Moved supported versions into ProxyConstants

This reverts commit 6361c0e8e9.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Auxilor Community Discord
+    url: https://discord.gg/ZcwpSsE/
+    about: Join the Auxilor discord to get help from support staff and the general community!
+  - name: The most common issues people have
+    url: https://github.com/Auxilor/eco/issues/78
+    about: Check the list of known common issues to see if your issue has already been solved

.github/ISSUE_TEMPLATE/report-a-bug.md

@@ -0,0 +1,31 @@
+---
+name: Report a Bug
+about: Report an issue with the plugin
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior: 
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Server Information (please complete the following information):**
+- Version: (output of `/ver` command)
+- Version of plugin and eco (`/ver eco`, `/ver <plugin>`)
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/request-a-feature.md

@@ -0,0 +1,20 @@
+---
+name: Request a Feature
+about: Suggest an idea for this plugin
+title: ''
+labels: enhancement
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.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

@@ -0,0 +1,42 @@
+name: Publish API (Dev)
+
+on: [ push, pull_request ]
+
+jobs:
+  publish-release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout latest code
+        uses: actions/checkout@v2
+
+      - name: Set outputs
+        id: vars
+        run: echo "::set-output name=sha_short::$(git rev-parse --short HEAD)"
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v2
+        with:
+          distribution: 'temurin'
+          java-version: 17
+
+      - name: Setup build cache
+        uses: actions/cache@v2.1.6
+        with:
+          path: ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle.kts') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+
+
+      - name: Publish artifact
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+        # The GITHUB_REF tag comes in the format 'refs/tags/xxx'.
+        # So if we split on '/' and take the 3rd value, we can get the release name.
+        run: |
+          NEW_VERSION=$(echo "${GITHUB_REF}" | cut -d "/" -f3)
+          echo "New version: ${{ steps.vars.outputs.sha_short }}"
+          echo "Github username: ${GITHUB_ACTOR}"
+          ./gradlew -Pversion=dev-${{ 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.

README.md

@@ -29,7 +29,7 @@ and many more.
 
 # For server owners
 - Requires ProtocolLib to be installed: get the latest version [here](https://www.spigotmc.org/resources/protocollib.1997/)
-- Supports 1.16.5+
+- Supports 1.17+
 
 ## Downloads
 

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 "7.0.0"
+    id("com.github.johnrengelman.shadow") version "7.1.2"
     id("maven-publish")
     id("java")
+    kotlin("jvm") version "1.6.10"
 }
 
 dependencies {
@@ -10,9 +21,8 @@ dependencies {
     implementation(project(":eco-core:core-plugin"))
     implementation(project(":eco-core:core-proxy"))
     implementation(project(":eco-core:core-backend"))
-    implementation(project(":eco-core:core-nms:v1_16_R3"))
     implementation(project(path = ":eco-core:core-nms:v1_17_R1", configuration = "reobf"))
-    implementation(project(":eco-core:core-nms:v1_18_R1"))
+    implementation(project(path = ":eco-core:core-nms:v1_18_R1", configuration = "reobf"))
 }
 
 allprojects {
@@ -20,6 +30,7 @@ allprojects {
     apply(plugin = "java-library")
     apply(plugin = "maven-publish")
     apply(plugin = "com.github.johnrengelman.shadow")
+    apply(plugin = "kotlin")
 
     repositories {
         mavenCentral()
@@ -35,7 +46,7 @@ allprojects {
         // NMS (for jitpack compilation)
         maven("https://repo.codemc.org/repository/nms/")
 
-        // bStats, mcMMO, BentoBox
+        // mcMMO, BentoBox
         maven("https://repo.codemc.org/repository/maven-public/")
 
         // Spigot API, Bungee API
@@ -61,19 +72,33 @@ allprojects {
 
         // IridiumSkyblock
         maven("https://nexus.iridiumdevelopment.net/repository/maven-releases/")
+
+        // MythicMobs
+        maven("https://mvn.lumine.io/repository/maven-public/")
+
+        // Crunch
+        maven("https://redempt.dev")
+
+        // LibsDisguises
+        maven("https://repo.md-5.net/content/groups/public/")
     }
 
     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")
-        testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.8.1")
+        testImplementation("org.junit.jupiter:junit-jupiter-api:5.8.2")
+        testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.8.2")
         
         // Adventure
         compileOnly("net.kyori:adventure-api:4.9.3")
         compileOnly("net.kyori:adventure-text-serializer-gson:4.9.3")
         compileOnly("net.kyori:adventure-text-serializer-legacy:4.9.3")
+
+        // Other
+        compileOnly("com.google.guava:guava:31.0.1-jre")
+        compileOnly("com.github.ben-manes.caffeine:caffeine:3.0.5")
     }
 
     tasks.withType<JavaCompile> {
@@ -90,7 +115,19 @@ allprojects {
         exclude(group = "com.github.cryptomorin", module = "XSeries")
     }
 
+    configurations.testImplementation {
+        setExtendsFrom(listOf(configurations.compileOnly.get()))
+    }
+
     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

@@ -1,10 +1,3 @@
-plugins {
-    id 'com.github.johnrengelman.shadow'
-}
-
-group 'com.willfp'
-version rootProject.version
-
 dependencies {
     // Adventure
     compileOnly 'net.kyori:adventure-platform-bukkit:4.0.0'
@@ -17,10 +10,8 @@ dependencies {
     compileOnly 'com.google.code.gson:gson:2.8.8'
 }
 
-java {
-    withJavadocJar()
-}
-
+group 'com.willfp'
+version rootProject.version
 
 build.dependsOn publishToMavenLocal
 

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

@@ -4,11 +4,20 @@ import org.apache.commons.lang.Validate;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
 /**
- * Base class to hold the handler.
+ * Holds the instance of the eco handler for bridging between the frontend
+ * and backend.
  *
+ * @see Eco#getHandler()
  * @see Handler
  */
+@ApiStatus.Internal
 public final class Eco {
     /**
      * Instance of eco handler.
@@ -18,6 +27,7 @@ public final class Eco {
 
     /**
      * Set the handler.
+     *
      * @param handler The handler.
      */
     @ApiStatus.Internal
@@ -28,18 +38,18 @@ public final class Eco {
     }
 
     /**
-     * Get the instance of the eco handler.
+     * Get the instance of the eco handler; the bridge between the api frontend
+     * and the implementation backend.
      * <p>
-     * The handler is, in essence, a way to interface between the eco-api
-     * frontend module, and the eco-backend implementations.
+     * <strong>Do not use the handler in your plugins!</strong> It can and will contain
+     * breaking changes between minor versions and even patches, and you will create
+     * compatibility issues by using the handler. All parts of the handler have been abstracted
+     * into logically named API components that you can use.
      * <p>
-     * There shouldn't really be any reason to ever use the handler
-     * in your own plugins, and you are likely to break things. All parts of
-     * the handler are abstracted into logically named parts of the API.
-     * <p>
-     * In versions of eco before 6.12.0, the handler was considered part of
-     * the eco API, however it has since been moved into an internal component
-     * that shouldn't be used in your plugins.
+     * Prior to version 6.12.0, the handler was considered as an API component, but it has
+     * since been moved into an internal component, and in 6.17.0, the first breaking change
+     * was introduced to {@link com.willfp.eco.core.config.wrapper.ConfigFactory}. This means
+     * that any usages of the handler can now cause problems in your plugins.
      *
      * @return The handler.
      */
@@ -48,6 +58,24 @@ public final class Eco {
         return handler;
     }
 
+    /**
+     * Eco Handler components are internals, so if a class is marked as a handler component,
+     * then it should be treated the same as if it was marked with {@link ApiStatus.Internal}.
+     * <p>
+     * If a class is marked with {@link HandlerComponent}, <strong>Do not reference it in
+     * your code!</strong> It can and will contain breaking changes between minor versions and
+     * even patches, and you will create compatibility issues by using them.
+     * <p>
+     * Handler components should also be marked with {@link ApiStatus.Internal} in order to
+     * cause compiler / IDE warnings.
+     */
+    @Documented
+    @Retention(RetentionPolicy.CLASS)
+    @Target({ElementType.TYPE})
+    public @interface HandlerComponent {
+
+    }
+
     private Eco() {
         throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
     }

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

@@ -14,7 +14,6 @@ import com.willfp.eco.core.factory.NamespacedKeyFactory;
 import com.willfp.eco.core.factory.RunnableFactory;
 import com.willfp.eco.core.integrations.IntegrationLoader;
 import com.willfp.eco.core.integrations.placeholder.PlaceholderManager;
-import com.willfp.eco.core.proxy.AbstractProxy;
 import com.willfp.eco.core.proxy.ProxyFactory;
 import com.willfp.eco.core.scheduling.Scheduler;
 import com.willfp.eco.core.web.UpdateChecker;
@@ -32,6 +31,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
@@ -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'
-        method that only exists in EcoSpigotPlugin - but that feels really dirty
+        The other alternative would be to use reflection to get a 'createHandler'
+        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;
-        this.bStatsId = bStatsId;
-        this.proxyPackage = proxyPackage;
-        this.color = color;
-        this.supportingExtensions = supportingExtensions;
+        PluginProps generatedProps = Eco.getHandler().getProps(pluginProps, this.getClass());
+        generatedProps.validate();
+        PluginProps props = this.mutateProps(generatedProps);
+        props.validate();
+
+        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
-        because they have an outdated version of eco installed.
+        can throw errors without it being obvious to the user that the reason is that
+        they have an outdated version of eco installed.
          */
 
         DefaultArtifactVersion runningVersion = new DefaultArtifactVersion(Eco.getHandler().getEcoPlugin().getDescription().getVersion());
@@ -327,11 +353,9 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
                 DefaultArtifactVersion mostRecentVersion = new DefaultArtifactVersion(version);
                 if (!(currentVersion.compareTo(mostRecentVersion) > 0 || currentVersion.equals(mostRecentVersion))) {
                     this.outdated = true;
-                    this.getScheduler().runTimer(() -> {
-                        this.getLogger().info("&c " + this.getName() + " is out of date! (Version " + this.getDescription().getVersion() + ")");
-                        this.getLogger().info("&cThe newest version is &f" + version);
-                        this.getLogger().info("&cDownload the new version!");
-                    }, 0, 864000);
+                    this.getLogger().warning("&c" + this.getName() + " is out of date! (Version " + this.getDescription().getVersion() + ")");
+                    this.getLogger().warning("&cThe newest version is &f" + version);
+                    this.getLogger().warning("&cDownload the new version!");
                 }
             });
         }
@@ -536,6 +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.
      *
@@ -636,8 +675,8 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
      * @param <T>        The proxy type.
      * @return The proxy.
      */
-    public final <T extends AbstractProxy> T getProxy(@NotNull final Class<T> proxyClass) {
-        Validate.notNull(proxyFactory, "Plugin does not support proxy!");
+    public final <T> T getProxy(@NotNull final Class<T> proxyClass) {
+        Validate.notNull(proxyFactory, "Plugin does not support proxies!");
 
         return proxyFactory.getProxy(proxyClass);
     }
@@ -655,7 +694,7 @@ public abstract class EcoPlugin extends JavaPlugin implements PluginLike {
     public final FileConfiguration getConfig() {
         this.getLogger().warning("Call to default config method in eco plugin!");
 
-        return this.getConfigYml().getBukkitHandle();
+        return Objects.requireNonNull(this.getConfigYml().getBukkitHandle());
     }
 
     /**

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

@@ -2,7 +2,7 @@ package com.willfp.eco.core;
 
 import com.willfp.eco.core.config.updating.ConfigHandler;
 import com.willfp.eco.core.config.wrapper.ConfigFactory;
-import com.willfp.eco.core.data.PlayerProfileHandler;
+import com.willfp.eco.core.data.ProfileHandler;
 import com.willfp.eco.core.data.keys.KeyRegistry;
 import com.willfp.eco.core.drops.DropQueueFactory;
 import com.willfp.eco.core.events.EventManager;
@@ -15,9 +15,11 @@ 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;
+import org.bukkit.NamespacedKey;
+import org.bukkit.entity.Entity;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
@@ -30,6 +32,7 @@ import java.util.logging.Logger;
  * @see Eco#getHandler()
  */
 @ApiStatus.Internal
+@SuppressWarnings("removal")
 public interface Handler {
     /**
      * Create a scheduler.
@@ -201,14 +204,6 @@ public interface Handler {
      */
     void registerBStats(@NotNull EcoPlugin plugin);
 
-    /**
-     * Get the requirement factory.
-     *
-     * @return The factory.
-     */
-    @NotNull
-    RequirementFactory getRequirementFactory();
-
     /**
      * Get Adventure audiences.
      *
@@ -230,5 +225,41 @@ public interface Handler {
      *
      * @return The handler.
      */
-    PlayerProfileHandler getPlayerProfileHandler();
+    @NotNull
+    ProfileHandler getProfileHandler();
+
+    /**
+     * Create dummy entity - never spawned, exists purely in code.
+     *
+     * @param location The location.
+     * @return The entity.
+     */
+    @NotNull
+    Entity createDummyEntity(@NotNull Location location);
+
+    /**
+     * Create a {@link NamespacedKey} quickly
+     * <p>
+     * Bypasses the constructor, allowing for the creation of invalid keys,
+     * therefore this is considered unsafe and should only be called after
+     * the key has been confirmed to be valid.
+     *
+     * @param namespace The namespace.
+     * @param key       The key.
+     * @return The key.
+     */
+    @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/PluginDependent.java

@@ -4,6 +4,13 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Quick DI class to manage passing eco plugins.
+ * <p>
+ * Basically just a quick bit of laziness if you can't be bothered to add a private field
+ * and a protected getter, don't use this in kotlin as you can just specify
+ * {@code
+ * private val plugin: EcoPlugin
+ * }
+ * in the constructor.
  *
  * @param <T> The eco plugin type.
  */

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

@@ -3,6 +3,7 @@ package com.willfp.eco.core;
 import com.willfp.eco.core.config.updating.ConfigHandler;
 
 import java.io.File;
+import java.util.logging.Logger;
 
 /**
  * Represents any class that acts like a plugin, for example {@link EcoPlugin}
@@ -26,4 +27,11 @@ public interface PluginLike {
      * @return The config handler.
      */
     ConfigHandler getConfigHandler();
+
+    /**
+     * Get the logger.
+     *
+     * @return The logger.
+     */
+    Logger getLogger();
 }

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/Prerequisite.java

@@ -51,7 +51,10 @@ public class Prerequisite {
 
     /**
      * Requires the server to be running 1.17.
+     *
+     * @deprecated eco no longer supports versions before 1.17.
      */
+    @Deprecated(since = "6.25.2")
     public static final Prerequisite HAS_1_17 = new Prerequisite(
             () -> ProxyConstants.NMS_VERSION.contains("17") || HAS_1_18.isMet(),
             "Requires server to be running 1.17+"

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

@@ -1,7 +1,12 @@
 package com.willfp.eco.core.command;
 
+import com.willfp.eco.core.EcoPlugin;
+import org.bukkit.command.CommandSender;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Interface for all command implementations.
  */
@@ -35,31 +40,77 @@ public interface CommandBase {
      */
     CommandBase addSubcommand(@NotNull CommandBase command);
 
+    /**
+     * Handle command execution.
+     * <p>
+     * Marked as default void with no implementation for backwards compatibility.
+     *
+     * @param sender The sender.
+     * @param args   The args.
+     */
+    default void onExecute(@NotNull CommandSender sender,
+                           @NotNull List<String> args) {
+        // Do nothing.
+    }
+
+    /**
+     * Handle tab completion.
+     * <p>
+     * Marked as default void with no implementation for backwards compatibility.
+     *
+     * @param sender The sender.
+     * @param args   The args.
+     * @return The results.
+     */
+    default List<String> tabComplete(@NotNull CommandSender sender,
+                                     @NotNull List<String> args) {
+        return new ArrayList<>();
+    }
+
+    /**
+     * Get the plugin.
+     *
+     * @return The plugin.
+     */
+    EcoPlugin getPlugin();
+
     /**
      * Get the handler.
      *
      * @return The handler.
+     * @see CommandHandler
+     * @deprecated Use {@link CommandBase#onExecute(CommandSender, List)} instead.
      */
+    @Deprecated
     CommandHandler getHandler();
 
     /**
      * Set the handler.
      *
      * @param handler The handler.
+     * @see CommandHandler
+     * @deprecated Handlers have been deprecated.
      */
+    @Deprecated
     void setHandler(@NotNull CommandHandler handler);
 
     /**
      * Get the tab completer.
      *
      * @return The tab completer.
+     * @see TabCompleteHandler
+     * @deprecated Use {@link CommandBase#tabComplete(CommandSender, List)} instead.
      */
+    @Deprecated
     TabCompleteHandler getTabCompleter();
 
     /**
      * Set the tab completer.
      *
      * @param handler The handler.
+     * @see TabCompleteHandler
+     * @deprecated Handlers have been deprecated.
      */
+    @Deprecated
     void setTabCompleter(@NotNull TabCompleteHandler handler);
 }

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

@@ -10,9 +10,13 @@ import java.util.List;
  * A command handler handles the actual code for a command.
  * <p>
  * The replacement for {@link org.bukkit.command.CommandExecutor#onCommand(CommandSender, Command, String, String[])}
+ *
  * @see CommandBase
+ * @deprecated Handlers have been deprecated. This legacy system will eventually be removed,
+ * update to use the new system: {@link CommandBase#onExecute(CommandSender, List)}.
  */
 @FunctionalInterface
+@Deprecated(since = "6.17.0")
 public interface CommandHandler {
     /**
      * The code to be called on execution.

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

@@ -10,9 +10,13 @@ import java.util.List;
  * A Tab Complete handler handles the actual tab-completion code.
  * <p>
  * The replacement for {@link org.bukkit.command.TabCompleter#onTabComplete(CommandSender, Command, String, String[])}
+ *
  * @see CommandBase
+ * @deprecated Handlers have been deprecated. This legacy system will eventually be removed,
+ * update to use the new system: {@link CommandBase#tabComplete(CommandSender, List)}
  */
 @FunctionalInterface
+@Deprecated(since = "6.17.0")
 public interface TabCompleteHandler {
     /**
      * Handle Tab Completion.

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;
@@ -9,6 +8,7 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.bukkit.util.StringUtil;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -23,7 +23,13 @@ import java.util.stream.Collectors;
  * in order to execute the command-specific code. It's essentially an internal
  * layer, hence why it's a package-private class.
  */
-abstract class HandledCommand extends PluginDependent<EcoPlugin> implements CommandBase {
+@SuppressWarnings({"DeprecatedIsStillUsed"})
+abstract class HandledCommand implements CommandBase {
+    /**
+     * The plugin.
+     */
+    private final EcoPlugin plugin;
+
     /**
      * The name of the command.
      */
@@ -46,14 +52,16 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
     /**
      * The actual code to be executed in the command.
      */
-    private CommandHandler handler = (sender, args) -> {
-        // Do nothing by default
-    };
+    @Deprecated
+    @Nullable
+    private CommandHandler handler = null;
 
     /**
      * The tab completion code to be executed in the command.
      */
-    private TabCompleteHandler tabCompleter = (sender, args) -> new ArrayList<>();
+    @Deprecated
+    @Nullable
+    private TabCompleteHandler tabCompleter = null;
 
     /**
      * All subcommands for the command.
@@ -74,7 +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;
@@ -94,6 +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.
      *
@@ -120,7 +138,16 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
             }
         }
 
-        this.getHandler().onExecute(sender, Arrays.asList(args));
+        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 {
+            this.onExecute(sender, Arrays.asList(args));
+        }
     }
 
     /**
@@ -167,7 +194,11 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
             }
         }
 
-        return this.getTabCompleter().tabComplete(sender, Arrays.asList(args));
+        if (this.getTabCompleter() != null) {
+            return this.getTabCompleter().tabComplete(sender, Arrays.asList(args));
+        } else {
+            return this.tabComplete(sender, Arrays.asList(args));
+        }
     }
 
     /**
@@ -181,11 +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;
@@ -221,24 +247,6 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
         return this.playersOnly;
     }
 
-    /**
-     * Get the actual code to be executed in the command.
-     *
-     * @return The code.
-     */
-    public CommandHandler getHandler() {
-        return this.handler;
-    }
-
-    /**
-     * Get the tab completion code to be executed in the command.
-     *
-     * @return The code.
-     */
-    public TabCompleteHandler getTabCompleter() {
-        return this.tabCompleter;
-    }
-
     /**
      * Get the subcommands of the command.
      *
@@ -248,21 +256,27 @@ abstract class HandledCommand extends PluginDependent<EcoPlugin> implements Comm
         return this.subcommands;
     }
 
-    /**
-     * Set the command handler.
-     *
-     * @param handler The handler.
-     */
-    public void setHandler(@NotNull final CommandHandler handler) {
+    @Deprecated
+    @Override
+    public @Nullable CommandHandler getHandler() {
+        return this.handler;
+    }
+
+    @Deprecated
+    @Override
+    public @Nullable TabCompleteHandler getTabCompleter() {
+        return this.tabCompleter;
+    }
+
+    @Deprecated
+    @Override
+    public void setHandler(@Nullable final CommandHandler handler) {
         this.handler = handler;
     }
 
-    /**
-     * Set the tab completer.
-     *
-     * @param tabCompleter The tab completer.
-     */
-    public void setTabCompleter(@NotNull final TabCompleteHandler tabCompleter) {
+    @Deprecated
+    @Override
+    public void setTabCompleter(@Nullable final TabCompleteHandler tabCompleter) {
         this.tabCompleter = tabCompleter;
     }
 }

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

@@ -12,7 +12,9 @@ import org.jetbrains.annotations.Nullable;
 import java.util.List;
 
 /**
- * PluginCommands are the class to be used instead of CommandExecutor.
+ * PluginCommands are the class to be used instead of CommandExecutor,
+ * they function as the base command, e.g. {@code /ecoenchants} would be a base command, with each
+ * subsequent argument functioning as subcommands.
  * <p>
  * The command will not be registered until register() is called.
  * <p>

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

@@ -0,0 +1,35 @@
+package com.willfp.eco.core.config;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.wrapper.LoadableConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
+ * <p>
+ * Automatically updates.
+ */
+public abstract class BaseConfig extends LoadableConfigWrapper {
+    /**
+     * Create new Base Config.
+     *
+     * @param plugin       The plugin or extension.
+     * @param configName   The config name (excluding extension).
+     * @param removeUnused If unused sections should be removed.
+     * @param type         The config type.
+     */
+    protected BaseConfig(@NotNull final String configName,
+                         @NotNull final PluginLike plugin,
+                         final boolean removeUnused,
+                         @NotNull final ConfigType type) {
+        super(Eco.getHandler().getConfigFactory().createUpdatableConfig(
+                configName,
+                plugin,
+                "",
+                plugin.getClass(),
+                removeUnused,
+                type
+        ));
+    }
+}

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

@@ -0,0 +1,16 @@
+package com.willfp.eco.core.config;
+
+/**
+ * Config types, classified by file extension.
+ */
+public enum ConfigType {
+    /**
+     * .json config.
+     */
+    JSON,
+
+    /**
+     * .yml config.
+     */
+    YAML
+}

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

@@ -0,0 +1,44 @@
+package com.willfp.eco.core.config;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.wrapper.LoadableConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Config implementation for configs present in one of two places:
+ * <ul>
+ *     <li>Plugin base directory (eg config.yml, lang.json)</li>
+ *     <li>Other extension's configs</li>
+ * </ul>
+ * <p>
+ * Automatically updates.
+ */
+public abstract class ExtendableConfig extends LoadableConfigWrapper {
+    /**
+     * @param configName       The name of the config
+     * @param removeUnused     Whether keys not present in the default config should be removed on update.
+     * @param plugin           The plugin.
+     * @param updateBlacklist  Substring of keys to not add/remove keys for.
+     * @param subDirectoryPath The subdirectory path.
+     * @param type             The config type.
+     * @param source           The class that owns the resource.
+     */
+    protected ExtendableConfig(@NotNull final String configName,
+                               final boolean removeUnused,
+                               @NotNull final PluginLike plugin,
+                               @NotNull final Class<?> source,
+                               @NotNull final String subDirectoryPath,
+                               @NotNull final ConfigType type,
+                               @NotNull final String... updateBlacklist) {
+        super(Eco.getHandler().getConfigFactory().createUpdatableConfig(
+                configName,
+                plugin,
+                subDirectoryPath,
+                source,
+                removeUnused,
+                type,
+                updateBlacklist
+        ));
+    }
+}

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

@@ -0,0 +1,32 @@
+package com.willfp.eco.core.config;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.wrapper.LoadableConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Non-updatable yaml config that exists within a plugin jar.
+ */
+public abstract class StaticBaseConfig extends LoadableConfigWrapper {
+    /**
+     * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
+     * <p>
+     * Does not automatically update.
+     *
+     * @param configName The name of the config
+     * @param plugin     The plugin.
+     * @param type       The config type.
+     */
+    protected StaticBaseConfig(@NotNull final String configName,
+                               @NotNull final PluginLike plugin,
+                               @NotNull final ConfigType type) {
+        super(Eco.getHandler().getConfigFactory().createLoadableConfig(
+                configName,
+                plugin,
+                "",
+                plugin.getClass(),
+                type
+        ));
+    }
+}

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

@@ -0,0 +1,60 @@
+package com.willfp.eco.core.config;
+
+import com.willfp.eco.core.Eco;
+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;
+
+/**
+ * Config that exists purely in the code, not linked to any file.
+ * <p>
+ * Use for inline configs to move data around or to add subsections to other configs.
+ */
+public class TransientConfig extends ConfigWrapper<Config> {
+    /**
+     * @param config The YamlConfiguration handle.
+     */
+    public TransientConfig(@NotNull final YamlConfiguration 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.
+     *
+     * @param values The values.
+     */
+    public TransientConfig(@NotNull final Map<String, Object> values) {
+        super(Eco.getHandler().getConfigFactory().createConfig(values));
+    }
+
+    /**
+     * Create a new empty transient config.
+     */
+    public TransientConfig() {
+        super(Eco.getHandler().getConfigFactory().createConfig("", ConfigType.YAML));
+    }
+
+    /**
+     * @param contents The contents of the config.
+     * @param type     The config type.
+     */
+    public TransientConfig(@NotNull final String contents,
+                           @NotNull final ConfigType type) {
+        super(Eco.getHandler().getConfigFactory().createConfig(contents, type));
+    }
+}

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

@@ -1,20 +1,21 @@
 package com.willfp.eco.core.config.base;
 
 import com.willfp.eco.core.EcoPlugin;
-import com.willfp.eco.core.config.yaml.YamlBaseConfig;
+import com.willfp.eco.core.config.BaseConfig;
+import com.willfp.eco.core.config.ConfigType;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Default plugin config.yml.
  */
-public class ConfigYml extends YamlBaseConfig {
+public class ConfigYml extends BaseConfig {
     /**
      * Config.yml.
      *
      * @param plugin The plugin.
      */
     public ConfigYml(@NotNull final EcoPlugin plugin) {
-        super("config", true, plugin);
+        super("config", plugin, true, ConfigType.YAML);
     }
 
     /**
@@ -25,7 +26,7 @@ public class ConfigYml extends YamlBaseConfig {
      */
     public ConfigYml(@NotNull final EcoPlugin plugin,
                      final boolean removeUnused) {
-        super("config", removeUnused, plugin);
+        super("config", plugin, removeUnused, ConfigType.YAML);
     }
 
     /**
@@ -36,7 +37,7 @@ public class ConfigYml extends YamlBaseConfig {
      */
     public ConfigYml(@NotNull final EcoPlugin plugin,
                      @NotNull final String name) {
-        super(name, true, plugin);
+        super(name, plugin, true, ConfigType.YAML);
     }
 
     /**
@@ -49,7 +50,6 @@ public class ConfigYml extends YamlBaseConfig {
     public ConfigYml(@NotNull final EcoPlugin plugin,
                      @NotNull final String name,
                      final boolean removeUnused) {
-        super(name, removeUnused, plugin);
+        super(name, plugin, removeUnused, ConfigType.YAML);
     }
-
 }

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

@@ -1,21 +1,22 @@
 package com.willfp.eco.core.config.base;
 
 import com.willfp.eco.core.EcoPlugin;
-import com.willfp.eco.core.config.yaml.YamlBaseConfig;
+import com.willfp.eco.core.config.BaseConfig;
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.util.StringUtils;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Default plugin lang.yml.
  */
-public class LangYml extends YamlBaseConfig {
+public class LangYml extends BaseConfig {
     /**
      * Lang.yml.
      *
      * @param plugin The plugin.
      */
     public LangYml(@NotNull final EcoPlugin plugin) {
-        super("lang", false, plugin);
+        super("lang", plugin, false, ConfigType.YAML);
     }
 
     /**

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

@@ -1,13 +1,19 @@
 package com.willfp.eco.core.config.interfaces;
 
+import com.willfp.eco.core.config.ConfigType;
+import com.willfp.eco.core.config.TransientConfig;
+import com.willfp.eco.util.NumberUtils;
 import com.willfp.eco.util.StringUtils;
+import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 /**
- * All canfigs implement this interface.
+ * All configs implement this interface.
  * <p>
  * Contains all methods that must exist in yaml and json configurations.
  */
@@ -66,10 +72,12 @@ public interface Config extends Cloneable {
      * Get subsection from config.
      *
      * @param path The key to check.
-     * @return The subsection. Throws NPE if not found.
+     * @return The subsection. Returns an empty section if not found.
      */
     @NotNull
-    Config getSubsection(@NotNull String path);
+    default Config getSubsection(@NotNull String path) {
+        return Objects.requireNonNullElse(getSubsectionOrNull(path), new TransientConfig());
+    }
 
     /**
      * Get subsection from config.
@@ -86,7 +94,44 @@ public interface Config extends Cloneable {
      * @param path The key to fetch the value from.
      * @return The found value, or 0 if not found.
      */
-    int getInt(@NotNull String path);
+    default int getInt(@NotNull String path) {
+        return Objects.requireNonNullElse(getIntOrNull(path), 0);
+    }
+
+    /**
+     * Get an integer from config with a specified default (not found) value.
+     *
+     * @param path The key to fetch the value from.
+     * @param def  The value to default to if not found.
+     * @return The found value, or the default.
+     */
+    default int getInt(@NotNull String path,
+                       int def) {
+        return Objects.requireNonNullElse(getIntOrNull(path), def);
+    }
+
+    /**
+     * Get a decimal value via a mathematical expression.
+     *
+     * @param path The key to fetch the value from.
+     * @return The computed value, or 0 if not found or invalid.
+     */
+    default int getIntFromExpression(@NotNull String path) {
+        return getIntFromExpression(path, null);
+    }
+
+    /**
+     * Get a decimal value via a mathematical expression.
+     *
+     * @param path   The key to fetch the value from.
+     * @param player The player to evaluate placeholders with respect to.
+     * @return The computed value, or 0 if not found or invalid.
+     */
+    default int getIntFromExpression(@NotNull String path,
+                                     @Nullable Player player) {
+        return Double.valueOf(getDoubleFromExpression(path, player)).intValue();
+    }
+
 
     /**
      * Get an integer from config.
@@ -97,16 +142,6 @@ public interface Config extends Cloneable {
     @Nullable
     Integer getIntOrNull(@NotNull String path);
 
-    /**
-     * Get an integer from config with a specified default (not found) value.
-     *
-     * @param path The key to fetch the value from.
-     * @param def  The value to default to if not found.
-     * @return The found value, or the default.
-     */
-    int getInt(@NotNull String path,
-               int def);
-
     /**
      * Get a list of integers from config.
      *
@@ -114,7 +149,9 @@ public interface Config extends Cloneable {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
-    List<Integer> getInts(@NotNull String path);
+    default List<Integer> getInts(@NotNull String path) {
+        return Objects.requireNonNullElse(getIntsOrNull(path), new ArrayList<>());
+    }
 
     /**
      * Get a list of integers from config.
@@ -131,7 +168,9 @@ public interface Config extends Cloneable {
      * @param path The key to fetch the value from.
      * @return The found value, or false if not found.
      */
-    boolean getBool(@NotNull String path);
+    default boolean getBool(@NotNull String path) {
+        return Objects.requireNonNullElse(getBoolOrNull(path), false);
+    }
 
     /**
      * Get a boolean from config.
@@ -149,7 +188,9 @@ public interface Config extends Cloneable {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
-    List<Boolean> getBools(@NotNull String path);
+    default List<Boolean> getBools(@NotNull String path) {
+        return Objects.requireNonNullElse(getBoolsOrNull(path), new ArrayList<>());
+    }
 
     /**
      * Get a list of booleans from config.
@@ -168,7 +209,7 @@ public interface Config extends Cloneable {
      */
     @NotNull
     default String getFormattedString(@NotNull String path) {
-        return getString(path, true);
+        return getString(path, true, StringUtils.FormatOption.WITH_PLACEHOLDERS);
     }
 
     /**
@@ -187,25 +228,25 @@ public interface Config extends Cloneable {
     /**
      * Get a string from config.
      * <p>
-     * Formatted by default.
+     * Not formatted.
      *
      * @param path The key to fetch the value from.
      * @return The found value, or an empty string if not found.
      */
     @NotNull
     default String getString(@NotNull String path) {
-        return getString(path, true);
+        return getString(path, false, StringUtils.FormatOption.WITHOUT_PLACEHOLDERS);
     }
 
     /**
      * Get a string from config.
-     * <p>
-     * This will be deprecated when {@link Config#getString(String)} no longer formats by default.
      *
      * @param path   The key to fetch the value from.
      * @param format If the string should be formatted.
      * @return The found value, or an empty string if not found.
+     * @deprecated Since 6.18.0, {@link Config#getString(String)} is not formatted by default.
      */
+    @Deprecated(since = "6.18.0")
     default String getString(@NotNull String path,
                              boolean format) {
         return this.getString(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
@@ -235,9 +276,11 @@ public interface Config extends Cloneable {
      * @return The found value, or an empty string if not found.
      */
     @NotNull
-    String getString(@NotNull String path,
-                     boolean format,
-                     @NotNull StringUtils.FormatOption option);
+    default String getString(@NotNull String path,
+                             boolean format,
+                             @NotNull StringUtils.FormatOption option) {
+        return Objects.requireNonNullElse(getStringOrNull(path, format, option), "");
+    }
 
     /**
      * Get a formatted string from config.
@@ -247,7 +290,7 @@ public interface Config extends Cloneable {
      */
     @Nullable
     default String getFormattedStringOrNull(@NotNull String path) {
-        return getStringOrNull(path, true);
+        return getStringOrNull(path, true, StringUtils.FormatOption.WITH_PLACEHOLDERS);
     }
 
     /**
@@ -273,19 +316,19 @@ public interface Config extends Cloneable {
      */
     @Nullable
     default String getStringOrNull(@NotNull String path) {
-        return getStringOrNull(path, true);
+        return getStringOrNull(path, false, StringUtils.FormatOption.WITH_PLACEHOLDERS);
     }
 
     /**
      * Get a string from config.
-     * <p>
-     * This will be deprecated when {@link Config#getStringOrNull(String)} no longer formats by default.
      *
      * @param path   The key to fetch the value from.
      * @param format If the string should be formatted.
      * @return The found value, or null if not found.
+     * @deprecated Since 6.18.0, {@link Config#getString(String)} is not formatted by default.
      */
     @Nullable
+    @Deprecated(since = "6.18.0")
     default String getStringOrNull(@NotNull String path,
                                    boolean format) {
         return this.getStringOrNull(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
@@ -350,28 +393,26 @@ public interface Config extends Cloneable {
     /**
      * Get a list of strings from config.
      * <p>
-     * Formatted by default.
-     * <p>
-     * This will be changed in newer versions to <b>not</b> format by default.
+     * Not formatted.
      *
      * @param path The key to fetch the value from.
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
     default List<String> getStrings(@NotNull String path) {
-        return getStrings(path, true);
+        return getStrings(path, false, StringUtils.FormatOption.WITH_PLACEHOLDERS);
     }
 
     /**
      * Get a list of strings from config.
-     * <p>
-     * This will be deprecated when {@link Config#getStrings(String)} no longer formats by default.
      *
      * @param path   The key to fetch the value from.
      * @param format If the strings should be formatted.
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
+     * @deprecated Since 6.18.0, {@link Config#getString(String)} is not formatted by default.
      */
     @NotNull
+    @Deprecated(since = "6.18.0")
     default List<String> getStrings(@NotNull String path,
                                     boolean format) {
         return this.getStrings(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
@@ -389,7 +430,7 @@ public interface Config extends Cloneable {
     @Deprecated
     default List<String> getStrings(@NotNull String path,
                                     @NotNull StringUtils.FormatOption option) {
-        return getStrings(path, true, option);
+        return getStrings(path, false, option);
     }
 
     /**
@@ -401,14 +442,16 @@ public interface Config extends Cloneable {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
-    List<String> getStrings(@NotNull String path,
-                            boolean format,
-                            @NotNull StringUtils.FormatOption option);
+    default List<String> getStrings(@NotNull String path,
+                                    boolean format,
+                                    @NotNull StringUtils.FormatOption option) {
+        return Objects.requireNonNullElse(getStringsOrNull(path, format, option), new ArrayList<>());
+    }
 
     /**
      * Get a list of strings from config.
      * <p>
-     * Formatted by default.
+     * Formatted.
      *
      * @param path The key to fetch the value from.
      * @return The found value, or null if not found.
@@ -421,7 +464,7 @@ public interface Config extends Cloneable {
     /**
      * Get a list of strings from config.
      * <p>
-     * Formatted by default.
+     * Formatted.
      *
      * @param path   The key to fetch the value from.
      * @param option The format option.
@@ -436,7 +479,7 @@ public interface Config extends Cloneable {
     /**
      * Get a list of strings from config.
      * <p>
-     * Formatted by default.
+     * Not formatted.
      * <p>
      * This will be changed in newer versions to <b>not</b> format by default.
      *
@@ -445,7 +488,7 @@ public interface Config extends Cloneable {
      */
     @Nullable
     default List<String> getStringsOrNull(@NotNull String path) {
-        return getStringsOrNull(path, true);
+        return getStringsOrNull(path, false, StringUtils.FormatOption.WITH_PLACEHOLDERS);
     }
 
     /**
@@ -454,8 +497,10 @@ public interface Config extends Cloneable {
      * @param path   The key to fetch the value from.
      * @param format If the strings should be formatted.
      * @return The found value, or null if not found.
+     * @deprecated Since 6.18.0, {@link Config#getString(String)} is not formatted by default.
      */
     @Nullable
+    @Deprecated(since = "6.18.0")
     default List<String> getStringsOrNull(@NotNull String path,
                                           boolean format) {
         return getStringsOrNull(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
@@ -473,7 +518,7 @@ public interface Config extends Cloneable {
     @Deprecated
     default List<String> getStringsOrNull(@NotNull String path,
                                           @NotNull StringUtils.FormatOption option) {
-        return getStringsOrNull(path, true, option);
+        return getStringsOrNull(path, false, option);
     }
 
     /**
@@ -495,7 +540,31 @@ public interface Config extends Cloneable {
      * @param path The key to fetch the value from.
      * @return The found value, or 0 if not found.
      */
-    double getDouble(@NotNull String path);
+    default double getDouble(@NotNull String path) {
+        return Objects.requireNonNullElse(getDoubleOrNull(path), 0.0);
+    }
+
+    /**
+     * Get a decimal value via a mathematical expression.
+     *
+     * @param path The key to fetch the value from.
+     * @return The computed value, or 0 if not found or invalid.
+     */
+    default double getDoubleFromExpression(@NotNull String path) {
+        return getDoubleFromExpression(path, null);
+    }
+
+    /**
+     * Get a decimal value via a mathematical expression.
+     *
+     * @param path   The key to fetch the value from.
+     * @param player The player to evaluate placeholders with respect to.
+     * @return The computed value, or 0 if not found or invalid.
+     */
+    default double getDoubleFromExpression(@NotNull String path,
+                                           @Nullable Player player) {
+        return NumberUtils.evaluateExpression(this.getString(path), player);
+    }
 
     /**
      * Get a decimal from config.
@@ -513,7 +582,9 @@ public interface Config extends Cloneable {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
-    List<Double> getDoubles(@NotNull String path);
+    default List<Double> getDoubles(@NotNull String path) {
+        return Objects.requireNonNullElse(getDoublesOrNull(path), new ArrayList<>());
+    }
 
     /**
      * Get a list of decimals from config.
@@ -524,6 +595,34 @@ public interface Config extends Cloneable {
     @Nullable
     List<Double> getDoublesOrNull(@NotNull String path);
 
+    /**
+     * Get a list of subsections from config.
+     *
+     * @param path The key to fetch the value from.
+     * @return The found value, or a blank {@link java.util.ArrayList} if not found.
+     */
+    @NotNull
+    default List<? extends Config> getSubsections(@NotNull String path) {
+        return Objects.requireNonNullElse(getSubsectionsOrNull(path), new ArrayList<>());
+    }
+
+    /**
+     * Get a list of subsections from config.
+     *
+     * @param path The key to fetch the value from.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
+    List<? extends Config> getSubsectionsOrNull(@NotNull String path);
+
+    /**
+     * Get config type.
+     *
+     * @return The type.
+     */
+    @NotNull
+    ConfigType getType();
+
     /**
      * Clone the config.
      *

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

@@ -3,13 +3,19 @@ package com.willfp.eco.core.config.interfaces;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 /**
- * JSON configs have extra methods compared to yaml configs.
- * <p>
- * If you need to use them, then use JSONConfig instead.
+ * JSON config.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
+@SuppressWarnings("DeprecatedIsStillUsed")
 public interface JSONConfig extends Config {
     /**
      * Get a list of subsections from config.
@@ -18,7 +24,9 @@ public interface JSONConfig extends Config {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
-    List<JSONConfig> getSubsections(@NotNull String path);
+    default List<JSONConfig> getSubsections(@NotNull String path) {
+        return Objects.requireNonNullElse(getSubsectionsOrNull(path), new ArrayList<>());
+    }
 
     /**
      * Get a list of subsections from config.

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

@@ -1,12 +1,16 @@
 package com.willfp.eco.core.config.interfaces;
 
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.Nullable;
+
 import java.io.File;
 import java.io.IOException;
 
 /**
  * Interface for configs that physically exist as files in plugins.
  */
-public interface LoadableConfig {
+public interface LoadableConfig extends Config {
     /**
      * Create the file.
      */
@@ -39,4 +43,18 @@ public interface LoadableConfig {
      * @return The name.
      */
     String getName();
+
+    /**
+     * Get bukkit {@link YamlConfiguration}.
+     * <p>
+     * This method is not recommended unless absolutely required as it
+     * only returns true if the type of config is {@link com.willfp.eco.core.config.ConfigType#YAML},
+     * and if the handle is an {@link YamlConfiguration} specifically. This depends on the internals
+     * and the implementation, and so may cause problems - it exists mostly for parity with
+     * {@link JavaPlugin#getConfig()}.
+     *
+     * @return The config, or null if config is not yaml-based.
+     */
+    @Nullable
+    YamlConfiguration getBukkitHandle();
 }

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

@@ -5,8 +5,12 @@ import org.bukkit.configuration.file.YamlConfiguration;
 /**
  * Interface for configs that wrap an {@link YamlConfiguration}.
  *
- * @see com.willfp.eco.core.config.yaml.wrapper.YamlConfigWrapper
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
+@SuppressWarnings("DeprecatedIsStillUsed")
 public interface WrappedYamlConfiguration {
     /**
      * Get the ConfigurationSection handle.

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

@@ -3,6 +3,8 @@ package com.willfp.eco.core.config.json;
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
+import com.willfp.eco.core.config.interfaces.JSONConfig;
 import com.willfp.eco.core.config.json.wrapper.LoadableJSONConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
@@ -10,7 +12,12 @@ import org.jetbrains.annotations.NotNull;
  * Config implementation for configs present in the plugin's base directory (eg config.json).
  * <p>
  * Automatically updates.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class JSONBaseConfig extends LoadableJSONConfigWrapper {
     /**
      * @param configName      The name of the config
@@ -23,13 +30,16 @@ public abstract class JSONBaseConfig extends LoadableJSONConfigWrapper {
                              @NotNull final PluginLike plugin,
                              @NotNull final String... updateBlacklist) {
         super(
-                Eco.getHandler().getConfigFactory().createUpdatableJSONConfig(
-                        configName,
-                        plugin,
-                        "",
-                        plugin.getClass(),
-                        removeUnused, updateBlacklist
-                )
+                (JSONConfig)
+                        Eco.getHandler().getConfigFactory().createUpdatableConfig(
+                                configName,
+                                plugin,
+                                "",
+                                plugin.getClass(),
+                                removeUnused,
+                                ConfigType.JSON,
+                                updateBlacklist
+                        )
         );
     }
 
@@ -42,13 +52,15 @@ public abstract class JSONBaseConfig extends LoadableJSONConfigWrapper {
                              final boolean removeUnused,
                              @NotNull final PluginLike plugin) {
         super(
-                Eco.getHandler().getConfigFactory().createUpdatableJSONConfig(
-                        configName,
-                        plugin,
-                        "",
-                        plugin.getClass(),
-                        removeUnused
-                )
+                (JSONConfig)
+                        Eco.getHandler().getConfigFactory().createUpdatableConfig(
+                                configName,
+                                plugin,
+                                "",
+                                plugin.getClass(),
+                                removeUnused,
+                                ConfigType.JSON
+                        )
         );
     }
 

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

@@ -3,6 +3,8 @@ package com.willfp.eco.core.config.json;
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
+import com.willfp.eco.core.config.interfaces.JSONConfig;
 import com.willfp.eco.core.config.json.wrapper.LoadableJSONConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
@@ -14,7 +16,12 @@ import org.jetbrains.annotations.NotNull;
  * </ul>
  * <p>
  * Automatically updates.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class JSONExtendableConfig extends LoadableJSONConfigWrapper {
     /**
      * @param configName       The name of the config
@@ -31,16 +38,19 @@ public abstract class JSONExtendableConfig extends LoadableJSONConfigWrapper {
                                    @NotNull final String subDirectoryPath,
                                    @NotNull final String... updateBlacklist) {
         super(
-                Eco.getHandler().getConfigFactory().createUpdatableJSONConfig(
-                        configName,
-                        plugin,
-                        subDirectoryPath,
-                        source,
-                        removeUnused,
-                        updateBlacklist
-                )
+                (JSONConfig)
+                        Eco.getHandler().getConfigFactory().createUpdatableConfig(
+                                configName,
+                                plugin,
+                                subDirectoryPath,
+                                source,
+                                removeUnused,
+                                ConfigType.JSON,
+                                updateBlacklist
+                        )
         );
     }
+
     /**
      * @param configName       The name of the config
      * @param removeUnused     Whether keys not present in the default config should be removed on update.

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

@@ -3,12 +3,19 @@ package com.willfp.eco.core.config.json;
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
+import com.willfp.eco.core.config.interfaces.JSONConfig;
 import com.willfp.eco.core.config.json.wrapper.LoadableJSONConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Non-updatable JSON config that exists within a plugin jar.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class JSONStaticBaseConfig extends LoadableJSONConfigWrapper {
     /**
      * Config implementation for configs present in the plugin's base directory (eg config.json, lang.json).
@@ -20,7 +27,7 @@ public abstract class JSONStaticBaseConfig extends LoadableJSONConfigWrapper {
      */
     protected JSONStaticBaseConfig(@NotNull final String configName,
                                    @NotNull final PluginLike plugin) {
-        super(Eco.getHandler().getConfigFactory().createLoadableJSONConfig(configName, plugin, "", plugin.getClass()));
+        super((JSONConfig) Eco.getHandler().getConfigFactory().createLoadableConfig(configName, plugin, "", plugin.getClass(), ConfigType.JSON));
     }
 
     /**

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

@@ -1,14 +1,21 @@
 package com.willfp.eco.core.config.json;
 
 import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.config.interfaces.JSONConfig;
 import com.willfp.eco.core.config.json.wrapper.JSONConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.HashMap;
 import java.util.Map;
 
 /**
  * Raw JSON config with a map of values at its core.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public class JSONTransientConfig extends JSONConfigWrapper {
     /**
      * Config implementation for passing maps.
@@ -18,6 +25,13 @@ public class JSONTransientConfig extends JSONConfigWrapper {
      * @param values The map of values.
      */
     public JSONTransientConfig(@NotNull final Map<String, Object> values) {
-        super(Eco.getHandler().getConfigFactory().createJSONConfig(values));
+        super((JSONConfig) Eco.getHandler().getConfigFactory().createConfig(values));
+    }
+
+    /**
+     * Empty JSON config.
+     */
+    public JSONTransientConfig() {
+        super((JSONConfig) Eco.getHandler().getConfigFactory().createConfig(new HashMap<>()));
     }
 }

eco-api/src/main/java/com/willfp/eco/core/config/json/wrapper/JSONConfigWrapper.java

@@ -9,7 +9,12 @@ import java.util.List;
 
 /**
  * Wrapper to handle the backend JSON config implementations.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class JSONConfigWrapper extends ConfigWrapper<JSONConfig> implements JSONConfig {
     /**
      * Create a config wrapper.

eco-api/src/main/java/com/willfp/eco/core/config/json/wrapper/LoadableJSONConfigWrapper.java

@@ -3,14 +3,21 @@ package com.willfp.eco.core.config.json.wrapper;
 import com.willfp.eco.core.config.interfaces.JSONConfig;
 import com.willfp.eco.core.config.interfaces.LoadableConfig;
 import org.apache.commons.lang.Validate;
+import org.bukkit.configuration.file.YamlConfiguration;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.io.IOException;
 
 /**
  * Wrapper to handle the backend loadable JSON config implementations.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class LoadableJSONConfigWrapper extends JSONConfigWrapper implements LoadableConfig {
     /**
      * Create a config wrapper.
@@ -48,4 +55,9 @@ public abstract class LoadableJSONConfigWrapper extends JSONConfigWrapper implem
     public String getName() {
         return ((LoadableConfig) this.getHandle()).getName();
     }
+
+    @Override
+    public @Nullable YamlConfiguration getBukkitHandle() {
+        return null;
+    }
 }

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

@@ -23,10 +23,14 @@ import java.lang.annotation.Target;
  * <p>
  * The second:
  * <pre>{@code
- * public static void update(EcoPlugin plugin) {}
+ * public static void update(EcoPlugin plugin) {
  *     // Update code
+ * }
  * }</pre>
  * <p>
+ * If using kotlin, you have to annotate the method with {@code @JvmStatic}
+ * in order to prevent null pointer exceptions.
+ * <p>
  * Config update methods in all classes in a plugin jar will be called
  * on reload.
  * <p>

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

@@ -1,9 +1,12 @@
 package com.willfp.eco.core.config.wrapper;
 
+import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.core.config.interfaces.Config;
-import com.willfp.eco.core.config.interfaces.JSONConfig;
+import com.willfp.eco.core.config.interfaces.LoadableConfig;
 import org.bukkit.configuration.file.YamlConfiguration;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Map;
@@ -11,6 +14,8 @@ import java.util.Map;
 /**
  * Internal component to create backend config implementations.
  */
+@ApiStatus.Internal
+@Eco.HandlerComponent
 public interface ConfigFactory {
     /**
      * Updatable config.
@@ -20,75 +25,57 @@ public interface ConfigFactory {
      * @param subDirectoryPath The subdirectory path.
      * @param source           The class that owns the resource.
      * @param removeUnused     Whether keys not present in the default config should be removed on update.
+     * @param type             The config type.
      * @param updateBlacklist  Substring of keys to not add/remove keys for.
      * @return The config implementation.
      */
-    Config createUpdatableYamlConfig(@NotNull String configName,
-                                     @NotNull PluginLike plugin,
-                                     @NotNull String subDirectoryPath,
-                                     @NotNull Class<?> source,
-                                     boolean removeUnused,
-                                     @NotNull String... updateBlacklist);
-
-    /**
-     * Updatable config.
-     *
-     * @param configName       The name of the config
-     * @param plugin           The plugin.
-     * @param subDirectoryPath The subdirectory path.
-     * @param source           The class that owns the resource.
-     * @param removeUnused     Whether keys not present in the default config should be removed on update.
-     * @param updateBlacklist  Substring of keys to not add/remove keys for.
-     * @return The config implementation.
-     */
-    JSONConfig createUpdatableJSONConfig(@NotNull String configName,
+    LoadableConfig createUpdatableConfig(@NotNull String configName,
                                          @NotNull PluginLike plugin,
                                          @NotNull String subDirectoryPath,
                                          @NotNull Class<?> source,
                                          boolean removeUnused,
+                                         @NotNull ConfigType type,
                                          @NotNull String... updateBlacklist);
 
     /**
-     * JSON loadable config.
+     * Loadable config.
      *
      * @param configName       The name of the config
      * @param plugin           The plugin.
      * @param subDirectoryPath The subdirectory path.
      * @param source           The class that owns the resource.
+     * @param type             The config type.
      * @return The config implementation.
      */
-    JSONConfig createLoadableJSONConfig(@NotNull String configName,
+    LoadableConfig createLoadableConfig(@NotNull String configName,
                                         @NotNull PluginLike plugin,
                                         @NotNull String subDirectoryPath,
-                                        @NotNull Class<?> source);
+                                        @NotNull Class<?> source,
+                                        @NotNull ConfigType type);
 
     /**
-     * Yaml loadable config.
-     *
-     * @param configName       The name of the config
-     * @param plugin           The plugin.
-     * @param subDirectoryPath The subdirectory path.
-     * @param source           The class that owns the resource.
-     * @return The config implementation.
-     */
-    Config createLoadableYamlConfig(@NotNull String configName,
-                                    @NotNull PluginLike plugin,
-                                    @NotNull String subDirectoryPath,
-                                    @NotNull Class<?> source);
-
-    /**
-     * Yaml config.
+     * Create config.
      *
      * @param config The handle.
      * @return The config implementation.
      */
-    Config createYamlConfig(@NotNull YamlConfiguration config);
+    Config createConfig(@NotNull YamlConfiguration config);
 
     /**
-     * JSON config.
+     * Create config.
      *
      * @param values The values.
      * @return The config implementation.
      */
-    JSONConfig createJSONConfig(@NotNull Map<String, Object> values);
+    Config createConfig(@NotNull Map<String, Object> values);
+
+    /**
+     * Create config.
+     *
+     * @param contents The file contents.
+     * @param type     The type.
+     * @return The config implementation.
+     */
+    Config createConfig(@NotNull String contents,
+                        @NotNull ConfigType type);
 }

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

@@ -1,5 +1,6 @@
 package com.willfp.eco.core.config.wrapper;
 
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.core.config.interfaces.Config;
 import com.willfp.eco.util.StringUtils;
 import org.jetbrains.annotations.NotNull;
@@ -15,6 +16,7 @@ import java.util.List;
  *
  * @param <T> The type of the handle.
  */
+@SuppressWarnings("MethodDoesntCallSuperMethod")
 public abstract class ConfigWrapper<T extends Config> implements Config {
     /**
      * Configs from eco have an internal implementation,
@@ -68,70 +70,31 @@ public abstract class ConfigWrapper<T extends Config> implements Config {
         handle.set(path, object);
     }
 
-    @Override
-    public @NotNull Config getSubsection(@NotNull final String path) {
-        return handle.getSubsection(path);
-    }
-
     @Override
     public @Nullable Config getSubsectionOrNull(@NotNull final String path) {
         return handle.getSubsectionOrNull(path);
     }
 
-    @Override
-    public int getInt(@NotNull final String path) {
-        return handle.getInt(path);
-    }
-
     @Override
     public @Nullable Integer getIntOrNull(@NotNull final String path) {
         return handle.getIntOrNull(path);
     }
 
-    @Override
-    public int getInt(@NotNull final String path,
-                      final int def) {
-        return handle.getInt(path, def);
-    }
-
-    @Override
-    public @NotNull List<Integer> getInts(@NotNull final String path) {
-        return handle.getInts(path);
-    }
-
     @Override
     public @Nullable List<Integer> getIntsOrNull(@NotNull final String path) {
         return handle.getIntsOrNull(path);
     }
 
-    @Override
-    public boolean getBool(@NotNull final String path) {
-        return handle.getBool(path);
-    }
-
     @Override
     public @Nullable Boolean getBoolOrNull(@NotNull final String path) {
         return handle.getBoolOrNull(path);
     }
 
-    @Override
-    public @NotNull List<Boolean> getBools(@NotNull final String path) {
-        return handle.getBools(path);
-    }
-
     @Override
     public @Nullable List<Boolean> getBoolsOrNull(@NotNull final String path) {
         return handle.getBoolsOrNull(path);
     }
 
-
-    @Override
-    public @NotNull String getString(@NotNull final String path,
-                                     final boolean format,
-                                     @NotNull final StringUtils.FormatOption option) {
-        return handle.getString(path, format, option);
-    }
-
     @Override
     public @Nullable String getStringOrNull(@NotNull final String path,
                                             final boolean format,
@@ -139,13 +102,6 @@ public abstract class ConfigWrapper<T extends Config> implements Config {
         return handle.getStringOrNull(path, format, option);
     }
 
-    @Override
-    public @NotNull List<String> getStrings(@NotNull final String path,
-                                            final boolean format,
-                                            @NotNull final StringUtils.FormatOption option) {
-        return handle.getStrings(path, format, option);
-    }
-
     @Override
     public @Nullable List<String> getStringsOrNull(@NotNull final String path,
                                                    final boolean format,
@@ -153,31 +109,31 @@ public abstract class ConfigWrapper<T extends Config> implements Config {
         return handle.getStringsOrNull(path, format, option);
     }
 
-    @Override
-    public double getDouble(@NotNull final String path) {
-        return handle.getDouble(path);
-    }
-
     @Override
     public @Nullable Double getDoubleOrNull(@NotNull final String path) {
         return handle.getDoubleOrNull(path);
     }
 
-    @Override
-    public @NotNull List<Double> getDoubles(@NotNull final String path) {
-        return handle.getDoubles(path);
-    }
-
     @Override
     public @Nullable List<Double> getDoublesOrNull(@NotNull final String path) {
         return handle.getDoublesOrNull(path);
     }
 
+    @Override
+    public @Nullable List<? extends Config> getSubsectionsOrNull(@NotNull final String path) {
+        return handle.getSubsectionsOrNull(path);
+    }
+
     @Override
     public Config clone() {
         return handle.clone();
     }
 
+    @Override
+    public @NotNull ConfigType getType() {
+        return handle.getType();
+    }
+
     /**
      * Get the handle.
      *

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

@@ -0,0 +1,53 @@
+package com.willfp.eco.core.config.wrapper;
+
+import com.willfp.eco.core.config.interfaces.LoadableConfig;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Wrapper to handle the backend loadable yaml config implementations.
+ */
+public abstract class LoadableConfigWrapper extends ConfigWrapper<LoadableConfig> implements LoadableConfig {
+    /**
+     * Create a config wrapper.
+     *
+     * @param handle The handle.
+     */
+    protected LoadableConfigWrapper(@NotNull final LoadableConfig handle) {
+        super(handle);
+    }
+
+    @Override
+    public void createFile() {
+        this.getHandle().createFile();
+    }
+
+    @Override
+    public String getResourcePath() {
+        return this.getHandle().getResourcePath();
+    }
+
+    @Override
+    public void save() throws IOException {
+        this.getHandle().save();
+    }
+
+    @Override
+    public File getConfigFile() {
+        return this.getHandle().getConfigFile();
+    }
+
+    @Override
+    public String getName() {
+        return this.getHandle().getName();
+    }
+
+    @Override
+    public @Nullable YamlConfiguration getBukkitHandle() {
+        return this.getHandle().getBukkitHandle();
+    }
+}

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

@@ -3,6 +3,7 @@ package com.willfp.eco.core.config.yaml;
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.core.config.yaml.wrapper.LoadableYamlConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
@@ -10,7 +11,12 @@ import org.jetbrains.annotations.NotNull;
  * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
  * <p>
  * Automatically updates.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class YamlBaseConfig extends LoadableYamlConfigWrapper {
     /**
      * @param configName      The name of the config
@@ -23,12 +29,14 @@ public abstract class YamlBaseConfig extends LoadableYamlConfigWrapper {
                              @NotNull final PluginLike plugin,
                              @NotNull final String... updateBlacklist) {
         super(
-                Eco.getHandler().getConfigFactory().createUpdatableYamlConfig(
+                Eco.getHandler().getConfigFactory().createUpdatableConfig(
                         configName,
                         plugin,
                         "",
                         plugin.getClass(),
-                        removeUnused, updateBlacklist
+                        removeUnused,
+                        ConfigType.YAML,
+                        updateBlacklist
                 )
         );
     }
@@ -42,12 +50,13 @@ public abstract class YamlBaseConfig extends LoadableYamlConfigWrapper {
                              final boolean removeUnused,
                              @NotNull final PluginLike plugin) {
         super(
-                Eco.getHandler().getConfigFactory().createUpdatableYamlConfig(
+                Eco.getHandler().getConfigFactory().createUpdatableConfig(
                         configName,
                         plugin,
                         "",
                         plugin.getClass(),
-                        removeUnused
+                        removeUnused,
+                        ConfigType.YAML
                 )
         );
     }

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

@@ -3,6 +3,7 @@ package com.willfp.eco.core.config.yaml;
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.core.config.yaml.wrapper.LoadableYamlConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
@@ -14,7 +15,12 @@ import org.jetbrains.annotations.NotNull;
  * </ul>
  * <p>
  * Automatically updates.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class YamlExtendableConfig extends LoadableYamlConfigWrapper {
     /**
      * @param configName       The name of the config
@@ -31,16 +37,18 @@ public abstract class YamlExtendableConfig extends LoadableYamlConfigWrapper {
                                    @NotNull final String subDirectoryPath,
                                    @NotNull final String... updateBlacklist) {
         super(
-                Eco.getHandler().getConfigFactory().createUpdatableYamlConfig(
+                Eco.getHandler().getConfigFactory().createUpdatableConfig(
                         configName,
                         plugin,
                         subDirectoryPath,
                         source,
                         removeUnused,
+                        ConfigType.YAML,
                         updateBlacklist
                 )
         );
     }
+
     /**
      * @param configName       The name of the config
      * @param removeUnused     Whether keys not present in the default config should be removed on update.

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

@@ -3,12 +3,18 @@ package com.willfp.eco.core.config.yaml;
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginLike;
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.core.config.yaml.wrapper.LoadableYamlConfigWrapper;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Non-updatable yaml config that exists within a plugin jar.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class YamlStaticBaseConfig extends LoadableYamlConfigWrapper {
     /**
      * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
@@ -20,7 +26,7 @@ public abstract class YamlStaticBaseConfig extends LoadableYamlConfigWrapper {
      */
     protected YamlStaticBaseConfig(@NotNull final String configName,
                                    @NotNull final PluginLike plugin) {
-        super(Eco.getHandler().getConfigFactory().createLoadableYamlConfig(configName, plugin, "", plugin.getClass()));
+        super(Eco.getHandler().getConfigFactory().createLoadableConfig(configName, plugin, "", plugin.getClass(), ConfigType.YAML));
     }
 
     /**

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

@@ -1,6 +1,7 @@
 package com.willfp.eco.core.config.yaml;
 
 import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.config.ConfigType;
 import com.willfp.eco.core.config.yaml.wrapper.YamlConfigWrapper;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.jetbrains.annotations.NotNull;
@@ -11,19 +12,31 @@ import java.io.StringReader;
  * Config implementation for passing YamlConfigurations.
  * <p>
  * Does not automatically update.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public class YamlTransientConfig extends YamlConfigWrapper {
     /**
-     * @param config     The YamlConfiguration handle.
+     * @param config The YamlConfiguration handle.
      */
     public YamlTransientConfig(@NotNull final YamlConfiguration config) {
-        super(Eco.getHandler().getConfigFactory().createYamlConfig(config));
+        super(Eco.getHandler().getConfigFactory().createConfig(config));
     }
 
     /**
-     * @param contents     The contents of the config.
+     * @param contents The contents of the config.
      */
     public YamlTransientConfig(@NotNull final String contents) {
-        super(Eco.getHandler().getConfigFactory().createYamlConfig(YamlConfiguration.loadConfiguration(new StringReader(contents))));
+        super(Eco.getHandler().getConfigFactory().createConfig(contents, ConfigType.YAML));
+    }
+
+    /**
+     * Create a new empty transient config.
+     */
+    public YamlTransientConfig() {
+        super(Eco.getHandler().getConfigFactory().createConfig(YamlConfiguration.loadConfiguration(new StringReader(""))));
     }
 }

eco-api/src/main/java/com/willfp/eco/core/config/yaml/wrapper/LoadableYamlConfigWrapper.java

@@ -3,14 +3,21 @@ package com.willfp.eco.core.config.yaml.wrapper;
 import com.willfp.eco.core.config.interfaces.Config;
 import com.willfp.eco.core.config.interfaces.LoadableConfig;
 import org.apache.commons.lang.Validate;
+import org.bukkit.configuration.file.YamlConfiguration;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.io.IOException;
 
 /**
  * Wrapper to handle the backend loadable yaml config implementations.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class LoadableYamlConfigWrapper extends YamlConfigWrapper implements LoadableConfig {
     /**
      * Create a config wrapper.
@@ -48,4 +55,9 @@ public abstract class LoadableYamlConfigWrapper extends YamlConfigWrapper implem
     public String getName() {
         return ((LoadableConfig) this.getHandle()).getName();
     }
+
+    @Override
+    public @Nullable YamlConfiguration getBukkitHandle() {
+        return ((LoadableConfig) this.getHandle()).getBukkitHandle();
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/config/yaml/wrapper/YamlConfigWrapper.java

@@ -8,7 +8,12 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Wrapper to handle the backend yaml config implementations.
+ *
+ * @deprecated JSON and yml have full parity, use configs without a prefix instead,
+ * eg {@link com.willfp.eco.core.config.TransientConfig}, {@link com.willfp.eco.core.config.BaseConfig}.
+ * These configs will be removed eventually.
  */
+@Deprecated(since = "6.17.0")
 public abstract class YamlConfigWrapper extends ConfigWrapper<Config> implements WrappedYamlConfiguration {
     /**
      * Create a config wrapper.

eco-api/src/main/java/com/willfp/eco/core/data/PlayerProfile.java

@@ -1,7 +1,6 @@
 package com.willfp.eco.core.data;
 
 import com.willfp.eco.core.Eco;
-import com.willfp.eco.core.data.keys.PersistentDataKey;
 import org.bukkit.OfflinePlayer;
 import org.jetbrains.annotations.NotNull;
 
@@ -12,26 +11,7 @@ import java.util.UUID;
  * <p>
  * Profiles save automatically, so there is no need to save after changes.
  */
-public interface PlayerProfile {
-    /**
-     * Write a key to a player's persistent data.
-     *
-     * @param key   The key.
-     * @param value The value.
-     * @param <T>   The type of the key.
-     */
-    <T> void write(@NotNull PersistentDataKey<T> key,
-                   @NotNull T value);
-
-    /**
-     * Read a key from a player's persistent data.
-     *
-     * @param key The key.
-     * @param <T> The type of the key.
-     * @return The value, or the default value if not found.
-     */
-    <T> @NotNull T read(@NotNull PersistentDataKey<T> key);
-
+public interface PlayerProfile extends Profile {
     /**
      * Load a player profile.
      *
@@ -51,6 +31,6 @@ public interface PlayerProfile {
      */
     @NotNull
     static PlayerProfile load(@NotNull final UUID uuid) {
-        return Eco.getHandler().getPlayerProfileHandler().load(uuid);
+        return Eco.getHandler().getProfileHandler().load(uuid);
     }
 }

eco-api/src/main/java/com/willfp/eco/core/data/Profile.java

@@ -0,0 +1,30 @@
+package com.willfp.eco.core.data;
+
+import com.willfp.eco.core.data.keys.PersistentDataKey;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Persistent data storage interface.
+ * <p>
+ * Profiles save automatically, so there is no need to save after changes.
+ */
+public interface Profile {
+    /**
+     * Write a key to persistent data.
+     *
+     * @param key   The key.
+     * @param value The value.
+     * @param <T>   The type of the key.
+     */
+    <T> void write(@NotNull PersistentDataKey<T> key,
+                   @NotNull T value);
+
+    /**
+     * Read a key from persistent data.
+     *
+     * @param key The key.
+     * @param <T> The type of the key.
+     * @return The value, or the default value if not found.
+     */
+    <T> @NotNull T read(@NotNull PersistentDataKey<T> key);
+}

eco-api/src/main/java/com/willfp/eco/core/data/ProfileHandler.java

@@ -1,15 +1,19 @@
 package com.willfp.eco.core.data;
 
+import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.data.keys.PersistentDataKey;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Set;
 import java.util.UUID;
 
 /**
- * API to handle player profiles.
+ * API to handle profiles.
  */
-public interface PlayerProfileHandler {
+@ApiStatus.Internal
+@Eco.HandlerComponent
+public interface ProfileHandler {
     /**
      * Load a player profile.
      *
@@ -18,6 +22,13 @@ public interface PlayerProfileHandler {
      */
     PlayerProfile load(@NotNull UUID uuid);
 
+    /**
+     * Load the server profile.
+     *
+     * @return The profile.
+     */
+    ServerProfile loadServerProfile();
+
     /**
      * Unload a player profile from memory.
      * <p>
@@ -37,7 +48,7 @@ public interface PlayerProfileHandler {
      */
     @Deprecated
     default void savePlayer(@NotNull UUID uuid) {
-        this.saveKeysForPlayer(uuid, PersistentDataKey.values());
+        this.saveKeysFor(uuid, PersistentDataKey.values());
     }
 
     /**
@@ -48,8 +59,8 @@ public interface PlayerProfileHandler {
      * @param uuid The uuid.
      * @param keys The keys.
      */
-    void saveKeysForPlayer(@NotNull UUID uuid,
-                           @NotNull Set<PersistentDataKey<?>> keys);
+    void saveKeysFor(@NotNull UUID uuid,
+                     @NotNull Set<PersistentDataKey<?>> keys);
 
     /**
      * Save all player data.

eco-api/src/main/java/com/willfp/eco/core/data/ServerProfile.java

@@ -0,0 +1,21 @@
+package com.willfp.eco.core.data;
+
+import com.willfp.eco.core.Eco;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Persistent data storage interface for servers.
+ * <p>
+ * Profiles save automatically, so there is no need to save after changes.
+ */
+public interface ServerProfile extends Profile {
+    /**
+     * Load the server profile.
+     *
+     * @return The profile.
+     */
+    @NotNull
+    static ServerProfile load() {
+        return Eco.getHandler().getProfileHandler().loadServerProfile();
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/data/keys/KeyRegistry.java

@@ -1,12 +1,18 @@
 package com.willfp.eco.core.data.keys;
 
+import com.willfp.eco.core.Eco;
+import org.bukkit.NamespacedKey;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Set;
 
 /**
  * API to register persistent data keys.
  */
+@ApiStatus.Internal
+@Eco.HandlerComponent
 public interface KeyRegistry {
     /**
      * Register a persistent data key to be stored.
@@ -21,4 +27,37 @@ public interface KeyRegistry {
      * @return The keys.
      */
     Set<PersistentDataKey<?>> getRegisteredKeys();
+
+    /**
+     * Mark key as category.
+     *
+     * @param key      The key.
+     * @param category The category.
+     */
+    void markKeyAs(@NotNull PersistentDataKey<?> key,
+                   @NotNull KeyRegistry.KeyCategory category);
+
+    /**
+     * Get persistent data key from namespaced key.
+     *
+     * @param namespacedKey The key.
+     * @return The key, or null if not found.
+     */
+    @Nullable
+    PersistentDataKey<?> getKeyFrom(@NotNull NamespacedKey namespacedKey);
+
+    /**
+     * Locations for key categorization.
+     */
+    enum KeyCategory {
+        /**
+         * Player keys.
+         */
+        PLAYER,
+
+        /**
+         * Server keys.
+         */
+        SERVER
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/data/keys/PersistentDataKey.java

@@ -3,7 +3,9 @@ package com.willfp.eco.core.data.keys;
 import com.willfp.eco.core.Eco;
 import org.bukkit.NamespacedKey;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
+import java.util.Objects;
 import java.util.Set;
 
 /**
@@ -11,7 +13,7 @@ import java.util.Set;
  *
  * @param <T> The type of the data.
  */
-public class PersistentDataKey<T> {
+public final class PersistentDataKey<T> {
     /**
      * The key of the persistent data value.
      */
@@ -25,7 +27,7 @@ public class PersistentDataKey<T> {
     /**
      * The persistent data key type.
      */
-    private final PersistentDataKeyType type;
+    private final PersistentDataKeyType<T> type;
 
     /**
      * Create a new Persistent Data Key.
@@ -35,7 +37,7 @@ public class PersistentDataKey<T> {
      * @param defaultValue The default value.
      */
     public PersistentDataKey(@NotNull final NamespacedKey key,
-                             @NotNull final PersistentDataKeyType type,
+                             @NotNull final PersistentDataKeyType<T> type,
                              @NotNull final T defaultValue) {
         this.key = key;
         this.defaultValue = defaultValue;
@@ -53,15 +55,6 @@ public class PersistentDataKey<T> {
                 + '}';
     }
 
-    /**
-     * Get all persistent data keys.
-     *
-     * @return The keys.
-     */
-    public static Set<PersistentDataKey<?>> values() {
-        return Eco.getHandler().getKeyRegistry().getRegisteredKeys();
-    }
-
     /**
      * Get the key.
      *
@@ -85,7 +78,58 @@ public class PersistentDataKey<T> {
      *
      * @return The key type.
      */
-    public PersistentDataKeyType getType() {
+    public PersistentDataKeyType<T> getType() {
         return this.type;
     }
+
+    /**
+     * Categorize key as a server key, will register new column to MySQL
+     * database immediately rather than waiting for auto-categorization.
+     * <p>
+     * This will improve performance.
+     *
+     * @return The key.
+     */
+    public PersistentDataKey<T> server() {
+        Eco.getHandler().getKeyRegistry().markKeyAs(this, KeyRegistry.KeyCategory.SERVER);
+        return this;
+    }
+
+    /**
+     * Categorize key as a player key, will register new column to MySQL
+     * database immediately rather than waiting for auto-categorization.
+     * <p>
+     * This will improve performance.
+     *
+     * @return The key.
+     */
+    public PersistentDataKey<T> player() {
+        Eco.getHandler().getKeyRegistry().markKeyAs(this, KeyRegistry.KeyCategory.PLAYER);
+        return this;
+    }
+
+    /**
+     * Get all persistent data keys.
+     *
+     * @return The keys.
+     */
+    public static Set<PersistentDataKey<?>> values() {
+        return Eco.getHandler().getKeyRegistry().getRegisteredKeys();
+    }
+
+    @Override
+    public boolean equals(@Nullable final Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof PersistentDataKey that)) {
+            return false;
+        }
+        return Objects.equals(this.getKey(), that.getKey());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.getKey());
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/data/keys/PersistentDataKeyType.java

@@ -1,26 +1,108 @@
 package com.willfp.eco.core.data.keys;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * All storable data key types.
+ *
+ * @param <T> The type.
  */
-public enum PersistentDataKeyType {
+public final class PersistentDataKeyType<T> {
+    /**
+     * The registered key types.
+     */
+    private static final List<PersistentDataKeyType<?>> VALUES = new ArrayList<>();
+
     /**
      * String.
      */
-    STRING,
+    public static final PersistentDataKeyType<String> STRING = new PersistentDataKeyType<>(String.class, "STRING");
 
     /**
      * Boolean.
      */
-    BOOLEAN,
+    public static final PersistentDataKeyType<Boolean> BOOLEAN = new PersistentDataKeyType<>(Boolean.class, "BOOLEAN");
 
     /**
-     * Integer.
+     * Int.
      */
-    INT,
+    public static final PersistentDataKeyType<Integer> INT = new PersistentDataKeyType<>(Integer.class, "INT");
 
     /**
      * Double.
      */
-    DOUBLE
+    public static final PersistentDataKeyType<Double> DOUBLE = new PersistentDataKeyType<>(Double.class, "DOUBLE");
+
+    /**
+     * The class of the type.
+     */
+    private final Class<T> typeClass;
+
+    /**
+     * The name of the key type.
+     */
+    private final String name;
+
+    /**
+     * Get the class of the type.
+     *
+     * @return The class.
+     */
+    public Class<T> getTypeClass() {
+        return typeClass;
+    }
+
+    /**
+     * Get the name of the key type.
+     *
+     * @return The name.
+     */
+    public String name() {
+        return name;
+    }
+
+    /**
+     * Create new PersistentDataKeyType.
+     *
+     * @param typeClass The type class.
+     * @param name      The name.
+     */
+    private PersistentDataKeyType(@NotNull final Class<T> typeClass,
+                                  @NotNull final String name) {
+        VALUES.add(this);
+
+        this.typeClass = typeClass;
+        this.name = name;
+    }
+
+    /**
+     * Get all registered {@link PersistentDataKeyType}s.
+     *
+     * @return The registered types.
+     */
+    @NotNull
+    public static PersistentDataKeyType<?>[] values() {
+        return VALUES.toArray(new PersistentDataKeyType[0]);
+    }
+
+    /**
+     * Get a key type from a name.
+     *
+     * @param name The name.
+     * @return The type, or null if not found.
+     */
+    @Nullable
+    public static PersistentDataKeyType<?> valueOf(@NotNull final String name) {
+        for (PersistentDataKeyType<?> type : VALUES) {
+            if (type.name.equalsIgnoreCase(name)) {
+                return type;
+            }
+        }
+
+        return null;
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/display/Display.java

@@ -60,7 +60,7 @@ public final class Display {
      * @return The ItemStack.
      */
     public static ItemStack displayAndFinalize(@NotNull final ItemStack itemStack,
-                                        @Nullable final Player player) {
+                                               @Nullable final Player player) {
         return finalize(display(itemStack, player));
     }
 

eco-api/src/main/java/com/willfp/eco/core/display/DisplayHandler.java

@@ -1,13 +1,17 @@
 package com.willfp.eco.core.display;
 
+import com.willfp.eco.core.Eco;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
  * Interface for display implementations.
  */
+@ApiStatus.Internal
+@Eco.HandlerComponent
 public interface DisplayHandler {
     /**
      * Register display module.

eco-api/src/main/java/com/willfp/eco/core/drops/DropQueueFactory.java

@@ -1,11 +1,15 @@
 package com.willfp.eco.core.drops;
 
+import com.willfp.eco.core.Eco;
 import org.bukkit.entity.Player;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Internal component to create backend DropQueue implementations.
  */
+@ApiStatus.Internal
+@Eco.HandlerComponent
 public interface DropQueueFactory {
     /**
      * Create a DropQueue.

eco-api/src/main/java/com/willfp/eco/core/drops/InternalDropQueue.java

@@ -1,7 +1,9 @@
 package com.willfp.eco.core.drops;
 
+import com.willfp.eco.core.Eco;
 import org.bukkit.Location;
 import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Collection;
@@ -9,6 +11,8 @@ import java.util.Collection;
 /**
  * Internal interface for backend DropQueue implementations.
  */
+@ApiStatus.Internal
+@Eco.HandlerComponent
 public interface InternalDropQueue {
     /**
      * Add item to queue.

eco-api/src/main/java/com/willfp/eco/core/entities/CustomEntity.java

@@ -0,0 +1,84 @@
+package com.willfp.eco.core.entities;
+
+import org.apache.commons.lang.Validate;
+import org.bukkit.Location;
+import org.bukkit.NamespacedKey;
+import org.bukkit.entity.Entity;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.function.Function;
+import java.util.function.Predicate;
+
+/**
+ * A custom entity has 3 components.
+ *
+ * <ul>
+ *     <li>The key to identify it</li>
+ *     <li>The test to check if any entity is this custom entity</li>
+ *     <li>The supplier to spawn the custom {@link org.bukkit.entity.Entity}</li>
+ * </ul>
+ */
+public class CustomEntity implements TestableEntity {
+    /**
+     * The key.
+     */
+    private final NamespacedKey key;
+
+    /**
+     * The test for Entities to pass.
+     */
+    private final Predicate<@NotNull Entity> test;
+
+    /**
+     * The provider to spawn the entity.
+     */
+    private final Function<Location, Entity> provider;
+
+    /**
+     * Create a new custom entity.
+     *
+     * @param key      The entity key.
+     * @param test     The test.
+     * @param provider The provider to spawn the entity.
+     */
+    public CustomEntity(@NotNull final NamespacedKey key,
+                        @NotNull final Predicate<@NotNull Entity> test,
+                        @NotNull final Function<Location, Entity> provider) {
+        this.key = key;
+        this.test = test;
+        this.provider = provider;
+    }
+
+    @Override
+    public boolean matches(@Nullable final Entity entity) {
+        if (entity == null) {
+            return false;
+        }
+
+        return test.test(entity);
+    }
+
+    @Override
+    public Entity spawn(@NotNull final Location location) {
+        Validate.notNull(location.getWorld());
+
+        return provider.apply(location);
+    }
+
+    /**
+     * Register the entity.
+     */
+    public void register() {
+        Entities.registerCustomEntity(this.getKey(), this);
+    }
+
+    /**
+     * Get the key.
+     *
+     * @return The key.
+     */
+    public NamespacedKey getKey() {
+        return this.key;
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/DummyEntity.java

@@ -0,0 +1,10 @@
+package com.willfp.eco.core.entities;
+
+import org.bukkit.entity.Entity;
+
+/**
+ * Interface for Dummy Entities in order to filter them using instanceof.
+ */
+public interface DummyEntity extends Entity {
+
+}

eco-api/src/main/java/com/willfp/eco/core/entities/Entities.java

@@ -0,0 +1,232 @@
+package com.willfp.eco.core.entities;
+
+import com.willfp.eco.core.entities.args.EntityArgParseResult;
+import com.willfp.eco.core.entities.args.EntityArgParser;
+import com.willfp.eco.core.entities.impl.EmptyTestableEntity;
+import com.willfp.eco.core.entities.impl.ModifiedTestableEntity;
+import com.willfp.eco.core.entities.impl.SimpleTestableEntity;
+import com.willfp.eco.util.NamespacedKeyUtils;
+import org.bukkit.Location;
+import org.bukkit.NamespacedKey;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.EntityType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Function;
+
+/**
+ * Class to manage all custom and vanilla entities.
+ */
+public final class Entities {
+    /**
+     * All entities.
+     */
+    private static final Map<NamespacedKey, TestableEntity> REGISTRY = new ConcurrentHashMap<>();
+
+    /**
+     * All entity parsers.
+     */
+    private static final List<EntityArgParser> ARG_PARSERS = new ArrayList<>();
+
+    /**
+     * The lookup handler.
+     */
+    private static final EntitiesLookupHandler ENTITIES_LOOKUP_HANDLER = new EntitiesLookupHandler(Entities::doParse);
+
+    /**
+     * Register a new custom item.
+     *
+     * @param key  The key of the item.
+     * @param item The item.
+     */
+    public static void registerCustomEntity(@NotNull final NamespacedKey key,
+                                            @NotNull final TestableEntity item) {
+        REGISTRY.put(key, item);
+    }
+
+    /**
+     * Register a new arg parser.
+     *
+     * @param parser The parser.
+     */
+    public static void registerArgParser(@NotNull final EntityArgParser parser) {
+        ARG_PARSERS.add(parser);
+    }
+
+    /**
+     * Remove an entity.
+     *
+     * @param key The key of the entity.
+     */
+    public static void removeCustomEntity(@NotNull final NamespacedKey key) {
+        REGISTRY.remove(key);
+    }
+
+    /**
+     * This is the backbone of the entire eco entity system.
+     * <p>
+     * You can look up a TestableEntity for any type or custom entity,
+     * and it will return it with any modifiers passed as parameters.
+     * <p>
+     * If you want to get an Entity instance from this, then just call
+     * {@link TestableEntity#spawn(Location)}.
+     * <p>
+     * The advantages of the testable entity system are that there is the inbuilt
+     * {@link TestableEntity#matches(Entity)} - this allows to check if any entity
+     * is that testable entity; which may sound negligible, but actually it allows for
+     * much more power and flexibility. For example, you can have an entity with an
+     * extra metadata tag, extra lore lines, different display name - and it
+     * will still work as long as the test passes.
+     *
+     * @param key The lookup string.
+     * @return The testable entity, or an empty testable entity if not found.
+     */
+    @NotNull
+    public static TestableEntity lookup(@NotNull final String key) {
+        return ENTITIES_LOOKUP_HANDLER.parseKey(key);
+    }
+
+    @NotNull
+    private static TestableEntity doParse(@NotNull final String[] args) {
+        if (args.length == 0) {
+            return new EmptyTestableEntity();
+        }
+
+        TestableEntity entity;
+
+        String[] split = args[0].toLowerCase().split(":");
+
+        if (split.length == 1) {
+            EntityType type;
+            try {
+                type = EntityType.valueOf(args[0].toUpperCase());
+            } catch (IllegalArgumentException e) {
+                return new EmptyTestableEntity();
+            }
+            entity = new SimpleTestableEntity(type);
+        } else {
+            String namespace = split[0];
+            String keyID = split[1];
+            NamespacedKey namespacedKey = NamespacedKeyUtils.create(namespace, keyID);
+
+            TestableEntity part = REGISTRY.get(namespacedKey);
+
+            if (part == null) {
+                return new EmptyTestableEntity();
+            }
+
+            entity = part;
+        }
+
+        String[] modifierArgs = Arrays.copyOfRange(args, 1, args.length);
+
+        List<EntityArgParseResult> parseResults = new ArrayList<>();
+
+        for (EntityArgParser argParser : ARG_PARSERS) {
+            EntityArgParseResult result = argParser.parseArguments(modifierArgs);
+            if (result != null) {
+                parseResults.add(result);
+            }
+        }
+
+        Function<Location, Entity> spawner = entity::spawn;
+
+        if (!parseResults.isEmpty()) {
+            entity = new ModifiedTestableEntity(
+                    entity,
+                    test -> {
+                        for (EntityArgParseResult parseResult : parseResults) {
+                            if (!parseResult.test().test(test)) {
+                                return false;
+                            }
+                        }
+
+                        return true;
+                    },
+                    location -> {
+                        Entity spawned = spawner.apply(location);
+
+                        for (EntityArgParseResult parseResult : parseResults) {
+                            parseResult.modifier().accept(spawned);
+                        }
+
+                        return spawned;
+                    }
+            );
+        }
+
+        return entity;
+    }
+
+    /**
+     * Get a Testable Entity from an ItemStack.
+     * <p>
+     * Will search for registered entity first. If there are no matches in the registry,
+     * then it will return a {@link com.willfp.eco.core.entities.impl.SimpleTestableEntity} matching the entity type.
+     * <p>
+     * If the entity is not custom and has unknown type, this will return null.
+     *
+     * @param entity The Entity.
+     * @return The found Testable Entity.
+     */
+    @Nullable
+    public static TestableEntity getEntity(@Nullable final Entity entity) {
+        if (entity == null) {
+            return null;
+        }
+
+        TestableEntity customEntity = getEntity(entity);
+
+        if (customEntity != null) {
+            return customEntity;
+        }
+
+        for (TestableEntity known : REGISTRY.values()) {
+            if (known.matches(entity)) {
+                return known;
+            }
+        }
+
+        if (entity.getType() == EntityType.UNKNOWN) {
+            return null;
+        }
+
+        return new SimpleTestableEntity(entity.getType());
+    }
+
+    /**
+     * Get if entity is a custom entity.
+     *
+     * @param entity The entity to check.
+     * @return If is custom.
+     */
+    public static boolean isCustomEntity(@NotNull final Entity entity) {
+        for (TestableEntity testable : REGISTRY.values()) {
+            if (testable.matches(entity)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Get all registered custom items.
+     *
+     * @return A set of all items.
+     */
+    public static Set<TestableEntity> getCustomEntities() {
+        return new HashSet<>(REGISTRY.values());
+    }
+
+    private Entities() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/EntitiesLookupHandler.java

@@ -0,0 +1,48 @@
+package com.willfp.eco.core.entities;
+
+import com.willfp.eco.core.entities.impl.EmptyTestableEntity;
+import com.willfp.eco.core.entities.impl.GroupedTestableEntities;
+import com.willfp.eco.core.lookup.LookupHandler;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Collection;
+import java.util.function.Function;
+
+/**
+ * Handle item lookup strings.
+ */
+public class EntitiesLookupHandler implements LookupHandler<TestableEntity> {
+    /**
+     * The parser.
+     */
+    private final Function<String[], @NotNull TestableEntity> parser;
+
+    /**
+     * Create new lookup handler.
+     *
+     * @param parser The parser.
+     */
+    public EntitiesLookupHandler(@NotNull final Function<String[], @NotNull TestableEntity> parser) {
+        this.parser = parser;
+    }
+
+    @Override
+    public @NotNull TestableEntity parse(@NotNull final String[] args) {
+        return parser.apply(args);
+    }
+
+    @Override
+    public boolean validate(@NotNull final TestableEntity object) {
+        return !(object instanceof EmptyTestableEntity);
+    }
+
+    @Override
+    public @NotNull TestableEntity getFailsafe() {
+        return new EmptyTestableEntity();
+    }
+
+    @Override
+    public @NotNull TestableEntity join(@NotNull final Collection<TestableEntity> options) {
+        return new GroupedTestableEntities(options);
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/TestableEntity.java

@@ -0,0 +1,29 @@
+package com.willfp.eco.core.entities;
+
+import com.willfp.eco.core.lookup.Testable;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * An item with a test to see if any item is that item.
+ */
+public interface TestableEntity extends Testable<Entity> {
+    /**
+     * If an Entity matches the test.
+     *
+     * @param entity The entity to test.
+     * @return If the entity matches.
+     */
+    @Override
+    boolean matches(@Nullable Entity entity);
+
+    /**
+     * Spawn the entity.
+     *
+     * @param location The location.
+     * @return The entity.
+     */
+    Entity spawn(@NotNull Location location);
+}

eco-api/src/main/java/com/willfp/eco/core/entities/args/EntityArgParseResult.java

@@ -0,0 +1,33 @@
+package com.willfp.eco.core.entities.args;
+
+import org.bukkit.entity.Entity;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+/**
+ * @param test     The test for the entity.
+ * @param modifier The modifier to apply to the entity.
+ * @see EntityArgParser
+ */
+public record EntityArgParseResult(@NotNull Predicate<Entity> test,
+                                   @NotNull Consumer<Entity> modifier) {
+    /**
+     * Kotlin destructuring support.
+     *
+     * @return The test.
+     */
+    public Predicate<Entity> component1() {
+        return test;
+    }
+
+    /**
+     * Kotlin destructuring support.
+     *
+     * @return The modifier.
+     */
+    public Consumer<Entity> component2() {
+        return modifier;
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/args/EntityArgParser.java

@@ -0,0 +1,20 @@
+package com.willfp.eco.core.entities.args;
+
+import com.willfp.eco.core.entities.TestableEntity;
+import org.bukkit.Location;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * An argument parser should generate the predicate as well
+ * as modify the Entity for {@link TestableEntity#spawn(Location)}.
+ */
+public interface EntityArgParser {
+    /**
+     * Parse the arguments.
+     *
+     * @param args The arguments.
+     * @return The predicate test to apply to the modified entity.
+     */
+    @Nullable EntityArgParseResult parseArguments(@NotNull String[] args);
+}

eco-api/src/main/java/com/willfp/eco/core/entities/impl/EmptyTestableEntity.java

@@ -0,0 +1,33 @@
+package com.willfp.eco.core.entities.impl;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.entities.TestableEntity;
+import org.apache.commons.lang.Validate;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Empty entity.
+ */
+public class EmptyTestableEntity implements TestableEntity {
+    /**
+     * Create a new empty testable entity.
+     */
+    public EmptyTestableEntity() {
+
+    }
+
+    @Override
+    public boolean matches(@Nullable final Entity entity) {
+        return false;
+    }
+
+    @Override
+    public Entity spawn(@NotNull final Location location) {
+        Validate.notNull(location.getWorld());
+
+        return Eco.getHandler().createDummyEntity(location);
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/impl/GroupedTestableEntities.java

@@ -0,0 +1,68 @@
+package com.willfp.eco.core.entities.impl;
+
+import com.willfp.eco.core.entities.TestableEntity;
+import com.willfp.eco.util.NumberUtils;
+import org.apache.commons.lang.Validate;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * A group of testable entities.
+ *
+ * @see com.willfp.eco.core.entities.CustomEntity
+ */
+public class GroupedTestableEntities implements TestableEntity {
+    /**
+     * The children.
+     */
+    private final Collection<TestableEntity> children;
+
+    /**
+     * Create a new group of testable entities.
+     *
+     * @param children The children.
+     */
+    public GroupedTestableEntities(@NotNull final Collection<TestableEntity> children) {
+        Validate.isTrue(!children.isEmpty(), "Group must have at least one child!");
+
+        this.children = children;
+    }
+
+    /**
+     * If the item matches any children.
+     *
+     * @param entity The entity to test.
+     * @return If the entity matches the test of any children.
+     */
+    @Override
+    public boolean matches(@Nullable final Entity entity) {
+        for (TestableEntity child : children) {
+            if (child.matches(entity)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public Entity spawn(@NotNull final Location location) {
+        return new ArrayList<>(children)
+                .get(NumberUtils.randInt(0, children.size() - 1))
+                .spawn(location);
+    }
+
+    /**
+     * Get the children.
+     *
+     * @return The children.
+     */
+    public Collection<TestableEntity> getChildren() {
+        return new ArrayList<>(children);
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/impl/ModifiedTestableEntity.java

@@ -0,0 +1,69 @@
+package com.willfp.eco.core.entities.impl;
+
+import com.willfp.eco.core.entities.TestableEntity;
+import org.apache.commons.lang.Validate;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.function.Function;
+import java.util.function.Predicate;
+
+/**
+ * Existing testable entity with an extra filter.
+ *
+ * @see com.willfp.eco.core.entities.CustomEntity
+ */
+public class ModifiedTestableEntity implements TestableEntity {
+    /**
+     * The item.
+     */
+    private final TestableEntity handle;
+
+    /**
+     * The amount.
+     */
+    private final Predicate<Entity> test;
+
+    /**
+     * The provider to spawn the entity.
+     */
+    private final Function<Location, Entity> provider;
+
+    /**
+     * Create a new modified testable entity.
+     *
+     * @param entity   The base entity.
+     * @param test     The test.
+     * @param provider The provider to spawn the entity.
+     */
+    public ModifiedTestableEntity(@NotNull final TestableEntity entity,
+                                  @NotNull final Predicate<@NotNull Entity> test,
+                                  @NotNull final Function<Location, Entity> provider) {
+        this.handle = entity;
+        this.test = test;
+        this.provider = provider;
+    }
+
+    @Override
+    public boolean matches(@Nullable final Entity entity) {
+        return entity != null && handle.matches(entity) && test.test(entity);
+    }
+
+    @Override
+    public Entity spawn(@NotNull final Location location) {
+        Validate.notNull(location.getWorld());
+
+        return provider.apply(location);
+    }
+
+    /**
+     * Get the handle.
+     *
+     * @return The handle.
+     */
+    public TestableEntity getHandle() {
+        return this.handle;
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/entities/impl/SimpleTestableEntity.java

@@ -0,0 +1,53 @@
+package com.willfp.eco.core.entities.impl;
+
+import com.willfp.eco.core.entities.TestableEntity;
+import org.apache.commons.lang.Validate;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.EntityType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Default vanilla entities.
+ */
+public class SimpleTestableEntity implements TestableEntity {
+    /**
+     * The entity type.
+     */
+    private final EntityType type;
+
+    /**
+     * Create a new simple testable entity.
+     *
+     * @param type The entity type.
+     */
+    public SimpleTestableEntity(@NotNull final EntityType type) {
+        this.type = type;
+
+        Validate.notNull(type.getEntityClass(), "Entity cannot be of unknown type!");
+    }
+
+    @Override
+    public boolean matches(@Nullable final Entity entity) {
+        return entity != null && entity.getType() == type;
+    }
+
+    @Override
+    public Entity spawn(@NotNull final Location location) {
+        Validate.notNull(location.getWorld());
+
+        assert type.getEntityClass() != null;
+
+        return location.getWorld().spawn(location, type.getEntityClass());
+    }
+
+    /**
+     * Get the type.
+     *
+     * @return The type.
+     */
+    public EntityType getType() {
+        return this.type;
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/events/DropQueuePushEvent.java

@@ -0,0 +1,143 @@
+package com.willfp.eco.core.events;
+
+import org.bukkit.Location;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Collection;
+
+/**
+ * Called on DropQueue push.
+ */
+public class DropQueuePushEvent extends PlayerEvent implements Cancellable {
+    /**
+     * Cancel state.
+     */
+    private boolean cancelled;
+
+    /**
+     * If telekinetic.
+     */
+    private final boolean isTelekinetic;
+
+    /**
+     * The items.
+     */
+    private final Collection<? extends ItemStack> items;
+
+    /**
+     * The xp.
+     */
+    private final int xp;
+
+    /**
+     * The location.
+     */
+    private final Location location;
+
+    /**
+     * Bukkit parity.
+     */
+    private static final HandlerList HANDLERS = new HandlerList();
+
+    /**
+     * Create a new DropQueuePushEvent.
+     *
+     * @param player        The player.
+     * @param items         The items.
+     * @param location      The location.
+     * @param xp            The xp.
+     * @param isTelekinetic If the event is telekinetic.
+     */
+    public DropQueuePushEvent(@NotNull final Player player,
+                              @NotNull final Collection<? extends ItemStack> items,
+                              @NotNull final Location location,
+                              final int xp,
+                              final boolean isTelekinetic) {
+        super(player);
+        this.items = items;
+        this.location = location;
+        this.xp = xp;
+        this.isTelekinetic = isTelekinetic;
+    }
+
+    /**
+     * Gets a list of handlers handling this event.
+     *
+     * @return A list of handlers handling this event.
+     */
+    @Override
+    @NotNull
+    public HandlerList getHandlers() {
+        return HANDLERS;
+    }
+
+    /**
+     * Bukkit parity.
+     *
+     * @return The handler list.
+     */
+    public static HandlerList getHandlerList() {
+        return HANDLERS;
+    }
+
+    /**
+     * Get cancel state.
+     *
+     * @return The cancel state.
+     */
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    /**
+     * Set cancel state.
+     *
+     * @param cancelled If cancelled.
+     */
+    @Override
+    public void setCancelled(final boolean cancelled) {
+        this.cancelled = cancelled;
+    }
+
+    /**
+     * Get the items to be dropped.
+     *
+     * @return The items.
+     */
+    public Collection<? extends ItemStack> getItems() {
+        return items;
+    }
+
+    /**
+     * Get the xp to be dropped.
+     *
+     * @return The xp.
+     */
+    public int getXp() {
+        return xp;
+    }
+
+    /**
+     * Get the location.
+     *
+     * @return The location.
+     */
+    public Location getLocation() {
+        return location;
+    }
+
+    /**
+     * Get force telekinesis state.
+     *
+     * @return The force telekinesis state.
+     */
+    public boolean isTelekinetic() {
+        return this.isTelekinetic;
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/events/EventManager.java

@@ -1,6 +1,7 @@
 package com.willfp.eco.core.events;
 
 import org.bukkit.event.Listener;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Manages listeners for a plugin.
@@ -11,14 +12,14 @@ public interface EventManager {
      *
      * @param listener The listener to register.
      */
-    void registerListener(Listener listener);
+    void registerListener(@NotNull Listener listener);
 
     /**
      * Unregister a listener with bukkit.
      *
      * @param listener The listener to unregister.
      */
-    void unregisterListener(Listener listener);
+    void unregisterListener(@NotNull Listener listener);
 
     /**
      * Unregister all listeners associated with the plugin.

eco-api/src/main/java/com/willfp/eco/core/extensions/Extension.java

@@ -7,6 +7,7 @@ import org.apache.commons.lang.Validate;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.File;
+import java.util.logging.Logger;
 
 /**
  * An extension is a separate jar file that hooks into the base plugin jar.
@@ -143,6 +144,11 @@ public abstract class Extension implements PluginLike {
         return this.plugin.getConfigHandler();
     }
 
+    @Override
+    public Logger getLogger() {
+        return this.plugin.getLogger();
+    }
+
     /**
      * Get the plugin for the extension.
      *

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/GUIFactory.java

@@ -1,15 +1,19 @@
 package com.willfp.eco.core.gui;
 
+import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.gui.menu.MenuBuilder;
 import com.willfp.eco.core.gui.slot.SlotBuilder;
 import com.willfp.eco.core.gui.slot.functional.SlotProvider;
 import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * Internal component used by {@link com.willfp.eco.core.gui.menu.Menu#builder(int)}
  * and {@link com.willfp.eco.core.gui.slot.Slot#builder(ItemStack)}.
  */
+@ApiStatus.Internal
+@Eco.HandlerComponent
 public interface GUIFactory {
     /**
      * Create slot builder.

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)) {
-            throw new IllegalArgumentException("Materials cannot be air!");
+        this(
+                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++) {
-            ItemStack itemStack = new ItemStackBuilder(materials.materials()[i])
+        for (int i = 0; i < items.items().length; 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/integrations/IntegrationLoader.java

@@ -1,7 +1,13 @@
 package com.willfp.eco.core.integrations;
 
+import org.bukkit.Bukkit;
+import org.bukkit.plugin.Plugin;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
 /**
  * An integration loader runs a runnable only if a specific plugin is present on the server.
  * <p>
@@ -9,7 +15,15 @@ import org.jetbrains.annotations.NotNull;
  */
 public class IntegrationLoader {
     /**
-     * The lambda to be ran if the plugin is present.
+     * All loaded plugins on the server.
+     */
+    private static final Set<String> LOADED_PLUGINS = Arrays.stream(Bukkit.getPluginManager().getPlugins())
+            .map(Plugin::getName)
+            .map(String::toLowerCase)
+            .collect(Collectors.toSet());
+
+    /**
+     * The lambda to be run if the plugin is present.
      */
     private final Runnable runnable;
 
@@ -22,7 +36,7 @@ public class IntegrationLoader {
      * Create a new Integration Loader.
      *
      * @param pluginName The plugin to require.
-     * @param onLoad     The lambda to be ran if the plugin is present.
+     * @param onLoad     The lambda to be run if the plugin is present.
      */
     public IntegrationLoader(@NotNull final String pluginName,
                              @NotNull final Runnable onLoad) {
@@ -30,6 +44,15 @@ public class IntegrationLoader {
         this.pluginName = pluginName;
     }
 
+    /**
+     * Load the integration if the specified plugin is present on the server.
+     */
+    public void loadIfPresent() {
+        if (LOADED_PLUGINS.contains(this.pluginName.toLowerCase())) {
+            this.load();
+        }
+    }
+
     /**
      * Load the integration.
      */

eco-api/src/main/java/com/willfp/eco/core/integrations/anticheat/AnticheatManager.java

@@ -24,7 +24,7 @@ public final class AnticheatManager {
      * @param anticheat The anticheat to register.
      */
     public static void register(@NotNull final EcoPlugin plugin,
-                         @NotNull final AnticheatWrapper anticheat) {
+                                @NotNull final AnticheatWrapper anticheat) {
         if (anticheat instanceof Listener) {
             plugin.getEventManager().registerListener((Listener) anticheat);
         }

eco-api/src/main/java/com/willfp/eco/core/integrations/antigrief/AntigriefManager.java

@@ -37,6 +37,18 @@ public final class AntigriefManager {
         REGISTERED.remove(antigrief);
     }
 
+    /**
+     * Can player pickup item.
+     *
+     * @param player   The player.
+     * @param location The location.
+     * @return If player can pick up item.
+     */
+    public static boolean canPickupItem(@NotNull final Player player,
+                                        @NotNull final Location location) {
+        return REGISTERED.stream().allMatch(antigriefWrapper -> antigriefWrapper.canPickupItem(player, location));
+    }
+
     /**
      * Can player break block.
      *
@@ -45,7 +57,7 @@ public final class AntigriefManager {
      * @return If player can break block.
      */
     public static boolean canBreakBlock(@NotNull final Player player,
-                                 @NotNull final Block block) {
+                                        @NotNull final Block block) {
         return REGISTERED.stream().allMatch(antigriefWrapper -> antigriefWrapper.canBreakBlock(player, block));
     }
 
@@ -57,7 +69,7 @@ public final class AntigriefManager {
      * @return If player can create explosion.
      */
     public static boolean canCreateExplosion(@NotNull final Player player,
-                                      @NotNull final Location location) {
+                                             @NotNull final Location location) {
         return REGISTERED.stream().allMatch(antigriefWrapper -> antigriefWrapper.canCreateExplosion(player, location));
     }
 
@@ -69,7 +81,7 @@ public final class AntigriefManager {
      * @return If player can place block.
      */
     public static boolean canPlaceBlock(@NotNull final Player player,
-                                 @NotNull final Block block) {
+                                        @NotNull final Block block) {
         return REGISTERED.stream().allMatch(antigriefWrapper -> antigriefWrapper.canPlaceBlock(player, block));
     }
 
@@ -81,7 +93,7 @@ public final class AntigriefManager {
      * @return If player can injure.
      */
     public static boolean canInjure(@NotNull final Player player,
-                             @NotNull final LivingEntity victim) {
+                                    @NotNull final LivingEntity victim) {
         return REGISTERED.stream().allMatch(antigriefWrapper -> antigriefWrapper.canInjure(player, victim));
     }
 

eco-api/src/main/java/com/willfp/eco/core/integrations/antigrief/AntigriefWrapper.java

@@ -5,6 +5,7 @@ import org.bukkit.Location;
 import org.bukkit.block.Block;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Wrapper class for antigrief integrations.
@@ -17,7 +18,7 @@ public interface AntigriefWrapper extends Integration {
      * @param block  The block.
      * @return If player can break block.
      */
-    boolean canBreakBlock(Player player, Block block);
+    boolean canBreakBlock(@NotNull Player player, @NotNull Block block);
 
     /**
      * Can player create explosion at location.
@@ -26,7 +27,7 @@ public interface AntigriefWrapper extends Integration {
      * @param location The location.
      * @return If player can create explosion.
      */
-    boolean canCreateExplosion(Player player, Location location);
+    boolean canCreateExplosion(@NotNull Player player, @NotNull Location location);
 
     /**
      * Can player place block.
@@ -35,7 +36,7 @@ public interface AntigriefWrapper extends Integration {
      * @param block  The block.
      * @return If player can place block.
      */
-    boolean canPlaceBlock(Player player, Block block);
+    boolean canPlaceBlock(@NotNull Player player, @NotNull Block block);
 
     /**
      * Can player injure living entity.
@@ -44,5 +45,16 @@ public interface AntigriefWrapper extends Integration {
      * @param victim The victim.
      * @return If player can injure.
      */
-    boolean canInjure(Player player, LivingEntity victim);
+    boolean canInjure(@NotNull Player player, @NotNull LivingEntity victim);
+
+    /**
+     * Can player pick up item.
+     *
+     * @param player   The player.
+     * @param location The location.
+     * @return If player can pick up item.
+     */
+    default boolean canPickupItem(@NotNull Player player, @NotNull Location location) {
+        return true;
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/integrations/customentities/CustomEntitiesManager.java

@@ -0,0 +1,40 @@
+package com.willfp.eco.core.integrations.customentities;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Class to handle custom entity integrations.
+ */
+public final class CustomEntitiesManager {
+    /**
+     * A set of all registered integrations.
+     */
+    private static final Set<CustomEntitiesWrapper> REGISTERED = new HashSet<>();
+
+    /**
+     * Register a new integration.
+     *
+     * @param integration The integration to register.
+     */
+    public static void register(@NotNull final CustomEntitiesWrapper integration) {
+        REGISTERED.add(integration);
+    }
+
+    /**
+     * Register all the custom entities for a specific plugin into eco.
+     *
+     * @see com.willfp.eco.core.entities.Entities
+     */
+    public static void registerAllEntities() {
+        for (CustomEntitiesWrapper wrapper : REGISTERED) {
+            wrapper.registerAllEntities();
+        }
+    }
+
+    private CustomEntitiesManager() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/customentities/CustomEntitiesWrapper.java

@@ -0,0 +1,15 @@
+package com.willfp.eco.core.integrations.customentities;
+
+import com.willfp.eco.core.integrations.Integration;
+
+/**
+ * Wrapper class for custom item integrations.
+ */
+public interface CustomEntitiesWrapper extends Integration {
+    /**
+     * Register all the custom entities for a specific plugin into eco.
+     *
+     * @see com.willfp.eco.core.entities.Entities
+     */
+    void registerAllEntities();
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/economy/EconomyManager.java

@@ -41,7 +41,7 @@ public final class EconomyManager {
      * @return If the player has the amount.
      */
     public static boolean hasAmount(@NotNull final OfflinePlayer player,
-                             final double amount) {
+                                    final double amount) {
         for (EconomyWrapper wrapper : REGISTERED) {
             return wrapper.hasAmount(player, amount);
         }
@@ -57,7 +57,7 @@ public final class EconomyManager {
      * @return If the transaction was a success.
      */
     public static boolean giveMoney(@NotNull final OfflinePlayer player,
-                             final double amount) {
+                                    final double amount) {
         for (EconomyWrapper wrapper : REGISTERED) {
             return wrapper.giveMoney(player, amount);
         }
@@ -73,7 +73,7 @@ public final class EconomyManager {
      * @return If the transaction was a success.
      */
     public static boolean removeMoney(@NotNull final OfflinePlayer player,
-                               final double amount) {
+                                      final double amount) {
         for (EconomyWrapper wrapper : REGISTERED) {
             return wrapper.removeMoney(player, amount);
         }

eco-api/src/main/java/com/willfp/eco/core/integrations/hologram/HologramManager.java

@@ -33,7 +33,7 @@ public final class HologramManager {
      * @return The hologram.
      */
     public static Hologram createHologram(@NotNull final Location location,
-                                   @NotNull final List<String> contents) {
+                                          @NotNull final List<String> contents) {
         for (HologramWrapper wrapper : REGISTERED) {
             return wrapper.createHologram(location, contents);
         }

eco-api/src/main/java/com/willfp/eco/core/integrations/placeholder/PlaceholderEntry.java

@@ -1,10 +1,12 @@
 package com.willfp.eco.core.integrations.placeholder;
 
+import com.willfp.eco.core.EcoPlugin;
 import org.apache.commons.lang.Validate;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Objects;
 import java.util.function.Function;
 
 /**
@@ -28,12 +30,20 @@ public class PlaceholderEntry {
      */
     private final boolean requiresPlayer;
 
+    /**
+     * The plugin for the placeholder.
+     */
+    @Nullable
+    private final EcoPlugin plugin;
+
     /**
      * Create a placeholder entry that doesn't require a player.
      *
      * @param identifier The identifier of the placeholder.
      * @param function   A lambda to get the result of the placeholder given a player.
+     * @deprecated Specify a plugin.
      */
+    @Deprecated
     public PlaceholderEntry(@NotNull final String identifier,
                             @NotNull final Function<Player, String> function) {
         this(identifier, function, false);
@@ -45,10 +55,41 @@ public class PlaceholderEntry {
      * @param identifier     The identifier of the placeholder.
      * @param function       A lambda to get the result of the placeholder.
      * @param requiresPlayer If the placeholder requires a player.
+     * @deprecated Specify a plugin.
      */
+    @Deprecated
     public PlaceholderEntry(@NotNull final String identifier,
                             @NotNull final Function<Player, String> function,
                             final boolean requiresPlayer) {
+        this(null, identifier, function, requiresPlayer);
+    }
+
+    /**
+     * Create a placeholder entry that doesn't require a player.
+     *
+     * @param plugin     The plugin for the placeholder.
+     * @param identifier The identifier of the placeholder.
+     * @param function   A lambda to get the result of the placeholder given a player.
+     */
+    public PlaceholderEntry(@Nullable final EcoPlugin plugin,
+                            @NotNull final String identifier,
+                            @NotNull final Function<Player, String> function) {
+        this(plugin, identifier, function, false);
+    }
+
+    /**
+     * Create a placeholder entry that may require a player.
+     *
+     * @param plugin         The plugin for the placeholder.
+     * @param identifier     The identifier of the placeholder.
+     * @param function       A lambda to get the result of the placeholder.
+     * @param requiresPlayer If the placeholder requires a player.
+     */
+    public PlaceholderEntry(@Nullable final EcoPlugin plugin,
+                            @NotNull final String identifier,
+                            @NotNull final Function<Player, String> function,
+                            final boolean requiresPlayer) {
+        this.plugin = plugin;
         this.identifier = identifier;
         this.function = function;
         this.requiresPlayer = requiresPlayer;
@@ -85,10 +126,37 @@ public class PlaceholderEntry {
         return identifier;
     }
 
+    /**
+     * Get the plugin.
+     *
+     * @return The plugin.
+     */
+    @Nullable
+    public EcoPlugin getPlugin() {
+        return plugin;
+    }
+
     /**
      * Register the placeholder.
      */
     public void register() {
         PlaceholderManager.registerPlaceholder(this);
     }
+
+    @Override
+    public boolean equals(@Nullable final Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof PlaceholderEntry entry)) {
+            return false;
+        }
+        return Objects.equals(this.getIdentifier(), entry.getIdentifier())
+                && Objects.equals(this.getPlugin(), entry.getPlugin());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.getIdentifier(), this.getPlugin());
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/integrations/placeholder/PlaceholderIntegration.java

@@ -5,6 +5,9 @@ import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Wrapper class for placeholder integrations.
  */
@@ -24,4 +27,14 @@ public interface PlaceholderIntegration extends Integration {
      */
     String translate(@NotNull String text,
                      @Nullable Player player);
+
+    /**
+     * Find all placeholders in a given text.
+     *
+     * @param text The text.
+     * @return The placeholders.
+     */
+    default List<String> findPlaceholdersIn(@NotNull String text) {
+        return new ArrayList<>();
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/integrations/placeholder/PlaceholderManager.java

@@ -1,13 +1,20 @@
 package com.willfp.eco.core.integrations.placeholder;
 
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.LoadingCache;
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.EcoPlugin;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Class to handle placeholder integrations.
@@ -16,17 +23,24 @@ public final class PlaceholderManager {
     /**
      * All registered placeholders.
      */
-    private static final Map<String, PlaceholderEntry> REGISTERED_PLACEHOLDERS = new HashMap<>();
+    private static final Map<EcoPlugin, Map<String, PlaceholderEntry>> REGISTERED_PLACEHOLDERS = new HashMap<>();
 
     /**
      * All registered placeholder integrations.
      */
     private static final Set<PlaceholderIntegration> REGISTERED_INTEGRATIONS = new HashSet<>();
 
+    /**
+     * Placeholder Cache.
+     */
+    private static final LoadingCache<EntryWithPlayer, String> PLACEHOLDER_CACHE = Caffeine.newBuilder()
+            .expireAfterWrite(50, TimeUnit.MILLISECONDS)
+            .build(key -> key.entry.getResult(key.player));
+
     /**
      * Register a new placeholder integration.
      *
-     * @param integration The {@link PlaceholderIntegration} to register.
+     * @param integration The {@link com.willfp.eco.core.integrations.placeholder.PlaceholderIntegration} to register.
      */
     public static void addIntegration(@NotNull final PlaceholderIntegration integration) {
         integration.registerIntegration();
@@ -36,11 +50,14 @@ public final class PlaceholderManager {
     /**
      * Register a placeholder.
      *
-     * @param expansion The {@link PlaceholderEntry} to register.
+     * @param expansion The {@link com.willfp.eco.core.integrations.placeholder.PlaceholderEntry} to register.
      */
     public static void registerPlaceholder(@NotNull final PlaceholderEntry expansion) {
-        REGISTERED_PLACEHOLDERS.remove(expansion.getIdentifier());
-        REGISTERED_PLACEHOLDERS.put(expansion.getIdentifier(), expansion);
+        EcoPlugin plugin = expansion.getPlugin() == null ? Eco.getHandler().getEcoPlugin() : expansion.getPlugin();
+        Map<String, PlaceholderEntry> pluginPlaceholders = REGISTERED_PLACEHOLDERS
+                .getOrDefault(plugin, new HashMap<>());
+        pluginPlaceholders.put(expansion.getIdentifier(), expansion);
+        REGISTERED_PLACEHOLDERS.put(plugin, pluginPlaceholders);
     }
 
     /**
@@ -49,10 +66,36 @@ public final class PlaceholderManager {
      * @param player     The player to get the result from.
      * @param identifier The placeholder identifier.
      * @return The value of the placeholder.
+     * @deprecated Specify a plugin to get the result from.
      */
+    @Deprecated
     public static String getResult(@Nullable final Player player,
                                    @NotNull final String identifier) {
-        PlaceholderEntry entry = REGISTERED_PLACEHOLDERS.get(identifier.toLowerCase());
+        return getResult(player, identifier, null);
+    }
+
+    /**
+     * Get the result of a placeholder with respect to a player.
+     *
+     * @param player     The player to get the result from.
+     * @param identifier The placeholder identifier.
+     * @param plugin     The plugin for the placeholder.
+     * @return The value of the placeholder.
+     */
+    public static String getResult(@Nullable final Player player,
+                                   @NotNull final String identifier,
+                                   @Nullable final EcoPlugin plugin) {
+        EcoPlugin owner = plugin == null ? Eco.getHandler().getEcoPlugin() : plugin;
+        PlaceholderEntry entry = REGISTERED_PLACEHOLDERS.getOrDefault(owner, new HashMap<>()).get(identifier.toLowerCase());
+
+        if (entry == null && plugin != null) {
+            PlaceholderEntry alternate = REGISTERED_PLACEHOLDERS.getOrDefault(Eco.getHandler().getEcoPlugin(), new HashMap<>())
+                    .get(identifier.toLowerCase());
+            if (alternate != null) {
+                entry = alternate;
+            }
+        }
+
         if (entry == null) {
             return "";
         }
@@ -61,7 +104,7 @@ public final class PlaceholderManager {
             return "";
         }
 
-        return entry.getResult(player);
+        return PLACEHOLDER_CACHE.get(new EntryWithPlayer(entry, player));
     }
 
     /**
@@ -80,6 +123,26 @@ public final class PlaceholderManager {
         return processed;
     }
 
+    /**
+     * Find all placeholders in a given text.
+     *
+     * @param text The text.
+     * @return The placeholders.
+     */
+    public static List<String> findPlaceholdersIn(@NotNull final String text) {
+        List<String> found = new ArrayList<>();
+        for (PlaceholderIntegration integration : REGISTERED_INTEGRATIONS) {
+            found.addAll(integration.findPlaceholdersIn(text));
+        }
+
+        return found;
+    }
+
+    private static record EntryWithPlayer(@NotNull PlaceholderEntry entry,
+                                          @Nullable Player player) {
+
+    }
+
     private PlaceholderManager() {
         throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
     }

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

@@ -66,7 +66,7 @@ public class CustomItem implements TestableItem {
 
     @Override
     public ItemStack getItem() {
-        return item;
+        return item.clone();
     }
 
     /**

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

@@ -0,0 +1,103 @@
+package com.willfp.eco.core.items;
+
+import com.willfp.eco.core.fast.FastItemStack;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * An item and its {@link com.willfp.eco.core.fast.FastItemStack} hash.
+ */
+public final class HashedItem {
+    /**
+     * The item.
+     */
+    private final ItemStack item;
+
+    /**
+     * The hash.
+     */
+    private final int hash;
+
+    /**
+     * Create new hashed item.
+     *
+     * @param item The item.
+     * @param hash The hash.
+     */
+    private HashedItem(@NotNull final ItemStack item,
+                       final int hash) {
+        this.item = item;
+        this.hash = hash;
+    }
+
+    /**
+     * Get the item.
+     *
+     * @return The ItemStack.
+     */
+    public ItemStack getItem() {
+        return this.item;
+    }
+
+    /**
+     * Get the hash.
+     *
+     * @return The hash.
+     */
+    public int getHash() {
+        return this.hash;
+    }
+
+    /**
+     * Kotlin destructuring support.
+     *
+     * @return The ItemStack.
+     */
+    public ItemStack component1() {
+        return this.getItem();
+    }
+
+    /**
+     * Kotlin destructuring support.
+     *
+     * @return The hash.
+     */
+    public int component2() {
+        return this.getHash();
+    }
+
+    @Override
+    public int hashCode() {
+        return this.hash;
+    }
+
+    @Override
+    public boolean equals(@Nullable final Object other) {
+        if (!(other instanceof HashedItem o)) {
+            return false;
+        }
+
+        return o.hash == this.hash;
+    }
+
+    /**
+     * Hashed item from an item.
+     *
+     * @param item The item.
+     * @return The hashed item.
+     */
+    public static HashedItem of(@NotNull final ItemStack item) {
+        return new HashedItem(item, FastItemStack.wrap(item).hashCode());
+    }
+
+    /**
+     * Hashed item from a fast item stack.
+     *
+     * @param item The item.
+     * @return The hashed item.
+     */
+    public static HashedItem of(@NotNull final FastItemStack item) {
+        return new HashedItem(item.unwrap(), item.hashCode());
+    }
+}

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

@@ -1,5 +1,7 @@
 package com.willfp.eco.core.items;
 
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.LoadingCache;
 import com.willfp.eco.core.items.args.LookupArgParser;
 import com.willfp.eco.core.items.provider.ItemProvider;
 import com.willfp.eco.core.recipe.parts.EmptyTestableItem;
@@ -17,10 +19,13 @@ 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;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
@@ -33,6 +38,25 @@ public final class Items {
      */
     private static final Map<NamespacedKey, TestableItem> REGISTRY = new ConcurrentHashMap<>();
 
+    /**
+     * Cached custom item lookups, using {@link HashedItem}.
+     */
+    private static final LoadingCache<HashedItem, Optional<TestableItem>> CACHE = Caffeine.newBuilder()
+            .expireAfterAccess(5, TimeUnit.MINUTES)
+            .build(
+                    key -> {
+                        TestableItem match = null;
+                        for (TestableItem item : REGISTRY.values()) {
+                            if (item.matches(key.getItem())) {
+                                match = item;
+                                break;
+                            }
+                        }
+
+                        return Optional.ofNullable(match);
+                    }
+            );
+
     /**
      * All item providers.
      */
@@ -43,6 +67,11 @@ public final class Items {
      */
     private static final List<LookupArgParser> ARG_PARSERS = new ArrayList<>();
 
+    /**
+     * The handler.
+     */
+    private static final ItemsLookupHandler ITEMS_LOOKUP_HANDLER = new ItemsLookupHandler(Items::doParse);
+
     /**
      * Register a new custom item.
      *
@@ -50,7 +79,7 @@ public final class Items {
      * @param item The item.
      */
     public static void registerCustomItem(@NotNull final NamespacedKey key,
-                                   @NotNull final TestableItem item) {
+                                          @NotNull final TestableItem item) {
         REGISTRY.put(key, item);
     }
 
@@ -84,7 +113,7 @@ public final class Items {
     /**
      * This is the backbone of the entire eco item system.
      * <p>
-     * You can lookup a TestableItem for any material, custom item,
+     * You can look up a TestableItem for any material, custom item,
      * or item in general, and it will return it with any modifiers
      * passed as parameters. This includes stack size (item amount)
      * and enchantments that should be present on the item.
@@ -94,8 +123,8 @@ public final class Items {
      * <p>
      * The advantages of the testable item system are that there is the inbuilt
      * {@link TestableItem#matches(ItemStack)} - this allows to check if any item
-     * is that testable item; which may sound negligible but actually it allows for
-     * much more power an flexibility. For example, you can have an item with an
+     * is that testable item; which may sound negligible, but actually it allows for
+     * much more power and flexibility. For example, you can have an item with an
      * extra metadata tag, extra lore lines, different display name - and it
      * will still work as long as the test passes. This is very important
      * for custom crafting recipes where other plugins may add metadata
@@ -104,20 +133,13 @@ public final class Items {
      * @param key The lookup string.
      * @return The testable item, or an {@link EmptyTestableItem}.
      */
+    @NotNull
     public static TestableItem lookup(@NotNull final String key) {
-        if (key.contains("?")) {
-            String[] options = key.split("\\?");
-            for (String option : options) {
-                TestableItem lookup = lookup(option);
-                if (!(lookup instanceof EmptyTestableItem)) {
-                    return lookup;
-                }
-            }
+        return ITEMS_LOOKUP_HANDLER.parseKey(key);
+    }
 
-            return new EmptyTestableItem();
-        }
-
-        String[] args = key.split(" ");
+    @NotNull
+    private static TestableItem doParse(@NotNull final String[] args) {
         if (args.length == 0) {
             return new EmptyTestableItem();
         }
@@ -191,7 +213,7 @@ public final class Items {
             }
         }
 
-        // Marked as redundant but i am covering all bases here
+        // Marked as redundant but I am covering all bases here
         if (item == null || item instanceof EmptyTestableItem) {
             return new EmptyTestableItem();
         }
@@ -235,6 +257,37 @@ public final class Items {
         }
     }
 
+    /**
+     * Get a Testable Item from an ItemStack.
+     * <p>
+     * Will search for registered items first. If there are no matches in the registry,
+     * then it will return a {@link MaterialTestableItem} matching the item type.
+     * <p>
+     * Does not account for modifiers (arg parser data).
+     *
+     * @param item The ItemStack.
+     * @return The found Testable Item.
+     */
+    @NotNull
+    public static TestableItem getItem(@Nullable final ItemStack item) {
+        if (item == null || item.getType().isAir()) {
+            return new EmptyTestableItem();
+        }
+
+        CustomItem customItem = getCustomItem(item);
+
+        if (customItem != null) {
+            return customItem;
+        }
+
+        for (TestableItem known : REGISTRY.values()) {
+            if (known.matches(item)) {
+                return known;
+            }
+        }
+        return new MaterialTestableItem(item.getType());
+    }
+
     /**
      * Get if itemStack is a custom item.
      *
@@ -242,12 +295,7 @@ public final class Items {
      * @return If is recipe.
      */
     public static boolean isCustomItem(@NotNull final ItemStack itemStack) {
-        for (TestableItem item : REGISTRY.values()) {
-            if (item.matches(itemStack)) {
-                return true;
-            }
-        }
-        return false;
+        return getCustomItem(itemStack) != null;
     }
 
     /**
@@ -258,12 +306,7 @@ public final class Items {
      */
     @Nullable
     public static CustomItem getCustomItem(@NotNull final ItemStack itemStack) {
-        for (TestableItem item : REGISTRY.values()) {
-            if (item.matches(itemStack)) {
-                return getOrWrap(item);
-            }
-        }
-        return null;
+        return CACHE.get(HashedItem.of(itemStack)).map(Items::getOrWrap).orElse(null);
     }
 
     /**
@@ -284,6 +327,7 @@ public final class Items {
      * @param item The item.
      * @return The CustomItem.
      */
+    @NotNull
     public static CustomItem getOrWrap(@NotNull final TestableItem item) {
         if (item instanceof CustomItem) {
             return (CustomItem) item;
@@ -296,6 +340,35 @@ 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/items/ItemsLookupHandler.java

@@ -0,0 +1,48 @@
+package com.willfp.eco.core.items;
+
+import com.willfp.eco.core.lookup.LookupHandler;
+import com.willfp.eco.core.recipe.parts.EmptyTestableItem;
+import com.willfp.eco.core.recipe.parts.GroupedTestableItems;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Collection;
+import java.util.function.Function;
+
+/**
+ * Handle item lookup strings.
+ */
+public class ItemsLookupHandler implements LookupHandler<TestableItem> {
+    /**
+     * The parser.
+     */
+    private final Function<String[], @NotNull TestableItem> parser;
+
+    /**
+     * Create new lookup handler.
+     *
+     * @param parser The parser.
+     */
+    public ItemsLookupHandler(@NotNull final Function<String[], @NotNull TestableItem> parser) {
+        this.parser = parser;
+    }
+
+    @Override
+    public @NotNull TestableItem parse(@NotNull final String[] args) {
+        return parser.apply(args);
+    }
+
+    @Override
+    public boolean validate(@NotNull final TestableItem object) {
+        return !(object instanceof EmptyTestableItem);
+    }
+
+    @Override
+    public @NotNull TestableItem getFailsafe() {
+        return new EmptyTestableItem();
+    }
+
+    @Override
+    public @NotNull TestableItem join(@NotNull final Collection<TestableItem> options) {
+        return new GroupedTestableItems(options);
+    }
+}

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

@@ -1,18 +1,20 @@
 package com.willfp.eco.core.items;
 
+import com.willfp.eco.core.lookup.Testable;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.Nullable;
 
 /**
  * An item with a test to see if any item is that item.
  */
-public interface TestableItem {
+public interface TestableItem extends Testable<ItemStack> {
     /**
      * If an ItemStack matches the recipe part.
      *
      * @param itemStack The item to test.
      * @return If the item matches.
      */
+    @Override
     boolean matches(@Nullable ItemStack itemStack);
 
     /**