
+    private static final class FakeNetworkManager {
+
+        private Channel channel;
+    }
+
+    private static final class SendAction implements Runnable {
+
+        private final Packet<?> packet;
+        private boolean ran;
+
+        private SendAction(Packet<?> packet) {
+            this.packet = packet;
+        }
+
+        @Override
+        public void run() {
+            this.ran = true;
+        }
+    }
+
+    private static ListenerManager createListenerManager(PacketType mainThreadPacketType) {
+        ListenerManager listenerManager = mock(ListenerManager.class);
+        when(listenerManager.hasMainThreadListener(mainThreadPacketType)).thenReturn(true);
+        return listenerManager;
+    }
+
+    private static PacketContainer createBundle(PacketContainer... packets) {
+        PacketContainer bundle = new PacketContainer(PacketType.Play.Server.BUNDLE);
+        bundle.getPacketBundles().write(0, List.of(packets));
+        return bundle;
+    }
+}

src/test/java/com/comphenix/protocol/injector/netty/manager/NetworkManagerInjectorTest.java

@@ -0,0 +1,78 @@
+package com.comphenix.protocol.injector.netty.manager;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.junit.jupiter.api.Test;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.embedded.EmbeddedChannel;
+
+class NetworkManagerInjectorTest {
+
+    @Test
+    void addsInjectionHandlerBeforeNetworkManager() {
+        EmbeddedChannel channel = new EmbeddedChannel();
+        channel.pipeline().addLast("before", new ChannelInboundHandlerAdapter());
+        channel.pipeline().addLast("network_manager", new TestNetworkManager());
+        channel.pipeline().addLast("after", new ChannelInboundHandlerAdapter());
+
+        NetworkManagerInjector.addInjectionHandler(
+                channel,
+                TestNetworkManager.class,
+                new ChannelInboundHandlerAdapter());
+
+        assertEquals(
+                channel.pipeline().names().indexOf("network_manager") - 1,
+                channel.pipeline().names().indexOf("protocol_lib_inbound_inject"));
+    }
+
+    @Test
+    void injectsAfterNetworkManagerFinishesChannelActivation() {
+        AtomicBoolean networkManagerInitialized = new AtomicBoolean();
+        AtomicBoolean observedInitializedNetworkManager = new AtomicBoolean();
+        EmbeddedChannel channel = new EmbeddedChannel();
+        channel.pipeline().addLast("network_manager", new TestNetworkManager() {
+            @Override
+            public void channelActive(ChannelHandlerContext ctx) {
+                ctx.fireChannelActive();
+                networkManagerInitialized.set(true);
+            }
+        });
+
+        NetworkManagerInjector.addInjectionHandler(
+                channel,
+                TestNetworkManager.class,
+                new ChannelInboundHandlerAdapter() {
+                    @Override
+                    public void channelActive(ChannelHandlerContext ctx) {
+                        ctx.fireChannelActive();
+                        observedInitializedNetworkManager.set(networkManagerInitialized.get());
+                    }
+                });
+        channel.pipeline().fireChannelActive();
+
+        assertTrue(observedInitializedNetworkManager.get());
+    }
+
+    @Test
+    void addsInjectionHandlerLastWhenNetworkManagerIsMissing() {
+        EmbeddedChannel channel = new EmbeddedChannel();
+        channel.pipeline().addLast("existing", new ChannelInboundHandlerAdapter());
+
+        NetworkManagerInjector.addInjectionHandler(
+                channel,
+                TestNetworkManager.class,
+                new ChannelInboundHandlerAdapter());
+
+        assertEquals(
+                channel.pipeline().names().indexOf("existing") + 1,
+                channel.pipeline().names().indexOf("protocol_lib_inbound_inject"));
+    }
+
+    private static class TestNetworkManager extends ChannelInboundHandlerAdapter {
+    }
+}

src/test/java/com/comphenix/protocol/injector/netty/manager/PlatformChannelInitializerTest.java

@@ -0,0 +1,42 @@
+package com.comphenix.protocol.injector.netty.manager;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import com.comphenix.protocol.internal.PlatformProvider;
+import com.comphenix.protocol.paper.PaperPlatformProvider;
+
+import io.netty.channel.Channel;
+import io.netty.channel.embedded.EmbeddedChannel;
+import io.papermc.paper.network.ChannelInitializeListenerHolder;
+
+class PlatformChannelInitializerTest {
+
+    @AfterEach
+    void resetHolder() {
+        ChannelInitializeListenerHolder.removeListener(PaperPlatformProvider.CHANNEL_INITIALIZER_KEY);
+    }
+
+    @Test
+    void registersInvokesAndRemovesListener() {
+        AtomicReference<Channel> initializedChannel = new AtomicReference<>();
+
+        PlatformProvider provider = PlatformProvider.get();
+        Runnable cleanup = provider.registerChannelInitializer(initializedChannel::set);
+        assertTrue(provider.hasEarlyChannelInitialization());
+        assertTrue(ChannelInitializeListenerHolder.hasListener(PaperPlatformProvider.CHANNEL_INITIALIZER_KEY));
+
+        Channel channel = new EmbeddedChannel();
+        ChannelInitializeListenerHolder.callListeners(channel);
+        assertSame(channel, initializedChannel.get());
+
+        cleanup.run();
+        assertFalse(ChannelInitializeListenerHolder.hasListener(PaperPlatformProvider.CHANNEL_INITIALIZER_KEY));
+    }
+}

src/test/java/com/comphenix/protocol/injector/packet/PacketRegistryTests.java

@@ -5,6 +5,7 @@ import java.util.List;
 
 import com.comphenix.protocol.BukkitInitialization;
 import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.utility.MinecraftVersion;
 
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -29,7 +30,8 @@ public class PacketRegistryTests {
 	public void testAllPacketsRegistered() {
 		List<PacketType> missing = new ArrayList<>();
 		for (PacketType type : PacketType.values()) {
-			if (type.isDeprecated()) {
+			if (type.isDeprecated()
+					|| type.getCurrentVersion().compareTo(MinecraftVersion.getCurrentVersion()) > 0) {
 				continue;
 			}
 			if (!PacketRegistry.tryGetPacketClass(type).isPresent()) {

src/test/java/com/comphenix/protocol/injector/temporary/TemporaryPlayerFactoryTest.java

@@ -1,5 +1,8 @@
 package com.comphenix.protocol.injector.temporary;
 
+import java.util.UUID;
+
+import com.comphenix.protocol.injector.netty.Injector;
 import org.bukkit.Server;
 import org.bukkit.entity.Player;
 import org.junit.jupiter.api.BeforeEach;
@@ -7,13 +10,18 @@ import org.junit.jupiter.api.Test;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.when;
 
 public class TemporaryPlayerFactoryTest {
 
     @Mock
     Server server;
 
+    @Mock
+    Injector injector;
+
     @BeforeEach
     public void initMocks() {
         MockitoAnnotations.openMocks(this);
@@ -24,4 +32,18 @@ public class TemporaryPlayerFactoryTest {
         Player player = TemporaryPlayerFactory.createTemporaryPlayer();
         assertThrows(IllegalStateException.class, player::getPlayer);
     }
+
+    @Test
+    public void testLoginProfile() {
+        Player player = TemporaryPlayerFactory.createTemporaryPlayer();
+        UUID uniqueId = UUID.randomUUID();
+
+        TemporaryPlayerFactory.setInjectorForPlayer(player, this.injector);
+        when(this.injector.getPlayer()).thenReturn(player);
+        when(this.injector.getPlayerName()).thenReturn("dmulloy2");
+        when(this.injector.getPlayerUniqueId()).thenReturn(uniqueId);
+
+        assertEquals("dmulloy2", player.getName());
+        assertEquals(uniqueId, player.getUniqueId());
+    }
 }

src/test/java/com/comphenix/protocol/utility/MinecraftReflectionTest.java

@@ -131,7 +131,7 @@ public class MinecraftReflectionTest {
 
         // The NMS handle for CraftItemStack is null with Material.AIR, make sure it is handled correctly
         assertNotNull(
-                MinecraftReflection.getMinecraftItemStack(CraftItemStack.asCraftCopy(new ItemStack(Material.AIR))));
+                MinecraftReflection.getMinecraftItemStack(CraftItemStack.getCraftStack(new ItemStack(Material.AIR))));
     }
 
     @Test

src/test/java/com/comphenix/protocol/utility/StreamSerializerTest.java

@@ -10,6 +10,8 @@ import com.comphenix.protocol.BukkitInitialization;
 import com.comphenix.protocol.wrappers.nbt.NbtCompound;
 import com.comphenix.protocol.wrappers.nbt.NbtFactory;
 
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import org.bukkit.ChatColor;
 import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
@@ -19,6 +21,7 @@ import org.junit.jupiter.api.Test;
 
 import static com.comphenix.protocol.utility.TestUtils.assertItemsEqual;
 
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class StreamSerializerTest {
@@ -86,4 +89,23 @@ public class StreamSerializerTest {
 
         assertItemsEqual(initial, deserialized);
     }
+
+    @Test
+    public void testGetBytesAndReleasePreservesReaderIndex() {
+        StreamSerializer serializer = new StreamSerializer();
+        ByteBuf[] buffers = {Unpooled.buffer(16), Unpooled.directBuffer(16)};
+
+        for (ByteBuf buffer : buffers) {
+            buffer.writeBytes(new byte[] {0, 1, 2, 3, 4});
+            buffer.readerIndex(2);
+            buffer.retain();
+
+            try {
+                assertArrayEquals(new byte[] {2, 3, 4}, serializer.getBytesAndRelease(buffer));
+                assertEquals(2, buffer.readerIndex());
+            } finally {
+                buffer.release();
+            }
+        }
+    }
 }

src/test/java/com/comphenix/protocol/wrappers/AutoWrapperTest.java

@@ -45,22 +45,18 @@ public class AutoWrapperTest {
         display.announceChat = false;
         display.showToast = true;
         display.hidden = true;
-        display.x = 5f;
-        display.y = 67f;
 
         DisplayInfo nms = (DisplayInfo) displayWrapper().unwrap(display);
 
-        assertTrue(nms.shouldShowToast());
-        assertTrue(nms.isHidden());
-        assertFalse(nms.shouldAnnounceChat());
-        assertTrue(nms.getBackground().isPresent());
-        assertEquals("test", nms.getBackground().get().id().getPath());
-        validateRawText(nms.getTitle(), "Test123");
-        validateRawText(nms.getDescription(), "Test567");
-        assertSame(AdvancementType.CHALLENGE, nms.getType());
-        assertSame(getItemStackTemplateConverter().getSpecific(nms.getIcon()).getType(), Material.GOLD_INGOT);
-        assertEquals(5f, nms.getX(), 0f);
-        assertEquals(67f, nms.getY(), 0f);
+        assertTrue(nms.showToast());
+        assertTrue(nms.hidden());
+        assertFalse(nms.announceToChat());
+        assertTrue(nms.background().isPresent());
+        assertEquals("test", nms.background().get().id().getPath());
+        validateRawText(nms.title(), "Test123");
+        validateRawText(nms.description(), "Test567");
+        assertSame(AdvancementType.CHALLENGE, nms.type());
+        assertSame(getItemStackTemplateConverter().getSpecific(nms.icon()).getType(), Material.GOLD_INGOT);
     }
 
     @Test
@@ -75,7 +71,6 @@ public class AutoWrapperTest {
               false,
               true
         );
-        display.setLocation(5f, 67f);
 
         WrappedAdvancementDisplay wrapped = displayWrapper().wrap(display);
 
@@ -88,16 +83,14 @@ public class AutoWrapperTest {
         assertEquals("\"Test567\"", wrapped.description.getJson());
         assertSame(WrappedFrameType.CHALLENGE, wrapped.frameType);
         assertSame(Material.ENDER_EYE, wrapped.item.getType());
-        assertEquals(5f, wrapped.x, 0f);
-        assertEquals(67f, wrapped.y, 0f);
     }
 
     private AutoWrapper<WrappedAdvancementDisplay> displayWrapper() {
         return AutoWrapper
                 .wrap(WrappedAdvancementDisplay.class, "advancements.AdvancementDisplay", "advancements.DisplayInfo")
-                .field(0, BukkitConverters.getWrappedChatComponentConverter())
+                .field(0, getItemStackTemplateConverter())
                 .field(1, BukkitConverters.getWrappedChatComponentConverter())
-                .field(2, getItemStackTemplateConverter())
+                .field(2, BukkitConverters.getWrappedChatComponentConverter())
                 .field(3, Converters.optional(Converters.passthrough(ClientAsset.class)))
                 .field(4, EnumWrappers.getGenericConverter(
                     getMinecraftClass("advancements.AdvancementType", "advancements.AdvancementFrameType", "advancements.FrameType"),
@@ -140,15 +133,13 @@ public class AutoWrapperTest {
 
     public static final class WrappedAdvancementDisplay {
 
+        public ItemStack item;
         public WrappedChatComponent title;
         public WrappedChatComponent description;
-        public ItemStack item;
         public Optional<ClientAsset> background;
         public WrappedFrameType frameType;
         public boolean showToast;
         public boolean announceChat;
         public boolean hidden;
-        public float x;
-        public float y;
     }
 }

src/test/java/com/comphenix/protocol/wrappers/BukkitConvertersTest.java

@@ -13,6 +13,7 @@ import org.apache.commons.lang.builder.EqualsBuilder;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.Material;
+import org.bukkit.damage.DamageType;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
@@ -63,6 +64,14 @@ public class BukkitConvertersTest {
         assertEquals(wrapped.right(), nmsEither.right());
     }
 
+    @Test
+    public void testDamageType() {
+        EquivalentConverter<DamageType> converter = BukkitConverters.getDamageTypeConverter();
+        Object generic = converter.getGeneric(DamageType.FALL);
+
+        assertEquals(DamageType.FALL, converter.getSpecific(generic));
+    }
+
     @Test
     @Disabled("Fails due to shared packet classes between protocol states")
     public void testPacketContainerConverter() {

src/test/java/com/comphenix/protocol/wrappers/WrappedBlockDataTest.java

@@ -58,7 +58,7 @@ public class WrappedBlockDataTest {
     @Test
     public void testDataCreation() {
         BlockState nmsData = CraftMagicNumbers.getBlock(Material.CYAN_STAINED_GLASS_PANE).defaultBlockState();
-        GlassPane data = (GlassPane) CraftBlockData.fromData(nmsData);
+        GlassPane data = (GlassPane) CraftBlockData.createData(nmsData);
         data.setFace(BlockFace.EAST, true);
 
         WrappedBlockData wrapper = WrappedBlockData.createData(data);

src/test/java/com/comphenix/protocol/wrappers/WrappedGameProfileTest.java

@@ -67,6 +67,20 @@ public class WrappedGameProfileTest {
         assertEquals(property.getSignature(), signature);
     }
 
+    @Test
+    void testMixedAccessorNames() {
+        MixedGameProfile profile = new MixedGameProfile();
+
+        assertEquals(profile.getId(), WrappedGameProfile.findMethodAccessor(
+                MixedGameProfile.class, "id", "getId").invoke(profile));
+        assertEquals(profile.name(), WrappedGameProfile.findMethodAccessor(
+                MixedGameProfile.class, "name", "getName").invoke(profile));
+        assertSame(profile.properties(), WrappedGameProfile.findMethodAccessor(
+                MixedGameProfile.class, "properties", "getProperties").invoke(profile));
+        assertEquals(profile.isComplete(), WrappedGameProfile.findMethodAccessor(
+                MixedGameProfile.class, "complete", "isComplete").invoke(profile));
+    }
+
     @Test
     void testAddProperties() {
         String name = "test";
@@ -85,4 +99,28 @@ public class WrappedGameProfileTest {
         assertEquals(property.value(), value);
         assertEquals(property.signature(), signature);
     }
+
+    private static final class MixedGameProfile {
+        private final UUID id = UUID.randomUUID();
+
+        public UUID getId() {
+            return this.id;
+        }
+
+        public String name() {
+            return "ProtocolLib";
+        }
+
+        public String getName() {
+            return "Legacy";
+        }
+
+        public PropertyMap properties() {
+            return PropertyMap.EMPTY;
+        }
+
+        public boolean isComplete() {
+            return true;
+        }
+    }
 }

src/test/java/com/comphenix/protocol/wrappers/WrappedParticleTest.java

@@ -37,8 +37,7 @@ public class WrappedParticleTest {
         assertEquals(before.getData(), after.getData());
     }
 
-    // @Test
-    // TODO: changed to ItemStackTemplate
+    @Test
     public void testItemStacks() {
         PacketContainer packet = new PacketContainer(PacketType.Play.Server.WORLD_PARTICLES);
         WrappedParticle before = WrappedParticle.create(Particle.ITEM, new ItemStack(Material.FLINT_AND_STEEL));

src/test/java/com/comphenix/protocol/wrappers/WrappedPositionMoveRotationTest.java

@@ -41,31 +41,11 @@ public class WrappedPositionMoveRotationTest {
     }
 
     @Test
-    public void testEntityPositionSyncPacket() {
+    public void testEntityPositionSyncPacketHasNoPositionMoveRotation() {
         PacketContainer packet = new PacketContainer(PacketType.Play.Server.ENTITY_POSITION_SYNC);
 
-        Vector position = new Vector(10.0, 70.0, -5.0);
-        Vector delta = new Vector(0.0, 0.0, 0.0);
-        float yRot = 90.0f;
-        float xRot = 0.0f;
-
-        packet.getPositionMoveRotation().write(0,
-                WrappedPositionMoveRotation.create(position, delta, yRot, xRot));
-
-        WrappedPositionMoveRotation result = packet.getPositionMoveRotation().read(0);
-
-        assertNotNull(result);
-
-        assertEquals(position.getX(), result.getPosition().getX(), 1e-6);
-        assertEquals(position.getY(), result.getPosition().getY(), 1e-6);
-        assertEquals(position.getZ(), result.getPosition().getZ(), 1e-6);
-
-        assertEquals(delta.getX(), result.getDeltaMovement().getX(), 1e-6);
-        assertEquals(delta.getY(), result.getDeltaMovement().getY(), 1e-6);
-        assertEquals(delta.getZ(), result.getDeltaMovement().getZ(), 1e-6);
-
-        assertEquals(yRot, result.getYRot(), 1e-6f);
-        assertEquals(xRot, result.getXRot(), 1e-6f);
+        assertEquals(0, packet.getPositionMoveRotation().size());
+        assertNull(packet.getPositionMoveRotation().readSafely(0));
     }
 
     @Test

src/test/java/com/comphenix/protocol/wrappers/WrappedPositionPathTest.java

@@ -0,0 +1,100 @@
+package com.comphenix.protocol.wrappers;
+
+import java.util.List;
+
+import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.PacketContainer;
+
+import io.netty.buffer.Unpooled;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.protocol.game.ClientboundEntityPositionSyncPacket;
+import net.minecraft.world.entity.PositionPath;
+import net.minecraft.world.phys.Vec3;
+import org.bukkit.util.Vector;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class WrappedPositionPathTest {
+
+    @BeforeAll
+    public static void beforeClass() {
+        BukkitInitialization.initializeAll();
+    }
+
+    @Test
+    public void testLinear() {
+        WrappedPositionPath path = WrappedPositionPath.linear(new Vector(1.5, 64.0, -3.5));
+
+        assertFalse(path.isStepped());
+        assertEquals(new Vector(1.5, 64.0, -3.5), path.getEndPosition());
+        assertThrows(IllegalStateException.class, path::getSteps);
+
+        assertEquals(PositionPath.of(new Vec3(1.5, 64.0, -3.5)), path.getHandle());
+    }
+
+    @Test
+    public void testStepped() {
+        List<WrappedPositionPath.Step> steps = List.of(
+                new WrappedPositionPath.Step(new Vector(1, 2, 3), 1),
+                new WrappedPositionPath.Step(new Vector(4, 5, 6), 3));
+        WrappedPositionPath path = WrappedPositionPath.stepped(steps);
+
+        assertTrue(path.isStepped());
+        assertEquals(steps, path.getSteps());
+        assertEquals(new Vector(4, 5, 6), path.getEndPosition());
+    }
+
+    @Test
+    public void testSteppedRequiresSteps() {
+        assertThrows(IllegalArgumentException.class, () -> WrappedPositionPath.stepped(List.of()));
+    }
+
+    @Test
+    public void testStepIsImmutable() {
+        Vector position = new Vector(1, 2, 3);
+        WrappedPositionPath.Step step = new WrappedPositionPath.Step(position, 1);
+
+        position.setX(10);
+        step.getPosition().setY(20);
+
+        assertEquals(new Vector(1, 2, 3), step.getPosition());
+    }
+
+    @Test
+    public void testEquality() {
+        WrappedPositionPath first = WrappedPositionPath.linear(new Vector(1, 2, 3));
+        WrappedPositionPath second = WrappedPositionPath.fromHandle(PositionPath.of(new Vec3(1, 2, 3)));
+
+        assertEquals(first, second);
+        assertEquals(first.hashCode(), second.hashCode());
+        assertNotEquals(first, WrappedPositionPath.linear(new Vector(1, 2, 4)));
+    }
+
+    @Test
+    public void testEntityPositionSyncPacketRoundTrip() {
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.ENTITY_POSITION_SYNC);
+        packet.getIntegers().write(0, 42);
+        packet.getFloat().write(0, 90.0f).write(1, -15.0f);
+        packet.getBooleans().write(0, true);
+
+        WrappedPositionPath path = WrappedPositionPath.stepped(List.of(
+                new WrappedPositionPath.Step(new Vector(10.0, 70.0, -5.0), 1),
+                new WrappedPositionPath.Step(new Vector(10.5, 70.0, -5.5), 2)));
+        packet.getPositionPaths().write(0, path);
+        assertEquals(path, packet.getPositionPaths().read(0));
+
+        FriendlyByteBuf buf = new FriendlyByteBuf(Unpooled.buffer());
+        ClientboundEntityPositionSyncPacket.STREAM_CODEC.encode(buf, (ClientboundEntityPositionSyncPacket) packet.getHandle());
+        ClientboundEntityPositionSyncPacket decoded = ClientboundEntityPositionSyncPacket.STREAM_CODEC.decode(buf);
+
+        PacketContainer roundTrip = PacketContainer.fromPacket(decoded);
+        assertEquals(path, roundTrip.getPositionPaths().read(0));
+        assertEquals(42, roundTrip.getIntegers().read(0));
+        assertEquals(90.0f, roundTrip.getFloat().read(0), 1e-6f);
+        assertEquals(-15.0f, roundTrip.getFloat().read(1), 1e-6f);
+        assertTrue(roundTrip.getBooleans().read(0));
+    }
+}

src/test/java/com/comphenix/protocol/wrappers/WrappedStatisticTest.java

@@ -0,0 +1,42 @@
+package com.comphenix.protocol.wrappers;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Map;
+
+import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.PacketContainer;
+
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import net.minecraft.network.protocol.game.ClientboundAwardStatsPacket;
+import net.minecraft.resources.Identifier;
+import net.minecraft.stats.Stat;
+import net.minecraft.stats.Stats;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class WrappedStatisticTest {
+
+    @BeforeAll
+    static void initializeBukkit() {
+        BukkitInitialization.initializeAll();
+    }
+
+    @Test
+    void testStatisticMap() {
+        Stat<Identifier> statistic = Stats.CUSTOM.get(Stats.JUMP);
+        Object2IntMap<Stat<?>> statistics = new Object2IntOpenHashMap<>();
+        statistics.put(statistic, 12);
+
+        PacketContainer packet = new PacketContainer(
+                PacketType.Play.Server.STATISTIC,
+                new ClientboundAwardStatsPacket(statistics));
+        Map<WrappedStatistic, Integer> wrappedStatistics = packet.getStatisticMaps().read(0);
+        WrappedStatistic wrappedStatistic = wrappedStatistics.keySet().iterator().next();
+
+        assertEquals(statistic.getName(), wrappedStatistic.getName());
+        assertEquals(12, wrappedStatistics.get(wrappedStatistic));
+    }
+}

src/test/java/com/comphenix/protocol/wrappers/WrappedStreamCodecTests.java

@@ -50,6 +50,6 @@ public class WrappedStreamCodecTests {
         codec.encode(buf, packet);
         ClientboundOpenBookPacket roundTrip = (ClientboundOpenBookPacket) codec.decode(buf);
 
-        assertEquals(InteractionHand.OFF_HAND, roundTrip.getHand());
+        assertEquals(InteractionHand.OFF_HAND, roundTrip.hand());
     }
 }

src/test/java/com/comphenix/protocol/wrappers/WrappedVecDeltaTest.java

@@ -0,0 +1,111 @@
+package com.comphenix.protocol.wrappers;
+
+import java.util.List;
+
+import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.PacketContainer;
+
+import io.netty.buffer.Unpooled;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.protocol.game.ClientboundMoveEntityPacket;
+import net.minecraft.network.protocol.game.VecDelta;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class WrappedVecDeltaTest {
+
+    @BeforeAll
+    public static void beforeClass() {
+        BukkitInitialization.initializeAll();
+    }
+
+    @Test
+    public void testLinear() {
+        WrappedVecDelta delta = WrappedVecDelta.linear((short) 1, (short) -2, (short) 4096);
+
+        assertFalse(delta.isStepped());
+        assertEquals(1, delta.getDeltaX());
+        assertEquals(-2, delta.getDeltaY());
+        assertEquals(4096, delta.getDeltaZ());
+        assertThrows(IllegalStateException.class, delta::getSteps);
+
+        assertEquals(new VecDelta.Linear((short) 1, (short) -2, (short) 4096), delta.getHandle());
+    }
+
+    @Test
+    public void testStepped() {
+        List<WrappedVecDelta.Step> steps = List.of(
+                new WrappedVecDelta.Step((short) 10, (short) 0, (short) -10, 1),
+                new WrappedVecDelta.Step((short) 5, (short) 6, (short) 7, 3));
+        WrappedVecDelta delta = WrappedVecDelta.stepped(steps);
+
+        assertTrue(delta.isStepped());
+        assertEquals(steps, delta.getSteps());
+        assertThrows(IllegalStateException.class, delta::getDeltaX);
+
+        VecDelta handle = (VecDelta) delta.getHandle();
+        assertEquals(2, handle.stepCount());
+        assertTrue(handle.hasDeltaX());
+    }
+
+    @Test
+    public void testSteppedRequiresSteps() {
+        assertThrows(IllegalArgumentException.class, () -> WrappedVecDelta.stepped(List.of()));
+    }
+
+    @Test
+    public void testEquality() {
+        WrappedVecDelta first = WrappedVecDelta.linear((short) 1, (short) 2, (short) 3);
+        WrappedVecDelta second = WrappedVecDelta.fromHandle(new VecDelta.Linear((short) 1, (short) 2, (short) 3));
+
+        assertEquals(first, second);
+        assertEquals(first.hashCode(), second.hashCode());
+        assertNotEquals(first, WrappedVecDelta.linear((short) 1, (short) 2, (short) 4));
+    }
+
+    @Test
+    public void testRelativeMovePacket() {
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.REL_ENTITY_MOVE);
+        packet.getIntegers().write(0, 123);
+        packet.getBooleans().write(0, true);
+
+        WrappedVecDelta delta = WrappedVecDelta.linear((short) 100, (short) 200, (short) -300);
+        packet.getVecDeltas().write(0, delta);
+
+        assertEquals(1, packet.getVecDeltas().size());
+        assertEquals(delta, packet.getVecDeltas().read(0));
+        assertEquals(123, packet.getIntegers().read(0));
+        assertTrue(packet.getBooleans().read(0));
+    }
+
+    @Test
+    public void testSteppedRelativeMovePacketRoundTrip() {
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.REL_ENTITY_MOVE);
+        packet.getIntegers().write(0, 7);
+        packet.getBooleans().write(0, true);
+
+        WrappedVecDelta delta = WrappedVecDelta.stepped(List.of(
+                new WrappedVecDelta.Step((short) 1, (short) 2, (short) 3, 1),
+                new WrappedVecDelta.Step((short) -4, (short) 5, (short) -6, 2)));
+        packet.getVecDeltas().write(0, delta);
+
+        FriendlyByteBuf buf = new FriendlyByteBuf(Unpooled.buffer());
+        ClientboundMoveEntityPacket.Pos.STREAM_CODEC.encode(buf, (ClientboundMoveEntityPacket.Pos) packet.getHandle());
+        ClientboundMoveEntityPacket.Pos decoded = ClientboundMoveEntityPacket.Pos.STREAM_CODEC.decode(buf);
+
+        PacketContainer roundTrip = PacketContainer.fromPacket(decoded);
+        assertEquals(delta.getSteps(), roundTrip.getVecDeltas().read(0).getSteps());
+        assertEquals(7, roundTrip.getIntegers().read(0));
+        assertTrue(roundTrip.getBooleans().read(0));
+    }
+
+    @Test
+    public void testNoShortsOnRelativeMovePacket() {
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.REL_ENTITY_MOVE_LOOK);
+        assertEquals(0, packet.getShorts().size());
+        assertEquals(1, packet.getVecDeltas().size());
+    }
+}