Updated to 6.24.4

This reverts commit 6361c0e8e9.

.github/workflows/checkstyle.yml

@@ -0,0 +1,15 @@
+name: Check PR Codestyle
+on: [ pull_request ]
+
+jobs:
+  checkstyle:
+    name: Checkstyle
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dbelyaev/action-checkstyle@v0.5.1
+        with:
+          github_token: ${{ secrets.github_token }}
+          reporter: github-pr-review
+          level: warning
+          checkstyle_config: ../../config/checkstyle/checkstyle.xml

.github/workflows/java-ci.yml

@@ -1,6 +1,6 @@
 name: Java CI
 
-on: [push]
+on: [ push, pull_request ]
 
 jobs:
   build:

.github/workflows/test-publish.yml

@@ -1,6 +1,6 @@
 name: Publish API (Dev)
 
-on: [push]
+on: [ push, pull_request ]
 
 jobs:
   publish-release:
@@ -39,4 +39,4 @@ jobs:
           NEW_VERSION=$(echo "${GITHUB_REF}" | cut -d "/" -f3)
           echo "New version: ${{ steps.vars.outputs.sha_short }}"
           echo "Github username: ${GITHUB_ACTOR}"
-          ./gradlew -Pversion=${{ steps.vars.outputs.sha_short }} publish
+          ./gradlew -Pversion=dev-${{ steps.vars.outputs.sha_short }} publish

CONTRIBUTING.md

@@ -1,24 +1,38 @@
 # How to contribute to eco
 
 ## Codestyle
+
 1. The eco checkstyle is in /config/checkstyle.xml
+
 - The pull request must not have any checkstyle issues.
 - Every method and field must have a javadoc attached.
 
 2. Use JetBrains annotations
+
 - Every parameter should be annotated with @NotNull or @Nullable
-- Use @NotNull over lombok @NonNull
 
 3. Imports
+
 - No group (*) imports.
 - No static imports.
 
+4. Kotlin
+
+- Kotlin should be the only language used in the backend, java should be the only language used in the frontend.
+- Kotlin API extensions should only be for creating extension functions and extra niceties that aren't possible in java.
+  Do not write API components in kotlin.
+- Kotlin code should never be called directly from the frontend Java API. Kotlin API extensions should always rely on
+  java, not the other way round.
+
 ## Dependency Injection
+
 - eco uses Dependency Injection
 - Any calls to Eco#getHandler#getEcoPlugin are code smells and should never be used unless **absolutely necessary**.
 - NamespacedKeys, FixedMetadataValues, Runnables, and Schedules should be managed using AbstractEcoPlugin through DI.
-- Any DI class should extend PluginDependent where possible. If the class extends another, then you **must** store the plugin instance in a private final variable called **plugin** with a private or protected getter.
+- Any DI class should extend PluginDependent where possible. If the class extends another, then you **must** store the
+  plugin instance in a private final variable called **plugin** with a private or protected getter.
 
 ## Other
+
 - All drops **must** be sent through a DropQueue - calls to World#dropItem will get your PR rejected.
 - eco is built with java 17.

build.gradle.kts

@@ -1,8 +1,19 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.10")
+    }
+}
+
 plugins {
     id("java-library")
-    id("com.github.johnrengelman.shadow") version "7.1.0"
+    id("com.github.johnrengelman.shadow") version "7.1.2"
     id("maven-publish")
     id("java")
+    kotlin("jvm") version "1.6.10"
 }
 
 dependencies {
@@ -20,6 +31,7 @@ allprojects {
     apply(plugin = "java-library")
     apply(plugin = "maven-publish")
     apply(plugin = "com.github.johnrengelman.shadow")
+    apply(plugin = "kotlin")
 
     repositories {
         mavenCentral()
@@ -73,10 +85,11 @@ allprojects {
     }
 
     dependencies {
+        compileOnly(kotlin("stdlib", version = "1.6.10"))
         compileOnly("org.jetbrains:annotations:23.0.0")
 
         // Test
-        testImplementation("org.junit.jupiter:junit-jupiter-api:5.8.1")
+        testImplementation("org.junit.jupiter:junit-jupiter-api:5.8.2")
         testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.8.2")
         
         // Adventure
@@ -104,6 +117,14 @@ allprojects {
     }
 
     tasks {
+        compileKotlin {
+            kotlinOptions {
+                jvmTarget = "17"
+            }
+            targetCompatibility = "17"
+            sourceCompatibility = "17"
+        }
+
         shadowJar {
             relocate("org.bstats", "com.willfp.eco.shaded.bstats")
             relocate("net.kyori.adventure.text.minimessage", "com.willfp.eco.shaded.minimessage")

config/checkstyle/checkstyle.xml

@@ -32,10 +32,6 @@
 -->
 
 <module name="Checker">
-    <module name="SuppressionFilter">
-        <property name="file" value="config/checkstyle/suppression.xml"/>
-    </module>
-
     <!--
         If you set the basedir property below, then all reported file
         names will be relative to the specified directory. See

config/checkstyle/suppression.xml

@@ -1,24 +0,0 @@
-<?xml version="1.0"?>
-
-<!DOCTYPE suppressions PUBLIC
-        "-//Puppy Crawl//DTD Suppressions 1.1//EN"
-        "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
-
-<suppressions>
-    <!-- Internals don't need javadoc. -->
-    <suppress files="[\\/]internal[\\/]" checks="MissingJavadocMethod"/>
-    <suppress files="[\\/]internal[\\/]" checks="JavadocVariable"/>
-    <suppress files="[\\/]eco[\\/]spigot[\\/]" checks="MissingJavadocMethod"/>
-    <suppress files="[\\/]eco[\\/]spigot[\\/]" checks="JavadocVariable"/>
-    <suppress files="[\\/]eco[\\/]proxy[\\/]" checks="MissingJavadocMethod"/>
-    <suppress files="[\\/]eco[\\/]proxy[\\/]" checks="JavadocVariable"/>
-
-    <!-- Modified version of library -->
-    <suppress files="ArmorEquipEvent.java" checks="JavadocVariable"/>
-    <suppress files="ArmorEquipEvent.java" checks="MissingJavadocMethod"/>
-    <suppress files="ArmorEquipEvent.java" checks="JavadocStyle"/>
-    <suppress files="ArmorListener.java" checks="JavadocVariable"/>
-    <suppress files="ArmorListener.java" checks="MissingJavadocMethod"/>
-    <suppress files="ArmorType.java" checks="JavadocVariable"/>
-    <suppress files="ArmorType.java" checks="MissingJavadocMethod"/>
-</suppressions>

eco-api/build.gradle

@@ -1,19 +1,4 @@
-buildscript {
-    repositories {
-        mavenCentral()
-    }
-
-    dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.0"
-    }
-}
-
-apply plugin: 'kotlin'
-
 dependencies {
-    // Kotlin
-    compileOnly 'org.jetbrains.kotlin:kotlin-stdlib:1.6.0'
-
     // Adventure
     compileOnly 'net.kyori:adventure-platform-bukkit:4.0.0'
     compileOnly 'net.kyori:adventure-text-minimessage:4.1.0-SNAPSHOT'
@@ -25,18 +10,6 @@ dependencies {
     compileOnly 'com.google.code.gson:gson:2.8.8'
 }
 
-compileKotlin {
-    kotlinOptions {
-        jvmTarget = "17"
-    }
-    targetCompatibility = JavaVersion.VERSION_17
-    sourceCompatibility = JavaVersion.VERSION_17
-}
-
-java {
-    withJavadocJar()
-}
-
 group 'com.willfp'
 version rootProject.version
 

eco-api/src/main/java/com/willfp/eco/core/EcoPlugin.java

@@ -152,10 +152,14 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
     private final ProxyFactory proxyFactory;
 
     /**
-     * Create a new plugin without a specified color, proxy support, polymart, or bStats.
+     * Create a new plugin.
+     * <p>
+     * Will read from eco.yml (like plugin.yml) to fetch values that would otherwise be passed
+     * into the constructor. If no eco.yml is present, the plugin will load without extension
+     * support, without proxy support, with no update-checker or bStats, and with the color white.
      */
     protected EcoPlugin() {
-        this("&f");
+        this((PluginProps) null);
     }
 
     /**
@@ -236,6 +240,23 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
                         @NotNull final String proxyPackage,
                         @NotNull final String color,
                         final boolean supportingExtensions) {
+        this(
+                PluginProps.createSimple(
+                        resourceId,
+                        bStatsId,
+                        proxyPackage,
+                        color,
+                        supportingExtensions
+                )
+        );
+    }
+
+    /**
+     * Create a new plugin.
+     *
+     * @param pluginProps The props. If left null, it will read from eco.yml.
+     */
+    protected EcoPlugin(@Nullable final PluginProps pluginProps) {
         /*
         The handler must be initialized before any plugin's constructors
         are called, as the constructors call Eco#getHandler().
@@ -253,15 +274,15 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
         a standalone handler class, but then there would be an interface
         left in the API that doesn't really help anything.
 
-        The other alternative would be do use reflection to get a 'createHandler'
+        The other alternative would be to use reflection to get a 'createHandler'
-        method that only exists in EcoSpigotPlugin - but that feels really dirty
+        method that only exists in EcoSpigotPlugin - but that feels filthy,
         and I'd rather only use reflection where necessary.
         */
 
         if (Eco.getHandler() == null && this instanceof Handler) {
             /*
             This code is only ever called by EcoSpigotPlugin (EcoHandler)
-            as it's the first plugin to load and it is a handler.
+            as it's the first plugin to load, and it is a handler.
 
             Any other plugins will never call this code as the handler
             will have already been initialized.
@@ -272,11 +293,16 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
 
         assert Eco.getHandler() != null;
 
-        this.resourceId = resourceId;
+        PluginProps generatedProps = Eco.getHandler().getProps(pluginProps, this.getClass());
-        this.bStatsId = bStatsId;
+        generatedProps.validate();
-        this.proxyPackage = proxyPackage;
+        PluginProps props = this.mutateProps(generatedProps);
-        this.color = color;
+        props.validate();
-        this.supportingExtensions = supportingExtensions;
+
+        this.resourceId = props.getResourceId();
+        this.bStatsId = props.getBStatsId();
+        this.proxyPackage = props.getProxyPackage();
+        this.color = props.getColor();
+        this.supportingExtensions = props.isSupportingExtensions();
 
         this.scheduler = Eco.getHandler().createScheduler(this);
         this.eventManager = Eco.getHandler().createEventManager(this);
@@ -296,8 +322,8 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
         /*
         The minimum eco version check was moved here because it's very common
         to add a lot of code in the constructor of plugins; meaning that the plugin
-        can throw errors without it being obvious to the user that the reason is
+        can throw errors without it being obvious to the user that the reason is that
-        because they have an outdated version of eco installed.
+        they have an outdated version of eco installed.
          */
 
         DefaultArtifactVersion runningVersion = new DefaultArtifactVersion(Eco.getHandler().getEcoPlugin().getDescription().getVersion());
@@ -534,6 +560,21 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
 
     }
 
+    /**
+     * Mutate the plugin props.
+     * <p>
+     * Useful for eco-based plugin libraries to enforce certain properties, such as
+     * forcing extensions to be enabled.
+     * <p>
+     * Props are validated both before and after calling this method.
+     *
+     * @param props The props.
+     * @return The mutated props.
+     */
+    protected PluginProps mutateProps(@NotNull final PluginProps props) {
+        return props;
+    }
+
     /**
      * The plugin-specific integrations to be tested and loaded.
      *
@@ -635,7 +676,7 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
      * @return The proxy.
      */
     public final <T> T getProxy(@NotNull final Class<T> proxyClass) {
-        Validate.notNull(proxyFactory, "Plugin does not support proxy!");
+        Validate.notNull(proxyFactory, "Plugin does not support proxies!");
 
         return proxyFactory.getProxy(proxyClass);
     }

eco-api/src/main/java/com/willfp/eco/core/Handler.java

@@ -15,7 +15,6 @@ import com.willfp.eco.core.gui.GUIFactory;
 import com.willfp.eco.core.integrations.placeholder.PlaceholderIntegration;
 import com.willfp.eco.core.proxy.Cleaner;
 import com.willfp.eco.core.proxy.ProxyFactory;
-import com.willfp.eco.core.requirement.RequirementFactory;
 import com.willfp.eco.core.scheduling.Scheduler;
 import net.kyori.adventure.platform.bukkit.BukkitAudiences;
 import org.bukkit.Location;
@@ -33,6 +32,7 @@ import java.util.logging.Logger;
  * @see Eco#getHandler()
  */
 @ApiStatus.Internal
+@SuppressWarnings("removal")
 public interface Handler {
     /**
      * Create a scheduler.
@@ -210,7 +210,8 @@ public interface Handler {
      * @return The factory.
      */
     @NotNull
-    RequirementFactory getRequirementFactory();
+    @Deprecated(forRemoval = true)
+    com.willfp.eco.core.requirement.RequirementFactory getRequirementFactory();
 
     /**
      * Get Adventure audiences.
@@ -259,4 +260,15 @@ public interface Handler {
     @NotNull
     NamespacedKey createNamespacedKey(@NotNull String namespace,
                                       @NotNull String key);
+
+    /**
+     * Return or get props for a plugin.
+     *
+     * @param existing The existing constructor props.
+     * @param plugin   The plugin.
+     * @return The props.
+     */
+    @NotNull
+    PluginProps getProps(@Nullable PluginProps existing,
+                         @NotNull Class<? extends EcoPlugin> plugin);
 }

eco-api/src/main/java/com/willfp/eco/core/PluginProps.java

@@ -0,0 +1,275 @@
+package com.willfp.eco.core;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Plugin props are the arguments related to the plugin that are required on start-up.
+ * <p>
+ * This class is complex in how it works intentionally. This is done so that fields can be
+ * added to the props without breaking API backwards compatibility. Thus, there is no public
+ * constructor and no way to instantiate props without creating a parser.
+ */
+public final class PluginProps {
+    /**
+     * All registered parsers.
+     */
+    private static final Map<Class<?>, PropsParser<?>> REGISTERED_PARSERS = new HashMap<>();
+
+    /**
+     * The polymart resource ID.
+     */
+    @Nullable
+    private Integer resourceId;
+
+    /**
+     * The bStats ID.
+     */
+    @Nullable
+    private Integer bStatsId;
+
+    /**
+     * The proxy package.
+     */
+    @Nullable
+    private String proxyPackage;
+
+    /**
+     * The color.
+     */
+    @Nullable
+    private String color;
+
+    /**
+     * If extensions are supported.
+     */
+    @Nullable
+    private Boolean supportingExtensions;
+
+    /**
+     * Create new blank props.
+     */
+    private PluginProps() {
+
+    }
+
+    /**
+     * Get resource ID.
+     *
+     * @return The resource ID.
+     */
+    public int getResourceId() {
+        assert resourceId != null;
+        return resourceId;
+    }
+
+    /**
+     * Set resource ID.
+     *
+     * @param resourceId The resource ID.
+     */
+    public void setResourceId(final int resourceId) {
+        this.resourceId = resourceId;
+    }
+
+    /**
+     * Get bStats ID.
+     *
+     * @return The bStats ID.
+     */
+    public int getBStatsId() {
+        assert bStatsId != null;
+        return bStatsId;
+    }
+
+    /**
+     * Set bStats ID.
+     *
+     * @param bStatsId The bStats ID.
+     */
+    public void setBStatsId(final int bStatsId) {
+        this.bStatsId = bStatsId;
+    }
+
+    /**
+     * Get the proxy package.
+     *
+     * @return The package.
+     */
+    @NotNull
+    public String getProxyPackage() {
+        assert proxyPackage != null;
+        return proxyPackage;
+    }
+
+    /**
+     * Set the proxy package.
+     *
+     * @param proxyPackage The proxy package.
+     */
+    public void setProxyPackage(@NotNull final String proxyPackage) {
+        this.proxyPackage = proxyPackage;
+    }
+
+    /**
+     * Get color.
+     *
+     * @return The color.
+     */
+    @NotNull
+    public String getColor() {
+        assert color != null;
+        return color;
+    }
+
+    /**
+     * Set the color.
+     *
+     * @param color The color.
+     */
+    public void setColor(@NotNull final String color) {
+        this.color = color;
+    }
+
+    /**
+     * Get if extensions are supported.
+     *
+     * @return If supported.
+     */
+    public boolean isSupportingExtensions() {
+        assert supportingExtensions != null;
+        return supportingExtensions;
+    }
+
+    /**
+     * Set if extensions are supported.
+     *
+     * @param supportingExtensions If supported.
+     */
+    public void setSupportingExtensions(final boolean supportingExtensions) {
+        this.supportingExtensions = supportingExtensions;
+    }
+
+    /**
+     * Ensure that all required props have been set.
+     */
+    public void validate() {
+        if (
+                supportingExtensions == null
+                        || proxyPackage == null
+                        || color == null
+                        || bStatsId == null
+                        || resourceId == null
+        ) {
+            throw new IllegalStateException("Missing required props!");
+        }
+    }
+
+    /**
+     * Parse props from source.
+     *
+     * @param source      The source.
+     * @param sourceClass The source class.
+     * @param <T>         The source type.
+     * @return The props.
+     */
+    public static <T> PluginProps parse(@NotNull final T source,
+                                        @NotNull final Class<? extends T> sourceClass) {
+        for (Map.Entry<Class<?>, PropsParser<?>> entry : REGISTERED_PARSERS.entrySet()) {
+            Class<?> clazz = entry.getKey();
+
+            if (clazz.equals(sourceClass)) {
+                @SuppressWarnings("unchecked")
+                PropsParser<T> parser = (PropsParser<T>) entry.getValue();
+                return parser.parseFrom(source);
+            }
+        }
+
+        throw new IllegalArgumentException("No parser exists for class " + sourceClass);
+    }
+
+    /**
+     * Register a parser for a type.
+     *
+     * @param clazz  The class.
+     * @param parser The parser.
+     * @param <T>    The source type.
+     */
+    public static <T> void registerParser(@NotNull final Class<T> clazz,
+                                          @NotNull final PropsParser<T> parser) {
+        REGISTERED_PARSERS.put(clazz, parser);
+    }
+
+    /**
+     * Get if there is a registered parser for a class.
+     *
+     * @param clazz The class.
+     * @return If there is a parser registered.
+     */
+    public static boolean hasParserFor(@NotNull final Class<?> clazz) {
+        for (Class<?> test : REGISTERED_PARSERS.keySet()) {
+            if (test.equals(clazz)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Create new props from known values.
+     *
+     * Marked as internal as this method will break whenever the properties themselves
+     * are updated (e.g. if a new property is added) - so to prevent any potential
+     * backwards-compatibility bugs, this method cannot be invoked outside eco itself.
+     *
+     * @param resourceId         The ID of the plugin on polymart.
+     * @param bStatsId           The ID of the plugin on bStats.
+     * @param proxyPackage       The package where proxies can be found.
+     * @param color              The primary color of the plugin.
+     * @param supportsExtensions If the plugin should attempt to look for extensions.
+     * @return The props.
+     */
+    @ApiStatus.Internal
+    static PluginProps createSimple(final int resourceId,
+                                    final int bStatsId,
+                                    @NotNull final String proxyPackage,
+                                    @NotNull final String color,
+                                    final boolean supportsExtensions) {
+        PluginProps props = new PluginProps();
+        props.setResourceId(resourceId);
+        props.setBStatsId(bStatsId);
+        props.setProxyPackage(proxyPackage);
+        props.setColor(color);
+        props.setSupportingExtensions(supportsExtensions);
+        return props;
+    }
+
+    /**
+     * Parse arguments into props for a plugin.
+     *
+     * @param <T> The type of source.
+     */
+    public interface PropsParser<T> {
+        /**
+         * Parse props from a given source.
+         *
+         * @param source The source.
+         * @return The props.
+         */
+        PluginProps parseFrom(@NotNull T source);
+
+        /**
+         * Get a new, blank props instance.
+         *
+         * @return Blank props.
+         */
+        default PluginProps getBlankProps() {
+            return new PluginProps();
+        }
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/command/CommandBase.java

@@ -1,5 +1,6 @@
 package com.willfp.eco.core.command;
 
+import com.willfp.eco.core.EcoPlugin;
 import org.bukkit.command.CommandSender;
 import org.jetbrains.annotations.NotNull;
 
@@ -66,6 +67,13 @@ public interface CommandBase {
         return new ArrayList<>();
     }
 
+    /**
+     * Get the plugin.
+     *
+     * @return The plugin.
+     */
+    EcoPlugin getPlugin();
+
     /**
      * Get the handler.
      *

eco-api/src/main/java/com/willfp/eco/core/command/impl/HandledCommand.java

@@ -1,7 +1,6 @@
 package com.willfp.eco.core.command.impl;
 
 import com.willfp.eco.core.EcoPlugin;
-import com.willfp.eco.core.PluginDependent;
 import com.willfp.eco.core.command.CommandBase;
 import com.willfp.eco.core.command.CommandHandler;
 import com.willfp.eco.core.command.TabCompleteHandler;
@@ -25,7 +24,12 @@ import java.util.stream.Collectors;
  * layer, hence why it's a package-private class.
  */
 @SuppressWarnings({"DeprecatedIsStillUsed"})
-abstract class HandledCommand extends PluginDependent<EcoPlugin> implements CommandBase {
+abstract class HandledCommand implements CommandBase {
+    /**
+     * The plugin.
+     */
+    private final EcoPlugin plugin;
+
     /**
      * The name of the command.
      */
@@ -78,7 +82,7 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
                    @NotNull final String name,
                    @NotNull final String permission,
                    final boolean playersOnly) {
-        super(plugin);
+        this.plugin = plugin;
         this.name = name;
         this.permission = permission;
         this.playersOnly = playersOnly;
@@ -98,6 +102,16 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
         return this;
     }
 
+    /**
+     * Get the plugin.
+     *
+     * @return The plugin.
+     */
+    @Override
+    public EcoPlugin getPlugin() {
+        return this.plugin;
+    }
+
     /**
      * Handle the command.
      *
@@ -124,6 +138,11 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
             }
         }
 
+        if (this.isPlayersOnly() && !(sender instanceof Player)) {
+            sender.sendMessage(this.getPlugin().getLangYml().getMessage("not-player"));
+            return;
+        }
+
         if (this.getHandler() != null) {
             this.getHandler().onExecute(sender, Arrays.asList(args));
         } else {
@@ -193,11 +212,6 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
     public static boolean canExecute(@NotNull final CommandSender sender,
                                      @NotNull final CommandBase command,
                                      @NotNull final EcoPlugin plugin) {
-        if (command.isPlayersOnly() && !(sender instanceof Player)) {
-            sender.sendMessage(plugin.getLangYml().getMessage("not-player"));
-            return false;
-        }
-
         if (!sender.hasPermission(command.getPermission()) && sender instanceof Player) {
             sender.sendMessage(plugin.getLangYml().getNoPermission());
             return false;

eco-api/src/main/java/com/willfp/eco/core/config/TransientConfig.java

@@ -5,7 +5,10 @@ import com.willfp.eco.core.config.interfaces.Config;
 import com.willfp.eco.core.config.wrapper.ConfigWrapper;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.util.Map;
 
 /**
@@ -21,6 +24,15 @@ public class TransientConfig extends ConfigWrapper<Config> {
         super(Eco.getHandler().getConfigFactory().createConfig(config));
     }
 
+    /**
+     * @param stream The InputStream.
+     */
+    public TransientConfig(@Nullable final InputStream stream) {
+        super(stream != null ? Eco.getHandler().getConfigFactory().createConfig(YamlConfiguration.loadConfiguration(
+                new InputStreamReader(stream)
+        )) : new TransientConfig());
+    }
+
     /**
      * Create a new empty transient config.
      *

eco-api/src/main/java/com/willfp/eco/core/config/interfaces/Config.java

@@ -235,7 +235,7 @@ public interface Config extends Cloneable {
      */
     @NotNull
     default String getString(@NotNull String path) {
-        return getString(path, false);
+        return getString(path, false, StringUtils.FormatOption.WITHOUT_PLACEHOLDERS);
     }
 
     /**

eco-api/src/main/java/com/willfp/eco/core/fast/FastItemStack.java

@@ -22,8 +22,30 @@ public interface FastItemStack {
      *
      * @param checkStored If stored NBT should also be checked.
      * @return A map of all enchantments.
+     * @deprecated Poorly named method. Use getEnchants instead.
      */
-    Map<Enchantment, Integer> getEnchantmentsOnItem(boolean checkStored);
+    @Deprecated(since = "6.24.0")
+    default Map<Enchantment, Integer> getEnchantmentsOnItem(boolean checkStored) {
+        return getEnchants(checkStored);
+    }
+
+    /**
+     * Get all enchantments on an item.
+     * Does not account for stored enchants.
+     *
+     * @return A map of all enchantments.
+     */
+    default Map<Enchantment, Integer> getEnchants() {
+        return getEnchants(false);
+    }
+
+    /**
+     * Get all enchantments on an item.
+     *
+     * @param checkStored If stored enchantments should be accounted for.
+     * @return A map of all enchantments.
+     */
+    Map<Enchantment, Integer> getEnchants(boolean checkStored);
 
     /**
      * Get the level of an enchantment on an item.

eco-api/src/main/java/com/willfp/eco/core/gui/slot/FillerMask.java

@@ -1,6 +1,8 @@
 package com.willfp.eco.core.gui.slot;
 
 import com.willfp.eco.core.items.builder.ItemStackBuilder;
+import com.willfp.eco.core.recipe.parts.EmptyTestableItem;
+import com.willfp.eco.core.recipe.parts.MaterialTestableItem;
 import com.willfp.eco.util.ListUtils;
 import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
@@ -38,7 +40,7 @@ public class FillerMask {
      */
     public FillerMask(@NotNull final Material material,
                       @NotNull final String... pattern) {
-        this(new MaskMaterials(material), pattern);
+        this(new MaskItems(new MaterialTestableItem(material)), pattern);
     }
 
     /**
@@ -46,17 +48,33 @@ public class FillerMask {
      *
      * @param materials The mask materials.
      * @param pattern   The pattern.
+     * @deprecated Use {@link MaskItems} instead.
      */
+    @Deprecated(since = "6.24.0")
     public FillerMask(@NotNull final MaskMaterials materials,
                       @NotNull final String... pattern) {
-        if (Arrays.stream(materials.materials()).anyMatch(material -> material == Material.AIR)) {
+        this(
-            throw new IllegalArgumentException("Materials cannot be air!");
+                materials.toMaskItems(),
+                pattern
+        );
+    }
+
+    /**
+     * Create a new filler mask.
+     *
+     * @param items   The mask items.
+     * @param pattern The pattern.
+     */
+    public FillerMask(@NotNull final MaskItems items,
+                      @NotNull final String... pattern) {
+        if (Arrays.stream(items.items()).anyMatch(item -> item instanceof EmptyTestableItem)) {
+            throw new IllegalArgumentException("Items cannot be empty!");
         }
 
         mask = ListUtils.create2DList(6, 9);
 
-        for (int i = 0; i < materials.materials().length; i++) {
+        for (int i = 0; i < items.items().length; i++) {
-            ItemStack itemStack = new ItemStackBuilder(materials.materials()[i])
+            ItemStack itemStack = new ItemStackBuilder(items.items()[i])
                     .setDisplayName("&r")
                     .build();
 

eco-api/src/main/java/com/willfp/eco/core/gui/slot/MaskItems.java

@@ -0,0 +1,45 @@
+package com.willfp.eco.core.gui.slot;
+
+import com.willfp.eco.core.items.Items;
+import com.willfp.eco.core.items.TestableItem;
+import com.willfp.eco.core.recipe.parts.EmptyTestableItem;
+import com.willfp.eco.core.recipe.parts.MaterialTestableItem;
+import org.bukkit.Material;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Mask materials store a set of items which can be accessed by
+ * a filler mask.
+ *
+ * @param items The items.
+ */
+public record MaskItems(@NotNull TestableItem... items) {
+    /**
+     * Create MaskItems from a list of item names.
+     *
+     * @param names The names.
+     * @return The mask items.
+     */
+    public static MaskItems fromItemNames(@NotNull final Iterable<String> names) {
+        List<TestableItem> items = new ArrayList<>();
+
+        for (String name : names) {
+            TestableItem item = Items.lookup(name);
+
+            if (item instanceof EmptyTestableItem) {
+                continue;
+            }
+
+            items.add(item);
+        }
+
+        if (items.isEmpty()) {
+            return new MaskItems(new MaterialTestableItem(Material.BLACK_STAINED_GLASS_PANE));
+        }
+
+        return new MaskItems(items.toArray(new TestableItem[0]));
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/MaskMaterials.java

@@ -1,5 +1,6 @@
 package com.willfp.eco.core.gui.slot;
 
+import com.willfp.eco.core.items.Items;
 import org.bukkit.Material;
 import org.jetbrains.annotations.NotNull;
 
@@ -8,7 +9,16 @@ import org.jetbrains.annotations.NotNull;
  * a filler mask.
  *
  * @param materials The materials.
+ * @deprecated Use {@link MaskItems} instead.
  */
+@Deprecated(since = "6.24.0")
 public record MaskMaterials(@NotNull Material... materials) {
-
+    /**
+     * Convert MaskMaterials to MaskItems.
+     *
+     * @return The MaskItems.
+     */
+    public MaskItems toMaskItems() {
+        return new MaskItems(Items.fromMaterials(this.materials()));
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/gui/slot/SlotBuilder.java

@@ -2,6 +2,7 @@ package com.willfp.eco.core.gui.slot;
 
 import com.willfp.eco.core.gui.slot.functional.SlotHandler;
 import com.willfp.eco.core.gui.slot.functional.SlotModifier;
+import com.willfp.eco.core.gui.slot.functional.SlotUpdater;
 import org.bukkit.event.inventory.InventoryClickEvent;
 import org.jetbrains.annotations.NotNull;
 
@@ -106,8 +107,23 @@ public interface SlotBuilder {
      *
      * @param modifier The modifier.
      * @return The builder.
+     * @deprecated Use {@link SlotBuilder#setUpdater(SlotUpdater)} instead.
      */
-    SlotBuilder setModifier(@NotNull SlotModifier modifier);
+    @Deprecated
+    default SlotBuilder setModifier(@NotNull SlotModifier modifier) {
+        return setUpdater((player, menu, previous) -> {
+            modifier.modify(player, menu, previous);
+            return previous;
+        });
+    }
+
+    /**
+     * Set the ItemStack updater.
+     *
+     * @param updater The updater.
+     * @return The builder.
+     */
+    SlotBuilder setUpdater(@NotNull SlotUpdater updater);
 
     /**
      * Set slot to be a captive slot.

eco-api/src/main/java/com/willfp/eco/core/gui/slot/functional/SlotModifier.java

@@ -7,8 +7,11 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Interface to run on slot modify.
+ *
+ * @deprecated Use {@link SlotUpdater} instead.
  */
 @FunctionalInterface
+@Deprecated
 public interface SlotModifier {
     /**
      * Performs this operation on the given arguments.

eco-api/src/main/java/com/willfp/eco/core/gui/slot/functional/SlotUpdater.java

@@ -0,0 +1,24 @@
+package com.willfp.eco.core.gui.slot.functional;
+
+import com.willfp.eco.core.gui.menu.Menu;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Interface to run on slot update.
+ */
+@FunctionalInterface
+public interface SlotUpdater {
+    /**
+     * Performs this operation on the given arguments.
+     *
+     * @param player   The player.
+     * @param menu     The menu.
+     * @param previous The previous ItemStack.
+     * @return The new ItemStack.
+     */
+    ItemStack update(@NotNull Player player,
+                     @NotNull Menu menu,
+                     @NotNull ItemStack previous);
+}

eco-api/src/main/java/com/willfp/eco/core/items/Items.java

@@ -20,6 +20,7 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -344,6 +345,35 @@ public final class Items {
         }
     }
 
+    /**
+     * Convert an array of materials to an array of testable items.
+     *
+     * @param materials The materials.
+     * @return An array of functionally identical testable items.
+     */
+    @NotNull
+    public static TestableItem[] fromMaterials(@NotNull final Material... materials) {
+        return Arrays.stream(materials)
+                .map(MaterialTestableItem::new)
+                .toArray(MaterialTestableItem[]::new);
+    }
+
+    /**
+     * Convert a collection of materials into a collection of testable items.
+     *
+     * @param materials The materials.
+     * @return A collection of functionally identical testable items.
+     */
+    @NotNull
+    public static Collection<TestableItem> fromMaterials(@NotNull final Iterable<Material> materials) {
+        List<TestableItem> items = new ArrayList<>();
+        for (Material material : materials) {
+            items.add(new MaterialTestableItem(material));
+        }
+
+        return items;
+    }
+
     private Items() {
         throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
     }

eco-api/src/main/java/com/willfp/eco/core/proxy/exceptions/ProxyError.java

@@ -5,12 +5,25 @@ import org.jetbrains.annotations.NotNull;
 /**
  * Generic error with proxy loading.
  */
-public class ProxyError extends RuntimeException {
+public class ProxyError extends Error {
     /**
      * Thrown if there is an error getting a proxy.
      *
      * @param message The message to send.
+     * @param cause   The cause.
      */
+    public ProxyError(@NotNull final String message,
+                      @NotNull final Throwable cause) {
+        super(message, cause);
+    }
+
+    /**
+     * Thrown if there is an error getting a proxy.
+     *
+     * @param message The message to send.
+     * @deprecated Proxy Errors should include a cause.
+     */
+    @Deprecated
     public ProxyError(@NotNull final String message) {
         super(message);
     }

eco-api/src/main/java/com/willfp/eco/core/proxy/exceptions/UnsupportedVersionError.java

@@ -0,0 +1,15 @@
+package com.willfp.eco.core.proxy.exceptions;
+
+import com.willfp.eco.core.proxy.ProxyConstants;
+
+/**
+ * Server running an unsupported version.
+ */
+public class UnsupportedVersionError extends Error {
+    /**
+     * Thrown if the server is running an unsupported version.
+     */
+    public UnsupportedVersionError() {
+        super("You're running an unsupported server version: " + ProxyConstants.NMS_VERSION);
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/proxy/exceptions/UnsupportedVersionException.java

@@ -1,17 +1,30 @@
 package com.willfp.eco.core.proxy.exceptions;
 
+import com.willfp.eco.core.proxy.ProxyConstants;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Error if the server is running an unsupported version.
+ *
+ * @deprecated Poorly named, exception when it's actually an error, contains doubly nested errors.
  */
+@Deprecated(since = "6.24.0", forRemoval = true)
 public class UnsupportedVersionException extends ProxyError {
     /**
      * Thrown if the server is running an unsupported NMS version.
      *
      * @param message The message to send.
+     * @deprecated Use the default constructor.
      */
+    @Deprecated(since = "6.24.0")
     public UnsupportedVersionException(@NotNull final String message) {
         super(message);
     }
+
+    /**
+     * Thrown if the server is running an unsupported NMS version.
+     */
+    public UnsupportedVersionException() {
+        super("You're running an unsupported server version: " + ProxyConstants.NMS_VERSION, new IllegalStateException());
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/recipe/Recipes.java

@@ -18,7 +18,6 @@ import java.util.List;
 /**
  * Utility class to manage and register crafting recipes.
  */
-@SuppressWarnings("deprecation")
 public final class Recipes {
     /**
      * Registry of all recipes.

eco-api/src/main/java/com/willfp/eco/core/recipe/recipes/ShapedCraftingRecipe.java

@@ -294,7 +294,7 @@ public final class ShapedCraftingRecipe extends PluginDependent<EcoPlugin> imple
          */
         public boolean isAir() {
             for (TestableItem recipePart : this.recipeParts) {
-                if (recipePart!= null && !(recipePart instanceof EmptyTestableItem)) {
+                if (recipePart != null && !(recipePart instanceof EmptyTestableItem)) {
                     return false;
                 }
             }

eco-api/src/main/java/com/willfp/eco/core/requirement/Requirement.java

@@ -7,7 +7,11 @@ import java.util.List;
 
 /**
  * A requirement is a defined goal that a player must meet.
+ *
+ * @deprecated No typing, weak definitions, and not an API component. Shouldn't be in eco.
  */
+@Deprecated(since = "6.24.0", forRemoval = true)
+@SuppressWarnings("DeprecatedIsStillUsed")
 public abstract class Requirement {
     /**
      * Create a new requirement.

eco-api/src/main/java/com/willfp/eco/core/requirement/RequirementFactory.java

@@ -6,9 +6,13 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Interface for internal requirement factory implementations.
+ *
+ * @deprecated See {@link Requirement}.
  */
 @ApiStatus.Internal
 @Eco.HandlerComponent
+@Deprecated(since = "6.24.0", forRemoval = true)
+@SuppressWarnings({"removal", "DeprecatedIsStillUsed"})
 public interface RequirementFactory {
     /**
      * Create a requirement.

eco-api/src/main/java/com/willfp/eco/core/requirement/Requirements.java

@@ -5,7 +5,11 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Contains methods and fields pertaining to requirements.
+ *
+ * @deprecated See {@link Requirement}.
  */
+@Deprecated(since = "6.24.0", forRemoval = true)
+@SuppressWarnings("removal")
 public final class Requirements {
     /**
      * Requires a player to have a permission.

eco-api/src/main/java/com/willfp/eco/util/DurabilityUtils.java

@@ -26,11 +26,26 @@ public final class DurabilityUtils {
      * @param item   The item to damage.
      * @param damage The amount of damage to deal.
      * @param slot   The slot in the inventory of the item.
+     * @deprecated The slot is not required.
      */
+    @Deprecated(since = "6.24.0")
     public static void damageItem(@NotNull final Player player,
                                   @NotNull final ItemStack item,
                                   final int damage,
                                   final int slot) {
+        damageItem(player, item, damage);
+    }
+
+    /**
+     * Damage an item in a player's inventory.
+     *
+     * @param player The player.
+     * @param item   The item to damage.
+     * @param damage The amount of damage to deal.
+     */
+    public static void damageItem(@NotNull final Player player,
+                                  @NotNull final ItemStack item,
+                                  final int damage) {
         if (item.getItemMeta() == null) {
             return;
         }
@@ -61,7 +76,7 @@ public final class DurabilityUtils {
                 item.setItemMeta((ItemMeta) meta);
                 PlayerItemBreakEvent event = new PlayerItemBreakEvent(player, item);
                 Bukkit.getPluginManager().callEvent(event);
-                player.getInventory().clear(slot);
+                item.setType(Material.AIR);
                 player.playSound(player.getLocation(), Sound.ENTITY_ITEM_BREAK, SoundCategory.BLOCKS, 1, 1);
             } else {
                 item.setItemMeta((ItemMeta) meta);
@@ -69,6 +84,44 @@ public final class DurabilityUtils {
         }
     }
 
+    /**
+     * Damage an item.
+     *
+     * @param item   The item to damage.
+     * @param damage The amount of damage to deal.
+     */
+    public static void damageItem(@NotNull final ItemStack item,
+                                  final int damage) {
+        if (item.getItemMeta() == null) {
+            return;
+        }
+
+        if (item.getItemMeta().isUnbreakable()) {
+            return;
+        }
+
+        if (!(item.getItemMeta() instanceof Damageable)) {
+            return;
+        }
+
+        // Special edge case
+        if (item.getType() == Material.CARVED_PUMPKIN || item.getType() == Material.PLAYER_HEAD) {
+            return;
+        }
+
+
+        Damageable meta = (Damageable) item.getItemMeta();
+        meta.setDamage(meta.getDamage() + damage);
+
+        if (meta.getDamage() >= item.getType().getMaxDurability()) {
+            meta.setDamage(item.getType().getMaxDurability());
+            item.setItemMeta((ItemMeta) meta);
+            item.setType(Material.AIR);
+        } else {
+            item.setItemMeta((ItemMeta) meta);
+        }
+    }
+
     /**
      * Damage an item in a player's inventory without breaking it.
      *

eco-api/src/main/java/com/willfp/eco/util/NamespacedKeyUtils.java

@@ -3,6 +3,9 @@ package com.willfp.eco.util;
 import com.willfp.eco.core.Eco;
 import org.bukkit.NamespacedKey;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Objects;
 
 /**
  * Utilities / API methods for {@link NamespacedKey}s.
@@ -45,8 +48,25 @@ public final class NamespacedKeyUtils {
      */
     @NotNull
     public static NamespacedKey fromString(@NotNull final String string) {
+        return Objects.requireNonNull(NamespacedKeyUtils.fromStringOrNull(string));
+    }
+
+    /**
+     * Create a NamespacedKey from a string.
+     * <p>
+     * Preferred over {@link NamespacedKey#fromString(String)} for performance reasons.
+     *
+     * @param string The string.
+     * @return The key, or null if not a key.
+     */
+    @Nullable
+    public static NamespacedKey fromStringOrNull(@NotNull final String string) {
         int index = string.indexOf(":");
 
+        if (index < 0) {
+            return null;
+        }
+
         return NamespacedKeyUtils.create(
                 string.substring(0, index),
                 string.substring(index + 1)

eco-api/src/main/java/com/willfp/eco/util/PlayerUtils.java

@@ -5,6 +5,7 @@ import com.willfp.eco.core.Prerequisite;
 import com.willfp.eco.core.data.PlayerProfile;
 import com.willfp.eco.core.data.keys.PersistentDataKey;
 import com.willfp.eco.core.data.keys.PersistentDataKeyType;
+import com.willfp.eco.core.integrations.anticheat.AnticheatManager;
 import net.kyori.adventure.audience.Audience;
 import net.kyori.adventure.platform.bukkit.BukkitAudiences;
 import org.bukkit.OfflinePlayer;
@@ -12,6 +13,8 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.function.Consumer;
+
 /**
  * Utilities / API methods for players.
  */
@@ -107,6 +110,38 @@ public final class PlayerUtils {
         profile.write(PLAYER_NAME_KEY, player.getDisplayName());
     }
 
+    /**
+     * Run something with the player exempted.
+     *
+     * @param player The player.
+     * @param action The action.
+     */
+    public static void runExempted(@NotNull final Player player,
+                                   @NotNull final Consumer<Player> action) {
+        try {
+            AnticheatManager.exemptPlayer(player);
+            action.accept(player);
+        } finally {
+            AnticheatManager.unexemptPlayer(player);
+        }
+    }
+
+    /**
+     * Run something with the player exempted.
+     *
+     * @param player The player.
+     * @param action The action.
+     */
+    public static void runExempted(@NotNull final Player player,
+                                   @NotNull final Runnable action) {
+        try {
+            AnticheatManager.exemptPlayer(player);
+            action.run();
+        } finally {
+            AnticheatManager.unexemptPlayer(player);
+        }
+    }
+
     private PlayerUtils() {
         throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
     }

eco-api/src/main/java/com/willfp/eco/util/TeamUtils.java

@@ -69,8 +69,10 @@ public final class TeamUtils {
      *
      * @param material The material to find the team from.
      * @return The team.
+     * @deprecated Stupid method.
      */
     @NotNull
+    @Deprecated(since = "6.24.0")
     public static Team getMaterialColorTeam(@NotNull final Material material) {
         return fromChatColor(MATERIAL_COLORS.getOrDefault(material, ChatColor.WHITE));
     }

eco-api/src/main/kotlin/com/willfp/eco/core/commands/CommandHelpers.kt

@@ -0,0 +1,142 @@
+@file:JvmName("CommandHelperExtensions")
+
+package com.willfp.eco.core.commands
+
+import com.willfp.eco.core.EcoPlugin
+import com.willfp.eco.core.command.CommandBase
+import com.willfp.eco.core.command.impl.PluginCommand
+import com.willfp.eco.core.command.impl.Subcommand
+import org.bukkit.command.CommandSender
+
+/**
+ * Helper class for creating commands with builders.
+ *
+ * @param plugin The plugin.
+ * @param name The command name.
+ * @param permission The permission.
+ * @param playersOnly If only players should run the command.
+ * @param executor The command executor.
+ * @param tabCompleter The tab completer.
+ */
+class BuiltPluginCommand internal constructor(
+    plugin: EcoPlugin,
+    name: String,
+    permission: String,
+    playersOnly: Boolean = false,
+    var executor: (CommandSender, List<String>) -> Unit,
+    var tabCompleter: (CommandSender, List<String>) -> List<String>,
+) : PluginCommand(plugin, name, permission, playersOnly) {
+    override fun onExecute(sender: CommandSender, args: List<String>) =
+        executor(sender, args)
+
+    override fun tabComplete(sender: CommandSender, args: List<String>): List<String> =
+        tabCompleter(sender, args)
+}
+
+
+/**
+ * Helper class for creating commands with builders.
+ *
+ * @param plugin The plugin.
+ * @param name The command name.
+ * @param permission The permission.
+ * @param playersOnly If only players should run the command.
+ * @param executor The command executor.
+ * @param tabCompleter The tab completer.
+ */
+class BuiltSubcommand internal constructor(
+    plugin: EcoPlugin,
+    name: String,
+    permission: String,
+    playersOnly: Boolean = false,
+    var executor: (CommandSender, List<String>) -> Unit,
+    var tabCompleter: (CommandSender, List<String>) -> List<String>,
+) : Subcommand(plugin, name, permission, playersOnly) {
+    internal constructor(
+        parent: CommandBase,
+        name: String,
+        executor: (CommandSender, List<String>) -> Unit,
+        tabCompleter: (CommandSender, List<String>) -> List<String>,
+    ) : this(parent.plugin, name, parent.permission, parent.isPlayersOnly, executor, tabCompleter)
+
+    override fun onExecute(sender: CommandSender, args: List<String>) =
+        executor(sender, args)
+
+    override fun tabComplete(sender: CommandSender, args: List<String>): List<String> =
+        tabCompleter(sender, args)
+}
+
+/**
+ * Kotlin builder for commands.
+ *
+ * @param plugin The plugin.
+ * @param name The command name.
+ * @param permission The permission.
+ * @param playersOnly If only players should execute the command.
+ * @param init The builder.
+ */
+fun command(
+    plugin: EcoPlugin,
+    name: String,
+    permission: String,
+    playersOnly: Boolean = false,
+    init: BuiltPluginCommand.() -> Unit
+): PluginCommand {
+    val command = BuiltPluginCommand(
+        plugin,
+        name,
+        permission,
+        playersOnly,
+        { _, _ -> },
+        { _, _ -> emptyList() }
+    )
+    init(command)
+    return command
+}
+
+/**
+ * Kotlin builder for commands.
+ *
+ * @param name The command name.
+ * @param permission The permission.
+ * @param playersOnly If only players should execute the command.
+ * @param init The builder.
+ */
+fun CommandBase.addSubcommand(
+    name: String,
+    permission: String,
+    playersOnly: Boolean = false,
+    init: BuiltSubcommand.() -> Unit
+): Subcommand {
+    val command = BuiltSubcommand(
+        this.plugin,
+        name,
+        permission,
+        playersOnly,
+        { _, _ -> },
+        { _, _ -> emptyList() }
+    )
+    init(command)
+    return command
+}
+
+/**
+ * Kotlin builder for commands.
+ * Inherits plugin, permission, players only.
+ *
+ * @param name The command name.
+ * @param init The builder.
+ */
+fun CommandBase.addSubcommand(
+    name: String,
+    init: BuiltSubcommand.() -> Unit
+): Subcommand {
+    val command = BuiltSubcommand(
+        this,
+        name,
+        { _, _ -> },
+        { _, _ -> emptyList() }
+    )
+    init(command)
+    return command
+}

eco-api/src/main/kotlin/com/willfp/eco/core/gui/GUIHelpers.kt

@@ -43,9 +43,18 @@ fun SlotBuilder.onMiddleClick(action: (InventoryClickEvent, Slot, Menu) -> Unit)
 
 /**
  * @see SlotBuilder.setModifier
+ * @deprecated Use SlotUpdater instead.
  */
+@Deprecated("Use SlotUpdater instead")
+@Suppress("DEPRECATION")
 fun SlotBuilder.setModifier(action: (Player, Menu, ItemStack) -> Unit): SlotBuilder =
-    this.setModifier { a, b, c -> action(a, b, c) }
+    this.setUpdater { a, b, c -> c.apply { action(a, b, c) } }
+
+/**
+ * @see SlotBuilder.setUpdater
+ */
+fun SlotBuilder.setUpdater(action: (Player, Menu, ItemStack) -> ItemStack): SlotBuilder =
+    this.setUpdater { a, b, c -> action(a, b, c) }
 
 /**
  * Kotlin builder for slots.

eco-api/src/main/kotlin/com/willfp/eco/util/DurabilityUtils.kt

@@ -0,0 +1,18 @@
+@file:JvmName("DurabilityUtilsExtensions")
+
+package com.willfp.eco.util
+
+import org.bukkit.entity.Player
+import org.bukkit.inventory.ItemStack
+
+/**
+ * @see DurabilityUtils.damageItem
+ */
+fun ItemStack.damage(damage: Int) =
+    DurabilityUtils.damageItem(this, damage)
+
+/**
+ * @see DurabilityUtils.damageItem
+ */
+fun ItemStack.damage(damage: Int, player: Player) =
+    DurabilityUtils.damageItem(player, this, damage)

eco-api/src/main/kotlin/com/willfp/eco/util/ListUtils.kt

@@ -13,3 +13,9 @@ fun <T> List<T>.toFrequencyMap(): Map<T, Int> =
  */
 fun Iterable<String>.containsIgnoreCase(element: String): Boolean =
     ListUtils.containsIgnoreCase(this, element)
+
+/**
+ * @see ListUtils.create2DList
+ */
+fun <T> create2DList(rows: Int, columns: Int): MutableList<MutableList<T>> =
+    ListUtils.create2DList(rows, columns)

eco-api/src/main/kotlin/com/willfp/eco/util/NamespacedKeyUtils.kt

@@ -0,0 +1,29 @@
+@file:JvmName("NamespacedKeyUtilsExtensions")
+
+package com.willfp.eco.util
+
+import com.willfp.eco.core.EcoPlugin
+
+/**
+ * @see NamespacedKeyUtils.fromString
+ */
+fun namespacedKeyOf(string: String) =
+    NamespacedKeyUtils.fromString(string)
+
+/**
+ * @see NamespacedKeyUtils.fromString
+ */
+fun safeNamespacedKeyOf(string: String) =
+    NamespacedKeyUtils.fromStringOrNull(string)
+
+/**
+ * @see NamespacedKeyUtils.create
+ */
+fun namespacedKeyOf(namespace: String, key: String) =
+    NamespacedKeyUtils.create(namespace, key)
+
+/**
+ * @see EcoPlugin.namespacedKeyFactory
+ */
+fun namespacedKeyOf(plugin: EcoPlugin, key: String) =
+    plugin.namespacedKeyFactory.create(key)

eco-api/src/main/kotlin/com/willfp/eco/util/NumberUtils.kt

@@ -0,0 +1,9 @@
+@file:JvmName("NumberUtilsExtensions")
+
+package com.willfp.eco.util
+
+/**
+ * @see NumberUtils.toNumeral
+ */
+fun Number.toNumeral(): String =
+    NumberUtils.toNumeral(this.toInt())

eco-api/src/main/kotlin/com/willfp/eco/util/PlayerUtils.kt

@@ -24,3 +24,9 @@ fun Player.asAudience(): Audience =
  */
 fun CommandSender.asAudience(): Audience =
     PlayerUtils.getAudience(this)
+
+/**
+ * @see PlayerUtils.runExempted
+ */
+fun Player.runExempted(action: () -> Unit) =
+    PlayerUtils.runExempted(this, action)

eco-api/src/main/kotlin/com/willfp/eco/util/StringUtils.kt

@@ -35,7 +35,7 @@ fun String.formatEco(
 fun List<String>.formatEco(
     player: Player? = null,
     formatPlaceholders: Boolean = false
-) = StringUtils.formatList(
+): List<String> = StringUtils.formatList(
     this,
     player,
     if (formatPlaceholders) StringUtils.FormatOption.WITH_PLACEHOLDERS else StringUtils.FormatOption.WITHOUT_PLACEHOLDERS

eco-core/build.gradle

@@ -1,29 +1,8 @@
-buildscript {
-    repositories {
-        mavenCentral()
-    }
-
-    dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.0"
-    }
-}
-
 group 'com.willfp'
 version rootProject.version
 
 subprojects {
-    apply plugin: "kotlin"
-
     dependencies {
         compileOnly project(":eco-api")
-        compileOnly 'org.jetbrains.kotlin:kotlin-stdlib:1.6.0'
     }
-
+}
-    compileKotlin {
-        kotlinOptions {
-            jvmTarget = "17"
-        }
-        targetCompatibility = JavaVersion.VERSION_17
-        sourceCompatibility = JavaVersion.VERSION_17
-    }
-}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/EcoPropsParser.kt

@@ -0,0 +1,35 @@
+package com.willfp.eco.internal
+
+import com.willfp.eco.core.EcoPlugin
+import com.willfp.eco.core.PluginProps
+import com.willfp.eco.core.config.TransientConfig
+import com.willfp.eco.core.config.interfaces.Config
+
+object EcoPropsParser : PluginProps.PropsParser<Config> {
+    override fun parseFrom(config: Config): PluginProps {
+        val resourceId = config.getIntOrNull("resource-id") ?: 0
+        val bStatsId = config.getIntOrNull("bstats-id") ?: 0
+        val proxyPackage = config.getStringOrNull("proxy-package") ?: ""
+        val color = config.getStringOrNull("color") ?: "&f"
+        val supportsExtensions = config.getBoolOrNull("supports-extensions") ?: false
+
+        return blankProps.apply {
+            this.resourceId = resourceId
+            this.bStatsId = bStatsId
+            this.proxyPackage = proxyPackage
+            this.color = color
+            this.isSupportingExtensions = supportsExtensions
+        }
+    }
+
+    fun parseForPlugin(plugin: Class<out EcoPlugin>): PluginProps {
+        if (!PluginProps.hasParserFor(Config::class.java)) {
+            PluginProps.registerParser(Config::class.java, this)
+        }
+
+        return PluginProps.parse(
+            TransientConfig(plugin.getResourceAsStream("/eco.yml")),
+            Config::class.java
+        )
+    }
+}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/config/EcoConfigFactory.kt

@@ -15,7 +15,7 @@ import com.willfp.eco.internal.config.yaml.EcoYamlConfigSection
 import org.bukkit.configuration.file.YamlConfiguration
 import java.io.StringReader
 
-class EcoConfigFactory : ConfigFactory {
+object EcoConfigFactory : ConfigFactory {
     override fun createConfig(config: YamlConfiguration): Config {
         return EcoYamlConfigSection(config)
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/display/EcoDisplayHandler.kt

@@ -5,7 +5,7 @@ import com.willfp.eco.core.display.Display
 import com.willfp.eco.core.display.DisplayHandler
 import com.willfp.eco.core.display.DisplayModule
 import com.willfp.eco.core.display.DisplayPriority
-import com.willfp.eco.core.fast.FastItemStack
+import com.willfp.eco.core.fast.fast
 import org.bukkit.NamespacedKey
 import org.bukkit.entity.Player
 import org.bukkit.inventory.ItemStack
@@ -60,7 +60,7 @@ class EcoDisplayHandler(plugin: EcoPlugin) : DisplayHandler {
             Display.unfinalize(itemStack)
         }
 
-        val fast = FastItemStack.wrap(itemStack)
+        val fast = itemStack.fast()
         val lore = fast.lore
 
         if (lore.isNotEmpty() && lore.removeIf { line: String ->

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/drops/impl/EcoDropQueue.kt

@@ -10,7 +10,6 @@ import org.bukkit.Material
 import org.bukkit.entity.EntityType
 import org.bukkit.entity.ExperienceOrb
 import org.bukkit.entity.Player
-import org.bukkit.event.player.PlayerExpChangeEvent
 import org.bukkit.inventory.ItemStack
 import org.bukkit.util.Vector
 

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/entities/EntityArgParserAdult.kt

@@ -2,7 +2,7 @@ package com.willfp.eco.internal.entities
 
 import com.willfp.eco.core.entities.args.EntityArgParseResult
 import com.willfp.eco.core.entities.args.EntityArgParser
-import org.bukkit.entity.Animals
+import org.bukkit.entity.Ageable
 
 class EntityArgParserAdult : EntityArgParser {
     override fun parseArguments(args: Array<out String>): EntityArgParseResult? {
@@ -20,14 +20,14 @@ class EntityArgParserAdult : EntityArgParser {
 
         return EntityArgParseResult(
             {
-                if (it !is Animals) {
+                if (it !is Ageable) {
                     return@EntityArgParseResult false
                 }
 
                 it.isAdult
             },
             {
-                (it as? Animals)?.setAdult()
+                (it as? Ageable)?.setAdult()
             }
         )
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/entities/EntityArgParserBaby.kt

@@ -2,7 +2,7 @@ package com.willfp.eco.internal.entities
 
 import com.willfp.eco.core.entities.args.EntityArgParseResult
 import com.willfp.eco.core.entities.args.EntityArgParser
-import org.bukkit.entity.Animals
+import org.bukkit.entity.Ageable
 
 class EntityArgParserBaby : EntityArgParser {
     override fun parseArguments(args: Array<out String>): EntityArgParseResult? {
@@ -20,14 +20,14 @@ class EntityArgParserBaby : EntityArgParser {
 
         return EntityArgParseResult(
             {
-                if (it !is Animals) {
+                if (it !is Ageable) {
                     return@EntityArgParseResult false
                 }
 
                 !it.isAdult
             },
             {
-                (it as? Animals)?.setBaby()
+                (it as? Ageable)?.setBaby()
             }
         )
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/entities/EntityArgParserEquipment.kt

@@ -0,0 +1,62 @@
+package com.willfp.eco.internal.entities
+
+import com.willfp.eco.core.entities.args.EntityArgParseResult
+import com.willfp.eco.core.entities.args.EntityArgParser
+import com.willfp.eco.core.items.Items
+import com.willfp.eco.core.items.TestableItem
+import org.bukkit.entity.LivingEntity
+import org.bukkit.inventory.EquipmentSlot
+
+class EntityArgParserEquipment : EntityArgParser {
+    override fun parseArguments(args: Array<out String>): EntityArgParseResult? {
+        val equipment = mutableMapOf<EquipmentSlot, TestableItem>()
+
+        for (arg in args) {
+            val argSplit = arg.split(":")
+            for (slot in EquipmentSlot.values()) {
+                if (!argSplit[0].equals(slot.name, ignoreCase = true)) {
+                    continue
+                }
+
+                if (argSplit.size < 2) {
+                    continue
+                }
+
+                equipment[slot] = Items.lookup(argSplit[1])
+            }
+        }
+
+        if (equipment.isEmpty()) {
+            return null
+        }
+
+        return EntityArgParseResult(
+            {
+                if (it !is LivingEntity) {
+                    return@EntityArgParseResult false
+                }
+
+                val entityEquipment = it.equipment ?: return@EntityArgParseResult false
+
+                for ((slot, item) in equipment) {
+                    if (!item.matches(entityEquipment.getItem(slot))) {
+                        return@EntityArgParseResult false
+                    }
+                }
+
+                return@EntityArgParseResult true
+            },
+            {
+                if (it !is LivingEntity) {
+                    return@EntityArgParseResult
+                }
+
+                val entityEquipment = it.equipment ?: return@EntityArgParseResult
+
+                for ((slot, item) in equipment) {
+                    entityEquipment.setItem(slot, item.item, false)
+                }
+            }
+        )
+    }
+}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/entities/EntityArgParserSilent.kt

@@ -2,7 +2,6 @@ package com.willfp.eco.internal.entities
 
 import com.willfp.eco.core.entities.args.EntityArgParseResult
 import com.willfp.eco.core.entities.args.EntityArgParser
-import org.bukkit.entity.Animals
 
 class EntityArgParserSilent : EntityArgParser {
     override fun parseArguments(args: Array<out String>): EntityArgParseResult? {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/slot/EcoCaptiveSlot.kt

@@ -12,7 +12,7 @@ class EcoCaptiveSlot(
     allowMovingItem,
     allowMovingItem,
     allowMovingItem,
-    { _, _, _ -> }
+    { _, _, prev -> prev }
 ) {
     override fun isCaptive(): Boolean {
         return true

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/slot/EcoFillerSlot.kt

@@ -9,5 +9,5 @@ class EcoFillerSlot(itemStack: ItemStack) : EcoSlot(
     { _, _, _ -> },
     { _, _, _ -> },
     { _, _, _ -> },
-    { _, _, _ -> }
+    { _, _, prev -> prev }
 )

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/slot/EcoSlot.kt

@@ -3,8 +3,8 @@ package com.willfp.eco.internal.gui.slot
 import com.willfp.eco.core.gui.menu.Menu
 import com.willfp.eco.core.gui.slot.Slot
 import com.willfp.eco.core.gui.slot.functional.SlotHandler
-import com.willfp.eco.core.gui.slot.functional.SlotModifier
 import com.willfp.eco.core.gui.slot.functional.SlotProvider
+import com.willfp.eco.core.gui.slot.functional.SlotUpdater
 import com.willfp.eco.internal.gui.menu.MenuHandler
 import org.bukkit.entity.Player
 import org.bukkit.event.inventory.ClickType
@@ -18,7 +18,7 @@ open class EcoSlot(
     private val onShiftLeftClick: SlotHandler,
     private val onShiftRightClick: SlotHandler,
     private val onMiddleClick: SlotHandler,
-    private val modifier: SlotModifier
+    private val updater: SlotUpdater
 ) : Slot {
 
     fun handleInventoryClick(
@@ -38,8 +38,7 @@ open class EcoSlot(
     override fun getItemStack(player: Player): ItemStack {
         val menu = MenuHandler.getMenu(player.openInventory.topInventory)!!
         val prev = provider.provide(player, menu)
-        modifier.modify(player, menu, prev)
+        return updater.update(player, menu, prev)
-        return prev
     }
 
     fun getItemStack(
@@ -47,8 +46,7 @@ open class EcoSlot(
         menu: Menu
     ): ItemStack {
         val prev = provider.provide(player, menu)
-        modifier.modify(player, menu, prev)
+        return updater.update(player, menu, prev)
-        return prev
     }
 
     override fun isCaptive(): Boolean {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/slot/EcoSlotBuilder.kt

@@ -3,12 +3,12 @@ package com.willfp.eco.internal.gui.slot
 import com.willfp.eco.core.gui.slot.Slot
 import com.willfp.eco.core.gui.slot.SlotBuilder
 import com.willfp.eco.core.gui.slot.functional.SlotHandler
-import com.willfp.eco.core.gui.slot.functional.SlotModifier
 import com.willfp.eco.core.gui.slot.functional.SlotProvider
+import com.willfp.eco.core.gui.slot.functional.SlotUpdater
 
 class EcoSlotBuilder(private val provider: SlotProvider) : SlotBuilder {
     private var captive = false
-    private var modifier: SlotModifier = SlotModifier { player, menu, _ -> provider.provide(player, menu) }
+    private var updater: SlotUpdater = SlotUpdater { player, menu, _ -> provider.provide(player, menu) }
 
     private var onLeftClick =
         SlotHandler { _, _, _ -> run { } }
@@ -51,8 +51,8 @@ class EcoSlotBuilder(private val provider: SlotProvider) : SlotBuilder {
         return this
     }
 
-    override fun setModifier(modifier: SlotModifier): SlotBuilder {
+    override fun setUpdater(updater: SlotUpdater): SlotBuilder {
-        this.modifier = modifier
+        this.updater = updater
         return this
     }
 
@@ -60,7 +60,7 @@ class EcoSlotBuilder(private val provider: SlotProvider) : SlotBuilder {
         return if (captive) {
             EcoCaptiveSlot(provider)
         } else {
-            EcoSlot(provider, onLeftClick, onRightClick, onShiftLeftClick, onShiftRightClick, onMiddleClick, modifier)
+            EcoSlot(provider, onLeftClick, onRightClick, onShiftLeftClick, onShiftRightClick, onMiddleClick, updater)
         }
     }
 }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/items/ArgParserEnchantment.kt

@@ -1,6 +1,6 @@
 package com.willfp.eco.internal.items
 
-import com.willfp.eco.core.fast.FastItemStack
+import com.willfp.eco.core.fast.fast
 import com.willfp.eco.core.items.args.LookupArgParser
 import com.willfp.eco.util.NamespacedKeyUtils
 import org.bukkit.enchantments.Enchantment
@@ -41,7 +41,7 @@ class ArgParserEnchantment : LookupArgParser {
         }
 
         return Predicate {
-            val onItem = FastItemStack.wrap(it).getEnchantmentsOnItem(true)
+            val onItem = it.fast().getEnchants(true)
 
             for ((enchant, level) in enchants) {
                 if ((onItem[enchant] ?: 0) < level) {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/proxy/EcoProxyFactory.kt

@@ -4,7 +4,7 @@ import com.willfp.eco.core.EcoPlugin
 import com.willfp.eco.core.proxy.ProxyConstants
 import com.willfp.eco.core.proxy.ProxyFactory
 import com.willfp.eco.core.proxy.exceptions.ProxyError
-import com.willfp.eco.core.proxy.exceptions.UnsupportedVersionException
+import com.willfp.eco.core.proxy.exceptions.UnsupportedVersionError
 import java.net.URLClassLoader
 import java.util.IdentityHashMap
 
@@ -34,21 +34,26 @@ class EcoProxyFactory(
                 return proxy
             }
         } catch (e: Exception) {
-            throwError(e)
+            throw proxyErrorFrom(e)
         }
 
-        throwError(IllegalArgumentException())
+        throw proxyErrorFrom(IllegalArgumentException("Class doesn't seem to be a proxy."))
-
-        throw RuntimeException("Something went wrong.")
     }
 
-    private fun throwError(e: Exception?) {
+    private fun proxyErrorFrom(e: Exception): Throwable {
-        e?.printStackTrace()
+        plugin.logger.severe("Fatal error with proxies! This plugin can't load.")
 
-        if (!SUPPORTED_VERSIONS.contains(ProxyConstants.NMS_VERSION)) {
+        return if (!SUPPORTED_VERSIONS.contains(ProxyConstants.NMS_VERSION)) {
-            throw UnsupportedVersionException("You're running an unsupported server version: " + ProxyConstants.NMS_VERSION)
+            ProxyError(
+                "Could not initialize proxy.",
+                UnsupportedVersionError()
+            )
         } else {
-            throw ProxyError("Error with proxies - here's a stacktrace. Only god can help you now.")
+            ProxyError(
+                "Could not initialize proxy. If you're seeing this error message"
+                        + ", something has gone badly wrong. This almost definitely isn't user error, blame the developer.",
+                e
+            )
         }
     }
 

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/requirement/EcoRequirementFactory.kt

@@ -1,14 +1,17 @@
+@file:Suppress("DEPRECATION")
+
 package com.willfp.eco.internal.requirement
 
+import com.willfp.eco.core.integrations.placeholder.PlaceholderManager
 import com.willfp.eco.core.requirement.Requirement
 import com.willfp.eco.core.requirement.RequirementFactory
-import com.willfp.eco.internal.requirement.requirements.RequirementHasPermission
+import org.bukkit.entity.Player
-import com.willfp.eco.internal.requirement.requirements.RequirementPlaceholderEquals
-import com.willfp.eco.internal.requirement.requirements.RequirementPlaceholderGreaterThan
-import com.willfp.eco.internal.requirement.requirements.RequirementPlaceholderLessThan
-import com.willfp.eco.internal.requirement.requirements.RequirementTrue
 
-class EcoRequirementFactory: RequirementFactory {
+@Deprecated(
+    "Requirement system is marked as for-removal from eco",
+    level = DeprecationLevel.WARNING
+)
+class EcoRequirementFactory : RequirementFactory {
     override fun create(name: String): Requirement {
         return when (name.lowercase()) {
             "has-permission" -> RequirementHasPermission()
@@ -18,4 +21,93 @@ class EcoRequirementFactory: RequirementFactory {
             else -> RequirementTrue()
         }
     }
-}
+}
+
+@Deprecated(
+    "Requirement system is marked as for-removal from eco",
+    level = DeprecationLevel.WARNING
+)
+class RequirementHasPermission : Requirement() {
+    override fun doesPlayerMeet(
+        player: Player,
+        args: List<String>
+    ): Boolean {
+        if (args.isEmpty()) {
+            return false
+        }
+
+        val permission = args[0]
+        return player.hasPermission(permission)
+    }
+}
+
+@Deprecated(
+    "Requirement system is marked as for-removal from eco",
+    level = DeprecationLevel.WARNING
+)
+class RequirementPlaceholderEquals : Requirement() {
+    override fun doesPlayerMeet(
+        player: Player,
+        args: List<String>
+    ): Boolean {
+        if (args.size < 2) {
+            return false
+        }
+
+        val placeholder = args[0]
+        val equals = args[1]
+        return PlaceholderManager.translatePlaceholders(placeholder, player).equals(equals, ignoreCase = true)
+    }
+}
+
+@Deprecated(
+    "Requirement system is marked as for-removal from eco",
+    level = DeprecationLevel.WARNING
+)
+@SuppressWarnings("DEPRECATION")
+class RequirementPlaceholderGreaterThan : Requirement() {
+    override fun doesPlayerMeet(
+        player: Player,
+        args: List<String>
+    ): Boolean {
+        if (args.size < 2) {
+            return false
+        }
+
+        val placeholder = args[0]
+        val equals = args[1].toDoubleOrNull() ?: return false
+        return (PlaceholderManager.translatePlaceholders(placeholder, player).toDoubleOrNull() ?: 0.0) >= equals
+    }
+}
+
+@Deprecated(
+    "Requirement system is marked as for-removal from eco",
+    level = DeprecationLevel.WARNING
+)
+class RequirementPlaceholderLessThan : Requirement() {
+    override fun doesPlayerMeet(
+        player: Player,
+        args: List<String>
+    ): Boolean {
+        if (args.size < 2) {
+            return false
+        }
+
+        val placeholder = args[0]
+        val equals = args[1].toDoubleOrNull() ?: return false
+        return (PlaceholderManager.translatePlaceholders(placeholder, player).toDoubleOrNull() ?: 0.0) < equals
+    }
+}
+
+@Deprecated(
+    "Requirement system is marked as for-removal from eco",
+    level = DeprecationLevel.WARNING
+)
+class RequirementTrue : Requirement() {
+    override fun doesPlayerMeet(
+        player: Player,
+        args: List<String>
+    ): Boolean {
+        return true
+    }
+}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/requirement/requirements/RequirementHasPermission.kt

@@ -1,18 +0,0 @@
-package com.willfp.eco.internal.requirement.requirements
-
-import com.willfp.eco.core.requirement.Requirement
-import org.bukkit.entity.Player
-
-class RequirementHasPermission : Requirement() {
-    override fun doesPlayerMeet(
-        player: Player,
-        args: List<String>
-    ): Boolean {
-        if (args.isEmpty()) {
-            return false
-        }
-
-        val permission = args[0]
-        return player.hasPermission(permission)
-    }
-}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/requirement/requirements/RequirementPlaceholderEquals.kt

@@ -1,20 +0,0 @@
-package com.willfp.eco.internal.requirement.requirements
-
-import com.willfp.eco.core.integrations.placeholder.PlaceholderManager
-import com.willfp.eco.core.requirement.Requirement
-import org.bukkit.entity.Player
-
-class RequirementPlaceholderEquals : Requirement() {
-    override fun doesPlayerMeet(
-        player: Player,
-        args: List<String>
-    ): Boolean {
-        if (args.size < 2) {
-            return false
-        }
-
-        val placeholder = args[0]
-        val equals = args[1]
-        return PlaceholderManager.translatePlaceholders(placeholder, player).equals(equals, ignoreCase = true)
-    }
-}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/requirement/requirements/RequirementPlaceholderGreaterThan.kt

@@ -1,20 +0,0 @@
-package com.willfp.eco.internal.requirement.requirements
-
-import com.willfp.eco.core.integrations.placeholder.PlaceholderManager
-import com.willfp.eco.core.requirement.Requirement
-import org.bukkit.entity.Player
-
-class RequirementPlaceholderGreaterThan : Requirement() {
-    override fun doesPlayerMeet(
-        player: Player,
-        args: List<String>
-    ): Boolean {
-        if (args.size < 2) {
-            return false
-        }
-
-        val placeholder = args[0]
-        val equals = args[1].toDoubleOrNull() ?: return false
-        return (PlaceholderManager.translatePlaceholders(placeholder, player).toDoubleOrNull() ?: 0.0) >= equals
-    }
-}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/requirement/requirements/RequirementPlaceholderLessThan.kt

@@ -1,20 +0,0 @@
-package com.willfp.eco.internal.requirement.requirements
-
-import com.willfp.eco.core.integrations.placeholder.PlaceholderManager
-import com.willfp.eco.core.requirement.Requirement
-import org.bukkit.entity.Player
-
-class RequirementPlaceholderLessThan : Requirement() {
-    override fun doesPlayerMeet(
-        player: Player,
-        args: List<String>
-    ): Boolean {
-        if (args.size < 2) {
-            return false
-        }
-
-        val placeholder = args[0]
-        val equals = args[1].toDoubleOrNull() ?: return false
-        return (PlaceholderManager.translatePlaceholders(placeholder, player).toDoubleOrNull() ?: 0.0) < equals
-    }
-}

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/requirement/requirements/RequirementTrue.kt

@@ -1,13 +0,0 @@
-package com.willfp.eco.internal.requirement.requirements
-
-import com.willfp.eco.core.requirement.Requirement
-import org.bukkit.entity.Player
-
-class RequirementTrue : Requirement() {
-    override fun doesPlayerMeet(
-        player: Player,
-        args: List<String>
-    ): Boolean {
-        return true
-    }
-}

eco-core/core-nms/v1_16_R3/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_16_R3/VillagerTrade.kt

@@ -8,7 +8,7 @@ import org.bukkit.inventory.MerchantRecipe
 import java.lang.reflect.Field
 
 class VillagerTrade : VillagerTradeProxy {
-    private var handle: Field
+    private val handle: Field = CraftMerchantRecipe::class.java.getDeclaredField("handle")
 
     override fun displayTrade(
         recipe: MerchantRecipe,
@@ -35,7 +35,6 @@ class VillagerTrade : VillagerTradeProxy {
     }
 
     init {
-        handle = CraftMerchantRecipe::class.java.getDeclaredField("handle")
         handle.isAccessible = true
     }
 }

eco-core/core-nms/v1_16_R3/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_16_R3/fast/NMSFastItemStack.kt

@@ -20,7 +20,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
     itemStack.getNMSStack(), itemStack
 ) {
     private var loreCache: List<String>? = null
-    override fun getEnchantmentsOnItem(checkStored: Boolean): Map<Enchantment, Int> {
+    override fun getEnchants(checkStored: Boolean): Map<Enchantment, Int> {
         val enchantmentNBT = if (checkStored && handle.item === Items.ENCHANTED_BOOK) ItemEnchantedBook.d(
             handle
         ) else handle.enchantments
@@ -29,7 +29,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
             val compound = base as NBTTagCompound
             val key = compound.getString("id")
             val level: Int = ('\uffff'.code.toShort() and compound.getShort("lvl")).toInt()
-            val found = Enchantment.getByKey(NamespacedKeyUtils.fromString(key))
+            val found = Enchantment.getByKey(NamespacedKeyUtils.fromStringOrNull(key))
             if (found != null) {
                 foundEnchantments[found] = level
             }

eco-core/core-nms/v1_17_R1/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_17_R1/fast/NMSFastItemStack.kt

@@ -21,7 +21,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
 ) {
     private var loreCache: List<String>? = null
 
-    override fun getEnchantmentsOnItem(checkStored: Boolean): Map<Enchantment, Int> {
+    override fun getEnchants(checkStored: Boolean): Map<Enchantment, Int> {
         val enchantmentNBT =
             if (checkStored && handle.item === Items.ENCHANTED_BOOK) EnchantedBookItem.getEnchantments(
                 handle
@@ -31,7 +31,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
             val compound = base as CompoundTag
             val key = compound.getString("id")
             val level = ('\uffff'.code.toShort() and compound.getShort("lvl")).toInt()
-            val found = Enchantment.getByKey(NamespacedKeyUtils.fromString(key))
+            val found = Enchantment.getByKey(NamespacedKeyUtils.fromStringOrNull(key))
             if (found != null) {
                 foundEnchantments[found] = level
             }
@@ -176,6 +176,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
     }
 
     override fun hashCode(): Int {
+        @Suppress("KotlinDeprecation")
         return handle.tag?.hashCode() ?: (0b00010101 * 31 + Item.getId(handle.item))
     }
 

eco-core/core-nms/v1_18_R1/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_18_R1/fast/NMSFastItemStack.kt

@@ -22,7 +22,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
 ) {
     private var loreCache: List<String>? = null
 
-    override fun getEnchantmentsOnItem(checkStored: Boolean): Map<Enchantment, Int> {
+    override fun getEnchants(checkStored: Boolean): Map<Enchantment, Int> {
         val enchantmentNBT =
             if (checkStored && handle.getItem() === Items.ENCHANTED_BOOK) EnchantedBookItem.getEnchantments(
                 handle
@@ -32,7 +32,7 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
             val compound = base as CompoundTag
             val key = compound.getString("id")
             val level = ('\uffff'.code.toShort() and compound.getShort("lvl")).toInt()
-            val found = Enchantment.getByKey(NamespacedKeyUtils.fromString(key))
+            val found = Enchantment.getByKey(NamespacedKeyUtils.fromStringOrNull(key))
             if (found != null) {
                 foundEnchantments[found] = level
             }

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/EcoHandler.kt

@@ -2,9 +2,11 @@ package com.willfp.eco.internal.spigot
 
 import com.willfp.eco.core.EcoPlugin
 import com.willfp.eco.core.Handler
+import com.willfp.eco.core.PluginProps
 import com.willfp.eco.core.fast.FastItemStack
 import com.willfp.eco.core.integrations.placeholder.PlaceholderIntegration
 import com.willfp.eco.internal.EcoCleaner
+import com.willfp.eco.internal.EcoPropsParser
 import com.willfp.eco.internal.Plugins
 import com.willfp.eco.internal.config.EcoConfigFactory
 import com.willfp.eco.internal.config.updating.EcoConfigHandler
@@ -21,12 +23,9 @@ import com.willfp.eco.internal.gui.EcoGUIFactory
 import com.willfp.eco.internal.integrations.PlaceholderIntegrationPAPI
 import com.willfp.eco.internal.logging.EcoLogger
 import com.willfp.eco.internal.proxy.EcoProxyFactory
-import com.willfp.eco.internal.requirement.EcoRequirementFactory
 import com.willfp.eco.internal.scheduling.EcoScheduler
 import com.willfp.eco.internal.spigot.data.EcoKeyRegistry
 import com.willfp.eco.internal.spigot.data.EcoProfileHandler
-import com.willfp.eco.internal.spigot.data.storage.MySQLDataHandler
-import com.willfp.eco.internal.spigot.data.storage.YamlDataHandler
 import com.willfp.eco.internal.spigot.integrations.bstats.MetricHandler
 import com.willfp.eco.internal.spigot.proxy.DummyEntityProxy
 import com.willfp.eco.internal.spigot.proxy.FastItemStackFactoryProxy
@@ -40,13 +39,12 @@ import java.util.logging.Logger
 @Suppress("UNUSED")
 class EcoHandler : EcoSpigotPlugin(), Handler {
     private val cleaner = EcoCleaner()
-    private val requirementFactory = EcoRequirementFactory()
+
+    @Suppress("DEPRECATION")
+    private val requirementFactory = com.willfp.eco.internal.requirement.EcoRequirementFactory()
     private var adventure: BukkitAudiences? = null
     private val keyRegistry = EcoKeyRegistry(this)
-    private val playerProfileHandler = EcoProfileHandler(
+    private val playerProfileHandler = EcoProfileHandler(this.configYml.getBool("mysql.enabled"), this)
-        if (this.configYml.getBool("mysql.enabled"))
-            MySQLDataHandler(this) else YamlDataHandler(this)
-    )
 
     @Suppress("RedundantNullableReturnType")
     private val keyFactory: InternalNamespacedKeyFactory? =
@@ -94,7 +92,7 @@ class EcoHandler : EcoSpigotPlugin(), Handler {
     }
 
     override fun getConfigFactory(): EcoConfigFactory {
-        return EcoConfigFactory()
+        return EcoConfigFactory
     }
 
     override fun getDropQueueFactory(): EcoDropQueueFactory {
@@ -133,7 +131,8 @@ class EcoHandler : EcoSpigotPlugin(), Handler {
         MetricHandler.createMetrics(plugin)
     }
 
-    override fun getRequirementFactory(): EcoRequirementFactory {
+    @Suppress("DEPRECATION")
+    override fun getRequirementFactory(): com.willfp.eco.internal.requirement.EcoRequirementFactory {
         return requirementFactory
     }
 
@@ -161,4 +160,8 @@ class EcoHandler : EcoSpigotPlugin(), Handler {
         @Suppress("DEPRECATION")
         return keyFactory?.create(namespace, key) ?: NamespacedKey(namespace, key)
     }
+
+    override fun getProps(existing: PluginProps?, plugin: Class<out EcoPlugin>): PluginProps {
+        return existing ?: EcoPropsParser.parseForPlugin(plugin)
+    }
 }

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/EcoSpigotPlugin.kt

@@ -24,6 +24,7 @@ import com.willfp.eco.internal.entities.EntityArgParserAttackDamage
 import com.willfp.eco.internal.entities.EntityArgParserAttackSpeed
 import com.willfp.eco.internal.entities.EntityArgParserBaby
 import com.willfp.eco.internal.entities.EntityArgParserCharged
+import com.willfp.eco.internal.entities.EntityArgParserEquipment
 import com.willfp.eco.internal.entities.EntityArgParserExplosionRadius
 import com.willfp.eco.internal.entities.EntityArgParserFlySpeed
 import com.willfp.eco.internal.entities.EntityArgParserFollowRange
@@ -120,12 +121,7 @@ import org.bukkit.Material
 import org.bukkit.event.Listener
 import org.bukkit.inventory.ItemStack
 
-abstract class EcoSpigotPlugin : EcoPlugin(
+abstract class EcoSpigotPlugin : EcoPlugin() {
-    773,
-    10043,
-    "com.willfp.eco.internal.spigot.proxy",
-    "&a"
-) {
     init {
         Items.registerArgParser(ArgParserEnchantment())
         Items.registerArgParser(ArgParserColor())
@@ -153,6 +149,7 @@ abstract class EcoSpigotPlugin : EcoPlugin(
         Entities.registerArgParser(EntityArgParserCharged())
         Entities.registerArgParser(EntityArgParserExplosionRadius())
         Entities.registerArgParser(EntityArgParserSilent())
+        Entities.registerArgParser(EntityArgParserEquipment())
 
         ShapedRecipeListener.registerListener(ComplexInComplex())
         ShapedRecipeListener.registerListener(ComplexInEco())

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/EcoProfileHandler.kt

@@ -5,17 +5,23 @@ import com.willfp.eco.core.data.Profile
 import com.willfp.eco.core.data.ProfileHandler
 import com.willfp.eco.core.data.ServerProfile
 import com.willfp.eco.core.data.keys.PersistentDataKey
+import com.willfp.eco.internal.spigot.EcoSpigotPlugin
 import com.willfp.eco.internal.spigot.data.storage.DataHandler
+import com.willfp.eco.internal.spigot.data.storage.MySQLDataHandler
+import com.willfp.eco.internal.spigot.data.storage.YamlDataHandler
 import java.util.UUID
 
 val serverProfileUUID = UUID(0, 0)
 
 class EcoProfileHandler(
-    private val handler: DataHandler
+    useSql: Boolean,
+    plugin: EcoSpigotPlugin
 ) : ProfileHandler {
     private val loaded = mutableMapOf<UUID, Profile>()
+    private val handler: DataHandler = if (useSql) MySQLDataHandler(plugin, this) else
+        YamlDataHandler(plugin, this)
 
-    private fun loadGenericProfile(uuid: UUID): Profile {
+    fun loadGenericProfile(uuid: UUID): Profile {
         val found = loaded[uuid]
         if (found != null) {
             return found

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/storage/MySQLDataHandler.kt

@@ -2,10 +2,10 @@ package com.willfp.eco.internal.spigot.data.storage
 
 import com.google.common.util.concurrent.ThreadFactoryBuilder
 import com.willfp.eco.core.Eco
-import com.willfp.eco.core.data.PlayerProfile
 import com.willfp.eco.core.data.keys.PersistentDataKey
 import com.willfp.eco.core.data.keys.PersistentDataKeyType
 import com.willfp.eco.internal.spigot.EcoSpigotPlugin
+import com.willfp.eco.internal.spigot.data.EcoProfileHandler
 import com.zaxxer.hikari.HikariConfig
 import com.zaxxer.hikari.HikariDataSource
 import org.apache.logging.log4j.Level
@@ -30,7 +30,8 @@ import java.util.concurrent.Executors
 
 @Suppress("UNCHECKED_CAST")
 class MySQLDataHandler(
-    plugin: EcoSpigotPlugin
+    plugin: EcoSpigotPlugin,
+    private val handler: EcoProfileHandler
 ) : DataHandler {
     private val columns = mutableMapOf<String, Column<*>>()
     private val threadFactory = ThreadFactoryBuilder().setNameFormat("eco-mysql-thread-%d").build()
@@ -104,7 +105,7 @@ class MySQLDataHandler(
     }
 
     private fun savePlayer(uuid: UUID, keys: Set<PersistentDataKey<*>>) {
-        val profile = PlayerProfile.load(uuid)
+        val profile = handler.loadGenericProfile(uuid)
 
         executor.submit {
             transaction {

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/storage/YamlDataHandler.kt

@@ -2,15 +2,16 @@ package com.willfp.eco.internal.spigot.data.storage
 
 import com.willfp.eco.core.config.BaseConfig
 import com.willfp.eco.core.config.ConfigType
-import com.willfp.eco.core.data.PlayerProfile
 import com.willfp.eco.core.data.keys.PersistentDataKey
 import com.willfp.eco.internal.spigot.EcoSpigotPlugin
+import com.willfp.eco.internal.spigot.data.EcoProfileHandler
 import org.bukkit.NamespacedKey
 import java.util.UUID
 
 @Suppress("UNCHECKED_CAST")
 class YamlDataHandler(
-    plugin: EcoSpigotPlugin
+    plugin: EcoSpigotPlugin,
+    private val handler: EcoProfileHandler
 ) : DataHandler {
     private val dataYml = DataYml(plugin)
 
@@ -27,7 +28,7 @@ class YamlDataHandler(
     }
 
     override fun saveKeysForPlayer(uuid: UUID, keys: Set<PersistentDataKey<*>>) {
-        val profile = PlayerProfile.load(uuid)
+        val profile = handler.loadGenericProfile(uuid)
 
         for (key in keys) {
             write(uuid, key.key, profile.read(key))

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/recipes/ShapedRecipeListener.kt

@@ -135,4 +135,4 @@ class ShapedRecipeListener : Listener {
             listeners.add(listener)
         }
     }
-}
+}

eco-core/core-plugin/src/main/resources/eco.yml

@@ -0,0 +1,5 @@
+resource-id: 773
+bstats-id: 10043
+proxy-package: com.willfp.eco.internal.spigot.proxy
+color: '&a'
+supports-extensions: false

eco-core/core-plugin/src/main/resources/plugin.yml

@@ -46,7 +46,7 @@ softdepend:
 libraries:
   - 'org.reflections:reflections:0.9.12'
   - 'org.apache.maven:maven-artifact:3.0.3'
-  - 'org.jetbrains.kotlin:kotlin-stdlib:1.6.0'
+  - 'org.jetbrains.kotlin:kotlin-stdlib:1.6.10'
   - 'net.kyori:adventure-platform-bukkit:4.0.0'
   - 'net.kyori:adventure-api:4.9.3'
   - 'net.kyori:adventure-text-serializer-gson:4.9.3'

gradle.properties

@@ -1,3 +1,3 @@
-version = 6.23.0
+version = 6.24.4
 plugin-name = eco
 kotlin.code.style = official