Bump version to 5.1.10 for release

Update to 1.21.5 (#300 )
Bump io.papermc.paperweight.userdev from 2.0.0-beta.14 to 2.0.0-beta.16 (#297 )
2026-11-04 16:50:04 -05:00 · 2025-04-25 11:49:43 -04:00 · 2025-04-25 15:47:20 +00:00 · 2025-04-01 17:34:11 +00:00 · 2025-04-01 17:33:47 +00:00 · 2025-03-21 17:27:54 -04:00
166 changed files with 4096 additions and 3593 deletions
@@ -4,7 +4,7 @@ updates:
    directory: "/"
    schedule:
      interval: "monthly"
-  - package-ecosystem: "maven"
+  - package-ecosystem: "gradle"
    directory: "/"
    schedule:
      interval: "monthly"
@@ -7,7 +7,7 @@ on:
    tags-ignore:
      - '**'
    paths-ignore:
-      - resource-pack/**
+      - resource-pack/openinv-legibility-pack/**
  # Enable running CI via other Actions, i.e. for drafting releases and handling PRs.
  workflow_call:

@@ -21,14 +21,22 @@ jobs:
        with:
          distribution: 'temurin'
          java-version: '21'
-          cache: 'maven'

-      # Install Spigot dependencies if necessary.
-      - name: Install Spigot Dependencies
-        run: . scripts/install_spigot_dependencies.sh
+      # We can't use 'maven' prebuilt cache setup because it requires that the project have a pom file.
+      # BuildTools installs to Maven local if available, so it's easier to just rely on that.
+      - name: Cache Spigot dependency
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.m2/repository/org/spigotmc/
+          key: ${{ runner.os }}-buildtools-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: |
+            ${{ runner.os }}-buildtools-

-      - name: Build With Maven
-        run: mvn -e clean package -am -P all
+      - uses: gradle/actions/setup-gradle@v4
+
+      - name: Build with Gradle
+        run: ./gradlew clean build

      # Upload artifacts
      - name: Upload Distributable Jar
@@ -36,10 +44,4 @@ jobs:
        uses: actions/upload-artifact@v4
        with:
          name: dist
-          path: ./target/*.jar
-      - name: Upload API Jar
-        id: upload-api
-        uses: actions/upload-artifact@v4
-        with:
-          name: api
-          path: ./api/target/openinvapi*.jar
+          path: ./dist/*
@@ -12,34 +12,25 @@ jobs:
    needs: [ run-ci ]
    runs-on: ubuntu-latest
    steps:
-      # Fetch all history - used to assemble changelog.
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-
-      - name: Set Release Variables
-        run: bash ./scripts/set_release_env.sh
-
      - name: Download build
        uses: actions/download-artifact@v4
        with:
          name: dist
          path: dist

-      - name: Package resource pack
-        run: |-
-          pushd resource-pack
-          zip -r ../dist/openinv-legibility-pack.zip .
-          popd
-
      - name: Create Release
        id: create-release
-        uses: softprops/action-gh-release@v2.0.8
+        uses: softprops/action-gh-release@v2.2.1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
-          name: ${{ env.VERSIONED_NAME }}
-          body: ${{ env.GENERATED_CHANGELOG }}
+          name: OpenInv ${{ env.VERSIONED_NAME }}
+          body: |-
+            ## Supported server versions
+            **Paper:** TODO VERSION, 1.21.4, 1.21.3, 1.21.1
+            **Spigot:** TODO VERSION
+            
+            TODO HELLO HUMAN, PRESS THE GENERATE CHANGELOG BUTTON PLEASE.
          draft: true
          prerelease: false
          files: ./dist/**
@@ -34,4 +34,4 @@ jobs:
          game_versions: "${{ env.CURSEFORGE_MINECRAFT_VERSIONS }}"
          release_type: release
          changelog_type: markdown
-          changelog: "${{ env.CURSEFORGE_CHANGELOG }}"
+          changelog: "${{ github.event.release.body }}"
@@ -7,7 +7,7 @@ on:
    tags-ignore:
      - '**'
    paths:
-      - resource-pack/**
+      - resource-pack/openinv-legibility-pack/**

 jobs:
  build:
@@ -20,5 +20,5 @@ jobs:
        uses: actions/upload-artifact@v4
        with:
          name: openinv-legibility-pack
-          path: ./resource-pack/
+          path: ./resource-pack/openinv-legibility-pack/
          compression-level: 9
@@ -2,9 +2,12 @@
 **/.project
 **/.classpath
 **/.idea/
+**/.gradle/
 **.iml
 **/target/
 **/bin/
 **/out/
+**/build/
+**/dist/
 **/dependency-reduced-pom.xml
 **/pom.xml.versionsBackup
@@ -36,22 +36,16 @@ The OpenInv API is available via [JitPack](https://jitpack.io/).
 ```xml
  <dependencies>
    <dependency>
-      <groupId>com.github.jikoo.OpenInv</groupId>
-      <artifactId>openinvapi</artifactId>
+      <groupId>com.github.Jikoo</groupId>
+      <artifactId>OpenInv</artifactId>
      <version>${openinv.version}</version>
    </dependency>
  </dependencies>
 ```
+Note that since JitPack only builds the API now, the "full" OpenInv jar on JitPack is actually the openinvapi artifact. This is a change from previous dependency declaration that I hope to revert.

 ### Compilation
-To compile, the relevant Spigot jars must be installed in the local repository.
-As OpenInv is compiled against Mojang's mappings, you must run BuildTools with the `--remapped` argument:  
-`java -jar BuildTools.jar --remapped --rev $serverVersion`  
-`$serverVersion` is the version of the server, i.e. `1.18.1`
+Execute the gradle wrapper:  
+`./gradlew build`

-To compile just the API, execute Maven as usual:  
-`mvn clean package`  
-
-To compile the full plugin, use the provided profile with `-P all`:  
-`mvn clean package -am -P all`  
-For more information, check out the [official Maven guide](http://maven.apache.org/guides/introduction/introduction-to-profiles.html).
+If you encounter issues with building the Spigot module, try running BuildTools manually.
@@ -0,0 +1,21 @@
+plugins {
+  `openinv-base`
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+}
+
+tasks.processResources {
+  expand("version" to version)
+}
+
+tasks.register<Copy>("distributeAddons") {
+  into(rootProject.layout.projectDirectory.dir("dist"))
+  from(tasks.jar)
+  rename("openinvtogglepersist.*\\.jar", "OITogglePersist.jar")
+}
+
+tasks.assemble {
+  dependsOn(tasks.named("distributeAddons"))
+}
@@ -1,72 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-
-    <parent>
-        <artifactId>openinvparent</artifactId>
-        <groupId>com.lishid</groupId>
-        <relativePath>../../pom.xml</relativePath>
-        <version>5.1.3</version>
-    </parent>
-
-    <artifactId>openinvtogglepersist</artifactId>
-
-    <dependencies>
-        <dependency>
-            <artifactId>annotations</artifactId>
-            <groupId>org.jetbrains</groupId>
-        </dependency>
-        <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
-        </dependency>
-        <dependency>
-            <artifactId>openinvapi</artifactId>
-            <groupId>com.lishid</groupId>
-            <scope>provided</scope>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <finalName>OITogglePersist</finalName>
-        <resources>
-            <resource>
-                <directory>src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
-
-        <plugins>
-            <plugin>
-                <artifactId>maven-compiler-plugin</artifactId>
-            </plugin>
-            <plugin>
-                <artifactId>maven-resources-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>copy-final-jar</id>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>copy-resources</goal>
-                        </goals>
-                        <configuration>
-                            <outputDirectory>${project.parent.build.directory}</outputDirectory>
-                            <resources>
-                                <resource>
-                                    <directory>${project.build.directory}</directory>
-                                    <includes>
-                                        <include>${project.build.finalName}.jar</include>
-                                    </includes>
-                                </resource>
-                            </resources>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-
-    </build>
-
-</project>
@@ -1,6 +1,6 @@
 name: OITogglePersist
 main: com.github.jikoo.openinv.togglepersist.TogglePersist
-version: ${project.version}
+version: ${version}
 author: Jikoo
 description: An OpenInv addon allowing /anycontainer and /silentcontainer to persist across sessions.
 api-version: "1.20"
@@ -0,0 +1,14 @@
+plugins {
+  `openinv-base`
+  `maven-publish`
+}
+
+publishing {
+  publications {
+    create<MavenPublication>("jitpack") {
+      groupId = "com.github.Jikoo.OpenInv"
+      artifactId = "openinvapi"
+      from(components["java"])
+    }
+  }
+}
@@ -1,49 +0,0 @@
-<!--
-  ~ Copyright (C) 2011-2022 lishid. All rights reserved.
-  ~
-  ~ 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, version 3.
-  ~
-  ~ This program is distributed in the hope that it will be useful,
-  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-  ~ GNU General Public License for more details.
-  ~
-  ~ You should have received a copy of the GNU General Public License
-  ~ along with this program. If not, see <http://www.gnu.org/licenses/>.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <parent>
-    <artifactId>openinvparent</artifactId>
-    <groupId>com.lishid</groupId>
-    <version>5.1.3</version>
-  </parent>
-
-  <artifactId>openinvapi</artifactId>
-  <name>OpenInvAPI</name>
-
-  <dependencies>
-    <dependency>
-      <artifactId>annotations</artifactId>
-      <groupId>org.jetbrains</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>spigot-api</artifactId>
-      <groupId>org.spigotmc</groupId>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-</project>
@@ -16,9 +16,17 @@

 package com.lishid.openinv.internal;

+import org.bukkit.event.inventory.InventoryType;
+import org.jetbrains.annotations.NotNull;
+
 /**
 * An {@link ISpecialInventory} representing an ender chest.
 */
 public interface ISpecialEnderChest extends ISpecialInventory {

+  @Override
+  default @NotNull InventoryType getBukkitType() {
+    return InventoryType.ENDER_CHEST;
+  }
+
 }
@@ -18,6 +18,7 @@ package com.lishid.openinv.internal;

 import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.jetbrains.annotations.NotNull;

@@ -33,6 +34,13 @@ public interface ISpecialInventory {
     */
    @NotNull Inventory getBukkitInventory();

+    /**
+     * Get the {@link InventoryType} corresponding to this {@code ISpecialInventory}.
+     *
+     * @return the type of Bukkit inventory
+     */
+    @NotNull InventoryType getBukkitType();
+
    /**
     * Set the owning {@link Player} instance to a newly-joined user.
     *
@@ -16,35 +16,17 @@

 package com.lishid.openinv.internal;

-import java.util.List;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.inventory.Inventory;
+import org.bukkit.event.inventory.InventoryType;
+import org.jetbrains.annotations.NotNull;

 /**
 * An {@link ISpecialInventory} representing a player inventory.
 */
 public interface ISpecialPlayerInventory extends ISpecialInventory {

-    /*
-     * Player inventory usage varies from all other inventories - as the inventory is technically open at all times,
-     * if the player is online or has been online while the inventory is open, they are in the viewer list.
-     */
    @Override
-    default boolean isInUse() {
-        Inventory inventory = getBukkitInventory();
-        List<HumanEntity> viewers = inventory.getViewers();
-
-        if (viewers.size() != 1) {
-            return !viewers.isEmpty();
-        }
-
-        HumanEntity viewer = viewers.get(0);
-
-        if (!viewer.getUniqueId().equals(getPlayer().getUniqueId())) {
-            return true;
-        }
-
-        return viewer.getOpenInventory().getTopInventory().equals(inventory);
+    default @NotNull InventoryType getBukkitType() {
+        return InventoryType.PLAYER;
    }

 }
@@ -0,0 +1,27 @@
+plugins {
+  `java-library`
+  alias(libs.plugins.paperweight) apply false
+  alias(libs.plugins.shadow) apply false
+}
+
+// Set by Spigot module, used by Paper module to convert to Spigot's version of Mojang mappings.
+project.ext.set("craftbukkitPackage", "UNKNOWN")
+
+repositories {
+  maven("https://repo.papermc.io/repository/maven-public/")
+}
+
+// Allow submodules to target higher Java release versions.
+// Not currently necessary (as lowest supported version is in the 1.21 range)
+// but may become relevant in the future.
+java.disableAutoTargetJvm()
+
+// Task to delete ./dist where final files are output.
+tasks.register("cleanDist") {
+  delete("dist")
+}
+
+tasks.clean {
+  // Also delete distribution folder when cleaning.
+  dependsOn(tasks.named("cleanDist"))
+}
@@ -0,0 +1,13 @@
+plugins {
+  `kotlin-dsl`
+}
+
+repositories {
+  gradlePluginPortal()
+  mavenCentral()
+}
+
+dependencies {
+  val libs = project.extensions.getByType(VersionCatalogsExtension::class.java).named("libs")
+  implementation(libs.findLibrary("specialsource").orElseThrow())
+}
@@ -0,0 +1,7 @@
+dependencyResolutionManagement {
+  versionCatalogs {
+    create("libs") {
+      from(files("../gradle/libs.versions.toml"))
+    }
+  }
+}
@@ -0,0 +1,98 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.provider.ValueSource
+import org.gradle.api.provider.ValueSourceParameters
+import org.gradle.process.ExecOperations
+import java.io.File
+import java.net.URI
+import java.nio.file.Files
+import javax.inject.Inject
+
+abstract class BuildToolsValueSource: ValueSource<File, BuildToolsValueSource.Parameters> {
+
+  @get:Inject
+  abstract val exec: ExecOperations
+
+  interface Parameters: ValueSourceParameters {
+    val mavenLocal: Property<File>
+    val workingDir: DirectoryProperty
+
+    val spigotVersion: Property<String>
+    val spigotRevision: Property<String>
+
+    val ignoreCached: Property<Boolean>
+
+    val javaHome: DirectoryProperty
+    val javaExecutable: Property<String>
+  }
+
+  override fun obtain(): File {
+    val version = parameters.spigotVersion.get()
+    val revision = parameters.spigotRevision.get()
+    val installLocation = getInstallLocation(version)
+    // If Spigot is already installed, don't reinstall.
+    if (!parameters.ignoreCached.get() && installLocation.exists()) {
+      println("Skipping Spigot installation, $version is present")
+      return installLocation
+    }
+
+    val buildTools = installBuildTools(parameters.workingDir.get().asFile)
+
+    println("Installing Spigot $version (rev $revision)")
+
+    exec.javaexec {
+      environment["JAVA_HOME"] = parameters.javaHome.get()
+      executable = parameters.javaExecutable.get()
+      workingDir = buildTools.parentFile
+      classpath(buildTools)
+      args = listOf("--nogui", "--rev", revision, "--remapped")
+    }.rethrowFailure()
+
+    // Mark work for delete.
+    cleanUp(buildTools.parentFile)
+
+    if (!installLocation.exists()) {
+      throw IllegalStateException(
+        "Failed to install Spigot $version from $revision. Does the revision point to a different version?")
+    }
+    return installLocation
+  }
+
+  private fun getInstallLocation(version: String): File {
+    return parameters.mavenLocal.get().resolve("org/spigotmc/spigot/$version/spigot-$version-remapped-mojang.jar")
+  }
+
+  private fun installBuildTools(workingDir: File): File {
+    val buildTools = workingDir.resolve("BuildTools.jar")
+    if (buildTools.exists()) {
+      return buildTools
+    }
+
+    workingDir.mkdirs()
+
+    val buildToolsUrl = "https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar"
+    println("Downloading $buildToolsUrl")
+    val stream = URI.create(buildToolsUrl).toURL().openStream()
+    Files.copy(stream, buildTools.toPath())
+    stream.close()
+
+    return buildTools
+  }
+
+  private fun cleanUp(dir: File) {
+    dir.deleteOnExit()
+    if (!dir.isDirectory) {
+      return
+    }
+
+    dir.listFiles()?.forEach {
+      if (it.isDirectory) {
+        cleanUp(it)
+      } else {
+        it.deleteOnExit()
+      }
+    }
+  }
+}
@@ -0,0 +1,21 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.model.ObjectFactory
+import org.gradle.jvm.toolchain.JavaToolchainSpec
+
+abstract class SpigotDependencyExtension (
+  objects: ObjectFactory
+) {
+
+  val version = objects.property(String::class.java)
+  val revision = objects.property(String::class.java)
+    .convention(version.map {
+      it.replace("-R\\d+\\.\\d+-SNAPSHOT".toRegex(), "")
+    })
+  val configuration = objects.property(String::class.java)
+  val classifier = objects.property(String::class.java).convention("remapped-mojang")
+  val ext = objects.property(String::class.java)
+  val java = objects.property(JavaToolchainSpec::class.java)
+  val ignoreCached = objects.property(Boolean::class.java).convention(false)
+
+}
@@ -0,0 +1,56 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.attributes.Bundling
+import org.gradle.api.attributes.Category
+import org.gradle.api.attributes.LibraryElements
+import org.gradle.api.attributes.Usage
+import org.gradle.jvm.tasks.Jar
+import org.gradle.kotlin.dsl.named
+import org.gradle.kotlin.dsl.register
+import java.nio.file.Paths
+
+class SpigotReobf: Plugin<Project> {
+
+  companion object {
+    const val ARTIFACT_CONFIG = "reobf"
+  }
+
+  override fun apply(target: Project) {
+    // Re-use extension from Spigot dependency declaration if available to reduce configuration requirements.
+    val spigotExt = target.dependencies.extensions.findByType(SpigotDependencyExtension::class.java)
+      ?: target.dependencies.extensions.create(
+        "spigot",
+        SpigotDependencyExtension::class.java,
+        target.objects
+      )
+
+    val mvnLocal = target.repositories.mavenLocal()
+
+    val reobfTask = target.tasks.register<SpigotReobfTask>("reobfTask") {
+      dependsOn(target.tasks.named("shadowJar"))
+      // ShadowJar extends Jar, so this should be a safe way to get the result without having
+      // to jump through hoops and shift around shadow declarations in the rest of the project.
+      inputFile.convention(target.tasks.named<Jar>("shadowJar").get().archiveFile)
+      spigotVersion.convention(spigotExt.version)
+      getMavenLocal().set(Paths.get(mvnLocal.url).toFile())
+    }
+
+    // Set up configuration for producing reobf jar.
+    target.configurations.consumable(ARTIFACT_CONFIG) {
+      attributes {
+        attribute(Category.CATEGORY_ATTRIBUTE, target.objects.named(Category.LIBRARY))
+        attribute(Usage.USAGE_ATTRIBUTE, target.objects.named(Usage.JAVA_RUNTIME))
+        attribute(Bundling.BUNDLING_ATTRIBUTE, target.objects.named(Bundling.EXTERNAL))
+        attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, target.objects.named(LibraryElements.JAR))
+      }
+    }
+
+    // Add artifact from reobf task.
+    target.artifacts {
+      add(ARTIFACT_CONFIG, reobfTask)
+    }
+  }
+
+}
@@ -0,0 +1,85 @@
+package com.github.jikoo.openinv
+
+import net.md_5.specialsource.Jar
+import net.md_5.specialsource.JarMapping
+import net.md_5.specialsource.JarRemapper
+import net.md_5.specialsource.RemapperProcessor
+import net.md_5.specialsource.provider.JarProvider
+import net.md_5.specialsource.provider.JointProvider
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.Internal
+import org.gradle.api.tasks.TaskAction
+import java.io.File
+
+abstract class SpigotReobfTask: org.gradle.api.tasks.bundling.Jar() {
+
+  @get:Input
+  val spigotVersion: Property<String> = objectFactory.property(String::class.java)
+
+  @get:InputFile
+  val inputFile: RegularFileProperty = objectFactory.fileProperty()
+
+  @get:Input
+  val intermediaryClassifier: Property<String> = objectFactory.property(String::class.java).convention("mojang-mapped")
+
+  private val mavenLocal: Property<File> = objectFactory.property(File::class.java)
+
+  init {
+    archiveClassifier.convention(SpigotReobf.ARTIFACT_CONFIG)
+  }
+
+  @TaskAction
+  override fun copy() {
+    val spigotVer = spigotVersion.get()
+    val inFile = inputFile.get().asFile
+    val obfPath = inFile.resolveSibling(inFile.name.replace(".jar", "-${intermediaryClassifier.get()}.jar"))
+
+    // https://www.spigotmc.org/threads/510208/#post-4184317
+    val repo = mavenLocal.get()
+    val spigotDir = repo.resolve("org/spigotmc/spigot/$spigotVer/")
+    val mappingDir = repo.resolve("org/spigotmc/minecraft-server/$spigotVer/")
+
+    // Remap original Mojang-mapped jar to obfuscated intermediary
+    val mojangServer = spigotDir.resolve("spigot-$spigotVer-remapped-mojang.jar")
+    val mojangMappings = mappingDir.resolve("minecraft-server-$spigotVer-maps-mojang.txt")
+    remapPartial(mojangServer, mojangMappings, inFile, obfPath, true)
+
+    // Remap obfuscated intermediary jar to Spigot and replace original
+    val obfServer = spigotDir.resolve("spigot-$spigotVer-remapped-obf.jar")
+    val spigotMappings = mappingDir.resolve("minecraft-server-$spigotVer-maps-spigot.csrg")
+    remapPartial(obfServer, spigotMappings, obfPath, archiveFile.get().asFile, false)
+  }
+
+  private fun remapPartial(server: File, mapping: File, input: File, output: File, reverse: Boolean) {
+    val jarMapping = JarMapping()
+    jarMapping.loadMappings(mapping.path, reverse, false, null, null)
+
+    val inheritance = JointProvider()
+    jarMapping.setFallbackInheritanceProvider(inheritance)
+
+    // Equivalent of --live with server jar on classpath.
+    val serverJar = Jar.init(server)
+    inheritance.add(JarProvider(serverJar))
+
+    val inputJar = Jar.init(input)
+    inheritance.add(JarProvider(inputJar))
+
+    // Remap reflective access.
+    val preprocessor = RemapperProcessor(null, jarMapping, null)
+
+    val remapper = JarRemapper(preprocessor, jarMapping, null)
+    remapper.remapJar(inputJar, output, emptySet())
+
+    serverJar.close()
+    inputJar.close()
+  }
+
+  @Internal
+  internal fun getMavenLocal(): Property<File> {
+    return mavenLocal
+  }
+
+}
@@ -0,0 +1,59 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.plugins.JavaPluginExtension
+import org.gradle.jvm.toolchain.JavaToolchainService
+import org.gradle.kotlin.dsl.create
+import java.nio.file.Paths
+import javax.inject.Inject
+
+abstract class SpigotSetup: Plugin<Project> {
+
+  @get:Inject
+  abstract val javaToolchainService: JavaToolchainService
+
+  override fun apply(target: Project) {
+    target.plugins.apply("java")
+
+    // Set up extension for configuring Spigot dependency.
+    val spigotExt = target.dependencies.extensions.findByType(SpigotDependencyExtension::class.java)
+      ?: target.dependencies.extensions.create(
+        "spigot",
+        SpigotDependencyExtension::class.java,
+        target.objects
+      )
+
+    val mvnLocal = target.repositories.mavenLocal()
+
+    target.afterEvaluate {
+      // Get Java requirements, defaulting to version used for compilation.
+      spigotExt.java.convention(target.extensions.getByType(JavaPluginExtension::class.java).toolchain)
+      val launcher = javaToolchainService.launcherFor(spigotExt.java.get()).get()
+
+      // Install Spigot with BuildTools.
+      target.providers.of(BuildToolsValueSource::class.java) {
+        parameters {
+          mavenLocal.set(Paths.get(mvnLocal.url).toFile())
+          workingDir.set(target.layout.buildDirectory.dir("tmp/buildtools"))
+          spigotVersion.set(spigotExt.version)
+          spigotRevision.set(spigotExt.revision)
+          ignoreCached.set(spigotExt.ignoreCached)
+          javaHome.set(launcher.metadata.installationPath)
+          javaExecutable.set(launcher.executablePath.asFile.path)
+        }
+      }.get()
+
+      // Add Spigot dependency.
+      val dependency = target.dependencies.create(
+        "org.spigotmc",
+        "spigot",
+        spigotExt.version.get(),
+        spigotExt.configuration.orNull,
+        spigotExt.classifier.orNull,
+        spigotExt.ext.orNull)
+      target.dependencies.add("compileOnly", dependency)
+    }
+  }
+
+}
@@ -0,0 +1,34 @@
+import org.gradle.jvm.toolchain.JavaLanguageVersion
+import org.gradle.kotlin.dsl.maven
+import org.gradle.kotlin.dsl.repositories
+import org.gradle.kotlin.dsl.dependencies
+
+plugins {
+  `java-library`
+}
+
+java {
+  toolchain.languageVersion = JavaLanguageVersion.of(21)
+}
+
+repositories {
+  mavenCentral()
+  maven("https://repo.papermc.io/repository/maven-public/")
+  maven("https://hub.spigotmc.org/nexus/content/groups/public/")
+}
+
+dependencies {
+  val libs = versionCatalogs.named("libs")
+  compileOnly(libs.findLibrary("annotations").orElseThrow())
+  compileOnly(libs.findLibrary("spigotapi").orElseThrow())
+}
+
+tasks {
+  withType<JavaCompile>().configureEach {
+    options.release = 21
+    options.encoding = Charsets.UTF_8.name()
+  }
+  withType<Javadoc>().configureEach {
+    options.encoding = Charsets.UTF_8.name()
+  }
+}
@@ -0,0 +1,7 @@
+plugins {
+  `openinv-base`
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+}
@@ -1,30 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-
-    <parent>
-        <groupId>com.lishid</groupId>
-        <artifactId>openinvparent</artifactId>
-        <version>5.1.3</version>
-    </parent>
-
-    <artifactId>openinvcommon</artifactId>
-
-    <dependencies>
-        <dependency>
-            <artifactId>annotations</artifactId>
-            <groupId>org.jetbrains</groupId>
-        </dependency>
-        <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
-        </dependency>
-        <dependency>
-            <artifactId>openinvapi</artifactId>
-            <groupId>com.lishid</groupId>
-        </dependency>
-    </dependencies>
-
-</project>
@@ -0,0 +1,9 @@
+# Project meta
+group=com.lishid.openinv
+version=5.1.10
+description=A Bukkit plugin for opening normally-inaccessible inventories.
+
+# Gradle configuration
+org.gradle.parallel=true
+org.gradle.caching=true
+org.gradle.configuration-cache=true
@@ -0,0 +1,19 @@
+[versions]
+spigotapi = "1.21.5-R0.1-SNAPSHOT"
+specialsource = "1.11.5"
+planarwrappers = "3.3.0"
+annotations = "26.0.2"
+paperweight = "2.0.0-beta.16"
+shadow = "8.3.6"
+folia-scheduler-wrapper = "v0.0.3"
+
+[libraries]
+spigotapi = { module = "org.spigotmc:spigot-api", version.ref = "spigotapi" }
+specialsource = { module = "net.md-5:SpecialSource", version.ref = "specialsource" }
+planarwrappers = { module = "com.github.jikoo:planarwrappers", version.ref = "planarwrappers" }
+annotations = { module = "org.jetbrains:annotations", version.ref = "annotations" }
+folia-scheduler-wrapper = { module = "com.github.NahuLD.folia-scheduler-wrapper:folia-scheduler-wrapper", version.ref = "folia-scheduler-wrapper" }
+
+[plugins]
+paperweight = { id = "io.papermc.paperweight.userdev", version.ref = "paperweight" }
+shadow = { id = "com.gradleup.shadow", version.ref = "shadow" }
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
@@ -0,0 +1,60 @@
+import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
+
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+//tasks {
+//  withType<JavaCompile> {
+//    // OpenPlayer unchecked warning is due to superclass' messy inheritance and legacy methods.
+//    options.compilerArgs.add("-Xlint:unchecked")
+//    // PlayerManager uses "deprecated" method matching vanilla to support legacy save data.
+//    // While vanilla still feels that it is appropriate to use in the load process, we will too.
+//    options.compilerArgs.add("-Xlint:deprecation")
+//  }
+//}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+
+  paperweight.paperDevBundle("1.21.5-R0.1-SNAPSHOT")
+}
+
+val spigot = tasks.register<ShadowJar>("spigotRelocations") {
+  dependsOn(tasks.jar)
+  from(sourceSets.main.get().output)
+  relocate("com.lishid.openinv.internal.common", "com.lishid.openinv.internal.reobf")
+  relocate("org.bukkit.craftbukkit", "org.bukkit.craftbukkit.${rootProject.extra["craftbukkitPackage"]}")
+  archiveClassifier = "spigot"
+}
+
+configurations {
+  consumable("spigotRelocated") {
+    attributes {
+      attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.LIBRARY))
+      attribute(Usage.USAGE_ATTRIBUTE, objects.named(Usage.JAVA_RUNTIME))
+      attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling.EXTERNAL))
+      attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objects.named(LibraryElements.JAR))
+    }
+  }
+}
+
+artifacts {
+  add("spigotRelocated", spigot)
+}
@@ -1,19 +1,19 @@
-package com.lishid.openinv.internal.v1_21_R1;
+package com.lishid.openinv.internal.common;

 import com.lishid.openinv.internal.Accessor;
 import com.lishid.openinv.internal.IAnySilentContainer;
 import com.lishid.openinv.internal.ISpecialEnderChest;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.ISpecialPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.AnySilentContainer;
-import com.lishid.openinv.internal.v1_21_R1.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R1.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
-import com.lishid.openinv.internal.v1_21_R1.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.AnySilentContainer;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.slot.placeholder.PlaceholderLoader;
+import com.lishid.openinv.internal.common.player.PlayerManager;
 import com.lishid.openinv.util.lang.LanguageManager;
 import net.minecraft.world.Container;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
 import org.jetbrains.annotations.NotNull;
@@ -24,7 +24,7 @@ import java.util.logging.Logger;

 public class InternalAccessor implements Accessor {

-  private final @NotNull Logger logger;
+  protected final @NotNull Logger logger;
  private final @NotNull PlayerManager manager;
  private final @NotNull AnySilentContainer anySilentContainer;

@@ -69,12 +69,11 @@ public class InternalAccessor implements Accessor {
  @Override
  public void reload(@NotNull ConfigurationSection config) {
    ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
-    if (placeholders != null) {
-      try {
-        Placeholders.load(placeholders);
-      } catch (Exception e) {
-        logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
-      }
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new PlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
    }
  }

@@ -14,11 +14,11 @@
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

-package com.lishid.openinv.internal.v1_21_R1.container;
+package com.lishid.openinv.internal.common.container;

 import com.lishid.openinv.internal.AnySilentContainerBase;
-import com.lishid.openinv.internal.v1_21_R1.container.menu.OpenChestMenu;
-import com.lishid.openinv.internal.v1_21_R1.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.menu.OpenChestMenu;
+import com.lishid.openinv.internal.common.player.PlayerManager;
 import com.lishid.openinv.util.ReflectionHelper;
 import com.lishid.openinv.util.lang.LanguageManager;
 import net.minecraft.core.BlockPos;
@@ -61,10 +61,10 @@ public class AnySilentContainer extends AnySilentContainerBase {
        this.lang = lang;
        try {
            try {
-                this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("b");
+                this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("gameModeForPlayer");
                this.serverPlayerGameModeGameType.setAccessible(true);
            } catch (NoSuchFieldException e) {
-                logger.warning("ServerPlayerGameMode#gameModeForPlayer's obfuscated name has changed!");
+                logger.warning("The field ServerPlayerGameMode#gameModeForPlayer is no longer present!");
                logger.warning("Please report this at https://github.com/Jikoo/OpenInv/issues");
                logger.warning("Attempting to fall through using reflection. Please verify that SilentContainer does not fail.");
                // N.B. gameModeForPlayer is (for now) declared before previousGameModeForPlayer so silent shouldn't break.
@@ -1,9 +1,9 @@
-package com.lishid.openinv.internal.v1_21_R2.container;
+package com.lishid.openinv.internal.common.container;

 import com.lishid.openinv.internal.ISpecialEnderChest;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R2.container.menu.OpenEnderChestMenu;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.menu.OpenEnderChestMenu;
+import com.lishid.openinv.internal.common.player.PlayerManager;
 import net.minecraft.core.NonNullList;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerPlayer;
@@ -15,8 +15,8 @@ import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.inventory.StackedContentsCompatible;
 import net.minecraft.world.item.ItemStack;
 import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
+import org.bukkit.craftbukkit.entity.CraftHumanEntity;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
@@ -90,12 +90,12 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
  }

  @Override
-  public ItemStack getItem(int index) {
+  public @NotNull ItemStack getItem(int index) {
    return index >= 0 && index < items.size() ? items.get(index) : ItemStack.EMPTY;
  }

  @Override
-  public ItemStack removeItem(int index, int amount) {
+  public @NotNull ItemStack removeItem(int index, int amount) {
    ItemStack itemstack = ContainerHelper.removeItem(items, index, amount);

    if (!itemstack.isEmpty()) {
@@ -106,12 +106,12 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
  }

  @Override
-  public ItemStack removeItemNoUpdate(int index) {
+  public @NotNull ItemStack removeItemNoUpdate(int index) {
    return index >= 0 && index < items.size() ? items.set(index, ItemStack.EMPTY) : ItemStack.EMPTY;
  }

  @Override
-  public void setItem(int index, ItemStack itemStack) {
+  public void setItem(int index, @NotNull ItemStack itemStack) {
    if (index >= 0 && index < items.size()) {
      items.set(index, itemStack);
    }
@@ -128,27 +128,27 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
  }

  @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
    return true;
  }

  @Override
-  public List<ItemStack> getContents() {
+  public @NotNull List<ItemStack> getContents() {
    return items;
  }

  @Override
-  public void onOpen(CraftHumanEntity craftHumanEntity) {
+  public void onOpen(@NotNull CraftHumanEntity craftHumanEntity) {
    transaction.add(craftHumanEntity);
  }

  @Override
-  public void onClose(CraftHumanEntity craftHumanEntity) {
+  public void onClose(@NotNull CraftHumanEntity craftHumanEntity) {
    transaction.remove(craftHumanEntity);
  }

  @Override
-  public List<HumanEntity> getViewers() {
+  public @NotNull List<HumanEntity> getViewers() {
    return transaction;
  }

@@ -174,7 +174,7 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
  }

  @Override
-  public void fillStackedContents(StackedItemContents stackedContents) {
+  public void fillStackedContents(@NotNull StackedItemContents stackedContents) {
    for (ItemStack itemstack : items) {
      stackedContents.accountStack(itemstack);
    }
@@ -1,20 +1,22 @@
-package com.lishid.openinv.internal.v1_21_R2.container;
+package com.lishid.openinv.internal.common.container;

 import com.lishid.openinv.internal.ISpecialPlayerInventory;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.menu.OpenInventoryMenu;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.Content;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentCrafting;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentCraftingResult;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentCursor;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentList;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentOffHand;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentViewOnly;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotViewOnly;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.bukkit.OpenPlayerInventory;
+import com.lishid.openinv.internal.common.container.menu.OpenInventoryMenu;
+import com.lishid.openinv.internal.common.container.slot.Content;
+import com.lishid.openinv.internal.common.container.slot.ContentCrafting;
+import com.lishid.openinv.internal.common.container.slot.ContentCraftingResult;
+import com.lishid.openinv.internal.common.container.slot.ContentCursor;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.ContentEquipment;
+import com.lishid.openinv.internal.common.container.slot.ContentList;
+import com.lishid.openinv.internal.common.container.slot.ContentOffHand;
+import com.lishid.openinv.internal.common.container.slot.ContentViewOnly;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.PlayerManager;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import net.minecraft.ChatFormatting;
 import net.minecraft.core.NonNullList;
 import net.minecraft.network.chat.Component;
@@ -29,21 +31,23 @@ import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
 import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
+import org.bukkit.craftbukkit.entity.CraftHumanEntity;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
+import java.util.Map;

 public class OpenInventory implements Container, InternalOwned<ServerPlayer>, ISpecialPlayerInventory {

-  private final List<Content> slots;
+  protected final List<Content> slots;
  private final int size;
-  private ServerPlayer owner;
+  protected ServerPlayer owner;
  private int maxStackSize = 99;
  private CraftInventory bukkitEntity;
  public List<HumanEntity> transaction = new ArrayList<>();
@@ -59,15 +63,14 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
    setupSlots();
  }

-  private void setupSlots() {
+  protected void setupSlots() {
    // Top of inventory: Regular contents.
    int nextIndex = addMainInventory();

    // If inventory is expected size, we can arrange slots to be pretty.
    Inventory ownerInv = owner.getInventory();
-    if (ownerInv.items.size() == 36
-        && ownerInv.armor.size() == 4
-        && ownerInv.offhand.size() == 1
+    if (ownerInv.getNonEquipmentItems().size() == 36
+        && Inventory.EQUIPMENT_SLOT_MAPPING.size() == 5
        && owner.inventoryMenu.getCraftSlots().getContainerSize() == 4) {
      // Armor slots: Bottom left.
      addArmor(36);
@@ -94,7 +97,7 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
  }

  private int addMainInventory() {
-    int listSize = owner.getInventory().items.size();
+    int listSize = owner.getInventory().getNonEquipmentItems().size();
    // Hotbar slots are 0-8. We want those to appear on the bottom of the inventory like a normal player inventory,
    // so everything else needs to move up a row.
    int hotbarDiff = listSize - 9;
@@ -112,7 +115,7 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
      slots.set(localIndex, new ContentList(owner, invIndex, type) {
        @Override
        public void setHolder(@NotNull ServerPlayer holder) {
-          items = holder.getInventory().items;
+          items = holder.getInventory().getNonEquipmentItems();
        }
      });
    }
@@ -120,50 +123,36 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
  }

  private int addArmor(int startIndex) {
-    int listSize = owner.getInventory().armor.size();
-
-    for (int i = 0; i < listSize; ++i) {
-      // Armor slots go bottom to top; boots are slot 0, helmet is slot 3.
-      // Since we have to display horizontally due to space restrictions,
-      // making the left side the "top" is more user-friendly.
-      int armorIndex;
-      EquipmentSlot slot;
-      switch (i) {
-        case 3 -> {
-          armorIndex = 0;
-          slot = EquipmentSlot.FEET;
-        }
-        case 2 -> {
-          armorIndex = 1;
-          slot = EquipmentSlot.LEGS;
-        }
-        case 1 -> {
-          armorIndex = 2;
-          slot = EquipmentSlot.CHEST;
-        }
-        case 0 -> {
-          armorIndex = 3;
-          slot = EquipmentSlot.HEAD;
-        }
-        default -> {
-          // In the event that new armor slots are added, they can be placed at the end.
-          armorIndex = i;
-          slot = EquipmentSlot.MAINHAND;
-        }
+    // Armor slots go bottom to top; boots are first and helmet is last.
+    // Since we have to display horizontally due to space restrictions,
+    // making the left side the "top" is more user-friendly.
+    EquipmentSlot[] sorted = Inventory.EQUIPMENT_SLOT_MAPPING.int2ObjectEntrySet()
+        .stream()
+        .sorted(Comparator.comparingInt(Int2ObjectMap.Entry::getIntKey))
+        .map(Map.Entry::getValue)
+        .toArray(EquipmentSlot[]::new);
+    int localIndex = 0;
+    for (int i = sorted.length - 1; i >= 0; --i) {
+      // Skip off-hand, handled separately.
+      if (sorted[i] == EquipmentSlot.OFFHAND) {
+        continue;
      }

-      slots.set(startIndex + i, new ContentEquipment(owner, armorIndex, slot));
+      slots.set(startIndex + localIndex, new ContentEquipment(owner, sorted[i]));
+      ++localIndex;
    }

-    return startIndex + listSize;
+    return startIndex + localIndex;
  }

  private int addOffHand(int startIndex) {
-    int listSize = owner.getInventory().offhand.size();
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      slots.set(startIndex + localIndex, new ContentOffHand(owner, localIndex));
+    // No off-hand?
+    if (!Inventory.EQUIPMENT_SLOT_MAPPING.containsValue(EquipmentSlot.OFFHAND)) {
+      return startIndex;
    }
-    return startIndex + listSize;
+
+    slots.set(startIndex, new ContentOffHand(owner));
+    return startIndex + 1;
  }

  private int addCrafting(int startIndex, boolean pretty) {
@@ -191,12 +180,16 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
          };
        }
      });
-      slots.set(startIndex + 11, new ContentCraftingResult(owner));
+      slots.set(startIndex + 11, getCraftingResult(owner));
    }

    return startIndex + listSize;
  }

+  protected Content getCraftingResult(@NotNull ServerPlayer serverPlayer) {
+    return new ContentCraftingResult(serverPlayer);
+  }
+
  public Slot getMenuSlot(int index, int x, int y) {
    return slots.get(index).asSlot(this, index, x, y);
  }
@@ -275,22 +268,22 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
  }

  @Override
-  public ItemStack getItem(int index) {
+  public @NotNull ItemStack getItem(int index) {
    return slots.get(index).get();
  }

  @Override
-  public ItemStack removeItem(int index, int amount) {
+  public @NotNull ItemStack removeItem(int index, int amount) {
    return slots.get(index).removePartial(amount);
  }

  @Override
-  public ItemStack removeItemNoUpdate(int index) {
+  public @NotNull ItemStack removeItemNoUpdate(int index) {
    return slots.get(index).remove();
  }

  @Override
-  public void setItem(int index, ItemStack itemStack) {
+  public void setItem(int index, @NotNull ItemStack itemStack) {
    slots.get(index).set(itemStack);
  }

@@ -308,12 +301,12 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
  public void setChanged() {}

  @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
    return true;
  }

  @Override
-  public List<ItemStack> getContents() {
+  public @NotNull List<ItemStack> getContents() {
    NonNullList<ItemStack> contents = NonNullList.withSize(getContainerSize(), ItemStack.EMPTY);
    for (int i = 0; i < getContainerSize(); ++i) {
      contents.set(i, getItem(i));
@@ -322,22 +315,22 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
  }

  @Override
-  public void onOpen(CraftHumanEntity viewer) {
+  public void onOpen(@NotNull CraftHumanEntity viewer) {
    transaction.add(viewer);
  }

  @Override
-  public void onClose(CraftHumanEntity viewer) {
+  public void onClose(@NotNull CraftHumanEntity viewer) {
    transaction.remove(viewer);
  }

  @Override
-  public List<HumanEntity> getViewers() {
+  public @NotNull List<HumanEntity> getViewers() {
    return transaction;
  }

  @Override
-  public org.bukkit.entity.Player getOwner() {
+  public @NotNull org.bukkit.entity.Player getOwner() {
    return owner.getBukkitEntity();
  }

@@ -1,9 +1,10 @@
-package com.lishid.openinv.internal.v1_21_R1.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;

 import com.lishid.openinv.internal.ViewOnly;
 import net.minecraft.world.Container;
 import org.bukkit.Material;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -17,8 +18,16 @@ import java.util.ListIterator;
 */
 public class OpenDummyInventory extends CraftInventory implements ViewOnly {

-  public OpenDummyInventory(Container inventory) {
+  private final InventoryType type;
+
+  public OpenDummyInventory(Container inventory, InventoryType type) {
    super(inventory);
+    this.type = type;
+  }
+
+  @Override
+  public @NotNull InventoryType getType() {
+    return type;
  }

  @Override
@@ -53,7 +62,7 @@ public class OpenDummyInventory extends CraftInventory implements ViewOnly {
  }

  @Override
-  public ItemStack[] getContents() {
+  public ItemStack @NotNull [] getContents() {
    return new ItemStack[getSize()];
  }

@@ -63,7 +72,7 @@ public class OpenDummyInventory extends CraftInventory implements ViewOnly {
  }

  @Override
-  public @NotNull ItemStack[] getStorageContents() {
+  public @NotNull ItemStack @NotNull [] getStorageContents() {
    return new ItemStack[getSize()];
  }

@@ -0,0 +1,136 @@
+package com.lishid.openinv.internal.common.container.bukkit;
+
+import net.minecraft.world.Container;
+import org.bukkit.Material;
+import org.bukkit.entity.HumanEntity;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.EquipmentSlot;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenDummyPlayerInventory extends OpenDummyInventory implements PlayerInventory {
+
+  public OpenDummyPlayerInventory(Container inventory) {
+    super(inventory, InventoryType.PLAYER);
+  }
+
+  @Override
+  public HumanEntity getHolder() {
+    return (HumanEntity) super.getHolder();
+  }
+
+  @Override
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
+    return new ItemStack[4];
+  }
+
+  @Override
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
+    return new ItemStack[4];
+  }
+
+  @Override
+  public @Nullable ItemStack getHelmet() {
+    return null;
+  }
+
+  @Override
+  public @Nullable ItemStack getChestplate() {
+    return null;
+  }
+
+  @Override
+  public @Nullable ItemStack getLeggings() {
+    return null;
+  }
+
+  @Override
+  public @Nullable ItemStack getBoots() {
+    return null;
+  }
+
+  @Override
+  public void setItem(@NotNull EquipmentSlot slot, @Nullable ItemStack item) {
+
+  }
+
+  @Override
+  public @NotNull ItemStack getItem(@NotNull EquipmentSlot slot) {
+    return new ItemStack(Material.AIR);
+  }
+
+  @Override
+  public void setArmorContents(ItemStack @NotNull [] items) {
+
+  }
+
+  @Override
+  public void setExtraContents(ItemStack @NotNull [] items) {
+
+  }
+
+  @Override
+  public void setHelmet(@Nullable ItemStack helmet) {
+
+  }
+
+  @Override
+  public void setChestplate(@Nullable ItemStack chestplate) {
+
+  }
+
+  @Override
+  public void setLeggings(@Nullable ItemStack leggings) {
+
+  }
+
+  @Override
+  public void setBoots(@Nullable ItemStack boots) {
+
+  }
+
+  @Override
+  public @NotNull ItemStack getItemInMainHand() {
+    return new ItemStack(Material.AIR);
+  }
+
+  @Override
+  public void setItemInMainHand(@Nullable ItemStack item) {
+
+  }
+
+  @Override
+  public @NotNull ItemStack getItemInOffHand() {
+    return new ItemStack(Material.AIR);
+  }
+
+  @Override
+  public void setItemInOffHand(@Nullable ItemStack item) {
+
+  }
+
+  @Deprecated
+  @Override
+  public @NotNull ItemStack getItemInHand() {
+    return new ItemStack(Material.AIR);
+  }
+
+  @Deprecated
+  @Override
+  public void setItemInHand(@Nullable ItemStack stack) {
+
+  }
+
+  @Override
+  public int getHeldItemSlot() {
+    return 0;
+  }
+
+  @Override
+  public void setHeldItemSlot(int slot) {
+
+  }
+
+}
@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R1.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;

 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R1.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.OpenInventory;
 import net.minecraft.core.NonNullList;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.entity.player.Inventory;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventory;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.entity.Player;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
@@ -14,6 +14,8 @@ import org.bukkit.inventory.PlayerInventory;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

+import java.util.List;
+
 public class OpenPlayerInventory extends CraftInventory implements PlayerInventory {

  public OpenPlayerInventory(@NotNull OpenInventory inventory) {
@@ -26,7 +28,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public ItemStack[] getContents() {
+  public ItemStack @NotNull [] getContents() {
    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getContents());
  }

@@ -46,13 +48,13 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public ItemStack[] getStorageContents() {
-    return asCraftMirror(getInventory().getOwnerHandle().getInventory().items);
+  public ItemStack @NotNull [] getStorageContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getNonEquipmentItems());
  }

  @Override
  public void setStorageContents(ItemStack[] items) throws IllegalArgumentException {
-    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().items;
+    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().getNonEquipmentItems();
    int size = list.size();
    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
    for (int index = 0; index < items.length; ++index) {
@@ -71,110 +73,113 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @NotNull ItemStack[] getArmorContents() {
-    return asCraftMirror(getInventory().getOwnerHandle().getInventory().armor);
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getArmorContents());
  }

  @Override
-  public void setArmorContents(@Nullable ItemStack[] items) {
-    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().armor;
-    int size = list.size();
+  public void setArmorContents(ItemStack @NotNull [] items) {
+    int size = Inventory.EQUIPMENT_SLOTS_SORTED_BY_INDEX.length;
    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
    for (int index = 0; index < items.length; ++index) {
-      list.set(index, CraftItemStack.asNMSCopy(items[index]));
+      getInventory().getOwnerHandle().getInventory().equipment.set(
+          Inventory.EQUIPMENT_SLOTS_SORTED_BY_INDEX[index],
+          CraftItemStack.asNMSCopy(items[index]));
    }
  }

  @Override
-  public @NotNull ItemStack[] getExtraContents() {
-    return asCraftMirror(getInventory().getOwnerHandle().getInventory().offhand);
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
+    return asCraftMirror(List.of(getInventory().getOwnerHandle().getInventory().equipment.get(EquipmentSlot.OFFHAND)));
  }

  @Override
-  public void setExtraContents(@Nullable ItemStack[] items) {
-    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().offhand;
-    int size = list.size();
-    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
-    for (int index = 0; index < items.length; ++index) {
-      list.set(index, CraftItemStack.asNMSCopy(items[index]));
+  public void setExtraContents(ItemStack @NotNull [] items) {
+    Preconditions.checkArgument(items.length <= 1, "items.length must be <= 1");
+    for (ItemStack item : items) {
+      getInventory().getOwnerHandle().getInventory().equipment.set(EquipmentSlot.OFFHAND, CraftItemStack.asNMSCopy(item));
    }
  }

  @Override
-  public @Nullable ItemStack getHelmet() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.HEAD.getIndex()));
+  public @NotNull ItemStack getHelmet() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.HEAD));
  }

  @Override
  public void setHelmet(@Nullable ItemStack helmet) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.HEAD.getIndex(), CraftItemStack.asNMSCopy(helmet));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.HEAD, CraftItemStack.asNMSCopy(helmet));
  }

  @Override
-  public @Nullable ItemStack getChestplate() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.HEAD.getIndex()));
+  public @NotNull ItemStack getChestplate() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.CHEST));
  }

  @Override
  public void setChestplate(@Nullable ItemStack chestplate) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.CHEST.getIndex(), CraftItemStack.asNMSCopy(chestplate));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.CHEST, CraftItemStack.asNMSCopy(chestplate));
  }

  @Override
-  public @Nullable ItemStack getLeggings() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.LEGS.getIndex()));
+  public @NotNull ItemStack getLeggings() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.LEGS));
  }

  @Override
  public void setLeggings(@Nullable ItemStack leggings) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.LEGS.getIndex(), CraftItemStack.asNMSCopy(leggings));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.LEGS, CraftItemStack.asNMSCopy(leggings));
  }

  @Override
-  public @Nullable ItemStack getBoots() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.FEET.getIndex()));
+  public @NotNull ItemStack getBoots() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.FEET));
  }

  @Override
  public void setBoots(@Nullable ItemStack boots) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.FEET.getIndex(), CraftItemStack.asNMSCopy(boots));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.FEET, CraftItemStack.asNMSCopy(boots));
  }

  @Override
  public @NotNull ItemStack getItemInMainHand() {
    Inventory internal = getInventory().getOwnerHandle().getInventory();
-    return CraftItemStack.asCraftMirror(internal.getItem(internal.selected));
+    return CraftItemStack.asCraftMirror(internal.getSelectedItem());
  }

  @Override
  public void setItemInMainHand(@Nullable ItemStack item) {
    Inventory internal = getInventory().getOwnerHandle().getInventory();
-    internal.setItem(internal.selected, CraftItemStack.asNMSCopy(item));
+    internal.setSelectedItem(CraftItemStack.asNMSCopy(item));
  }

  @Override
  public @NotNull ItemStack getItemInOffHand() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().offhand.getFirst());
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.OFFHAND));
  }

  @Override
  public void setItemInOffHand(@Nullable ItemStack item) {
-    getInventory().getOwnerHandle().getInventory().offhand.set(0, CraftItemStack.asNMSCopy(item));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.OFFHAND, CraftItemStack.asNMSCopy(item));
  }

+  @Deprecated
  @Override
  public @NotNull ItemStack getItemInHand() {
    return getItemInMainHand();
  }

+  @Deprecated
  @Override
  public void setItemInHand(@Nullable ItemStack stack) {
    setItemInMainHand(stack);
@@ -183,17 +188,17 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  @Override
  public int getHeldItemSlot() {
    Inventory internal = getInventory().getOwnerHandle().getInventory();
-    return internal.items.size() - 9 + internal.selected;
+    return internal.getNonEquipmentItems().size() - 9 + internal.getSelectedSlot();
  }

  @Override
  public void setHeldItemSlot(int slot) {
    slot %= 9;
-    getInventory().getOwnerHandle().getInventory().selected = slot;
+    getInventory().getOwnerHandle().getInventory().setSelectedSlot(slot);
  }

  @Override
-  public @Nullable ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
+  public @NotNull ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
    return switch (slot) {
      case HAND -> getItemInMainHand();
      case OFF_HAND -> getItemInOffHand();
@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R1.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;

-import com.lishid.openinv.internal.v1_21_R1.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.OpenInventory;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;

@@ -1,13 +1,14 @@
-package com.lishid.openinv.internal.v1_21_R1.container.menu;
+package com.lishid.openinv.internal.common.container.menu;

 import com.google.common.base.Suppliers;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R1.container.bukkit.OpenDummyInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.SlotPlaceholder;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyInventory;
+import com.lishid.openinv.internal.common.container.slot.SlotPlaceholder;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
 import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
+import net.minecraft.network.HashedStack;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.player.Player;
@@ -19,9 +20,10 @@ import net.minecraft.world.inventory.ContainerListener;
 import net.minecraft.world.inventory.ContainerSynchronizer;
 import net.minecraft.world.inventory.DataSlot;
 import net.minecraft.world.inventory.MenuType;
+import net.minecraft.world.inventory.RemoteSlot;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -47,12 +49,12 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  protected final int topSize;
  private CraftInventoryView<OpenChestMenu<T>, Inventory> bukkitEntity;
  // Syncher fields
-  private @Nullable ContainerSynchronizer synchronizer;
-  private final List<DataSlot> dataSlots = new ArrayList<>();
-  private final IntList remoteDataSlots = new IntArrayList();
-  private final List<ContainerListener> containerListeners = new ArrayList<>();
-  private ItemStack remoteCarried = ItemStack.EMPTY;
-  private boolean suppressRemoteUpdates;
+  protected @Nullable ContainerSynchronizer synchronizer;
+  protected final List<DataSlot> dataSlots = new ArrayList<>();
+  protected final IntList remoteDataSlots = new IntArrayList();
+  protected final List<ContainerListener> containerListeners = new ArrayList<>();
+  private RemoteSlot remoteCarried = RemoteSlot.PLACEHOLDER;
+  protected boolean suppressRemoteUpdates;

  protected OpenChestMenu(
      @NotNull MenuType<ChestMenu> type,
@@ -124,10 +126,11 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  protected void preSlotSetup() {}

  protected @NotNull Slot getUpperSlot(int index, int x, int y) {
+    Slot slot = new Slot(container, index, x, y);
    if (viewOnly) {
-      return new SlotViewOnly(container, index, x, y);
+      return SlotViewOnly.wrap(slot);
    }
-    return new Slot(container, index, x, y);
+    return slot;
  }


@@ -143,7 +146,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  protected @NotNull CraftInventoryView<OpenChestMenu<T>, Inventory> createBukkitEntity() {
    Inventory top;
    if (viewOnly) {
-      top = new OpenDummyInventory(container);
+      top = new OpenDummyInventory(container, container.getBukkitType());
    } else {
      top = container.getBukkitInventory();
    }
@@ -176,9 +179,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In

  private int getTopSize(ServerPlayer viewer) {
    MenuType<?> menuType = getType();
-    if (menuType == null) {
-      throw new IllegalStateException("MenuType cannot be null!");
-    } else if (menuType == MenuType.GENERIC_9x1) {
+    if (menuType == MenuType.GENERIC_9x1) {
      return 9;
    } else if (menuType == MenuType.GENERIC_9x2) {
      return 18;
@@ -284,7 +285,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void clicked(int i, int j, ClickType clickType, Player player) {
+  public void clicked(int i, int j, @NotNull ClickType clickType, @NotNull Player player) {
    if (viewOnly) {
      if (clickType == ClickType.QUICK_CRAFT) {
        sendAllDataToRemote();
@@ -295,22 +296,22 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
    return true;
  }

  // Overrides from here on are purely to modify the sync process to send placeholder items.
  @Override
-  protected Slot addSlot(Slot slot) {
+  protected @NotNull Slot addSlot(@NotNull Slot slot) {
    slot.index = this.slots.size();
    this.slots.add(slot);
    this.lastSlots.add(ItemStack.EMPTY);
-    this.remoteSlots.add(ItemStack.EMPTY);
+    this.remoteSlots.add(this.synchronizer != null ? this.synchronizer.createSlot() : RemoteSlot.PLACEHOLDER);
    return slot;
  }

  @Override
-  protected DataSlot addDataSlot(DataSlot dataSlot) {
+  protected @NotNull DataSlot addDataSlot(@NotNull DataSlot dataSlot) {
    this.dataSlots.add(dataSlot);
    this.remoteDataSlots.add(0);
    return dataSlot;
@@ -324,7 +325,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void addSlotListener(ContainerListener containerListener) {
+  public void addSlotListener(@NotNull ContainerListener containerListener) {
    if (!this.containerListeners.contains(containerListener)) {
      this.containerListeners.add(containerListener);
      this.broadcastChanges();
@@ -332,39 +333,45 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void setSynchronizer(ContainerSynchronizer containerSynchronizer) {
+  public void setSynchronizer(@NotNull ContainerSynchronizer containerSynchronizer) {
    this.synchronizer = containerSynchronizer;
+    this.remoteCarried = synchronizer.createSlot();
+    this.remoteSlots.replaceAll(slot -> synchronizer.createSlot());
    this.sendAllDataToRemote();
  }

  @Override
  public void sendAllDataToRemote() {
+    List<ItemStack> contentsCopy = new ArrayList<>();
    for (int index = 0; index < slots.size(); ++index) {
      Slot slot = slots.get(index);
-      this.remoteSlots.set(index, (slot instanceof SlotPlaceholder placeholder ? placeholder.getOrDefault() : slot.getItem()).copy());
+      ItemStack itemStack = slot instanceof SlotPlaceholder placeholder ? placeholder.getOrDefault() : slot.getItem();
+      contentsCopy.add(itemStack);
+      this.remoteSlots.get(index).force(itemStack);
    }

-    remoteCarried = getCarried().copy();
+    remoteCarried.force(getCarried());

    for (int index = 0; index < this.dataSlots.size(); ++index) {
      this.remoteDataSlots.set(index, this.dataSlots.get(index).get());
    }

    if (this.synchronizer != null) {
-      this.synchronizer.sendInitialData(this, this.remoteSlots, this.remoteCarried, this.remoteDataSlots.toIntArray());
+      this.synchronizer.sendInitialData(this, contentsCopy, this.getCarried().copy(), this.remoteDataSlots.toIntArray());
    }
  }

  @Override
  public void broadcastCarriedItem() {
-    this.remoteCarried = this.getCarried().copy();
+    ItemStack carried = this.getCarried();
+    this.remoteCarried.force(carried);
    if (this.synchronizer != null) {
-      this.synchronizer.sendCarriedChange(this, this.remoteCarried);
+      this.synchronizer.sendCarriedChange(this, carried.copy());
    }
  }

  @Override
-  public void removeSlotListener(ContainerListener containerListener) {
+  public void removeSlotListener(@NotNull ContainerListener containerListener) {
    this.containerListeners.remove(containerListener);
  }

@@ -428,12 +435,11 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In

  private void synchronizeSlotToRemote(int i, ItemStack itemStack, Supplier<ItemStack> supplier) {
    if (!this.suppressRemoteUpdates) {
-      ItemStack itemStack1 = this.remoteSlots.get(i);
-      if (!ItemStack.matches(itemStack1, itemStack)) {
-        ItemStack itemstack2 = supplier.get();
-        this.remoteSlots.set(i, itemstack2);
+      RemoteSlot slot = this.remoteSlots.get(i);
+      if (!slot.matches(itemStack)) {
+        slot.force(itemStack);
        if (this.synchronizer != null) {
-          this.synchronizer.sendSlotChange(this, i, itemstack2);
+          this.synchronizer.sendSlotChange(this, i, supplier.get());
        }
      }
    }
@@ -452,17 +458,20 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  private void synchronizeCarriedToRemote() {
-    if (!this.suppressRemoteUpdates && !ItemStack.matches(this.getCarried(), this.remoteCarried)) {
-      this.remoteCarried = this.getCarried().copy();
-      if (this.synchronizer != null) {
-        this.synchronizer.sendCarriedChange(this, this.remoteCarried);
+    if (!this.suppressRemoteUpdates) {
+      ItemStack carried = this.getCarried();
+      if (!this.remoteCarried.matches(carried)) {
+        this.remoteCarried.force(carried);
+        if (this.synchronizer != null) {
+          this.synchronizer.sendCarriedChange(this, carried.copy());
+        }
      }
    }
  }

  @Override
-  public void setRemoteCarried(ItemStack itemstack) {
-    this.remoteCarried = itemstack.copy();
+  public void setRemoteCarried(@NotNull HashedStack stack) {
+    this.remoteCarried.receive(stack);
  }

  @Override
@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R1.container.menu;
+package com.lishid.openinv.internal.common.container.menu;

-import com.lishid.openinv.internal.v1_21_R1.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.Slot;
@@ -18,7 +18,7 @@ public class OpenEnderChestMenu extends OpenChestMenu<OpenEnderChest> {
  }

  @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
    if (viewOnly) {
      return ItemStack.EMPTY;
    }
@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R2.container.menu;
+package com.lishid.openinv.internal.common.container.menu;

 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenDummyInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenPlayerInventorySelf;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyPlayerInventory;
+import com.lishid.openinv.internal.common.container.bukkit.OpenPlayerInventorySelf;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.ContentEquipment;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
 import com.lishid.openinv.util.Permissions;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.EquipmentSlot;
@@ -15,8 +15,8 @@ import net.minecraft.world.inventory.ChestMenu;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventoryView;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -35,7 +35,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
    int size = inventory.getContainerSize();
    // Disallow duplicate access to own main inventory contents.
    if (inventory.getOwnerHandle().equals(viewer)) {
-      size -= viewer.getInventory().items.size();
+      size -= viewer.getInventory().getNonEquipmentItems().size();
      size = ((int) Math.ceil(size / 9.0)) * 9;
    }

@@ -44,7 +44,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {

  @Override
  protected void preSlotSetup() {
-    offset = ownContainer ? viewer.getInventory().items.size() : 0;
+    offset = ownContainer ? viewer.getInventory().getNonEquipmentItems().size() : 0;
  }

  @Override
@@ -102,7 +102,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
  protected @NotNull CraftInventoryView<OpenChestMenu<OpenInventory>, Inventory> createBukkitEntity() {
    org.bukkit.inventory.Inventory bukkitInventory;
    if (viewOnly) {
-      bukkitInventory = new OpenDummyInventory(container);
+      bukkitInventory = new OpenDummyPlayerInventory(container);
    } else if (ownContainer) {
      bukkitInventory = new OpenPlayerInventorySelf(container, offset);
    } else {
@@ -195,7 +195,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
  }

  @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
    if (viewOnly) {
      return ItemStack.EMPTY;
    }
@@ -221,7 +221,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
        // If this is gear, try to move it to the correct slot first.
        case OFFHAND, FEET, LEGS, CHEST, HEAD -> {
          // Locate the correct slot in the contents following the main inventory.
-          for (int extra = container.getOwnerHandle().getInventory().items.size() - offset; extra < topSize; ++extra) {
+          for (int extra = container.getOwnerHandle().getInventory().getNonEquipmentItems().size() - offset; extra < topSize; ++extra) {
            Slot extraSlot = getSlot(extra);
            if (extraSlot instanceof ContentEquipment.SlotEquipment equipSlot
                && equipSlot.getEquipmentSlot() == equipmentSlot) {
@@ -244,7 +244,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
        }
      } else {
        // If we didn't move to a gear slot, try to move to a main inventory slot.
-        if (!movedGear && !this.moveItemStackTo(itemStack, 0, container.getOwnerHandle().getInventory().items.size(), true)) {
+        if (!movedGear && !this.moveItemStackTo(itemStack, 0, container.getOwnerHandle().getInventory().getNonEquipmentItems().size(), true)) {
          return ItemStack.EMPTY;
        }
      }
@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
@@ -1,6 +1,7 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.OpenPlayer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.ContainerHelper;
@@ -30,11 +31,11 @@ public class ContentCrafting implements Content {
    return isAvailable(holder);
  }

-  static boolean isAvailable(@NotNull ServerPlayer holder) {
+  public static boolean isAvailable(@NotNull ServerPlayer holder) {
    // Player must be online and not in creative - since the creative client is (semi-)authoritative,
    // it ignores changes without extra help, and will delete the item as a result.
    // Spectator mode is technically possible but may cause the item to be dropped if the client opens an inventory.
-    return holder.connection != null && !holder.connection.isDisconnected() && holder.gameMode.isSurvival();
+    return OpenPlayer.isConnected(holder.connection) && holder.gameMode.isSurvival();
  }

  @Override
@@ -107,12 +108,12 @@ public class ContentCrafting implements Content {
    }

    @Override
-    public boolean mayPickup(Player player) {
+    public boolean mayPickup(@NotNull Player player) {
      return isAvailable();
    }

    @Override
-    public boolean mayPlace(ItemStack itemStack) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
      return isAvailable();
    }

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.InventoryMenu;
@@ -1,6 +1,7 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.OpenPlayer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.player.Player;
@@ -63,7 +64,7 @@ public class ContentCursor implements Content {
    // Player must be online and not in creative - since the creative client is (semi-)authoritative,
    // it ignores changes without extra help, and will delete the item as a result.
    // Spectator mode is technically possible but may cause the item to be dropped if the client opens an inventory.
-    return holder.connection != null && !holder.connection.isDisconnected() && holder.gameMode.isSurvival();
+    return OpenPlayer.isConnected(holder.connection) && holder.gameMode.isSurvival();
  }

  @Override
@@ -93,12 +94,12 @@ public class ContentCursor implements Content {
    }

    @Override
-    public boolean mayPickup(Player player) {
+    public boolean mayPickup(@NotNull Player player) {
      return isAvailable();
    }

    @Override
-    public boolean mayPlace(ItemStack itemStack) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
      return isAvailable();
    }

@@ -1,6 +1,7 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.OpenPlayer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.Slot;
@@ -63,14 +64,14 @@ public class ContentDrop implements Content {

    @Override
    public ItemStack getOrDefault() {
-      return holder.connection != null && !holder.connection.isDisconnected()
+      return OpenPlayer.isConnected(holder.connection)
          ? Placeholders.drop
          : Placeholders.blockedOffline;
    }

    @Override
-    public boolean mayPlace(ItemStack itemStack) {
-      return holder.connection != null && !holder.connection.isDisconnected();
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
+      return OpenPlayer.isConnected(holder.connection);
    }

    @Override
@@ -1,8 +1,10 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
+import net.minecraft.world.ContainerHelper;
+import net.minecraft.world.entity.EntityEquipment;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
@@ -12,13 +14,14 @@ import org.jetbrains.annotations.NotNull;
 /**
 * A slot for equipment that displays placeholders if empty.
 */
-public class ContentEquipment extends ContentList {
+public class ContentEquipment implements Content {

+  private EntityEquipment equipment;
  private final ItemStack placeholder;
  private final EquipmentSlot equipmentSlot;

-  public ContentEquipment(ServerPlayer holder, int index, EquipmentSlot equipmentSlot) {
-    super(holder, index, InventoryType.SlotType.ARMOR);
+  public ContentEquipment(ServerPlayer holder, EquipmentSlot equipmentSlot) {
+    setHolder(holder);
    placeholder = switch (equipmentSlot) {
      case HEAD -> Placeholders.emptyHelmet;
      case CHEST -> Placeholders.emptyChestplate;
@@ -31,7 +34,31 @@ public class ContentEquipment extends ContentList {

  @Override
  public void setHolder(@NotNull ServerPlayer holder) {
-    this.items = holder.getInventory().armor;
+    this.equipment = holder.getInventory().equipment;
+  }
+
+  @Override
+  public ItemStack get() {
+    return equipment.get(equipmentSlot);
+  }
+
+  @Override
+  public ItemStack remove() {
+    return equipment.set(equipmentSlot, ItemStack.EMPTY);
+  }
+
+  @Override
+  public ItemStack removePartial(int amount) {
+    ItemStack current = get();
+    if (!current.isEmpty() && amount > 0) {
+      return current.split(amount);
+    }
+    return ItemStack.EMPTY;
+  }
+
+  @Override
+  public void set(ItemStack itemStack) {
+    equipment.set(equipmentSlot, itemStack);
  }

  @Override
@@ -39,6 +66,11 @@ public class ContentEquipment extends ContentList {
    return new SlotEquipment(container, slot, x, y);
  }

+  @Override
+  public InventoryType.SlotType getSlotType() {
+    return InventoryType.SlotType.ARMOR;
+  }
+
  public class SlotEquipment extends SlotPlaceholder {

    private ServerPlayer viewer;
@@ -65,12 +97,12 @@ public class ContentEquipment extends ContentList {
    }

    @Override
-    public boolean mayPlace(ItemStack var0) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
      if (viewer == null) {
        return true;
      }

-      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(var0) == equipmentSlot;
+      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(itemStack) == equipmentSlot;
    }

  }
@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
@@ -1,8 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

+import com.lishid.openinv.internal.common.player.OpenPlayer;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.InventoryMenu;
 import net.minecraft.world.inventory.Slot;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
@@ -14,13 +17,13 @@ public class ContentOffHand extends ContentEquipment {

  private ServerPlayer holder;

-  public ContentOffHand(ServerPlayer holder, int localIndex) {
-    super(holder, localIndex, EquipmentSlot.OFFHAND);
+  public ContentOffHand(ServerPlayer holder) {
+    super(holder, EquipmentSlot.OFFHAND);
  }

  @Override
  public void setHolder(@NotNull ServerPlayer holder) {
-    this.items = holder.getInventory().offhand;
+    super.setHolder(holder);
    this.holder = holder;
  }

@@ -34,10 +37,13 @@ public class ContentOffHand extends ContentEquipment {
    return new SlotEquipment(container, slot, x, y) {
      @Override
      public void setChanged() {
-        if (holder.connection != null
-            && !holder.connection.isDisconnected()
-            && holder.containerMenu != holder.inventoryMenu) {
-          holder.resendItemInHands();
+        if (OpenPlayer.isConnected(holder.connection) && holder.containerMenu != holder.inventoryMenu) {
+          holder.connection.send(
+              new ClientboundContainerSetSlotPacket(
+                  holder.inventoryMenu.containerId,
+                  holder.inventoryMenu.incrementStateId(),
+                  InventoryMenu.SHIELD_SLOT,
+                  holder.getOffhandItem()));
        }
      }
    };
@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
@@ -12,7 +12,7 @@ import org.jetbrains.annotations.NotNull;
 */
 public class ContentViewOnly implements Content {

-  @NotNull ServerPlayer holder;
+  protected @NotNull ServerPlayer holder;

  public ContentViewOnly(@NotNull ServerPlayer holder) {
    this.holder = holder;
@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.Slot;
@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;

-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.Slot;
@@ -45,20 +45,20 @@ public class SlotViewOnly extends SlotPlaceholder {
  }

  @Override
-  public void onQuickCraft(ItemStack var0, ItemStack var1) {
+  public void onQuickCraft(@NotNull ItemStack itemStack1, @NotNull ItemStack itemStack2) {
  }

  @Override
-  public void onTake(Player var0, ItemStack var1) {
+  public void onTake(@NotNull Player player, @NotNull ItemStack itemStack) {
  }

  @Override
-  public boolean mayPlace(ItemStack var0) {
+  public boolean mayPlace(@NotNull ItemStack itemStack) {
    return false;
  }

  @Override
-  public ItemStack getItem() {
+  public @NotNull ItemStack getItem() {
    return ItemStack.EMPTY;
  }

@@ -68,15 +68,15 @@ public class SlotViewOnly extends SlotPlaceholder {
  }

  @Override
-  public void setByPlayer(ItemStack newStack) {
+  public void setByPlayer(@NotNull ItemStack newStack) {
  }

  @Override
-  public void setByPlayer(ItemStack newStack, ItemStack oldStack) {
+  public void setByPlayer(@NotNull ItemStack newStack, @NotNull ItemStack oldStack) {
  }

  @Override
-  public void set(ItemStack var0) {
+  public void set(@NotNull ItemStack itemStack) {
  }

  @Override
@@ -89,17 +89,17 @@ public class SlotViewOnly extends SlotPlaceholder {
  }

  @Override
-  public int getMaxStackSize(ItemStack itemStack) {
+  public int getMaxStackSize(@NotNull ItemStack itemStack) {
    return 0;
  }

  @Override
-  public ItemStack remove(int amount) {
+  public @NotNull ItemStack remove(int amount) {
    return ItemStack.EMPTY;
  }

  @Override
-  public boolean mayPickup(Player var0) {
+  public boolean mayPickup(@NotNull Player player) {
    return false;
  }

@@ -109,27 +109,27 @@ public class SlotViewOnly extends SlotPlaceholder {
  }

  @Override
-  public Optional<ItemStack> tryRemove(int var0, int var1, Player var2) {
+  public @NotNull Optional<ItemStack> tryRemove(int var0, int var1, @NotNull Player player) {
    return Optional.empty();
  }

  @Override
-  public ItemStack safeTake(int var0, int var1, Player var2) {
+  public @NotNull ItemStack safeTake(int var0, int var1, @NotNull Player player) {
    return ItemStack.EMPTY;
  }

  @Override
-  public ItemStack safeInsert(ItemStack itemStack) {
+  public @NotNull ItemStack safeInsert(@NotNull ItemStack itemStack) {
    return itemStack;
  }

  @Override
-  public ItemStack safeInsert(ItemStack itemStack, int amount) {
+  public @NotNull ItemStack safeInsert(@NotNull ItemStack itemStack, int amount) {
    return itemStack;
  }

  @Override
-  public boolean allowModification(Player var0) {
+  public boolean allowModification(@NotNull Player player) {
    return false;
  }

@@ -0,0 +1,40 @@
+package com.lishid.openinv.internal.common.container.slot.placeholder;
+
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.TagParser;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.CustomModelData;
+import net.minecraft.world.item.component.DyedItemColor;
+import net.minecraft.world.item.component.TooltipDisplay;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+
+public class PlaceholderLoader extends PlaceholderLoaderBase {
+
+  private static final CustomModelData DEFAULT_CUSTOM_MODEL_DATA = new CustomModelData(List.of(), List.of(), List.of("openinv:custom"), List.of());
+  private static final TooltipDisplay HIDE_TOOLTIP = new TooltipDisplay(true, new LinkedHashSet<>());
+
+  @Override
+  protected @NotNull CompoundTag parseTag(@NotNull String itemText) throws Exception {
+    return TagParser.parseCompoundFully(itemText);
+  }
+
+  @Override
+  protected void addModelData(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+  }
+
+  @Override
+  protected void hideTooltip(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.TOOLTIP_DISPLAY, HIDE_TOOLTIP);
+  }
+
+  @Override
+  protected DyedItemColor getDye(int rgb) {
+    return new DyedItemColor(rgb);
+  }
+
+}
@@ -1,18 +1,14 @@
-package com.lishid.openinv.internal.v1_21_R2.container;
+package com.lishid.openinv.internal.common.container.slot.placeholder;

 import net.minecraft.core.Registry;
 import net.minecraft.core.RegistryAccess;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.TagParser;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.util.Unit;
 import net.minecraft.world.item.DyeColor;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
-import net.minecraft.world.item.component.CustomModelData;
 import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.level.GameType;
 import net.minecraft.world.level.ItemLike;
@@ -20,86 +16,87 @@ import net.minecraft.world.level.block.entity.BannerPattern;
 import net.minecraft.world.level.block.entity.BannerPatternLayers;
 import net.minecraft.world.level.block.entity.BannerPatterns;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R2.CraftRegistry;
+import org.bukkit.craftbukkit.CraftRegistry;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;

-import java.util.EnumMap;
 import java.util.List;
 import java.util.Optional;

-public final class Placeholders {
+public abstract class PlaceholderLoaderBase {

-  private static final CustomModelData DEFAULT_CUSTOM_MODEL_DATA = new CustomModelData(9999);
-  public static final @NotNull EnumMap<GameType, ItemStack> BLOCKED_GAME_TYPE = new EnumMap<>(GameType.class);
-  public static @NotNull ItemStack craftingOutput = defaultCraftingOutput();
-  public static @NotNull ItemStack cursor = defaultCursor();
-  public static @NotNull ItemStack drop = defaultDrop();
-  public static @NotNull ItemStack emptyHelmet = getEmptyArmor(Items.LEATHER_HELMET);
-  public static @NotNull ItemStack emptyChestplate = getEmptyArmor(Items.LEATHER_CHESTPLATE);
-  public static @NotNull ItemStack emptyLeggings = getEmptyArmor(Items.LEATHER_LEGGINGS);
-  public static @NotNull ItemStack emptyBoots = getEmptyArmor(Items.LEATHER_BOOTS);
-  public static @NotNull ItemStack emptyOffHand = getEmptyShield();
-  public static @NotNull ItemStack notSlot = defaultNotSlot();
-  public static @NotNull ItemStack blockedOffline = defaultBlockedOffline();
-
-  static {
+  protected PlaceholderLoaderBase() {
    for (GameType type : GameType.values()) {
      // Barrier: "Not available - Creative" etc.
      ItemStack typeItem = new ItemStack(Items.BARRIER);
      typeItem.set(
          DataComponents.ITEM_NAME,
          Component.translatable("options.narrator.notavailable").append(" - ").append(type.getShortDisplayName()));
-      BLOCKED_GAME_TYPE.put(type, typeItem);
+      Placeholders.BLOCKED_GAME_TYPE.put(type, typeItem);
    }
+    Placeholders.craftingOutput = defaultCraftingOutput();
+    Placeholders.cursor = defaultCursor();
+    Placeholders.drop = defaultDrop();
+    Placeholders.emptyHelmet = getEmptyArmor(Items.LEATHER_HELMET);
+    Placeholders.emptyChestplate = getEmptyArmor(Items.LEATHER_CHESTPLATE);
+    Placeholders.emptyLeggings = getEmptyArmor(Items.LEATHER_LEGGINGS);
+    Placeholders.emptyBoots = getEmptyArmor(Items.LEATHER_BOOTS);
+    Placeholders.emptyOffHand = defaultShield();
+    Placeholders.notSlot = defaultNotSlot();
+    Placeholders.blockedOffline = defaultBlockedOffline();
  }

-  public static void load(@NotNull ConfigurationSection section) throws Exception {
-    craftingOutput = parse(section, "crafting-output", craftingOutput);
-    cursor = parse(section, "cursor", cursor);
-    drop = parse(section, "drop", drop);
-    emptyHelmet = parse(section, "empty-helmet", emptyHelmet);
-    emptyChestplate = parse(section, "empty-chestplate", emptyChestplate);
-    emptyLeggings = parse(section, "empty-leggings", emptyLeggings);
-    emptyBoots = parse(section, "empty-boots", emptyBoots);
-    emptyOffHand = parse(section, "empty-off-hand", emptyOffHand);
-    notSlot = parse(section, "not-a-slot", notSlot);
-    blockedOffline = parse(section, "blocked.offline", blockedOffline);
-    BLOCKED_GAME_TYPE.put(GameType.CREATIVE, parse(section, "blocked.creative", BLOCKED_GAME_TYPE.get(GameType.CREATIVE)));
-    BLOCKED_GAME_TYPE.put(GameType.SPECTATOR, parse(section, "blocked.spectator", BLOCKED_GAME_TYPE.get(GameType.SPECTATOR)));
+  public void load(@Nullable ConfigurationSection section) throws Exception {
+    Placeholders.craftingOutput = parse(section, "crafting-output", Placeholders.craftingOutput);
+    Placeholders.cursor = parse(section, "cursor", Placeholders.cursor);
+    Placeholders.drop = parse(section, "drop", Placeholders.drop);
+    Placeholders.emptyHelmet = parse(section, "empty-helmet", Placeholders.emptyHelmet);
+    Placeholders.emptyChestplate = parse(section, "empty-chestplate", Placeholders.emptyChestplate);
+    Placeholders.emptyLeggings = parse(section, "empty-leggings", Placeholders.emptyLeggings);
+    Placeholders.emptyBoots = parse(section, "empty-boots", Placeholders.emptyBoots);
+    Placeholders.emptyOffHand = parse(section, "empty-off-hand", Placeholders.emptyOffHand);
+    Placeholders.notSlot = parse(section, "not-a-slot", Placeholders.notSlot);
+    Placeholders.blockedOffline = parse(section, "blocked.offline", Placeholders.blockedOffline);
+    Placeholders.BLOCKED_GAME_TYPE.put(GameType.CREATIVE, parse(section, "blocked.creative", Placeholders.BLOCKED_GAME_TYPE.get(GameType.CREATIVE)));
+    Placeholders.BLOCKED_GAME_TYPE.put(GameType.SPECTATOR, parse(section, "blocked.spectator", Placeholders.BLOCKED_GAME_TYPE.get(GameType.SPECTATOR)));
  }

-  private static @NotNull ItemStack parse(
-      @NotNull ConfigurationSection section,
+  private @NotNull ItemStack parse(
+      @Nullable ConfigurationSection section,
      @NotNull String path,
      @NotNull ItemStack defaultStack) throws Exception {
+    if (section == null) {
+      return defaultStack;
+    }
+
    String itemText = section.getString(path);

    if (itemText == null) {
      return defaultStack;
    }

-    CompoundTag compoundTag = TagParser.parseTag(itemText);
+    CompoundTag compoundTag = parseTag(itemText);
    Optional<ItemStack> parsed = ItemStack.parse(CraftRegistry.getMinecraftRegistry(), compoundTag);
    return parsed.filter(itemStack -> !itemStack.isEmpty()).orElse(defaultStack);
  }

-  public static ItemStack survivalOnly(@NotNull ServerPlayer serverPlayer) {
-    if (serverPlayer.connection == null || serverPlayer.connection.isDisconnected()) {
-      return blockedOffline;
-    }
+  protected abstract @NotNull CompoundTag parseTag(@NotNull String itemText) throws Exception;

-    return BLOCKED_GAME_TYPE.getOrDefault(serverPlayer.gameMode.getGameModeForPlayer(), ItemStack.EMPTY);
-  }
+  protected abstract void addModelData(@NotNull ItemStack itemStack);

-  private static ItemStack defaultCraftingOutput() {
+  protected abstract void hideTooltip(@NotNull ItemStack itemStack);
+
+  protected abstract DyedItemColor getDye(int rgb);
+
+  protected @NotNull ItemStack defaultCraftingOutput() {
    // Crafting table: "Crafting"
    ItemStack itemStack = new ItemStack(Items.CRAFTING_TABLE);
    itemStack.set(DataComponents.ITEM_NAME, Component.translatable("container.crafting"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    addModelData(itemStack);
    return itemStack;
  }

-  private static ItemStack defaultCursor() {
+  protected @NotNull ItemStack defaultCursor() {
    // Cursor-like banner with no tooltip
    ItemStack itemStack = new ItemStack(Items.WHITE_BANNER);
    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
@@ -112,31 +109,32 @@ public final class Placeholders {
            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfDiagBottomRight), DyeColor.GRAY),
            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(downRight), DyeColor.WHITE),
            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(border), DyeColor.GRAY))));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+    addModelData(itemStack);
+    hideTooltip(itemStack);
    return itemStack;
  }

-  private static ItemStack defaultDrop() {
+  protected @NotNull ItemStack defaultDrop() {
    // Dropper: "Drop Selected Item"
    ItemStack itemStack = new ItemStack(Items.DROPPER);
    // Note: translatable component, not keybind component! We want the text identifying the keybind, not the key.
    itemStack.set(DataComponents.ITEM_NAME, Component.translatable("key.drop"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    addModelData(itemStack);
    return itemStack;
  }

-  private static ItemStack getEmptyArmor(ItemLike item) {
+  protected @NotNull ItemStack getEmptyArmor(@NotNull ItemLike item) {
    // Inventory-background-grey-ish leather armor with no tooltip
    ItemStack itemStack = new ItemStack(item);
-    DyedItemColor color = new DyedItemColor(0xC8C8C8, false);
+    DyedItemColor color = getDye(0xC8C8C8);
    itemStack.set(DataComponents.DYED_COLOR, color);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    hideTooltip(itemStack);
+    addModelData(itemStack);
    return itemStack;
  }

-  private static ItemStack getEmptyShield() {
+  protected @NotNull ItemStack defaultShield() {
+    // Shield with "missing texture" pattern, magenta and black squares.
    ItemStack itemStack = new ItemStack(Items.SHIELD);
    itemStack.set(DataComponents.BASE_COLOR, DyeColor.MAGENTA);
    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
@@ -153,20 +151,20 @@ public final class Placeholders {
            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomLeft), DyeColor.MAGENTA),
            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topRight), DyeColor.BLACK),
            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomRight), DyeColor.BLACK))));
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    hideTooltip(itemStack);
+    addModelData(itemStack);
    return itemStack;
  }

-  private static ItemStack defaultNotSlot() {
+  protected @NotNull ItemStack defaultNotSlot() {
    // White pane with no tooltip
    ItemStack itemStack = new ItemStack(Items.WHITE_STAINED_GLASS_PANE);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    hideTooltip(itemStack);
+    addModelData(itemStack);
    return itemStack;
  }

-  private static ItemStack defaultBlockedOffline() {
+  protected @NotNull ItemStack defaultBlockedOffline() {
    // Barrier: "Not available - Offline"
    ItemStack itemStack = new ItemStack(Items.BARRIER);
    itemStack.set(DataComponents.ITEM_NAME,
@@ -176,8 +174,4 @@ public final class Placeholders {
    return itemStack;
  }

-  private Placeholders() {
-    throw new IllegalStateException("Cannot create instance of utility class.");
-  }
-
 }
@@ -0,0 +1,37 @@
+package com.lishid.openinv.internal.common.container.slot.placeholder;
+
+import com.lishid.openinv.internal.common.player.OpenPlayer;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.GameType;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.EnumMap;
+
+public final class Placeholders {
+
+  static final @NotNull EnumMap<GameType, ItemStack> BLOCKED_GAME_TYPE = new EnumMap<>(GameType.class);
+  public static @NotNull ItemStack craftingOutput = ItemStack.EMPTY;
+  public static @NotNull ItemStack cursor = ItemStack.EMPTY;
+  public static @NotNull ItemStack drop = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyHelmet = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyChestplate = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyLeggings = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyBoots = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyOffHand = ItemStack.EMPTY;
+  public static @NotNull ItemStack notSlot = ItemStack.EMPTY;
+  public static @NotNull ItemStack blockedOffline = ItemStack.EMPTY;
+
+  public static ItemStack survivalOnly(@NotNull ServerPlayer serverPlayer) {
+    if (!OpenPlayer.isConnected(serverPlayer.connection)) {
+      return blockedOffline;
+    }
+
+    return BLOCKED_GAME_TYPE.getOrDefault(serverPlayer.gameMode.getGameModeForPlayer(), ItemStack.EMPTY);
+  }
+
+  private Placeholders() {
+    throw new IllegalStateException("Cannot create instance of utility class.");
+  }
+
+}
@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.player;
+package com.lishid.openinv.internal.common.player;

 import com.lishid.openinv.event.OpenEvents;
 import com.mojang.logging.LogUtils;
@@ -8,12 +8,14 @@ import net.minecraft.nbt.NbtIo;
 import net.minecraft.nbt.NumericTag;
 import net.minecraft.nbt.Tag;
 import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerGamePacketListenerImpl;
 import net.minecraft.world.level.storage.PlayerDataStorage;
-import org.bukkit.craftbukkit.v1_21_R2.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftPlayer;
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.Unmodifiable;

 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -29,7 +31,8 @@ public class OpenPlayer extends CraftPlayer {
   * @see net.minecraft.world.entity.player.Player#addAdditionalSaveData(CompoundTag)
   * @see net.minecraft.world.entity.LivingEntity#addAdditionalSaveData(CompoundTag)
   */
-  private static final Set<String> RESET_TAGS = Set.of(
+  @Unmodifiable
+  protected static final Set<String> RESET_TAGS = Set.of(
      // Entity#saveWithoutId(CompoundTag)
      "CustomName",
      "CustomNameVisible",
@@ -42,6 +45,7 @@ public class OpenPlayer extends CraftPlayer {
      "Passengers",
      // ServerPlayer#addAdditionalSaveData(CompoundTag)
      // Intentional omissions to prevent mount loss: Attach, Entity, and RootVehicle
+      // As of 1.21.5 only ender_pearls tag still needs to be reset. Rest are for backwards compatibility.
      "warden_spawn_tracker",
      "enteredNetherPosition",
      "SpawnX",
@@ -56,18 +60,23 @@ public class OpenPlayer extends CraftPlayer {
      "ShoulderEntityLeft",
      "ShoulderEntityRight",
      "LastDeathLocation",
-      "current_explosion_impact_pos",
+      "current_explosion_impact_pos", // Unnecessary in 1.21.5
      // LivingEntity#addAdditionalSaveData(CompoundTag)
      "active_effects",
      "SleepingX",
      "SleepingY",
      "SleepingZ",
-      "Brain"
+      "Brain",
+      "last_hurt_by_player",
+      "last_hurt_by_player_memory_time",
+      "last_hurt_by_mob",
+      "ticks_since_last_hurt_by_mob",
+      "equipment"
  );

  private final PlayerManager manager;

-  OpenPlayer(CraftServer server, ServerPlayer entity, PlayerManager manager) {
+  protected OpenPlayer(CraftServer server, ServerPlayer entity, PlayerManager manager) {
    super(server, entity);
    this.manager = manager;
  }
@@ -110,7 +119,7 @@ public class OpenPlayer extends CraftPlayer {
  }

  @Contract("null -> new")
-  private @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
+  protected @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
    if (oldData == null) {
      return new CompoundTag();
    }
@@ -119,8 +128,7 @@ public class OpenPlayer extends CraftPlayer {
    oldData = oldData.copy();

    // Remove vanilla/server data that is not written every time.
-    oldData.getAllKeys()
-        .removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit"));
+    oldData.keySet().removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit") || key.startsWith("Paper") && key.length() > 5);

    return oldData;
  }
@@ -175,4 +183,8 @@ public class OpenPlayer extends CraftPlayer {
    }
  }

+  public static boolean isConnected(@Nullable ServerGamePacketListenerImpl connection) {
+    return connection != null && !connection.isDisconnected();
+  }
+
 }
@@ -1,16 +1,18 @@
-package com.lishid.openinv.internal.v1_21_R1.player;
+package com.lishid.openinv.internal.common.player;

 import com.lishid.openinv.internal.ISpecialInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R1.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenInventory;
 import com.mojang.authlib.GameProfile;
 import com.mojang.serialization.Dynamic;
+import io.papermc.paper.adventure.PaperAdventure;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.NbtOps;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ClientboundOpenScreenPacket;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ClientInformation;
+import net.minecraft.server.level.ParticleStatus;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.Entity;
@@ -22,34 +24,24 @@ import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.Server;
 import org.bukkit.World;
-import org.bukkit.craftbukkit.v1_21_R1.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R1.CraftWorld;
-import org.bukkit.craftbukkit.v1_21_R1.entity.CraftPlayer;
-import org.bukkit.craftbukkit.v1_21_R1.event.CraftEventFactory;
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.InventoryView;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import java.lang.reflect.Field;
+import java.util.Optional;
 import java.util.UUID;
 import java.util.logging.Logger;

 public class PlayerManager implements com.lishid.openinv.internal.PlayerManager {

-  private static boolean paper;
-
-  static {
-    try {
-      Class.forName("io.papermc.paper.configuration.Configuration");
-      paper = true;
-    } catch (ClassNotFoundException ignored) {
-      paper = false;
-    }
-  }
-
-  private final @NotNull Logger logger;
-  private @Nullable Field bukkitEntity;
+  protected final @NotNull Logger logger;
+  protected @Nullable Field bukkitEntity;

  public PlayerManager(@NotNull Logger logger) {
    this.logger = logger;
@@ -106,7 +98,7 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
    return null;
  }

-  private @NotNull ServerPlayer createNewPlayer(
+  protected @NotNull ServerPlayer createNewPlayer(
      @NotNull MinecraftServer server,
      @NotNull ServerLevel worldServer,
      @NotNull final OfflinePlayer offline) {
@@ -123,7 +115,8 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
        ServerPlayer.DEFAULT_MODEL_CUSTOMIZATION,
        ServerPlayer.DEFAULT_MAIN_HAND,
        true,
-        false // Don't list in player list (not that this player is in the list anyway).
+        false, // Don't list in player list (not that this player is in the list anyway).
+        ParticleStatus.MINIMAL
    );

    ServerPlayer entity = new ServerPlayer(server, worldServer, profile, dummyInfo);
@@ -156,40 +149,54 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
    // Game type settings are also loaded separately.
    player.loadGameTypes(loadedData);

-    if (paper) {
-      // Paper: world is not loaded by ServerPlayer#load(CompoundTag).
-      parseWorld(player, loadedData);
-    }
+    // World is not loaded by ServerPlayer#load(CompoundTag) on Paper.
+    parseWorld(player, loadedData);

    return true;
  }

-  private void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
+  protected void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
    // See PlayerList#placeNewPlayer
    World bukkitWorld;
-    if (loadedData.contains("WorldUUIDMost") && loadedData.contains("WorldUUIDLeast")) {
+    Optional<Long> msbs = loadedData.getLong("WorldUUIDMost");
+    Optional<Long> lsbs = loadedData.getLong("WorldUUIDLeast");
+    if (msbs.isPresent() && lsbs.isPresent()) {
      // Modern Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(new UUID(loadedData.getLong("WorldUUIDMost"), loadedData.getLong("WorldUUIDLeast")));
-    } else if (loadedData.contains("world", net.minecraft.nbt.Tag.TAG_STRING)) {
-      // Legacy Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(loadedData.getString("world"));
+      bukkitWorld = Bukkit.getServer().getWorld(new UUID(msbs.get(), lsbs.get()));
    } else {
-      // Vanilla player data.
-      DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
-          .resultOrPartial(logger::warning)
-          .map(player.server::getLevel)
-          // If ServerLevel exists, set, otherwise move to spawn.
-          .ifPresentOrElse(player::setServerLevel, () -> player.spawnIn(null));
-      return;
+      Optional<String> worldName = loadedData.getString("world");
+      if (worldName.isPresent()) {
+        // Legacy Bukkit world.
+        bukkitWorld = Bukkit.getServer().getWorld(worldName.get());
+      } else {
+        // Vanilla player data.
+        DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
+            .resultOrPartial(logger::warning)
+            .map(player.server::getLevel)
+            // If ServerLevel exists, set, otherwise move to spawn.
+            .ifPresentOrElse(player::setServerLevel, () -> spawnInDefaultWorld(player));
+        return;
+      }
    }
    if (bukkitWorld == null) {
-      player.spawnIn(null);
+      spawnInDefaultWorld(player);
      return;
    }
    player.setServerLevel(((CraftWorld) bukkitWorld).getHandle());
  }

-  private void injectPlayer(ServerPlayer player) throws IllegalAccessException {
+  protected void spawnInDefaultWorld(ServerPlayer player) {
+    ServerLevel level = player.server.getLevel(Level.OVERWORLD);
+    if (level != null) {
+      // Adjust player to default spawn (in keeping with Paper handling) when world not found.
+      player.snapTo(player.adjustSpawnLocation(level, level.getSharedSpawnPos()).getBottomCenter(), level.getSharedSpawnAngle(), 0.0F);
+      player.spawnIn(level);
+    } else {
+      logger.warning("Tried to load player with invalid world when no fallback was available!");
+    }
+  }
+
+  protected void injectPlayer(ServerPlayer player) throws IllegalAccessException {
    if (bukkitEntity == null) {
      return;
    }
@@ -221,7 +228,7 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
  public @Nullable InventoryView openInventory(@NotNull Player bukkitPlayer, @NotNull ISpecialInventory inventory, boolean viewOnly) {
    ServerPlayer player = getHandle(bukkitPlayer);

-    if (player.connection == null) {
+    if (!OpenPlayer.isConnected(player.connection)) {
      return null;
    }

@@ -248,15 +255,21 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
    // resulting in a title change but no other state modifications (like cursor position).
    menu.setTitle(title);

-    menu = CraftEventFactory.callInventoryOpenEvent(player, menu, false);
+    var pair = CraftEventFactory.callInventoryOpenEventWithTitle(player, menu);
+    menu = pair.getSecond();

    // Menu is null if event is cancelled.
    if (menu == null) {
      return null;
    }

+    var newTitle = pair.getFirst();
+    if (newTitle != null) {
+      title = PaperAdventure.asVanilla(newTitle);
+    }
+
    player.containerMenu = menu;
-    player.connection.send(new ClientboundOpenScreenPacket(menu.containerId, menu.getType(), menu.getTitle()));
+    player.connection.send(new ClientboundOpenScreenPacket(menu.containerId, menu.getType(), title));
    player.initMenu(menu);

    return menu.getBukkitView();
@@ -0,0 +1,28 @@
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+  implementation(project(":openinvadaptercommon"))
+  implementation(project(":openinvadapterpaper1_21_4"))
+  implementation(project(":openinvadapterpaper1_21_3"))
+
+  paperweight.paperDevBundle("1.21.1-R0.1-SNAPSHOT")
+}
@@ -0,0 +1,80 @@
+package com.lishid.openinv.internal.paper1_21_1;
+
+import com.lishid.openinv.internal.Accessor;
+import com.lishid.openinv.internal.IAnySilentContainer;
+import com.lishid.openinv.internal.ISpecialEnderChest;
+import com.lishid.openinv.internal.ISpecialInventory;
+import com.lishid.openinv.internal.ISpecialPlayerInventory;
+import com.lishid.openinv.internal.common.container.AnySilentContainer;
+import com.lishid.openinv.internal.paper1_21_1.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_1.container.slot.placeholder.PlaceholderLoader;
+import com.lishid.openinv.internal.paper1_21_1.player.PlayerManager;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenEnderChest;
+import com.lishid.openinv.util.lang.LanguageManager;
+import net.minecraft.world.Container;
+import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.Inventory;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class InternalAccessor implements Accessor {
+
+  private final @NotNull Logger logger;
+  private final @NotNull PlayerManager manager;
+  private final @NotNull AnySilentContainer anySilentContainer;
+
+  public InternalAccessor(@NotNull Logger logger, @NotNull LanguageManager lang) {
+    this.logger = logger;
+    this.manager = new PlayerManager(logger);
+    this.anySilentContainer = new AnySilentContainer(logger, lang);
+  }
+
+  @Override
+  public @NotNull PlayerManager getPlayerManager() {
+    return manager;
+  }
+
+  @Override
+  public @NotNull IAnySilentContainer getAnySilentContainer() {
+    return anySilentContainer;
+  }
+
+  @Override
+  public @NotNull ISpecialPlayerInventory createPlayerInventory(@NotNull Player player) {
+    return new OpenInventory(player);
+  }
+
+  @Override
+  public @NotNull ISpecialEnderChest createEnderChest(@NotNull Player player) {
+    return new OpenEnderChest(player);
+  }
+
+  @Override
+  public <T extends ISpecialInventory> @Nullable T get(@NotNull Inventory bukkitInventory, @NotNull Class<T> clazz) {
+    if (!(bukkitInventory instanceof CraftInventory craftInventory)) {
+      return null;
+    }
+    Container container = craftInventory.getInventory();
+    if (clazz.isInstance(container)) {
+      return clazz.cast(container);
+    }
+    return null;
+  }
+
+  @Override
+  public void reload(@NotNull ConfigurationSection config) {
+    ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new PlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
+    }
+  }
+
+}
@@ -0,0 +1,20 @@
+package com.lishid.openinv.internal.paper1_21_1.container;
+
+import com.lishid.openinv.internal.common.container.slot.Content;
+import com.lishid.openinv.internal.paper1_21_1.container.slot.ContentCraftingResult;
+import net.minecraft.server.level.ServerPlayer;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+public class OpenInventory extends com.lishid.openinv.internal.paper1_21_4.container.OpenInventory {
+
+  public OpenInventory(@NotNull Player bukkitPlayer) {
+    super(bukkitPlayer);
+  }
+
+  @Override
+  protected Content getCraftingResult(@NotNull ServerPlayer serverPlayer) {
+    return new ContentCraftingResult(serverPlayer);
+  }
+
+}
@@ -1,6 +1,9 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.paper1_21_1.container.slot;

-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.ContentCrafting;
+import com.lishid.openinv.internal.common.container.slot.ContentViewOnly;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.InventoryMenu;
@@ -9,11 +12,6 @@ import net.minecraft.world.item.ItemStack;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;

-/**
- * A slot allowing viewing of the crafting result.
- *
- * <p>Unmodifiable because I said so. Use your own crafting grid.</p>
- */
 public class ContentCraftingResult extends ContentViewOnly {

  public ContentCraftingResult(@NotNull ServerPlayer holder) {
@@ -0,0 +1,65 @@
+package com.lishid.openinv.internal.paper1_21_1.container.slot.placeholder;
+
+import com.lishid.openinv.internal.paper1_21_3.container.slot.placeholder.NumericDataPlaceholderLoader;
+import net.minecraft.core.Registry;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.util.Unit;
+import net.minecraft.world.item.DyeColor;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.block.entity.BannerPattern;
+import net.minecraft.world.level.block.entity.BannerPatternLayers;
+import net.minecraft.world.level.block.entity.BannerPatterns;
+import org.bukkit.craftbukkit.CraftRegistry;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class PlaceholderLoader extends NumericDataPlaceholderLoader {
+
+  @Override
+  protected @NotNull ItemStack defaultCursor() {
+    // Cursor-like banner with no tooltip
+    ItemStack itemStack = new ItemStack(Items.WHITE_BANNER);
+    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
+    Registry<BannerPattern> bannerPatterns = minecraftRegistry.registryOrThrow(Registries.BANNER_PATTERN);
+    BannerPattern halfDiagBottomRight = bannerPatterns.getOrThrow(BannerPatterns.DIAGONAL_RIGHT);
+    BannerPattern downRight = bannerPatterns.getOrThrow(BannerPatterns.STRIPE_DOWNRIGHT);
+    BannerPattern border = bannerPatterns.getOrThrow(BannerPatterns.BORDER);
+    itemStack.set(DataComponents.BANNER_PATTERNS,
+        new BannerPatternLayers(List.of(
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfDiagBottomRight), DyeColor.GRAY),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(downRight), DyeColor.WHITE),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(border), DyeColor.GRAY))));
+    addModelData(itemStack);
+    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+    return itemStack;
+  }
+
+  @Override
+  protected @NotNull ItemStack defaultShield() {
+    // Shield with "missing texture" pattern, magenta and black squares.
+    ItemStack itemStack = new ItemStack(Items.SHIELD);
+    itemStack.set(DataComponents.BASE_COLOR, DyeColor.MAGENTA);
+    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
+    Registry<BannerPattern> bannerPatterns = minecraftRegistry.registryOrThrow(Registries.BANNER_PATTERN);
+    BannerPattern halfLeft = bannerPatterns.getOrThrow(BannerPatterns.HALF_VERTICAL);
+    BannerPattern topLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_LEFT);
+    BannerPattern topRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_RIGHT);
+    BannerPattern bottomLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_LEFT);
+    BannerPattern bottomRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_RIGHT);
+    itemStack.set(DataComponents.BANNER_PATTERNS,
+        new BannerPatternLayers(List.of(
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfLeft), DyeColor.BLACK),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topLeft), DyeColor.MAGENTA),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomLeft), DyeColor.MAGENTA),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topRight), DyeColor.BLACK),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomRight), DyeColor.BLACK))));
+    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+    addModelData(itemStack);
+    return itemStack;
+  }
+
+}
@@ -0,0 +1,55 @@
+package com.lishid.openinv.internal.paper1_21_1.player;
+
+import com.mojang.authlib.GameProfile;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ClientInformation;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.entity.player.ChatVisiblity;
+import org.bukkit.OfflinePlayer;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.logging.Logger;
+
+public class PlayerManager extends com.lishid.openinv.internal.paper1_21_4.player.PlayerManager {
+
+  public PlayerManager(@NotNull Logger logger) {
+    super(logger);
+  }
+
+  @Override
+  protected @NotNull ServerPlayer createNewPlayer(
+      @NotNull MinecraftServer server,
+      @NotNull ServerLevel worldServer,
+      @NotNull final OfflinePlayer offline) {
+    // See net.minecraft.server.players.PlayerList#canPlayerLogin(ServerLoginPacketListenerImpl, GameProfile)
+    // See net.minecraft.server.network.ServerLoginPacketListenerImpl#handleHello(ServerboundHelloPacket)
+    GameProfile profile = new GameProfile(offline.getUniqueId(),
+        offline.getName() != null ? offline.getName() : offline.getUniqueId().toString());
+
+    ClientInformation dummyInfo = new ClientInformation(
+        "en_us",
+        1, // Reduce distance just in case.
+        ChatVisiblity.HIDDEN, // Don't accept chat.
+        false,
+        ServerPlayer.DEFAULT_MODEL_CUSTOMIZATION,
+        ServerPlayer.DEFAULT_MAIN_HAND,
+        true,
+        false // Don't list in player list (not that this player is in the list anyway).
+    );
+
+    ServerPlayer entity = new ServerPlayer(server, worldServer, profile, dummyInfo);
+
+    try {
+      injectPlayer(entity);
+    } catch (IllegalAccessException e) {
+      logger.log(
+          java.util.logging.Level.WARNING,
+          e,
+          () -> "Unable to inject ServerPlayer, certain player data may be lost when saving!");
+    }
+
+    return entity;
+  }
+
+}
@@ -0,0 +1,27 @@
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+  implementation(project(":openinvadaptercommon"))
+  implementation(project(":openinvadapterpaper1_21_4"))
+
+  paperweight.paperDevBundle("1.21.3-R0.1-SNAPSHOT")
+}
@@ -0,0 +1,28 @@
+package com.lishid.openinv.internal.paper1_21_3;
+
+import com.lishid.openinv.internal.paper1_21_3.container.slot.placeholder.NumericDataPlaceholderLoader;
+import com.lishid.openinv.util.lang.LanguageManager;
+import org.bukkit.configuration.ConfigurationSection;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class InternalAccessor extends com.lishid.openinv.internal.paper1_21_4.InternalAccessor {
+
+  public InternalAccessor(@NotNull Logger logger, @NotNull LanguageManager lang) {
+    super(logger, lang);
+  }
+
+  @Override
+  public void reload(@NotNull ConfigurationSection config) {
+    ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new NumericDataPlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
+    }
+  }
+
+}
@@ -0,0 +1,12 @@
+package com.lishid.openinv.internal.paper1_21_3.container.slot.placeholder;
+
+import com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder.CustomModelBase;
+import net.minecraft.world.item.component.CustomModelData;
+
+public class NumericDataPlaceholderLoader extends CustomModelBase {
+
+  public NumericDataPlaceholderLoader() {
+    super(new CustomModelData(9999));
+  }
+
+}
@@ -0,0 +1,26 @@
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+  implementation(project(":openinvadaptercommon"))
+
+  paperweight.paperDevBundle("1.21.4-R0.1-SNAPSHOT")
+}
@@ -1,19 +1,19 @@
-package com.lishid.openinv.internal.v1_21_R2;
+package com.lishid.openinv.internal.paper1_21_4;

 import com.lishid.openinv.internal.Accessor;
 import com.lishid.openinv.internal.IAnySilentContainer;
 import com.lishid.openinv.internal.ISpecialEnderChest;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.ISpecialPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.AnySilentContainer;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.AnySilentContainer;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenEnderChest;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder.CustomModelPlaceholderLoader;
+import com.lishid.openinv.internal.paper1_21_4.player.PlayerManager;
 import com.lishid.openinv.util.lang.LanguageManager;
 import net.minecraft.world.Container;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
 import org.jetbrains.annotations.NotNull;
@@ -24,7 +24,7 @@ import java.util.logging.Logger;

 public class InternalAccessor implements Accessor {

-  private final @NotNull Logger logger;
+  protected final @NotNull Logger logger;
  private final @NotNull PlayerManager manager;
  private final @NotNull AnySilentContainer anySilentContainer;

@@ -69,12 +69,11 @@ public class InternalAccessor implements Accessor {
  @Override
  public void reload(@NotNull ConfigurationSection config) {
    ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
-    if (placeholders != null) {
-      try {
-        Placeholders.load(placeholders);
-      } catch (Exception e) {
-        logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
-      }
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new CustomModelPlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
    }
  }

@@ -0,0 +1,23 @@
+package com.lishid.openinv.internal.paper1_21_4.container;
+
+import com.lishid.openinv.internal.paper1_21_4.container.menu.OpenEnderChestMenu;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenEnderChest extends com.lishid.openinv.internal.common.container.OpenEnderChest{
+
+  public OpenEnderChest(@NotNull Player player) {
+    super(player);
+  }
+
+  public @Nullable AbstractContainerMenu createMenu(net.minecraft.world.entity.player.Player player, int i, boolean viewOnly) {
+    if (player instanceof ServerPlayer serverPlayer) {
+      return new OpenEnderChestMenu(this, serverPlayer, i, viewOnly);
+    }
+    return null;
+  }
+
+}
@@ -0,0 +1,177 @@
+package com.lishid.openinv.internal.paper1_21_4.container;
+
+import com.lishid.openinv.internal.common.container.slot.ContentCrafting;
+import com.lishid.openinv.internal.common.container.slot.ContentCursor;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.ContentList;
+import com.lishid.openinv.internal.common.container.slot.ContentViewOnly;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.paper1_21_4.container.menu.OpenInventoryMenu;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.ContentEquipment;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.ContentOffHand;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Container;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.event.inventory.InventoryType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenInventory extends com.lishid.openinv.internal.common.container.OpenInventory {
+
+  public OpenInventory(@NotNull org.bukkit.entity.Player bukkitPlayer) {
+    super(bukkitPlayer);
+  }
+
+  @Override
+  protected void setupSlots() {
+    // Top of inventory: Regular contents.
+    int nextIndex = addMainInventory();
+
+    // If inventory is expected size, we can arrange slots to be pretty.
+    Inventory ownerInv = owner.getInventory();
+    if (ownerInv.items.size() == 36
+        && ownerInv.armor.size() == 4
+        && ownerInv.offhand.size() == 1
+        && owner.inventoryMenu.getCraftSlots().getContainerSize() == 4) {
+      // Armor slots: Bottom left.
+      addArmor(36);
+      // Off-hand: Below chestplate.
+      addOffHand(46);
+      // Drop slot: Bottom right.
+      slots.set(53, new ContentDrop(owner));
+      // Cursor slot: Above drop.
+      slots.set(44, new ContentCursor(owner));
+
+      // Crafting is displayed in the bottom right corner.
+      // As we're using the pretty view, this is a 3x2.
+      addCrafting(41, true);
+      return;
+    }
+
+    // Otherwise we'll just add elements linearly.
+    nextIndex = addArmor(nextIndex);
+    nextIndex = addOffHand(nextIndex);
+    nextIndex = addCrafting(nextIndex, false);
+    slots.set(nextIndex, new ContentCursor(owner));
+    // Drop slot last.
+    slots.set(slots.size() - 1, new ContentDrop(owner));
+  }
+
+  private int addMainInventory() {
+    int listSize = owner.getInventory().items.size();
+    // Hotbar slots are 0-8. We want those to appear on the bottom of the inventory like a normal player inventory,
+    // so everything else needs to move up a row.
+    int hotbarDiff = listSize - 9;
+    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
+      InventoryType.SlotType type;
+      int invIndex;
+      if (localIndex < hotbarDiff) {
+        invIndex = localIndex + 9;
+        type = InventoryType.SlotType.CONTAINER;
+      } else {
+        type = InventoryType.SlotType.QUICKBAR;
+        invIndex = localIndex - hotbarDiff;
+      }
+
+      slots.set(localIndex, new ContentList(owner, invIndex, type) {
+        @Override
+        public void setHolder(@NotNull ServerPlayer holder) {
+          items = holder.getInventory().items;
+        }
+      });
+    }
+    return listSize;
+  }
+
+  private int addArmor(int startIndex) {
+    int listSize = owner.getInventory().armor.size();
+
+    for (int i = 0; i < listSize; ++i) {
+      // Armor slots go bottom to top; boots are slot 0, helmet is slot 3.
+      // Since we have to display horizontally due to space restrictions,
+      // making the left side the "top" is more user-friendly.
+      int armorIndex;
+      EquipmentSlot slot;
+      switch (i) {
+        case 3 -> {
+          armorIndex = 0;
+          slot = EquipmentSlot.FEET;
+        }
+        case 2 -> {
+          armorIndex = 1;
+          slot = EquipmentSlot.LEGS;
+        }
+        case 1 -> {
+          armorIndex = 2;
+          slot = EquipmentSlot.CHEST;
+        }
+        case 0 -> {
+          armorIndex = 3;
+          slot = EquipmentSlot.HEAD;
+        }
+        default -> {
+          // In the event that new armor slots are added, they can be placed at the end.
+          armorIndex = i;
+          slot = EquipmentSlot.MAINHAND;
+        }
+      }
+
+      slots.set(startIndex + i, new ContentEquipment(owner, armorIndex, slot));
+    }
+
+    return startIndex + listSize;
+  }
+
+  private int addOffHand(int startIndex) {
+    int listSize = owner.getInventory().offhand.size();
+    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
+      slots.set(startIndex + localIndex, new ContentOffHand(owner, localIndex));
+    }
+    return startIndex + listSize;
+  }
+
+  private int addCrafting(int startIndex, boolean pretty) {
+    int listSize = owner.inventoryMenu.getCraftSlots().getContents().size();
+    pretty &= listSize == 4;
+
+    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
+      // Pretty display is a 2x2 rather than linear.
+      // If index is in top row, grid is not 2x2, or pretty is disabled, just use current index.
+      // Otherwise, subtract 2 and add 9 to start in the same position on the next row.
+      int modIndex = startIndex + (localIndex < 2 || !pretty ? localIndex : localIndex + 7);
+
+      slots.set(modIndex, new ContentCrafting(owner, localIndex));
+    }
+
+    if (pretty) {
+      slots.set(startIndex + 2, new ContentViewOnly(owner) {
+        @Override
+        public Slot asSlot(Container container, int slot, int x, int y) {
+          return new SlotViewOnly(container, slot, x, y) {
+            @Override
+            public ItemStack getOrDefault() {
+              return Placeholders.craftingOutput;
+            }
+          };
+        }
+      });
+      slots.set(startIndex + 11, getCraftingResult(owner));
+    }
+
+    return startIndex + listSize;
+  }
+
+  public @Nullable AbstractContainerMenu createMenu(Player player, int i, boolean viewOnly) {
+    if (player instanceof ServerPlayer serverPlayer) {
+      return new OpenInventoryMenu(this, serverPlayer, i, viewOnly);
+    }
+    return null;
+  }
+
+}
@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R2.container.bukkit;
+package com.lishid.openinv.internal.paper1_21_4.container.bukkit;

 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
 import net.minecraft.core.NonNullList;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.entity.player.Inventory;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.entity.Player;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
@@ -26,7 +26,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public ItemStack[] getContents() {
+  public ItemStack @NotNull [] getContents() {
    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getContents());
  }

@@ -46,7 +46,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public ItemStack[] getStorageContents() {
+  public ItemStack @NotNull [] getStorageContents() {
    return asCraftMirror(getInventory().getOwnerHandle().getInventory().items);
  }

@@ -71,12 +71,12 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @NotNull ItemStack[] getArmorContents() {
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
    return asCraftMirror(getInventory().getOwnerHandle().getInventory().armor);
  }

  @Override
-  public void setArmorContents(@Nullable ItemStack[] items) {
+  public void setArmorContents(ItemStack @NotNull [] items) {
    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().armor;
    int size = list.size();
    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
@@ -86,12 +86,12 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @NotNull ItemStack[] getExtraContents() {
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
    return asCraftMirror(getInventory().getOwnerHandle().getInventory().offhand);
  }

  @Override
-  public void setExtraContents(@Nullable ItemStack[] items) {
+  public void setExtraContents(ItemStack @NotNull [] items) {
    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().offhand;
    int size = list.size();
    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
@@ -101,7 +101,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @Nullable ItemStack getHelmet() {
+  public @NotNull ItemStack getHelmet() {
    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
        .getArmor(EquipmentSlot.HEAD.getIndex()));
  }
@@ -113,9 +113,9 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @Nullable ItemStack getChestplate() {
+  public @NotNull ItemStack getChestplate() {
    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.HEAD.getIndex()));
+        .getArmor(EquipmentSlot.CHEST.getIndex()));
  }

  @Override
@@ -125,7 +125,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @Nullable ItemStack getLeggings() {
+  public @NotNull ItemStack getLeggings() {
    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
        .getArmor(EquipmentSlot.LEGS.getIndex()));
  }
@@ -137,7 +137,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @Nullable ItemStack getBoots() {
+  public @NotNull ItemStack getBoots() {
    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
        .getArmor(EquipmentSlot.FEET.getIndex()));
  }
@@ -170,11 +170,13 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
    getInventory().getOwnerHandle().getInventory().offhand.set(0, CraftItemStack.asNMSCopy(item));
  }

+  @Deprecated
  @Override
  public @NotNull ItemStack getItemInHand() {
    return getItemInMainHand();
  }

+  @Deprecated
  @Override
  public void setItemInHand(@Nullable ItemStack stack) {
    setItemInMainHand(stack);
@@ -193,7 +195,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
  }

  @Override
-  public @Nullable ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
+  public @NotNull ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
    return switch (slot) {
      case HAND -> getItemInMainHand();
      case OFF_HAND -> getItemInOffHand();
@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.bukkit;
+package com.lishid.openinv.internal.paper1_21_4.container.bukkit;

-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;

@@ -1,11 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R2.container.menu;
+package com.lishid.openinv.internal.paper1_21_4.container.menu;

 import com.google.common.base.Suppliers;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenDummyInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotPlaceholder;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyInventory;
+import com.lishid.openinv.internal.common.container.slot.SlotPlaceholder;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
 import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
 import net.minecraft.server.level.ServerPlayer;
@@ -21,7 +21,7 @@ import net.minecraft.world.inventory.DataSlot;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -108,26 +108,14 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
    }
  }

-  public static @NotNull MenuType<ChestMenu> getChestMenuType(int inventorySize) {
-    inventorySize = ((int) Math.ceil(inventorySize / 9.0)) * 9;
-    return switch (inventorySize) {
-      case 9 -> MenuType.GENERIC_9x1;
-      case 18 -> MenuType.GENERIC_9x2;
-      case 27 -> MenuType.GENERIC_9x3;
-      case 36 -> MenuType.GENERIC_9x4;
-      case 45 -> MenuType.GENERIC_9x5;
-      case 54 -> MenuType.GENERIC_9x6;
-      default -> throw new IllegalArgumentException("Inventory size unsupported: " + inventorySize);
-    };
-  }
-
  protected void preSlotSetup() {}

  protected @NotNull Slot getUpperSlot(int index, int x, int y) {
+    Slot slot = new Slot(container, index, x, y);
    if (viewOnly) {
-      return new SlotViewOnly(container, index, x, y);
+      return SlotViewOnly.wrap(slot);
    }
-    return new Slot(container, index, x, y);
+    return slot;
  }


@@ -143,7 +131,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  protected @NotNull CraftInventoryView<OpenChestMenu<T>, Inventory> createBukkitEntity() {
    Inventory top;
    if (viewOnly) {
-      top = new OpenDummyInventory(container);
+      top = new OpenDummyInventory(container, container.getBukkitType());
    } else {
      top = container.getBukkitInventory();
    }
@@ -176,9 +164,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In

  private int getTopSize(ServerPlayer viewer) {
    MenuType<?> menuType = getType();
-    if (menuType == null) {
-      throw new IllegalStateException("MenuType cannot be null!");
-    } else if (menuType == MenuType.GENERIC_9x1) {
+    if (menuType == MenuType.GENERIC_9x1) {
      return 9;
    } else if (menuType == MenuType.GENERIC_9x2) {
      return 18;
@@ -284,7 +270,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void clicked(int i, int j, ClickType clickType, Player player) {
+  public void clicked(int i, int j, @NotNull ClickType clickType, @NotNull Player player) {
    if (viewOnly) {
      if (clickType == ClickType.QUICK_CRAFT) {
        sendAllDataToRemote();
@@ -295,13 +281,13 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
    return true;
  }

  // Overrides from here on are purely to modify the sync process to send placeholder items.
  @Override
-  protected Slot addSlot(Slot slot) {
+  protected @NotNull Slot addSlot(@NotNull Slot slot) {
    slot.index = this.slots.size();
    this.slots.add(slot);
    this.lastSlots.add(ItemStack.EMPTY);
@@ -310,7 +296,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  protected DataSlot addDataSlot(DataSlot dataSlot) {
+  protected @NotNull DataSlot addDataSlot(@NotNull DataSlot dataSlot) {
    this.dataSlots.add(dataSlot);
    this.remoteDataSlots.add(0);
    return dataSlot;
@@ -324,7 +310,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void addSlotListener(ContainerListener containerListener) {
+  public void addSlotListener(@NotNull ContainerListener containerListener) {
    if (!this.containerListeners.contains(containerListener)) {
      this.containerListeners.add(containerListener);
      this.broadcastChanges();
@@ -332,7 +318,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void setSynchronizer(ContainerSynchronizer containerSynchronizer) {
+  public void setSynchronizer(@NotNull ContainerSynchronizer containerSynchronizer) {
    this.synchronizer = containerSynchronizer;
    this.sendAllDataToRemote();
  }
@@ -364,7 +350,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
  }

  @Override
-  public void removeSlotListener(ContainerListener containerListener) {
+  public void removeSlotListener(@NotNull ContainerListener containerListener) {
    this.containerListeners.remove(containerListener);
  }

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.menu;
+package com.lishid.openinv.internal.paper1_21_4.container.menu;

-import com.lishid.openinv.internal.v1_21_R2.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.Slot;
@@ -14,11 +14,17 @@ public class OpenEnderChestMenu extends OpenChestMenu<OpenEnderChest> {
      @NotNull ServerPlayer viewer,
      int containerId,
      boolean viewOnly) {
-    super(getChestMenuType(enderChest.getContainerSize()), containerId, enderChest, viewer, viewOnly);
+    super(
+        com.lishid.openinv.internal.common.container.menu.OpenChestMenu.getChestMenuType(enderChest.getContainerSize()),
+        containerId,
+        enderChest,
+        viewer,
+        viewOnly
+    );
  }

  @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
    if (viewOnly) {
      return ItemStack.EMPTY;
    }
@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R1.container.menu;
+package com.lishid.openinv.internal.paper1_21_4.container.menu;

 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R1.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.bukkit.OpenDummyInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.bukkit.OpenPlayerInventorySelf;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyPlayerInventory;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.bukkit.OpenPlayerInventorySelf;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.ContentEquipment;
 import com.lishid.openinv.util.Permissions;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.EquipmentSlot;
@@ -15,8 +15,8 @@ import net.minecraft.world.inventory.ChestMenu;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventoryView;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -39,7 +39,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
      size = ((int) Math.ceil(size / 9.0)) * 9;
    }

-    return getChestMenuType(size);
+    return com.lishid.openinv.internal.common.container.menu.OpenChestMenu.getChestMenuType(size);
  }

  @Override
@@ -102,7 +102,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
  protected @NotNull CraftInventoryView<OpenChestMenu<OpenInventory>, Inventory> createBukkitEntity() {
    org.bukkit.inventory.Inventory bukkitInventory;
    if (viewOnly) {
-      bukkitInventory = new OpenDummyInventory(container);
+      bukkitInventory = new OpenDummyPlayerInventory(container);
    } else if (ownContainer) {
      bukkitInventory = new OpenPlayerInventorySelf(container, offset);
    } else {
@@ -195,7 +195,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
  }

  @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
    if (viewOnly) {
      return ItemStack.EMPTY;
    }
@@ -1,6 +1,8 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.paper1_21_4.container.slot;

-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.ContentList;
+import com.lishid.openinv.internal.common.container.slot.SlotPlaceholder;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.EquipmentSlot;
@@ -65,12 +67,12 @@ public class ContentEquipment extends ContentList {
    }

    @Override
-    public boolean mayPlace(ItemStack var0) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
      if (viewer == null) {
        return true;
      }

-      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(var0) == equipmentSlot;
+      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(itemStack) == equipmentSlot;
    }

  }
@@ -1,8 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
+package com.lishid.openinv.internal.paper1_21_4.container.slot;

+import com.lishid.openinv.internal.common.player.OpenPlayer;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.InventoryMenu;
 import net.minecraft.world.inventory.Slot;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
@@ -34,10 +37,13 @@ public class ContentOffHand extends ContentEquipment {
    return new SlotEquipment(container, slot, x, y) {
      @Override
      public void setChanged() {
-        if (holder.connection != null
-            && !holder.connection.isDisconnected()
-            && holder.containerMenu != holder.inventoryMenu) {
-          holder.resendItemInHands();
+        if (OpenPlayer.isConnected(holder.connection) && holder.containerMenu != holder.inventoryMenu) {
+          holder.connection.send(
+              new ClientboundContainerSetSlotPacket(
+                  holder.inventoryMenu.containerId,
+                  holder.inventoryMenu.incrementStateId(),
+                  InventoryMenu.SHIELD_SLOT,
+                  holder.getOffhandItem()));
        }
      }
    };
@@ -0,0 +1,41 @@
+package com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder;
+
+import com.lishid.openinv.internal.common.container.slot.placeholder.PlaceholderLoaderBase;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.TagParser;
+import net.minecraft.util.Unit;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.CustomModelData;
+import net.minecraft.world.item.component.DyedItemColor;
+import org.jetbrains.annotations.NotNull;
+
+public class CustomModelBase extends PlaceholderLoaderBase {
+
+  private final @NotNull CustomModelData defaultCustomModelData;
+
+  public CustomModelBase(@NotNull CustomModelData defaultCustomModelData) {
+    this.defaultCustomModelData = defaultCustomModelData;
+  }
+
+  @Override
+  protected @NotNull CompoundTag parseTag(@NotNull String itemText) throws Exception {
+    return TagParser.parseTag(itemText);
+  }
+
+  @Override
+  protected void addModelData(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, defaultCustomModelData);
+  }
+
+  @Override
+  protected void hideTooltip(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+  }
+
+  @Override
+  protected DyedItemColor getDye(int rgb) {
+    return new DyedItemColor(rgb, false);
+  }
+
+}
@@ -0,0 +1,13 @@
+package com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder;
+
+import net.minecraft.world.item.component.CustomModelData;
+
+import java.util.List;
+
+public class CustomModelPlaceholderLoader extends CustomModelBase {
+
+  public CustomModelPlaceholderLoader() {
+    super(new CustomModelData(List.of(), List.of(), List.of("openinv:custom"), List.of()));
+  }
+
+}
@@ -0,0 +1,35 @@
+package com.lishid.openinv.internal.paper1_21_4.player;
+
+import com.lishid.openinv.internal.common.player.PlayerManager;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ServerPlayer;
+import org.bukkit.craftbukkit.CraftServer;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenPlayer extends com.lishid.openinv.internal.common.player.OpenPlayer {
+
+  protected OpenPlayer(CraftServer server, ServerPlayer entity,
+      PlayerManager manager) {
+    super(server, entity, manager);
+  }
+
+  @Contract("null -> new")
+  @Override
+  protected @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
+    if (oldData == null) {
+      return new CompoundTag();
+    }
+
+    // Copy old data. This is a deep clone, so operating on it should be safe.
+    oldData = oldData.copy();
+
+    // Remove vanilla/server data that is not written every time.
+    oldData.getAllKeys()
+        .removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit"));
+
+    return oldData;
+  }
+
+}
@@ -0,0 +1,70 @@
+package com.lishid.openinv.internal.paper1_21_4.player;
+
+import com.mojang.serialization.Dynamic;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtOps;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.dimension.DimensionType;
+import org.bukkit.Bukkit;
+import org.bukkit.World;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.UUID;
+import java.util.logging.Logger;
+
+public class PlayerManager extends com.lishid.openinv.internal.common.player.PlayerManager {
+
+  public PlayerManager(@NotNull Logger logger) {
+    super(logger);
+  }
+
+  protected void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
+    // See PlayerList#placeNewPlayer
+    World bukkitWorld;
+    if (loadedData.contains("WorldUUIDMost") && loadedData.contains("WorldUUIDLeast")) {
+      // Modern Bukkit world.
+      bukkitWorld = Bukkit.getServer().getWorld(new UUID(loadedData.getLong("WorldUUIDMost"), loadedData.getLong("WorldUUIDLeast")));
+    } else if (loadedData.contains("world", net.minecraft.nbt.Tag.TAG_STRING)) {
+      // Legacy Bukkit world.
+      bukkitWorld = Bukkit.getServer().getWorld(loadedData.getString("world"));
+    } else {
+      // Vanilla player data.
+      DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
+          .resultOrPartial(logger::warning)
+          .map(player.server::getLevel)
+          // If ServerLevel exists, set, otherwise move to spawn.
+          .ifPresentOrElse(player::setServerLevel, () -> spawnInDefaultWorld(player));
+      return;
+    }
+    if (bukkitWorld == null) {
+      spawnInDefaultWorld(player);
+      return;
+    }
+    player.setServerLevel(((CraftWorld) bukkitWorld).getHandle());
+  }
+
+  @Override
+  protected void spawnInDefaultWorld(ServerPlayer player) {
+    ServerLevel level = player.server.getLevel(Level.OVERWORLD);
+    if (level != null) {
+      // Adjust player to default spawn (in keeping with Paper handling) when world not found.
+      player.moveTo(player.adjustSpawnLocation(level, level.getSharedSpawnPos()).getBottomCenter(), level.getSharedSpawnAngle(), 0.0F);
+      player.spawnIn(level);
+    } else {
+      logger.warning("Tried to load player with invalid world when no fallback was available!");
+    }
+  }
+
+  protected void injectPlayer(ServerPlayer player) throws IllegalAccessException {
+    if (bukkitEntity == null) {
+      return;
+    }
+
+    bukkitEntity.setAccessible(true);
+    bukkitEntity.set(player, new OpenPlayer(player.server.server, player, this));
+  }
+
+}
@@ -0,0 +1,44 @@
+import com.github.jikoo.openinv.SpigotDependencyExtension
+import com.github.jikoo.openinv.SpigotReobf
+import com.github.jikoo.openinv.SpigotSetup
+
+plugins {
+  `openinv-base`
+  alias(libs.plugins.shadow)
+}
+
+apply<SpigotSetup>()
+apply<SpigotReobf>()
+
+val spigotVer = "1.21.5-R0.1-SNAPSHOT"
+// Used by common adapter to relocate Craftbukkit classes to a versioned package.
+rootProject.extra["craftbukkitPackage"] = "v1_21_R4"
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val spigot = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "spigot-api"
+      }
+    }
+    if (spigot != null) {
+      select(spigot)
+    }
+    because("module is written for Spigot servers")
+  }
+}
+
+dependencies {
+  compileOnly(libs.spigotapi)
+  extensions.getByType(SpigotDependencyExtension::class.java).version = spigotVer
+
+  compileOnly(project(":openinvapi"))
+  compileOnly(project(":openinvcommon"))
+
+  // Reduce duplicate code by lightly remapping common adapter.
+  implementation(project(":openinvadaptercommon", configuration = "spigotRelocated"))
+}
+
+tasks.shadowJar {
+  relocate("com.lishid.openinv.internal.common", "com.lishid.openinv.internal.reobf")
+}
@@ -0,0 +1,194 @@
+package com.lishid.openinv.internal.reobf.container;
+
+import com.lishid.openinv.internal.AnySilentContainerBase;
+import com.lishid.openinv.internal.reobf.container.menu.OpenChestMenu;
+import com.lishid.openinv.internal.reobf.player.PlayerManager;
+import com.lishid.openinv.util.ReflectionHelper;
+import com.lishid.openinv.util.lang.LanguageManager;
+import net.minecraft.core.BlockPos;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.ServerPlayerGameMode;
+import net.minecraft.world.MenuProvider;
+import net.minecraft.world.SimpleMenuProvider;
+import net.minecraft.world.inventory.ChestMenu;
+import net.minecraft.world.inventory.MenuType;
+import net.minecraft.world.inventory.PlayerEnderChestContainer;
+import net.minecraft.world.level.GameType;
+import net.minecraft.world.level.block.BarrelBlock;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.ChestBlock;
+import net.minecraft.world.level.block.ShulkerBoxBlock;
+import net.minecraft.world.level.block.TrappedChestBlock;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.entity.EnderChestBlockEntity;
+import net.minecraft.world.level.block.entity.RandomizableContainerBlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import org.bukkit.GameMode;
+import org.bukkit.Material;
+import org.bukkit.Statistic;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.lang.reflect.Field;
+import java.util.logging.Logger;
+
+public class AnySilentContainer extends AnySilentContainerBase {
+
+  private final @NotNull Logger logger;
+  private final @NotNull LanguageManager lang;
+  private @Nullable Field serverPlayerGameModeGameType;
+
+  public AnySilentContainer(@NotNull Logger logger, @NotNull LanguageManager lang) {
+    this.logger = logger;
+    this.lang = lang;
+    try {
+      try {
+        this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("gameModeForPlayer");
+        this.serverPlayerGameModeGameType.setAccessible(true);
+      } catch (NoSuchFieldException e) {
+        logger.warning("The field ServerPlayerGameMode#gameModeForPlayer is no longer present!");
+        logger.warning("Please report this at https://github.com/Jikoo/OpenInv/issues");
+        logger.warning("Attempting to fall through using reflection. Please verify that SilentContainer does not fail.");
+        // N.B. gameModeForPlayer is (for now) declared before previousGameModeForPlayer so silent shouldn't break.
+        this.serverPlayerGameModeGameType = ReflectionHelper.grabFieldByType(ServerPlayerGameMode.class, GameType.class);
+      }
+    } catch (SecurityException e) {
+      logger.warning("Unable to directly write player game mode! SilentContainer will fail.");
+      logger.log(java.util.logging.Level.WARNING, "Error obtaining GameType field", e);
+    }
+  }
+
+  @Override
+  public boolean activateContainer(
+      @NotNull final Player bukkitPlayer,
+      final boolean silentchest,
+      @NotNull final org.bukkit.block.Block bukkitBlock) {
+
+    // Silent ender chest is API-only
+    if (silentchest && bukkitBlock.getType() == Material.ENDER_CHEST) {
+      bukkitPlayer.openInventory(bukkitPlayer.getEnderChest());
+      bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
+      return true;
+    }
+
+    ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
+
+    final net.minecraft.world.level.Level level = player.level();
+    final BlockPos blockPos = new BlockPos(bukkitBlock.getX(), bukkitBlock.getY(), bukkitBlock.getZ());
+    final BlockEntity blockEntity = level.getBlockEntity(blockPos);
+
+    if (blockEntity == null) {
+      return false;
+    }
+
+    if (blockEntity instanceof EnderChestBlockEntity enderChestTile) {
+      // Anychest ender chest. See net.minecraft.world.level.block.EnderChestBlock
+      PlayerEnderChestContainer enderChest = player.getEnderChestInventory();
+      enderChest.setActiveChest(enderChestTile);
+      player.openMenu(new SimpleMenuProvider((containerCounter, playerInventory, ignored) -> {
+        MenuType<?> containers = OpenChestMenu.getChestMenuType(enderChest.getContainerSize());
+        int rows = enderChest.getContainerSize() / 9;
+        return new ChestMenu(containers, containerCounter, playerInventory, enderChest, rows);
+      }, Component.translatable("container.enderchest")));
+      bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
+      return true;
+    }
+
+    if (!(blockEntity instanceof MenuProvider menuProvider)) {
+      return false;
+    }
+
+    BlockState blockState = level.getBlockState(blockPos);
+    Block block = blockState.getBlock();
+
+    if (block instanceof ChestBlock chestBlock) {
+
+      // boolean flag: do not check if chest is blocked
+      menuProvider = chestBlock.getMenuProvider(blockState, level, blockPos, true);
+
+      if (menuProvider == null) {
+        lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
+        return false;
+      }
+
+      if (block instanceof TrappedChestBlock) {
+        bukkitPlayer.incrementStatistic(Statistic.TRAPPED_CHEST_TRIGGERED);
+      } else {
+        bukkitPlayer.incrementStatistic(Statistic.CHEST_OPENED);
+      }
+    }
+
+    if (block instanceof ShulkerBoxBlock) {
+      bukkitPlayer.incrementStatistic(Statistic.SHULKER_BOX_OPENED);
+    }
+
+    if (block instanceof BarrelBlock) {
+      bukkitPlayer.incrementStatistic(Statistic.OPEN_BARREL);
+    }
+
+    // AnyChest only - SilentChest not active, container unsupported, or unnecessary.
+    if (!silentchest || player.gameMode.getGameModeForPlayer() == GameType.SPECTATOR) {
+      player.openMenu(menuProvider);
+      return true;
+    }
+
+    // SilentChest requires access to setting players' game mode directly.
+    if (this.serverPlayerGameModeGameType == null) {
+      return false;
+    }
+
+    if (blockEntity instanceof RandomizableContainerBlockEntity lootable) {
+      if (lootable.lootTable != null) {
+        lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
+        return false;
+      }
+    }
+
+    GameType gameType = player.gameMode.getGameModeForPlayer();
+    this.forceGameType(player, GameType.SPECTATOR);
+    player.openMenu(menuProvider);
+    this.forceGameType(player, gameType);
+    return true;
+  }
+
+  @Override
+  public void deactivateContainer(@NotNull final Player bukkitPlayer) {
+    if (this.serverPlayerGameModeGameType == null || bukkitPlayer.getGameMode() == GameMode.SPECTATOR) {
+      return;
+    }
+
+    ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
+
+    // Force game mode change without informing plugins or players.
+    // Regular game mode set calls GameModeChangeEvent and is cancellable.
+    GameType gameType = player.gameMode.getGameModeForPlayer();
+    this.forceGameType(player, GameType.SPECTATOR);
+
+    // ServerPlayer#closeContainer cannot be called without entering an
+    // infinite loop because this method is called during inventory close.
+    // From ServerPlayer#closeContainer -> CraftEventFactory#handleInventoryCloseEvent
+    player.containerMenu.transferTo(player.inventoryMenu, player.getBukkitEntity());
+    // From ServerPlayer#closeContainer
+    player.doCloseContainer();
+    // Regular inventory close will handle the rest - packet sending, etc.
+
+    // Revert forced game mode.
+    this.forceGameType(player, gameType);
+  }
+
+  private void forceGameType(final ServerPlayer player, final GameType gameMode) {
+    if (this.serverPlayerGameModeGameType == null) {
+      // No need to warn repeatedly, error on startup and lack of function should be enough.
+      return;
+    }
+    try {
+      this.serverPlayerGameModeGameType.setAccessible(true);
+      this.serverPlayerGameModeGameType.set(player.gameMode, gameMode);
+    } catch (IllegalArgumentException | IllegalAccessException e) {
+      logger.log(java.util.logging.Level.WARNING, "Error bypassing GameModeChangeEvent", e);
+    }
+  }
+
+}
@@ -0,0 +1,188 @@
+package com.lishid.openinv.internal.reobf.container.bukkit;
+
+import com.google.common.base.Preconditions;
+import com.lishid.openinv.internal.reobf.container.OpenInventory;
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.entity.player.Inventory;
+import org.bukkit.craftbukkit.v1_21_R4.inventory.CraftInventory;
+import org.bukkit.craftbukkit.v1_21_R4.inventory.CraftItemStack;
+import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenPlayerInventory extends CraftInventory implements PlayerInventory {
+
+  public OpenPlayerInventory(@NotNull OpenInventory inventory) {
+    super(inventory);
+  }
+
+  @Override
+  public @NotNull OpenInventory getInventory() {
+    return (OpenInventory) super.getInventory();
+  }
+
+  @Override
+  public ItemStack @NotNull [] getContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getContents());
+  }
+
+  @Override
+  public void setContents(ItemStack[] items) {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    int size = internal.getContainerSize();
+    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
+
+    for (int index = 0; index < size; ++index) {
+      if (index < items.length) {
+        internal.setItem(index, CraftItemStack.asNMSCopy(items[index]));
+      } else {
+        internal.setItem(index, net.minecraft.world.item.ItemStack.EMPTY);
+      }
+    }
+  }
+
+  @Override
+  public ItemStack @NotNull [] getStorageContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getNonEquipmentItems());
+  }
+
+  @Override
+  public void setStorageContents(ItemStack[] items) throws IllegalArgumentException {
+    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().getNonEquipmentItems();
+    int size = list.size();
+    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
+    for (int index = 0; index < items.length; ++index) {
+      list.set(index, CraftItemStack.asNMSCopy(items[index]));
+    }
+  }
+
+  @Override
+  public @NotNull InventoryType getType() {
+    return InventoryType.PLAYER;
+  }
+
+  @Override
+  public @NotNull Player getHolder() {
+    return getInventory().getOwner();
+  }
+
+  @Override
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getArmorContents();
+  }
+
+  @Override
+  public void setArmorContents(ItemStack @NotNull [] items) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setArmorContents(items);
+  }
+
+  @Override
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getExtraContents();
+  }
+
+  @Override
+  public void setExtraContents(ItemStack @NotNull [] items) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setExtraContents(items);
+  }
+
+  @Override
+  public @Nullable ItemStack getHelmet() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getHelmet();
+  }
+
+  @Override
+  public void setHelmet(@Nullable ItemStack helmet) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setHelmet(helmet);
+  }
+
+  @Override
+  public @Nullable ItemStack getChestplate() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getChestplate();
+  }
+
+  @Override
+  public void setChestplate(@Nullable ItemStack chestplate) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setChestplate(chestplate);
+  }
+
+  @Override
+  public @Nullable ItemStack getLeggings() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getLeggings();
+  }
+
+  @Override
+  public void setLeggings(@Nullable ItemStack leggings) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setLeggings(leggings);
+  }
+
+  @Override
+  public @Nullable ItemStack getBoots() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getBoots();
+  }
+
+  @Override
+  public void setBoots(@Nullable ItemStack boots) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setBoots(boots);
+  }
+
+  @Override
+  public @NotNull ItemStack getItemInMainHand() {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    return CraftItemStack.asCraftMirror(internal.getSelectedItem());
+  }
+
+  @Override
+  public void setItemInMainHand(@Nullable ItemStack item) {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    internal.setSelectedItem(CraftItemStack.asNMSCopy(item));
+  }
+
+  @Override
+  public @NotNull ItemStack getItemInOffHand() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getItemInOffHand();
+  }
+
+  @Override
+  public void setItemInOffHand(@Nullable ItemStack item) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setItemInOffHand(item);
+  }
+
+  @Deprecated
+  @Override
+  public @NotNull ItemStack getItemInHand() {
+    return getItemInMainHand();
+  }
+
+  @Deprecated
+  @Override
+  public void setItemInHand(@Nullable ItemStack stack) {
+    setItemInMainHand(stack);
+  }
+
+  @Override
+  public int getHeldItemSlot() {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    return internal.getNonEquipmentItems().size() - 9 + internal.getSelectedSlot();
+  }
+
+  @Override
+  public void setHeldItemSlot(int slot) {
+    slot %= 9;
+    getInventory().getOwnerHandle().getInventory().setSelectedSlot(slot);
+  }
+
+  @Override
+  public @Nullable ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getItem(slot);
+  }
+
+  @Override
+  public void setItem(@NotNull org.bukkit.inventory.EquipmentSlot slot, @Nullable ItemStack item) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setItem(slot, item);
+  }
+
+}
@@ -0,0 +1,116 @@
+package com.lishid.openinv.internal.reobf.container.slot;
+
+import com.lishid.openinv.internal.reobf.container.slot.placeholder.Placeholders;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Container;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.craftbukkit.v1_21_R4.CraftEquipmentSlot;
+import org.bukkit.craftbukkit.v1_21_R4.inventory.CraftItemStack;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.PlayerInventory;
+import org.jetbrains.annotations.NotNull;
+
+public class ContentEquipment implements Content {
+
+  private PlayerInventory equipment;
+  private final ItemStack placeholder;
+  private final org.bukkit.inventory.EquipmentSlot equipmentSlot;
+
+  public ContentEquipment(ServerPlayer holder, EquipmentSlot equipmentSlot) {
+    setHolder(holder);
+    placeholder = switch (equipmentSlot) {
+      case HEAD -> Placeholders.emptyHelmet;
+      case CHEST -> Placeholders.emptyChestplate;
+      case LEGS -> Placeholders.emptyLeggings;
+      case FEET -> Placeholders.emptyBoots;
+      default -> Placeholders.emptyOffHand;
+    };
+    this.equipmentSlot = CraftEquipmentSlot.getSlot(equipmentSlot);
+  }
+
+  @Override
+  public void setHolder(@NotNull ServerPlayer holder) {
+    this.equipment = holder.getBukkitEntity().getInventory();
+  }
+
+  @Override
+  public ItemStack get() {
+    return CraftItemStack.asNMSCopy(equipment.getItem(equipmentSlot));
+  }
+
+  @Override
+  public ItemStack remove() {
+    org.bukkit.inventory.ItemStack old = equipment.getItem(equipmentSlot);
+    equipment.setItem(equipmentSlot, null);
+    return CraftItemStack.asNMSCopy(old);
+  }
+
+  @Override
+  public ItemStack removePartial(int amount) {
+    if (amount <= 0) {
+      return ItemStack.EMPTY;
+    }
+    ItemStack current = get();
+    if (current.isEmpty()) {
+      return ItemStack.EMPTY;
+    }
+    ItemStack split = current.split(amount);
+    set(current);
+    return split;
+  }
+
+  @Override
+  public void set(ItemStack itemStack) {
+    equipment.setItem(equipmentSlot, CraftItemStack.asCraftMirror(itemStack));
+  }
+
+  @Override
+  public Slot asSlot(Container container, int slot, int x, int y) {
+    return new SlotEquipment(container, slot, x, y);
+  }
+
+  @Override
+  public InventoryType.SlotType getSlotType() {
+    return InventoryType.SlotType.ARMOR;
+  }
+
+  public class SlotEquipment extends SlotPlaceholder {
+
+    private ServerPlayer viewer;
+
+    SlotEquipment(Container container, int index, int x, int y) {
+      super(container, index, x, y);
+    }
+
+    @Override
+    public ItemStack getOrDefault() {
+      ItemStack itemStack = getItem();
+      if (!itemStack.isEmpty()) {
+        return itemStack;
+      }
+      return placeholder;
+    }
+
+    public EquipmentSlot getEquipmentSlot() {
+      return CraftEquipmentSlot.getNMS(equipmentSlot);
+    }
+
+    public void onlyEquipmentFor(ServerPlayer viewer) {
+      this.viewer = viewer;
+    }
+
+    @Override
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
+      if (viewer == null) {
+        return true;
+      }
+
+      return equipmentSlot == org.bukkit.inventory.EquipmentSlot.OFF_HAND
+          || viewer.getEquipmentSlotForItem(itemStack) == CraftEquipmentSlot.getNMS(equipmentSlot);
+    }
+
+  }
+
+}
@@ -0,0 +1,49 @@
+package com.lishid.openinv.internal.reobf.container.slot;
+
+import com.lishid.openinv.internal.reobf.player.OpenPlayer;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Container;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.InventoryMenu;
+import net.minecraft.world.inventory.Slot;
+import org.bukkit.event.inventory.InventoryType;
+import org.jetbrains.annotations.NotNull;
+
+public class ContentOffHand extends ContentEquipment {
+
+  private ServerPlayer holder;
+
+  public ContentOffHand(ServerPlayer holder) {
+    super(holder, EquipmentSlot.OFFHAND);
+  }
+
+  @Override
+  public void setHolder(@NotNull ServerPlayer holder) {
+    super.setHolder(holder);
+    this.holder = holder;
+  }
+
+  @Override
+  public InventoryType.SlotType getSlotType() {
+    return InventoryType.SlotType.QUICKBAR;
+  }
+
+  @Override
+  public Slot asSlot(Container container, int slot, int x, int y) {
+    return new SlotEquipment(container, slot, x, y) {
+      @Override
+      public void setChanged() {
+        if (OpenPlayer.isConnected(holder.connection) && holder.containerMenu != holder.inventoryMenu) {
+          holder.connection.send(
+              new ClientboundContainerSetSlotPacket(
+                  holder.inventoryMenu.containerId,
+                  holder.inventoryMenu.incrementStateId(),
+                  InventoryMenu.SHIELD_SLOT,
+                  holder.getOffhandItem()));
+        }
+      }
+    };
+  }
+
+}
@@ -1,12 +1,10 @@
-package com.lishid.openinv.internal.v1_21_R2.player;
+package com.lishid.openinv.internal.reobf.player;

 import com.lishid.openinv.internal.ISpecialInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
+import com.lishid.openinv.internal.reobf.container.OpenEnderChest;
+import com.lishid.openinv.internal.reobf.container.OpenInventory;
 import com.mojang.authlib.GameProfile;
-import com.mojang.serialization.Dynamic;
 import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.NbtOps;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ClientboundOpenScreenPacket;
 import net.minecraft.server.MinecraftServer;
@@ -18,37 +16,22 @@ import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.player.ChatVisiblity;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.level.Level;
-import net.minecraft.world.level.dimension.DimensionType;
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.Server;
-import org.bukkit.World;
-import org.bukkit.craftbukkit.v1_21_R2.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R2.CraftWorld;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftPlayer;
-import org.bukkit.craftbukkit.v1_21_R2.event.CraftEventFactory;
+import org.bukkit.craftbukkit.v1_21_R4.CraftServer;
+import org.bukkit.craftbukkit.v1_21_R4.entity.CraftPlayer;
+import org.bukkit.craftbukkit.v1_21_R4.event.CraftEventFactory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.InventoryView;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import java.lang.reflect.Field;
-import java.util.UUID;
 import java.util.logging.Logger;

 public class PlayerManager implements com.lishid.openinv.internal.PlayerManager {

-  private static boolean paper;
-
-  static {
-    try {
-      Class.forName("io.papermc.paper.configuration.Configuration");
-      paper = true;
-    } catch (ClassNotFoundException ignored) {
-      paper = false;
-    }
-  }
-
  private final @NotNull Logger logger;
  private @Nullable Field bukkitEntity;

@@ -158,39 +141,9 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
    // Game type settings are also loaded separately.
    player.loadGameTypes(loadedData);

-    if (paper) {
-      // Paper: world is not loaded by ServerPlayer#load(CompoundTag).
-      parseWorld(player, loadedData);
-    }
-
    return true;
  }

-  private void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
-    // See PlayerList#placeNewPlayer
-    World bukkitWorld;
-    if (loadedData.contains("WorldUUIDMost") && loadedData.contains("WorldUUIDLeast")) {
-      // Modern Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(new UUID(loadedData.getLong("WorldUUIDMost"), loadedData.getLong("WorldUUIDLeast")));
-    } else if (loadedData.contains("world", net.minecraft.nbt.Tag.TAG_STRING)) {
-      // Legacy Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(loadedData.getString("world"));
-    } else {
-      // Vanilla player data.
-      DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
-          .resultOrPartial(logger::warning)
-          .map(player.server::getLevel)
-          // If ServerLevel exists, set, otherwise move to spawn.
-          .ifPresentOrElse(player::setServerLevel, () -> player.spawnIn(null));
-      return;
-    }
-    if (bukkitWorld == null) {
-      player.spawnIn(null);
-      return;
-    }
-    player.setServerLevel(((CraftWorld) bukkitWorld).getHandle());
-  }
-
  private void injectPlayer(ServerPlayer player) throws IllegalAccessException {
    if (bukkitEntity == null) {
      return;
@@ -223,7 +176,7 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
  public @Nullable InventoryView openInventory(@NotNull Player bukkitPlayer, @NotNull ISpecialInventory inventory, boolean viewOnly) {
    ServerPlayer player = getHandle(bukkitPlayer);

-    if (player.connection == null) {
+    if (!OpenPlayer.isConnected(player.connection)) {
      return null;
    }

@@ -1,77 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!--
-  ~ Copyright (C) 2011-2023 lishid. All rights reserved.
-  ~
-  ~ 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, version 3.
-  ~
-  ~ This program is distributed in the hope that it will be useful,
-  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-  ~ GNU General Public License for more details.
-  ~
-  ~ You should have received a copy of the GNU General Public License
-  ~ along with this program. If not, see <http://www.gnu.org/licenses/>.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <parent>
-    <artifactId>openinvparent</artifactId>
-    <groupId>com.lishid</groupId>
-    <relativePath>../../pom.xml</relativePath>
-    <version>5.1.3</version>
-  </parent>
-
-  <artifactId>openinvadapter1_21_R1</artifactId>
-  <name>OpenInvAdapter1_21_R1</name>
-
-  <properties>
-    <maven.compiler.system>21</maven.compiler.system>
-    <maven.compiler.release>21</maven.compiler.release>
-    <spigot.version>1.21.1-R0.1-SNAPSHOT</spigot.version>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>org.spigotmc</groupId>
-      <artifactId>spigot-api</artifactId>
-      <version>${spigot.version}</version>
-    </dependency>
-    <dependency>
-      <artifactId>spigot</artifactId>
-      <groupId>org.spigotmc</groupId>
-      <scope>provided</scope>
-      <version>${spigot.version}</version>
-      <classifier>remapped-mojang</classifier>
-    </dependency>
-    <dependency>
-      <artifactId>openinvapi</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>openinvcommon</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>annotations</artifactId>
-      <groupId>org.jetbrains</groupId>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-      </plugin>
-      <plugin>
-        <groupId>net.md-5</groupId>
-        <artifactId>specialsource-maven-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-</project>
@@ -1,196 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.container;
-
-import com.lishid.openinv.internal.ISpecialEnderChest;
-import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R1.container.menu.OpenEnderChestMenu;
-import com.lishid.openinv.internal.v1_21_R1.player.PlayerManager;
-import net.minecraft.core.NonNullList;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.ContainerHelper;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.entity.player.StackedContents;
-import net.minecraft.world.inventory.AbstractContainerMenu;
-import net.minecraft.world.inventory.StackedContentsCompatible;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R1.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventory;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.event.inventory.InventoryType;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class OpenEnderChest implements Container, StackedContentsCompatible, InternalOwned<ServerPlayer>,
-    ISpecialEnderChest {
-
-  private CraftInventory inventory;
-  private @NotNull ServerPlayer owner;
-  private NonNullList<ItemStack> items;
-  private int maxStack = 64;
-  private final List<HumanEntity> transaction = new ArrayList<>();
-
-  public OpenEnderChest(@NotNull org.bukkit.entity.Player player) {
-    this.owner = PlayerManager.getHandle(player);
-    this.items = owner.getEnderChestInventory().items;
-  }
-
-  @Override
-  public @NotNull ServerPlayer getOwnerHandle() {
-    return owner;
-  }
-
-  @Override
-  public @NotNull org.bukkit.inventory.Inventory getBukkitInventory() {
-    if (inventory == null) {
-      inventory = new CraftInventory(this) {
-        @Override
-        public @NotNull InventoryType getType() {
-          return InventoryType.ENDER_CHEST;
-        }
-      };
-    }
-    return inventory;
-  }
-
-  @Override
-  public void setPlayerOnline(@NotNull org.bukkit.entity.Player player) {
-    owner = PlayerManager.getHandle(player);
-    NonNullList<ItemStack> activeItems = owner.getEnderChestInventory().items;
-
-    // Guard against size changing. Theoretically on Purpur all row variations still have 6 rows internally.
-    int max = Math.min(items.size(), activeItems.size());
-    for (int index = 0; index < max; ++index) {
-      activeItems.set(index, items.get(index));
-    }
-
-    items = activeItems;
-  }
-
-  @Override
-  public void setPlayerOffline() {}
-
-  @Override
-  public @NotNull org.bukkit.entity.Player getPlayer() {
-    return owner.getBukkitEntity();
-  }
-
-  @Override
-  public int getContainerSize() {
-    return items.size();
-  }
-
-  @Override
-  public boolean isEmpty() {
-    return items.stream().allMatch(ItemStack::isEmpty);
-  }
-
-  @Override
-  public ItemStack getItem(int index) {
-    return index >= 0 && index < items.size() ? items.get(index) : ItemStack.EMPTY;
-  }
-
-  @Override
-  public ItemStack removeItem(int index, int amount) {
-    ItemStack itemstack = ContainerHelper.removeItem(items, index, amount);
-
-    if (!itemstack.isEmpty()) {
-      setChanged();
-    }
-
-    return itemstack;
-  }
-
-  @Override
-  public ItemStack removeItemNoUpdate(int index) {
-    return index >= 0 && index < items.size() ? items.set(index, ItemStack.EMPTY) : ItemStack.EMPTY;
-  }
-
-  @Override
-  public void setItem(int index, ItemStack itemStack) {
-    if (index >= 0 && index < items.size()) {
-      items.set(index, itemStack);
-    }
-  }
-
-  @Override
-  public int getMaxStackSize() {
-    return maxStack;
-  }
-
-  @Override
-  public void setChanged() {
-    this.owner.getEnderChestInventory().setChanged();
-  }
-
-  @Override
-  public boolean stillValid(Player player) {
-    return true;
-  }
-
-  @Override
-  public List<ItemStack> getContents() {
-    return items;
-  }
-
-  @Override
-  public void onOpen(CraftHumanEntity craftHumanEntity) {
-    transaction.add(craftHumanEntity);
-  }
-
-  @Override
-  public void onClose(CraftHumanEntity craftHumanEntity) {
-    transaction.remove(craftHumanEntity);
-  }
-
-  @Override
-  public List<HumanEntity> getViewers() {
-    return transaction;
-  }
-
-  @Override
-  public org.bukkit.entity.Player getOwner() {
-    return getPlayer();
-  }
-
-  @Override
-  public void setMaxStackSize(int size) {
-    maxStack = size;
-  }
-
-  @Override
-  public @Nullable Location getLocation() {
-    return null;
-  }
-
-  @Override
-  public void clearContent() {
-    items.clear();
-    setChanged();
-  }
-
-  @Override
-  public void fillStackedContents(StackedContents stackedContents) {
-    for (ItemStack itemstack : items) {
-      stackedContents.accountStack(itemstack);
-    }
-  }
-
-  public Component getTitle() {
-    return Component.translatableWithFallback("openinv.container.enderchest.prefix", "", owner.getName())
-        .append(Component.translatable("container.enderchest"))
-        .append(Component.translatableWithFallback("openinv.container.enderchest.suffix", " - %s", owner.getName()));
-  }
-
-  public @Nullable AbstractContainerMenu createMenu(Player player, int i, boolean viewOnly) {
-    if (player instanceof ServerPlayer serverPlayer) {
-      return new OpenEnderChestMenu(this, serverPlayer, i, viewOnly);
-    }
-    return null;
-  }
-
-}
@@ -1,364 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.container;
-
-import com.lishid.openinv.internal.ISpecialPlayerInventory;
-import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R1.container.bukkit.OpenPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R1.container.menu.OpenInventoryMenu;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.Content;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentCrafting;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentCraftingResult;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentCursor;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentList;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentOffHand;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.ContentViewOnly;
-import com.lishid.openinv.internal.v1_21_R1.container.slot.SlotViewOnly;
-import com.lishid.openinv.internal.v1_21_R1.player.PlayerManager;
-import net.minecraft.ChatFormatting;
-import net.minecraft.core.NonNullList;
-import net.minecraft.network.chat.Component;
-import net.minecraft.network.chat.MutableComponent;
-import net.minecraft.resources.ResourceLocation;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.entity.EquipmentSlot;
-import net.minecraft.world.entity.player.Inventory;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.inventory.AbstractContainerMenu;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R1.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R1.inventory.CraftInventory;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.event.inventory.InventoryType;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class OpenInventory implements Container, InternalOwned<ServerPlayer>, ISpecialPlayerInventory {
-
-  private final List<Content> slots;
-  private final int size;
-  private ServerPlayer owner;
-  private int maxStackSize = 99;
-  private CraftInventory bukkitEntity;
-  public List<HumanEntity> transaction = new ArrayList<>();
-
-  public OpenInventory(@NotNull org.bukkit.entity.Player bukkitPlayer) {
-    owner = PlayerManager.getHandle(bukkitPlayer);
-
-    // Get total size, rounding up to nearest 9 for client compatibility.
-    int rawSize = owner.getInventory().getContainerSize() + owner.inventoryMenu.getCraftSlots().getContainerSize() + 1;
-    size = ((int) Math.ceil(rawSize / 9.0)) * 9;
-
-    slots = NonNullList.withSize(size, new ContentViewOnly(owner));
-    setupSlots();
-  }
-
-  private void setupSlots() {
-    // Top of inventory: Regular contents.
-    int nextIndex = addMainInventory();
-
-    // If inventory is expected size, we can arrange slots to be pretty.
-    Inventory ownerInv = owner.getInventory();
-    if (ownerInv.items.size() == 36
-        && ownerInv.armor.size() == 4
-        && ownerInv.offhand.size() == 1
-        && owner.inventoryMenu.getCraftSlots().getContainerSize() == 4) {
-      // Armor slots: Bottom left.
-      addArmor(36);
-      // Off-hand: Below chestplate.
-      addOffHand(46);
-      // Drop slot: Bottom right.
-      slots.set(53, new ContentDrop(owner));
-      // Cursor slot: Above drop.
-      slots.set(44, new ContentCursor(owner));
-
-      // Crafting is displayed in the bottom right corner.
-      // As we're using the pretty view, this is a 3x2.
-      addCrafting(41, true);
-      return;
-    }
-
-    // Otherwise we'll just add elements linearly.
-    nextIndex = addArmor(nextIndex);
-    nextIndex = addOffHand(nextIndex);
-    nextIndex = addCrafting(nextIndex, false);
-    slots.set(nextIndex, new ContentCursor(owner));
-    // Drop slot last.
-    slots.set(slots.size() - 1, new ContentDrop(owner));
-  }
-
-  private int addMainInventory() {
-    int listSize = owner.getInventory().items.size();
-    // Hotbar slots are 0-8. We want those to appear on the bottom of the inventory like a normal player inventory,
-    // so everything else needs to move up a row.
-    int hotbarDiff = listSize - 9;
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      InventoryType.SlotType type;
-      int invIndex;
-      if (localIndex < hotbarDiff) {
-        invIndex = localIndex + 9;
-        type = InventoryType.SlotType.CONTAINER;
-      } else {
-        type = InventoryType.SlotType.QUICKBAR;
-        invIndex = localIndex - hotbarDiff;
-      }
-
-      slots.set(localIndex, new ContentList(owner, invIndex, type) {
-        @Override
-        public void setHolder(@NotNull ServerPlayer holder) {
-          items = holder.getInventory().items;
-        }
-      });
-    }
-    return listSize;
-  }
-
-  private int addArmor(int startIndex) {
-    int listSize = owner.getInventory().armor.size();
-
-    for (int i = 0; i < listSize; ++i) {
-      // Armor slots go bottom to top; boots are slot 0, helmet is slot 3.
-      // Since we have to display horizontally due to space restrictions,
-      // making the left side the "top" is more user-friendly.
-      int armorIndex;
-      EquipmentSlot slot;
-      switch (i) {
-        case 3 -> {
-          armorIndex = 0;
-          slot = EquipmentSlot.FEET;
-        }
-        case 2 -> {
-          armorIndex = 1;
-          slot = EquipmentSlot.LEGS;
-        }
-        case 1 -> {
-          armorIndex = 2;
-          slot = EquipmentSlot.CHEST;
-        }
-        case 0 -> {
-          armorIndex = 3;
-          slot = EquipmentSlot.HEAD;
-        }
-        default -> {
-          // In the event that new armor slots are added, they can be placed at the end.
-          armorIndex = i;
-          slot = EquipmentSlot.MAINHAND;
-        }
-      }
-
-      slots.set(startIndex + i, new ContentEquipment(owner, armorIndex, slot));
-    }
-
-    return startIndex + listSize;
-  }
-
-  private int addOffHand(int startIndex) {
-    int listSize = owner.getInventory().offhand.size();
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      slots.set(startIndex + localIndex, new ContentOffHand(owner, localIndex));
-    }
-    return startIndex + listSize;
-  }
-
-  private int addCrafting(int startIndex, boolean pretty) {
-    int listSize = owner.inventoryMenu.getCraftSlots().getContents().size();
-    pretty &= listSize == 4;
-
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      // Pretty display is a 2x2 rather than linear.
-      // If index is in top row, grid is not 2x2, or pretty is disabled, just use current index.
-      // Otherwise, subtract 2 and add 9 to start in the same position on the next row.
-      int modIndex = startIndex + (localIndex < 2 || !pretty ? localIndex : localIndex + 7);
-
-      slots.set(modIndex, new ContentCrafting(owner, localIndex));
-    }
-
-    if (pretty) {
-      slots.set(startIndex + 2, new ContentViewOnly(owner) {
-        @Override
-        public Slot asSlot(Container container, int slot, int x, int y) {
-          return new SlotViewOnly(container, slot, x, y) {
-            @Override
-            public ItemStack getOrDefault() {
-              return Placeholders.craftingOutput;
-            }
-          };
-        }
-      });
-      slots.set(startIndex + 11, new ContentCraftingResult(owner));
-    }
-
-    return startIndex + listSize;
-  }
-
-  public Slot getMenuSlot(int index, int x, int y) {
-    return slots.get(index).asSlot(this, index, x, y);
-  }
-
-  public InventoryType.SlotType getSlotType(int index) {
-    return slots.get(index).getSlotType();
-  }
-
-  public @NotNull Component getTitle(@Nullable ServerPlayer viewer) {
-    MutableComponent component = Component.empty();
-    // Prefix for use with custom bitmap image fonts.
-    if (owner.equals(viewer)) {
-      component.append(
-          Component.translatableWithFallback("openinv.container.inventory.self", "")
-              .withStyle(style -> style
-                  .withFont(ResourceLocation.parse("openinv:font/inventory"))
-                  .withColor(ChatFormatting.WHITE)));
-    } else {
-      component.append(
-          Component.translatableWithFallback("openinv.container.inventory.other", "")
-              .withStyle(style -> style
-                  .withFont(ResourceLocation.parse("openinv:font/inventory"))
-                  .withColor(ChatFormatting.WHITE)));
-    }
-    // Normal title: "Inventory - OwnerName"
-    component.append(Component.translatableWithFallback("openinv.container.inventory.prefix", "", owner.getName()))
-        .append(Component.translatable("container.inventory"))
-        .append(Component.translatableWithFallback("openinv.container.inventory.suffix", " - %s", owner.getName()));
-    return component;
-  }
-
-  @Override
-  public ServerPlayer getOwnerHandle() {
-    return owner;
-  }
-
-  @Override
-  public @NotNull org.bukkit.inventory.Inventory getBukkitInventory() {
-    if (bukkitEntity == null) {
-      bukkitEntity = new OpenPlayerInventory(this);
-    }
-    return bukkitEntity;
-  }
-
-  @Override
-  public void setPlayerOnline(@NotNull org.bukkit.entity.Player player) {
-    ServerPlayer newOwner = PlayerManager.getHandle(player);
-    // Only transfer regular inventory - crafting and cursor slots are transient.
-    newOwner.getInventory().replaceWith(owner.getInventory());
-    owner = newOwner;
-    // Update slots to point to new inventory.
-    slots.forEach(slot -> slot.setHolder(newOwner));
-  }
-
-  @Override
-  public void setPlayerOffline() {}
-
-  @Override
-  public boolean isInUse() {
-    return !transaction.isEmpty();
-  }
-
-  @Override
-  public @NotNull org.bukkit.entity.Player getPlayer() {
-    return getOwner();
-  }
-
-  @Override
-  public int getContainerSize() {
-    return size;
-  }
-
-  @Override
-  public boolean isEmpty() {
-    return slots.stream().map(Content::get).allMatch(ItemStack::isEmpty);
-  }
-
-  @Override
-  public ItemStack getItem(int index) {
-    return slots.get(index).get();
-  }
-
-  @Override
-  public ItemStack removeItem(int index, int amount) {
-    return slots.get(index).removePartial(amount);
-  }
-
-  @Override
-  public ItemStack removeItemNoUpdate(int index) {
-    return slots.get(index).remove();
-  }
-
-  @Override
-  public void setItem(int index, ItemStack itemStack) {
-    slots.get(index).set(itemStack);
-  }
-
-  @Override
-  public int getMaxStackSize() {
-    return maxStackSize;
-  }
-
-  @Override
-  public void setMaxStackSize(int maxStackSize) {
-    this.maxStackSize = maxStackSize;
-  }
-
-  @Override
-  public void setChanged() {}
-
-  @Override
-  public boolean stillValid(Player player) {
-    return true;
-  }
-
-  @Override
-  public List<ItemStack> getContents() {
-    NonNullList<ItemStack> contents = NonNullList.withSize(getContainerSize(), ItemStack.EMPTY);
-    for (int i = 0; i < getContainerSize(); ++i) {
-      contents.set(i, getItem(i));
-    }
-    return contents;
-  }
-
-  @Override
-  public void onOpen(CraftHumanEntity viewer) {
-    transaction.add(viewer);
-  }
-
-  @Override
-  public void onClose(CraftHumanEntity viewer) {
-    transaction.remove(viewer);
-  }
-
-  @Override
-  public List<HumanEntity> getViewers() {
-    return transaction;
-  }
-
-  @Override
-  public org.bukkit.entity.Player getOwner() {
-    return owner.getBukkitEntity();
-  }
-
-  @Override
-  public Location getLocation() {
-    return owner.getBukkitEntity().getLocation();
-  }
-
-  @Override
-  public void clearContent() {
-    owner.getInventory().clearContent();
-    owner.inventoryMenu.getCraftSlots().clearContent();
-    owner.inventoryMenu.slotsChanged(owner.inventoryMenu.getCraftSlots());
-    owner.containerMenu.setCarried(ItemStack.EMPTY);
-  }
-
-  public @Nullable AbstractContainerMenu createMenu(Player player, int i, boolean viewOnly) {
-    if (player instanceof ServerPlayer serverPlayer) {
-      return new OpenInventoryMenu(this, serverPlayer, i, viewOnly);
-    }
-    return null;
-  }
-
-}
@@ -1,183 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.container;
-
-import net.minecraft.core.Registry;
-import net.minecraft.core.RegistryAccess;
-import net.minecraft.core.component.DataComponents;
-import net.minecraft.core.registries.Registries;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.TagParser;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.util.Unit;
-import net.minecraft.world.item.DyeColor;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
-import net.minecraft.world.item.component.CustomModelData;
-import net.minecraft.world.item.component.DyedItemColor;
-import net.minecraft.world.level.GameType;
-import net.minecraft.world.level.ItemLike;
-import net.minecraft.world.level.block.entity.BannerPattern;
-import net.minecraft.world.level.block.entity.BannerPatternLayers;
-import net.minecraft.world.level.block.entity.BannerPatterns;
-import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R1.CraftRegistry;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.EnumMap;
-import java.util.List;
-import java.util.Optional;
-
-public final class Placeholders {
-
-  private static final CustomModelData DEFAULT_CUSTOM_MODEL_DATA = new CustomModelData(9999);
-  public static final @NotNull EnumMap<GameType, ItemStack> BLOCKED_GAME_TYPE = new EnumMap<>(GameType.class);
-  public static @NotNull ItemStack craftingOutput = defaultCraftingOutput();
-  public static @NotNull ItemStack cursor = defaultCursor();
-  public static @NotNull ItemStack drop = defaultDrop();
-  public static @NotNull ItemStack emptyHelmet = getEmptyArmor(Items.LEATHER_HELMET);
-  public static @NotNull ItemStack emptyChestplate = getEmptyArmor(Items.LEATHER_CHESTPLATE);
-  public static @NotNull ItemStack emptyLeggings = getEmptyArmor(Items.LEATHER_LEGGINGS);
-  public static @NotNull ItemStack emptyBoots = getEmptyArmor(Items.LEATHER_BOOTS);
-  public static @NotNull ItemStack emptyOffHand = getEmptyShield();
-  public static @NotNull ItemStack notSlot = defaultNotSlot();
-  public static @NotNull ItemStack blockedOffline = defaultBlockedOffline();
-
-  static {
-    for (GameType type : GameType.values()) {
-      // Barrier: "Not available - Creative" etc.
-      ItemStack typeItem = new ItemStack(Items.BARRIER);
-      typeItem.set(
-          DataComponents.ITEM_NAME,
-          Component.translatable("options.narrator.notavailable").append(" - ").append(type.getShortDisplayName()));
-      BLOCKED_GAME_TYPE.put(type, typeItem);
-    }
-  }
-
-  public static void load(@NotNull ConfigurationSection section) throws Exception {
-    craftingOutput = parse(section, "crafting-output", craftingOutput);
-    cursor = parse(section, "cursor", cursor);
-    drop = parse(section, "drop", drop);
-    emptyHelmet = parse(section, "empty-helmet", emptyHelmet);
-    emptyChestplate = parse(section, "empty-chestplate", emptyChestplate);
-    emptyLeggings = parse(section, "empty-leggings", emptyLeggings);
-    emptyBoots = parse(section, "empty-boots", emptyBoots);
-    emptyOffHand = parse(section, "empty-off-hand", emptyOffHand);
-    notSlot = parse(section, "not-a-slot", notSlot);
-    blockedOffline = parse(section, "blocked.offline", blockedOffline);
-    BLOCKED_GAME_TYPE.put(GameType.CREATIVE, parse(section, "blocked.creative", BLOCKED_GAME_TYPE.get(GameType.CREATIVE)));
-    BLOCKED_GAME_TYPE.put(GameType.SPECTATOR, parse(section, "blocked.spectator", BLOCKED_GAME_TYPE.get(GameType.SPECTATOR)));
-  }
-
-  private static @NotNull ItemStack parse(
-      @NotNull ConfigurationSection section,
-      @NotNull String path,
-      @NotNull ItemStack defaultStack) throws Exception {
-    String itemText = section.getString(path);
-
-    if (itemText == null) {
-      return defaultStack;
-    }
-
-    CompoundTag compoundTag = TagParser.parseTag(itemText);
-    Optional<ItemStack> parsed = ItemStack.parse(CraftRegistry.getMinecraftRegistry(), compoundTag);
-    return parsed.filter(itemStack -> !itemStack.isEmpty()).orElse(defaultStack);
-  }
-
-  public static ItemStack survivalOnly(@NotNull ServerPlayer serverPlayer) {
-    if (serverPlayer.connection == null || serverPlayer.connection.isDisconnected()) {
-      return blockedOffline;
-    }
-
-    return BLOCKED_GAME_TYPE.getOrDefault(serverPlayer.gameMode.getGameModeForPlayer(), ItemStack.EMPTY);
-  }
-
-  private static ItemStack defaultCraftingOutput() {
-    // Crafting table: "Crafting"
-    ItemStack itemStack = new ItemStack(Items.CRAFTING_TABLE);
-    itemStack.set(DataComponents.ITEM_NAME, Component.translatable("container.crafting"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack defaultCursor() {
-    // Cursor-like banner with no tooltip
-    ItemStack itemStack = new ItemStack(Items.WHITE_BANNER);
-    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
-    Registry<BannerPattern> bannerPatterns = minecraftRegistry.registryOrThrow(Registries.BANNER_PATTERN);
-    BannerPattern halfDiagBottomRight = bannerPatterns.getOrThrow(BannerPatterns.DIAGONAL_RIGHT);
-    BannerPattern downRight = bannerPatterns.getOrThrow(BannerPatterns.STRIPE_DOWNRIGHT);
-    BannerPattern border = bannerPatterns.getOrThrow(BannerPatterns.BORDER);
-    itemStack.set(DataComponents.BANNER_PATTERNS,
-        new BannerPatternLayers(List.of(
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfDiagBottomRight), DyeColor.GRAY),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(downRight), DyeColor.WHITE),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(border), DyeColor.GRAY))));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    return itemStack;
-  }
-
-  private static ItemStack defaultDrop() {
-    // Dropper: "Drop Selected Item"
-    ItemStack itemStack = new ItemStack(Items.DROPPER);
-    // Note: translatable component, not keybind component! We want the text identifying the keybind, not the key.
-    itemStack.set(DataComponents.ITEM_NAME, Component.translatable("key.drop"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack getEmptyArmor(ItemLike item) {
-    // Inventory-background-grey-ish leather armor with no tooltip
-    ItemStack itemStack = new ItemStack(item);
-    DyedItemColor color = new DyedItemColor(0xC8C8C8, false);
-    itemStack.set(DataComponents.DYED_COLOR, color);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack getEmptyShield() {
-    ItemStack itemStack = new ItemStack(Items.SHIELD);
-    itemStack.set(DataComponents.BASE_COLOR, DyeColor.MAGENTA);
-    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
-    Registry<BannerPattern> bannerPatterns = minecraftRegistry.registryOrThrow(Registries.BANNER_PATTERN);
-    BannerPattern halfLeft = bannerPatterns.getOrThrow(BannerPatterns.HALF_VERTICAL);
-    BannerPattern topLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_LEFT);
-    BannerPattern topRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_RIGHT);
-    BannerPattern bottomLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_LEFT);
-    BannerPattern bottomRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_RIGHT);
-    itemStack.set(DataComponents.BANNER_PATTERNS,
-        new BannerPatternLayers(List.of(
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfLeft), DyeColor.BLACK),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topLeft), DyeColor.MAGENTA),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomLeft), DyeColor.MAGENTA),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topRight), DyeColor.BLACK),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomRight), DyeColor.BLACK))));
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack defaultNotSlot() {
-    // White pane with no tooltip
-    ItemStack itemStack = new ItemStack(Items.WHITE_STAINED_GLASS_PANE);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack defaultBlockedOffline() {
-    // Barrier: "Not available - Offline"
-    ItemStack itemStack = new ItemStack(Items.BARRIER);
-    itemStack.set(DataComponents.ITEM_NAME,
-        Component.translatable("options.narrator.notavailable")
-            .append(Component.literal(" - "))
-            .append(Component.translatable("gui.socialInteractions.status_offline")));
-    return itemStack;
-  }
-
-  private Placeholders() {
-    throw new IllegalStateException("Cannot create instance of utility class.");
-  }
-
-}
@@ -1,69 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
-
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.jetbrains.annotations.NotNull;
-
-/**
- * An interface defining behaviors for entries in a {@link Container}. Used to reduce duplicate content reordering.
- */
-public interface Content {
-
-  /**
-   * Update internal holder.
-   *
-   * @param holder the new holder
-   */
-  void setHolder(@NotNull ServerPlayer holder);
-
-  /**
-   * Get the current item.
-   *
-   * @return the current item
-   */
-  ItemStack get();
-
-  /**
-   * Remove the current item.
-   *
-   * @return the current item
-   */
-  ItemStack remove();
-
-  /**
-   * Remove some of the current item.
-   *
-   * @return the current item
-   */
-  ItemStack removePartial(int amount);
-
-  /**
-   * Set the current item. If slot is currently not usable, will drop item instead.
-   *
-   * @param itemStack the item to set
-   */
-  void set(ItemStack itemStack);
-
-  /**
-   * Get a {@link Slot} for use in a {@link net.minecraft.world.inventory.AbstractContainerMenu ContainerMenu}. Will
-   * impose any specific restrictions to insertion or removal.
-   *
-   * @param container the backing container
-   * @param slot the slot of the backing container represented
-   * @param x clientside x dimension from top left of inventory, not used
-   * @param y clientside y dimension from top left of inventory, not used
-   * @return a menu slot
-   */
-  Slot asSlot(Container container, int slot, int x, int y);
-
-  /**
-   * Get a loose Bukkit translation of what this slot stores. For example, any slot that drops items at the owner rather
-   * than insert them will report itself as being {@link org.bukkit.event.inventory.InventoryType.SlotType#OUTSIDE}.
-   *
-   * @return the closes Bukkit slot type
-   */
-  org.bukkit.event.inventory.InventoryType.SlotType getSlotType();
-
-}
@@ -1,58 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
-
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.ContainerHelper;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.event.inventory.InventoryType;
-
-import java.util.List;
-
-/**
- * A normal slot backed by an item list.
- */
-public abstract class ContentList implements Content {
-
-  private final int index;
-  private final InventoryType.SlotType slotType;
-  protected List<ItemStack> items;
-
-  public ContentList(ServerPlayer holder, int index, InventoryType.SlotType slotType) {
-    this.index = index;
-    this.slotType = slotType;
-    setHolder(holder);
-  }
-
-  @Override
-  public ItemStack get() {
-    return items.get(index);
-  }
-
-  @Override
-  public ItemStack remove() {
-    ItemStack removed = items.remove(index);
-    return removed == null || removed.isEmpty() ? ItemStack.EMPTY : removed;
-  }
-
-  @Override
-  public ItemStack removePartial(int amount) {
-    return ContainerHelper.removeItem(items, index, amount);
-  }
-
-  @Override
-  public void set(ItemStack itemStack) {
-    items.set(index, itemStack);
-  }
-
-  @Override
-  public Slot asSlot(Container container, int slot, int x, int y) {
-    return new Slot(container, slot, x, y);
-  }
-
-  @Override
-  public InventoryType.SlotType getSlotType() {
-    return slotType;
-  }
-
-}
@@ -1,151 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.container.slot;
-
-import com.lishid.openinv.internal.v1_21_R1.container.Placeholders;
-import net.minecraft.world.Container;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Optional;
-
-/**
- * A view-only {@link Slot}. "Blank" by default, but can wrap another slot to display its content.
- */
-public class SlotViewOnly extends SlotPlaceholder {
-
-  public static @NotNull SlotViewOnly wrap(@NotNull Slot wrapped) {
-    SlotViewOnly wrapper;
-    if (wrapped instanceof SlotPlaceholder placeholder) {
-      wrapper = new SlotViewOnly(wrapped.container, wrapped.slot, wrapped.x, wrapped.y) {
-        @Override
-        public ItemStack getOrDefault() {
-          return placeholder.getOrDefault();
-        }
-      };
-    } else {
-      wrapper = new SlotViewOnly(wrapped.container, wrapped.slot, wrapped.x, wrapped.y) {
-        @Override
-        public ItemStack getOrDefault() {
-          return wrapped.getItem();
-        }
-      };
-    }
-    wrapper.index = wrapped.index;
-    return wrapper;
-  }
-
-  public SlotViewOnly(Container container, int index, int x, int y) {
-    super(container, index, x, y);
-  }
-
-  @Override
-  public ItemStack getOrDefault() {
-    return Placeholders.notSlot;
-  }
-
-  @Override
-  public void onQuickCraft(ItemStack var0, ItemStack var1) {
-  }
-
-  @Override
-  public void onTake(Player var0, ItemStack var1) {
-  }
-
-  @Override
-  public boolean mayPlace(ItemStack var0) {
-    return false;
-  }
-
-  @Override
-  public ItemStack getItem() {
-    return ItemStack.EMPTY;
-  }
-
-  @Override
-  public boolean hasItem() {
-    return false;
-  }
-
-  @Override
-  public void setByPlayer(ItemStack newStack) {
-  }
-
-  @Override
-  public void setByPlayer(ItemStack newStack, ItemStack oldStack) {
-  }
-
-  @Override
-  public void set(ItemStack var0) {
-  }
-
-  @Override
-  public void setChanged() {
-  }
-
-  @Override
-  public int getMaxStackSize() {
-    return 0;
-  }
-
-  @Override
-  public int getMaxStackSize(ItemStack itemStack) {
-    return 0;
-  }
-
-  @Override
-  public ItemStack remove(int amount) {
-    return ItemStack.EMPTY;
-  }
-
-  @Override
-  public boolean mayPickup(Player var0) {
-    return false;
-  }
-
-  @Override
-  public boolean isActive() {
-    return false;
-  }
-
-  @Override
-  public Optional<ItemStack> tryRemove(int var0, int var1, Player var2) {
-    return Optional.empty();
-  }
-
-  @Override
-  public ItemStack safeTake(int var0, int var1, Player var2) {
-    return ItemStack.EMPTY;
-  }
-
-  @Override
-  public ItemStack safeInsert(ItemStack itemStack) {
-    return itemStack;
-  }
-
-  @Override
-  public ItemStack safeInsert(ItemStack itemStack, int amount) {
-    return itemStack;
-  }
-
-  @Override
-  public boolean allowModification(Player var0) {
-    return false;
-  }
-
-  @Override
-  public int getContainerSlot() {
-    return this.slot;
-  }
-
-  @Override
-  public boolean isHighlightable() {
-    return false;
-  }
-
-  @Override
-  public boolean isFake() {
-    return true;
-  }
-
-}
@@ -1,177 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R1.player;
-
-import com.lishid.openinv.event.OpenEvents;
-import com.mojang.logging.LogUtils;
-import net.minecraft.Util;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.NbtIo;
-import net.minecraft.nbt.NumericTag;
-import net.minecraft.nbt.Tag;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.level.storage.PlayerDataStorage;
-import org.bukkit.craftbukkit.v1_21_R1.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R1.entity.CraftPlayer;
-import org.jetbrains.annotations.Contract;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.Set;
-
-public class OpenPlayer extends CraftPlayer {
-
-  /**
-   * List of tags to always reset when saving.
-   *
-   * @see net.minecraft.world.entity.Entity#saveWithoutId(CompoundTag)
-   * @see net.minecraft.server.level.ServerPlayer#addAdditionalSaveData(CompoundTag)
-   * @see net.minecraft.world.entity.player.Player#addAdditionalSaveData(CompoundTag)
-   * @see net.minecraft.world.entity.LivingEntity#addAdditionalSaveData(CompoundTag)
-   */
-  private static final Set<String> RESET_TAGS = Set.of(
-      // Entity#saveWithoutId(CompoundTag)
-      "CustomName",
-      "CustomNameVisible",
-      "Silent",
-      "NoGravity",
-      "Glowing",
-      "TicksFrozen",
-      "HasVisualFire",
-      "Tags",
-      "Passengers",
-      // ServerPlayer#addAdditionalSaveData(CompoundTag)
-      // Intentional omissions to prevent mount loss: Attach, Entity, and RootVehicle
-      "warden_spawn_tracker",
-      "enteredNetherPosition",
-      "SpawnX",
-      "SpawnY",
-      "SpawnZ",
-      "SpawnForced",
-      "SpawnAngle",
-      "SpawnDimension",
-      "raid_omen_position",
-      // Player#addAdditionalSaveData(CompoundTag)
-      "ShoulderEntityLeft",
-      "ShoulderEntityRight",
-      "LastDeathLocation",
-      "current_explosion_impact_pos",
-      // LivingEntity#addAdditionalSaveData(CompoundTag)
-      "active_effects",
-      "SleepingX",
-      "SleepingY",
-      "SleepingZ",
-      "Brain"
-  );
-
-  private final PlayerManager manager;
-
-  OpenPlayer(CraftServer server, ServerPlayer entity, PlayerManager manager) {
-    super(server, entity);
-    this.manager = manager;
-  }
-
-  @Override
-  public void loadData() {
-    manager.loadData(getHandle());
-  }
-
-  @Override
-  public void saveData() {
-    if (OpenEvents.saveCancelled(this)) {
-      return;
-    }
-
-    ServerPlayer player = this.getHandle();
-    // See net.minecraft.world.level.storage.PlayerDataStorage#save(EntityHuman)
-    try {
-      PlayerDataStorage worldNBTStorage = player.server.getPlayerList().playerIo;
-
-      CompoundTag oldData = isOnline() ? null : worldNBTStorage.load(player.getName().getString(), player.getStringUUID()).orElse(null);
-      CompoundTag playerData = getWritableTag(oldData);
-      playerData = player.saveWithoutId(playerData);
-      setExtraData(playerData);
-
-      if (oldData != null) {
-        // Revert certain special data values when offline.
-        revertSpecialValues(playerData, oldData);
-      }
-
-      Path playerDataDir = worldNBTStorage.getPlayerDir().toPath();
-      Path tempFile = Files.createTempFile(playerDataDir, player.getStringUUID() + "-", ".dat");
-      NbtIo.writeCompressed(playerData, tempFile);
-      Path dataFile = playerDataDir.resolve(player.getStringUUID() + ".dat");
-      Path backupFile = playerDataDir.resolve(player.getStringUUID() + ".dat_old");
-      Util.safeReplaceFile(dataFile, tempFile, backupFile);
-    } catch (Exception e) {
-      LogUtils.getLogger().warn("Failed to save player data for {}: {}", player.getScoreboardName(), e);
-    }
-  }
-
-  @Contract("null -> new")
-  private @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
-    if (oldData == null) {
-      return new CompoundTag();
-    }
-
-    // Copy old data. This is a deep clone, so operating on it should be safe.
-    oldData = oldData.copy();
-
-    // Remove vanilla/server data that is not written every time.
-    oldData.getAllKeys()
-        .removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit"));
-
-    return oldData;
-  }
-
-  private void revertSpecialValues(@NotNull CompoundTag newData, @NotNull CompoundTag oldData) {
-    // Revert automatic updates to play timestamps.
-    copyValue(oldData, newData, "bukkit", "lastPlayed", NumericTag.class);
-    copyValue(oldData, newData, "Paper", "LastSeen", NumericTag.class);
-    copyValue(oldData, newData, "Paper", "LastLogin", NumericTag.class);
-  }
-
-  private <T extends Tag> void copyValue(
-      @NotNull CompoundTag source,
-      @NotNull CompoundTag target,
-      @NotNull String container,
-      @NotNull String key,
-      @SuppressWarnings("SameParameterValue") @NotNull Class<T> tagType) {
-    CompoundTag oldContainer = getTag(source, container, CompoundTag.class);
-    CompoundTag newContainer = getTag(target, container, CompoundTag.class);
-
-    // New container being null means the server implementation doesn't store this data.
-    if (newContainer == null) {
-      return;
-    }
-
-    // If old tag exists, copy it to new location, removing otherwise.
-    setTag(newContainer, key, getTag(oldContainer, key, tagType));
-  }
-
-  private <T extends Tag> @Nullable T getTag(
-      @Nullable CompoundTag container,
-      @NotNull String key,
-      @NotNull Class<T> dataType) {
-    if (container == null) {
-      return null;
-    }
-    Tag value = container.get(key);
-    if (value == null || !dataType.isAssignableFrom(value.getClass())) {
-      return null;
-    }
-    return dataType.cast(value);
-  }
-
-  private <T extends Tag> void setTag(
-      @NotNull CompoundTag container,
-      @NotNull String key,
-      @Nullable T data) {
-    if (data == null) {
-      container.remove(key);
-    } else {
-      container.put(key, data);
-    }
-  }
-
-}
@@ -1,77 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!--
-  ~ Copyright (C) 2011-2023 lishid. All rights reserved.
-  ~
-  ~ 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, version 3.
-  ~
-  ~ This program is distributed in the hope that it will be useful,
-  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-  ~ GNU General Public License for more details.
-  ~
-  ~ You should have received a copy of the GNU General Public License
-  ~ along with this program. If not, see <http://www.gnu.org/licenses/>.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <parent>
-    <artifactId>openinvparent</artifactId>
-    <groupId>com.lishid</groupId>
-    <relativePath>../../pom.xml</relativePath>
-    <version>5.1.3</version>
-  </parent>
-
-  <artifactId>openinvadapter1_21_R2</artifactId>
-  <name>OpenInvAdapter1_21_R2</name>
-
-  <properties>
-    <maven.compiler.system>21</maven.compiler.system>
-    <maven.compiler.release>21</maven.compiler.release>
-    <spigot.version>1.21.3-R0.1-SNAPSHOT</spigot.version>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>org.spigotmc</groupId>
-      <artifactId>spigot-api</artifactId>
-      <version>${spigot.version}</version>
-    </dependency>
-    <dependency>
-      <artifactId>spigot</artifactId>
-      <groupId>org.spigotmc</groupId>
-      <scope>provided</scope>
-      <version>${spigot.version}</version>
-      <classifier>remapped-mojang</classifier>
-    </dependency>
-    <dependency>
-      <artifactId>openinvapi</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>openinvcommon</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>annotations</artifactId>
-      <groupId>org.jetbrains</groupId>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-      </plugin>
-      <plugin>
-        <groupId>net.md-5</groupId>
-        <artifactId>specialsource-maven-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-</project>
@@ -1,210 +0,0 @@
-/*
- * Copyright (C) 2011-2023 lishid. All rights reserved.
- *
- * 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, version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package com.lishid.openinv.internal.v1_21_R2.container;
-
-import com.lishid.openinv.internal.AnySilentContainerBase;
-import com.lishid.openinv.internal.v1_21_R2.container.menu.OpenChestMenu;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
-import com.lishid.openinv.util.ReflectionHelper;
-import com.lishid.openinv.util.lang.LanguageManager;
-import net.minecraft.core.BlockPos;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.server.level.ServerPlayerGameMode;
-import net.minecraft.world.MenuProvider;
-import net.minecraft.world.SimpleMenuProvider;
-import net.minecraft.world.inventory.ChestMenu;
-import net.minecraft.world.inventory.MenuType;
-import net.minecraft.world.inventory.PlayerEnderChestContainer;
-import net.minecraft.world.level.GameType;
-import net.minecraft.world.level.block.BarrelBlock;
-import net.minecraft.world.level.block.Block;
-import net.minecraft.world.level.block.ChestBlock;
-import net.minecraft.world.level.block.ShulkerBoxBlock;
-import net.minecraft.world.level.block.TrappedChestBlock;
-import net.minecraft.world.level.block.entity.BlockEntity;
-import net.minecraft.world.level.block.entity.EnderChestBlockEntity;
-import net.minecraft.world.level.block.entity.RandomizableContainerBlockEntity;
-import net.minecraft.world.level.block.state.BlockState;
-import org.bukkit.GameMode;
-import org.bukkit.Material;
-import org.bukkit.Statistic;
-import org.bukkit.entity.Player;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.lang.reflect.Field;
-import java.util.logging.Logger;
-
-public class AnySilentContainer extends AnySilentContainerBase {
-
-    private final @NotNull Logger logger;
-    private final @NotNull LanguageManager lang;
-    private @Nullable Field serverPlayerGameModeGameType;
-
-    public AnySilentContainer(@NotNull Logger logger, @NotNull LanguageManager lang) {
-        this.logger = logger;
-        this.lang = lang;
-        try {
-            try {
-                this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("b");
-                this.serverPlayerGameModeGameType.setAccessible(true);
-            } catch (NoSuchFieldException e) {
-                logger.warning("ServerPlayerGameMode#gameModeForPlayer's obfuscated name has changed!");
-                logger.warning("Please report this at https://github.com/Jikoo/OpenInv/issues");
-                logger.warning("Attempting to fall through using reflection. Please verify that SilentContainer does not fail.");
-                // N.B. gameModeForPlayer is (for now) declared before previousGameModeForPlayer so silent shouldn't break.
-                this.serverPlayerGameModeGameType = ReflectionHelper.grabFieldByType(ServerPlayerGameMode.class, GameType.class);
-            }
-        } catch (SecurityException e) {
-            logger.warning("Unable to directly write player game mode! SilentContainer will fail.");
-            logger.log(java.util.logging.Level.WARNING, "Error obtaining GameType field", e);
-        }
-    }
-
-    @Override
-    public boolean activateContainer(
-            @NotNull final Player bukkitPlayer,
-            final boolean silentchest,
-            @NotNull final org.bukkit.block.Block bukkitBlock) {
-
-        // Silent ender chest is API-only
-        if (silentchest && bukkitBlock.getType() == Material.ENDER_CHEST) {
-            bukkitPlayer.openInventory(bukkitPlayer.getEnderChest());
-            bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
-            return true;
-        }
-
-        ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
-
-        final net.minecraft.world.level.Level level = player.level();
-        final BlockPos blockPos = new BlockPos(bukkitBlock.getX(), bukkitBlock.getY(), bukkitBlock.getZ());
-        final BlockEntity blockEntity = level.getBlockEntity(blockPos);
-
-        if (blockEntity == null) {
-            return false;
-        }
-
-        if (blockEntity instanceof EnderChestBlockEntity enderChestTile) {
-            // Anychest ender chest. See net.minecraft.world.level.block.EnderChestBlock
-            PlayerEnderChestContainer enderChest = player.getEnderChestInventory();
-            enderChest.setActiveChest(enderChestTile);
-            player.openMenu(new SimpleMenuProvider((containerCounter, playerInventory, ignored) -> {
-                MenuType<?> containers = OpenChestMenu.getChestMenuType(enderChest.getContainerSize());
-                int rows = enderChest.getContainerSize() / 9;
-                return new ChestMenu(containers, containerCounter, playerInventory, enderChest, rows);
-            }, Component.translatable("container.enderchest")));
-            bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
-            return true;
-        }
-
-        if (!(blockEntity instanceof MenuProvider menuProvider)) {
-            return false;
-        }
-
-        BlockState blockState = level.getBlockState(blockPos);
-        Block block = blockState.getBlock();
-
-        if (block instanceof ChestBlock chestBlock) {
-
-            // boolean flag: do not check if chest is blocked
-            menuProvider = chestBlock.getMenuProvider(blockState, level, blockPos, true);
-
-            if (menuProvider == null) {
-                lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
-                return false;
-            }
-
-            if (block instanceof TrappedChestBlock) {
-                bukkitPlayer.incrementStatistic(Statistic.TRAPPED_CHEST_TRIGGERED);
-            } else {
-                bukkitPlayer.incrementStatistic(Statistic.CHEST_OPENED);
-            }
-        }
-
-        if (block instanceof ShulkerBoxBlock) {
-            bukkitPlayer.incrementStatistic(Statistic.SHULKER_BOX_OPENED);
-        }
-
-        if (block instanceof BarrelBlock) {
-            bukkitPlayer.incrementStatistic(Statistic.OPEN_BARREL);
-        }
-
-        // AnyChest only - SilentChest not active, container unsupported, or unnecessary.
-        if (!silentchest || player.gameMode.getGameModeForPlayer() == GameType.SPECTATOR) {
-            player.openMenu(menuProvider);
-            return true;
-        }
-
-        // SilentChest requires access to setting players' game mode directly.
-        if (this.serverPlayerGameModeGameType == null) {
-            return false;
-        }
-
-        if (blockEntity instanceof RandomizableContainerBlockEntity lootable) {
-            if (lootable.lootTable != null) {
-                lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
-                return false;
-            }
-        }
-
-        GameType gameType = player.gameMode.getGameModeForPlayer();
-        this.forceGameType(player, GameType.SPECTATOR);
-        player.openMenu(menuProvider);
-        this.forceGameType(player, gameType);
-        return true;
-    }
-
-    @Override
-    public void deactivateContainer(@NotNull final Player bukkitPlayer) {
-        if (this.serverPlayerGameModeGameType == null || bukkitPlayer.getGameMode() == GameMode.SPECTATOR) {
-            return;
-        }
-
-        ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
-
-        // Force game mode change without informing plugins or players.
-        // Regular game mode set calls GameModeChangeEvent and is cancellable.
-        GameType gameType = player.gameMode.getGameModeForPlayer();
-        this.forceGameType(player, GameType.SPECTATOR);
-
-        // ServerPlayer#closeContainer cannot be called without entering an
-        // infinite loop because this method is called during inventory close.
-        // From ServerPlayer#closeContainer -> CraftEventFactory#handleInventoryCloseEvent
-        player.containerMenu.transferTo(player.inventoryMenu, player.getBukkitEntity());
-        // From ServerPlayer#closeContainer
-        player.doCloseContainer();
-        // Regular inventory close will handle the rest - packet sending, etc.
-
-        // Revert forced game mode.
-        this.forceGameType(player, gameType);
-    }
-
-    private void forceGameType(final ServerPlayer player, final GameType gameMode) {
-        if (this.serverPlayerGameModeGameType == null) {
-            // No need to warn repeatedly, error on startup and lack of function should be enough.
-            return;
-        }
-        try {
-            this.serverPlayerGameModeGameType.setAccessible(true);
-            this.serverPlayerGameModeGameType.set(player.gameMode, gameMode);
-        } catch (IllegalArgumentException | IllegalAccessException e) {
-            logger.log(java.util.logging.Level.WARNING, "Error bypassing GameModeChangeEvent", e);
-        }
-    }
-
-}
Author	SHA1	Message	Date
Jikoo	8c2ec2121a	Bump version to 5.1.10 for release	2025-04-25 11:49:43 -04:00
Adam	ad06b46b37	Update to 1.21.5 (#300 )	2025-04-25 15:47:20 +00:00
dependabot[bot]	05ac5c92c8	Bump io.papermc.paperweight.userdev from 2.0.0-beta.14 to 2.0.0-beta.16 (#297 )	2025-04-01 17:34:11 +00:00
dependabot[bot]	0c8c364c45	Bump org.spigotmc:spigot-api (#298 )	2025-04-01 17:33:47 +00:00
Jikoo	b89f34915e	Hack around JitPack building Spigot and publishing it, but we don't talk about that	2025-03-21 17:27:54 -04:00
mooviies	ada819b30a	Fix JitPack API build (#296 )	2025-03-19 16:08:13 +00:00
Adam	7a2cef50ec	Update SpecialSource to 1.11.5 (#295 )	2025-03-11 10:37:32 -04:00
Jikoo	268e91007c	Fix array types In my defense, reading is really hard	2025-03-09 12:55:39 -04:00
Jikoo	f4ed616fb8	Consider any class name format valid This technically allows edge cases where the package (or class, for classes with no package) can start with L and be incorrectly matched, but that feels like a case of play stupid games, win stupid prizes. Classes should be packaged, and package names should be lower case. Requires a much less hacky change to JarMapping to optimize.	2025-03-09 10:34:18 -04:00
Jikoo	456909966f	Reduce remapping maintenance burden I don't think SpecialSource is likely to make major changes to JarMapping, but RemapperProcessor hasn't been changed in 4 years. This is less efficient in terms of lookup speed, but does not require the hacky JarMapping extension and doesn't require a second copy of the field mappings to be kept in memory.	2025-03-08 20:58:49 -05:00
Adam	51649bf2ab	Remap reflection (#294 ) * Hack around SpecialSource limitations with ProGuard mappings * Relocate PlanarWrappers * Use libs for shadow exclusion	2025-03-08 17:53:41 -05:00
Adam	e44697f856	Parse CurseForge MC versions from release body (#293 )	2025-03-07 20:04:17 +00:00
Adam	414b141b37	Improve Gradle build (#290 ) * Fix warnings about task not being cacheable * Add plugin to install Spigot * Explicitly cache BuildTools products * Move reobfuscation to a plugin * Update compilation instructions	2025-03-02 15:55:00 +00:00
Elmar (Cody) BlumeandR00tB33rMan	0db487c6eb	Add Folia support (#292 ) * feat(folia): added folia support * chore(folia): apply folia-supported: true label --------- Co-authored-by: R00tB33rMan <rootb33rman@gmail.com>	2025-02-18 22:26:34 -05:00
Jikoo	3b907e1b37	Bump version to 5.1.10-SNAPSHOT for development	2025-02-14 11:33:47 -05:00
Jikoo	d564773be6	Bump version to 5.1.9 for release	2025-02-14 11:33:31 -05:00
Adam	e834e940e2	Convert to precompiled task (#289 )	2025-02-14 01:02:24 -05:00
Jikoo	cd73430bb2	Try to resolve remote cache issues The weird part is that I don't have any of these problems locally. Remote is executing tasks in a really weird order, common adapter is building after Spigot adapter despite Spigot adapter depending on an output from it. May just have to disable caching, but would like to avoid that if possible.	2025-02-13 12:19:03 -05:00
Jikoo	1c1dc9505b	Bump version to 5.1.9-SNAPSHOT for development	2025-02-13 11:49:04 -05:00
Jikoo	1a76e6fd57	Bump version to 5.1.8 for release	2025-02-13 11:48:59 -05:00
Jikoo	48a61e6043	Update release script Now I can do things like have unstaged changes on the master branch when I cut a release! Not good!	2025-02-13 11:48:47 -05:00
Adam	4de2c2fe6d	Code health (#288 ) * Fix some missing nullity/deprecation annotations * Remove unnecessary Paper checks * Respect title changes from InventoryOpenEvent	2025-02-13 16:08:59 +00:00
Adam	e4fdd613ae	Expand support back to Paper 1.21.1 (#287 )	2025-02-12 13:01:53 +00:00
Jikoo	9f50de5dfe	Unify Spigot dependency version information declaration May be worth adding an entry for latest MC version that is shared between common Paper and current Spigot modules.	2025-02-11 10:44:25 -05:00
dependabot[bot]	e9d63f31ed	Bump com.gradleup.shadow from 8.3.5 to 8.3.6 (#285 )	2025-02-10 03:45:09 +00:00
Jikoo	73e003bde4	Update dependabot ecosystem	2025-02-09 22:40:28 -05:00
Jikoo	04ed652073	Bump version to 5.1.8-SNAPSHOT for development	2025-02-09 22:38:34 -05:00
Jikoo	49e408ee7a	Bump version to 5.1.7 for release	2025-02-09 22:38:13 -05:00
Jikoo	0df5e39a6d	Correct release notes Paper 1.21.3 requires changes to placeholders and is not currently supported.	2025-02-09 22:37:37 -05:00
Adam	7ab3e0c03f	Compile against Paper (#282 ) * Convert to Gradle * Reduce script usage * Simplify release process	2025-02-09 22:15:37 -05:00
dependabot[bot]	348fde9173	Bump org.jetbrains:annotations from 26.0.1 to 26.0.2 (#283 )	2025-02-01 17:35:05 +00:00
Jikoo	6c69350c30	Bump version to 5.1.7-SNAPSHOT for development	2025-01-18 13:58:16 -05:00
Jikoo	19eafddfac	Bump version to 5.1.6 for release	2025-01-18 13:57:48 -05:00
Adam	8a388b5620	Fix view-only ender chest (#278 ) Fixes access permissions being checked against self	2025-01-18 17:45:44 +00:00
Adam	206fff2c0a	Fix off-hand update relying on Spigot method (#277 )	2025-01-18 11:56:22 -05:00
Jikoo	6656e431b6	Bump version to 5.1.6-SNAPSHOT for development	2025-01-10 11:02:10 -05:00
Jikoo	f8df83b31d	Bump version to 5.1.5 for release	2025-01-10 11:01:37 -05:00
Jikoo	eb98bd79d3	Update release action	2025-01-10 11:01:18 -05:00
Adam	e948fdc011	Improve compatibility of view-only inventories (#273 )	2025-01-10 10:35:48 -05:00
Jikoo	f5c31c32d3	Correct edit other permission See discussion #266	2025-01-04 21:37:29 -05:00
dependabot[bot]	56f8cf4d71	Bump softprops/action-gh-release from 2.1.0 to 2.2.0 (#271 ) Bumps [softprops/action-gh-release](https://github.com/softprops/action-gh-release) from 2.1.0 to 2.2.0. - [Release notes](https://github.com/softprops/action-gh-release/releases) - [Changelog](https://github.com/softprops/action-gh-release/blob/master/CHANGELOG.md) - [Commits](https://github.com/softprops/action-gh-release/compare/v2.1.0...v2.2.0) --- updated-dependencies: - dependency-name: softprops/action-gh-release dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2025-01-01 13:11:50 -05:00
dependabot[bot]	7f1f6ccc82	Bump com.github.jikoo:planarwrappers from 3.2.3 to 3.3.0 (#270 )	2025-01-01 17:39:40 +00:00
Adam	9196ab3e61	Improve equal access (#269 ) * Respect deny equals mode if viewer cannot edit * Revert default mode to allow equals	2024-12-29 13:47:09 +00:00
Adam	0ac7575bad	Re-add rpack support for 1.21.3 (#264 ) * Re-add support for 1.21.3 to resource pack * Add pack icon	2024-12-14 13:18:44 -05:00
Jikoo	b0c7c8421e	Bump version to 5.1.5-SNAPSHOT for development	2024-12-08 20:09:37 -05:00
Jikoo	9b54e4e22e	Bump version to 5.1.4 for release	2024-12-08 20:08:52 -05:00
Adam	5ac09bc5a3	Add support for 1.21.4 (#262 ) * Add 1.21.4 adapter * Update resource pack to 1.21.4	2024-12-08 20:07:34 -05:00
Jikoo	4e89a04b36	Correct header	2024-12-02 00:26:07 -05:00
dependabot[bot]andJikoo	73a9c743a6	Bump com.google.errorprone:error_prone_core from 2.35.1 to 2.36.0 (#260 ) * Bump com.google.errorprone:error_prone_core from 2.35.1 to 2.36.0 Bumps [com.google.errorprone:error_prone_core](https://github.com/google/error-prone) from 2.35.1 to 2.36.0. - [Release notes](https://github.com/google/error-prone/releases) - [Commits](https://github.com/google/error-prone/compare/v2.35.1...v2.36.0) --- updated-dependencies: - dependency-name: com.google.errorprone:error_prone_core dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> * Add new required arg --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: Jikoo <jikoo.games@gmail.com>	2024-12-02 05:10:31 +00:00
dependabot[bot]	8d897664ef	Bump softprops/action-gh-release from 2.0.9 to 2.1.0 (#259 ) Bumps [softprops/action-gh-release](https://github.com/softprops/action-gh-release) from 2.0.9 to 2.1.0. - [Release notes](https://github.com/softprops/action-gh-release/releases) - [Changelog](https://github.com/softprops/action-gh-release/blob/master/CHANGELOG.md) - [Commits](https://github.com/softprops/action-gh-release/compare/v2.0.9...v2.1.0) --- updated-dependencies: - dependency-name: softprops/action-gh-release dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2024-12-01 12:27:53 -05:00
Christoffer Tibell	03ea798ee0	Add support for 1.21.3 to legibility pack (#258 )	2024-11-01 18:39:01 -04:00
dependabot[bot]	08d4a0ea27	Bump softprops/action-gh-release from 2.0.8 to 2.0.9 (#257 ) Bumps [softprops/action-gh-release](https://github.com/softprops/action-gh-release) from 2.0.8 to 2.0.9. - [Release notes](https://github.com/softprops/action-gh-release/releases) - [Changelog](https://github.com/softprops/action-gh-release/blob/master/CHANGELOG.md) - [Commits](https://github.com/softprops/action-gh-release/compare/v2.0.8...v2.0.9) --- updated-dependencies: - dependency-name: softprops/action-gh-release dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2024-11-01 18:38:06 -04:00
dependabot[bot]	cd7219f472	Bump com.google.errorprone:error_prone_core from 2.33.0 to 2.35.1 (#256 )	2024-11-01 17:18:22 +00:00
dependabot[bot]	532dffc068	Bump org.apache.maven.plugins:maven-dependency-plugin (#255 )	2024-11-01 17:17:31 +00:00
Jikoo	6df4de1dd3	Bump version to 5.1.4-SNAPSHOT for development	2024-10-29 10:53:32 -04:00