diff --git a/InvUI/pom.xml b/InvUI/pom.xml
index c13185b..cb937e6 100644
--- a/InvUI/pom.xml
+++ b/InvUI/pom.xml
@@ -45,7 +45,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>0.1-SNAPSHOT</version>
         </dependency>
         <dependency>
diff --git a/InvUI/src/main/java/de/studiocode/invui/InvUI.java b/InvUI/src/main/java/de/studiocode/invui/InvUI.java
index 153bb6e..21b18f1 100644
--- a/InvUI/src/main/java/de/studiocode/invui/InvUI.java
+++ b/InvUI/src/main/java/de/studiocode/invui/InvUI.java
@@ -1,6 +1,6 @@
 package de.studiocode.invui;
 
-import de.studiocode.invui.util.reflection.ReflectionUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import org.bukkit.Bukkit;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
@@ -10,7 +10,7 @@ import org.bukkit.plugin.Plugin;
 import java.util.ArrayList;
 import java.util.List;
 
-import static de.studiocode.invui.util.reflection.ReflectionRegistry.PLUGIN_CLASS_LOADER_PLUGIN_FIELD;
+import static de.studiocode.inventoryaccess.util.ReflectionRegistry.PLUGIN_CLASS_LOADER_PLUGIN_FIELD;
 
 public class InvUI implements Listener {
     
diff --git a/InvUI/src/main/java/de/studiocode/invui/item/ItemBuilder.java b/InvUI/src/main/java/de/studiocode/invui/item/ItemBuilder.java
index 7cfa0e4..c764434 100644
--- a/InvUI/src/main/java/de/studiocode/invui/item/ItemBuilder.java
+++ b/InvUI/src/main/java/de/studiocode/invui/item/ItemBuilder.java
@@ -5,10 +5,10 @@ import com.google.common.cache.CacheBuilder;
 import com.mojang.authlib.GameProfile;
 import com.mojang.authlib.properties.Property;
 import com.mojang.authlib.properties.PropertyMap;
+import de.studiocode.inventoryaccess.util.ReflectionRegistry;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import de.studiocode.invui.util.MojangApiUtils;
 import de.studiocode.invui.util.Pair;
-import de.studiocode.invui.util.reflection.ReflectionRegistry;
-import de.studiocode.invui.util.reflection.ReflectionUtils;
 import de.studiocode.invui.window.impl.BaseWindow;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
diff --git a/InvUI/src/main/java/de/studiocode/invui/resourcepack/ForceResourcePack.java b/InvUI/src/main/java/de/studiocode/invui/resourcepack/ForceResourcePack.java
index ec422b0..bfda54a 100644
--- a/InvUI/src/main/java/de/studiocode/invui/resourcepack/ForceResourcePack.java
+++ b/InvUI/src/main/java/de/studiocode/invui/resourcepack/ForceResourcePack.java
@@ -1,7 +1,7 @@
 package de.studiocode.invui.resourcepack;
 
+import de.studiocode.inventoryaccess.util.ReflectionRegistry;
 import de.studiocode.invui.InvUI;
-import de.studiocode.invui.util.reflection.ReflectionRegistry;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
diff --git a/InvUI/src/main/java/de/studiocode/invui/util/reflection/ReflectionRegistry.java b/InvUI/src/main/java/de/studiocode/invui/util/reflection/ReflectionRegistry.java
deleted file mode 100644
index 2d65980..0000000
--- a/InvUI/src/main/java/de/studiocode/invui/util/reflection/ReflectionRegistry.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package de.studiocode.invui.util.reflection;
-
-import java.lang.reflect.Field;
-
-import static de.studiocode.invui.util.reflection.ReflectionUtils.*;
-
-public class ReflectionRegistry {
-    
-    public static final int VERSION = getVersion();
-    
-    public static final String NET_MINECRAFT_SERVER_PACKAGE_PATH = getNMS();
-    public static final String CRAFT_BUKKIT_PACKAGE_PATH = getCB();
-    public static final String BUKKIT_PACKAGE_PATH = "org.bukkit.";
-    
-    // Classes
-    public static final Class<?> CB_CRAFT_META_SKULL_CLASS = getCBClass("inventory.CraftMetaSkull");
-    public static final Class<?> PLUGIN_CLASS_LOADER_CLASS = getBukkitClass("plugin.java.PluginClassLoader");
-    
-    // Fields
-    public static final Field CB_CRAFT_META_SKULL_PROFILE_FIELD = getField(CB_CRAFT_META_SKULL_CLASS, true, "profile");
-    public static final Field PLUGIN_CLASS_LOADER_PLUGIN_FIELD = getField(PLUGIN_CLASS_LOADER_CLASS, true, "plugin");
-    
-}
diff --git a/InvUI/src/main/java/de/studiocode/invui/util/reflection/ReflectionUtils.java b/InvUI/src/main/java/de/studiocode/invui/util/reflection/ReflectionUtils.java
deleted file mode 100644
index 08146ec..0000000
--- a/InvUI/src/main/java/de/studiocode/invui/util/reflection/ReflectionUtils.java
+++ /dev/null
@@ -1,112 +0,0 @@
-package de.studiocode.invui.util.reflection;
-
-import org.bukkit.Bukkit;
-
-import java.lang.reflect.Constructor;
-import java.lang.reflect.Field;
-import java.lang.reflect.Method;
-
-import static de.studiocode.invui.util.reflection.ReflectionRegistry.*;
-
-public class ReflectionUtils {
-    
-    protected static String getCB() {
-        String path = Bukkit.getServer().getClass().getPackage().getName();
-        String version = path.substring(path.lastIndexOf(".") + 1);
-        return "org.bukkit.craftbukkit." + version + ".";
-    }
-    
-    protected static String getNMS() {
-        String path = Bukkit.getServer().getClass().getPackage().getName();
-        String version = path.substring(path.lastIndexOf(".") + 1);
-        return "net.minecraft.server." + version + ".";
-    }
-    
-    protected static int getVersion() {
-        String version = Bukkit.getVersion();
-        version = version.substring(version.indexOf("MC: "), version.length() - 1).substring(4);
-        return Integer.parseInt(version.split("\\.")[1]);
-    }
-    
-    public static Class<?> getBukkitClass(String path) {
-        try {
-            return Class.forName(BUKKIT_PACKAGE_PATH + path);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static Class<?> getNMSClass(String path) {
-        try {
-            return Class.forName(NET_MINECRAFT_SERVER_PACKAGE_PATH + path);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static Class<?> getCBClass(String path) {
-        try {
-            return Class.forName(CRAFT_BUKKIT_PACKAGE_PATH + path);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static Field getField(Class<?> clazz, boolean declared, String name) {
-        try {
-            Field field = declared ? clazz.getDeclaredField(name) : clazz.getField(name);
-            if (declared) field.setAccessible(true);
-            return field;
-        } catch (NoSuchFieldException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static Constructor<?> getConstructor(Class<?> clazz, boolean declared, Class<?> parameterTypes) {
-        try {
-            return declared ? clazz.getDeclaredConstructor(parameterTypes) : clazz.getConstructor(parameterTypes);
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static Method getMethod(Class<?> clazz, boolean declared, String name, Class<?>... parameterTypes) {
-        try {
-            return declared ? clazz.getDeclaredMethod(name, parameterTypes) : clazz.getMethod(name, parameterTypes);
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static void setFieldValue(Field field, Object obj, Object value) {
-        try {
-            field.set(obj, value);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        }
-    }
-    
-    @SuppressWarnings("unchecked")
-    public static <T> T getFieldValue(Field field, Object obj) {
-        try {
-            return (T) field.get(obj);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-}
diff --git a/InvUI/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventoryManager.java b/InvUI/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventoryManager.java
index 45a925c..957966c 100644
--- a/InvUI/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventoryManager.java
+++ b/InvUI/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventoryManager.java
@@ -1,6 +1,6 @@
 package de.studiocode.invui.virtualinventory;
 
-import de.studiocode.inventoryaccess.api.version.InventoryAccess;
+import de.studiocode.inventoryaccess.version.InventoryAccess;
 import de.studiocode.invui.InvUI;
 import de.studiocode.invui.util.DataUtils;
 import org.bukkit.configuration.file.YamlConfiguration;
diff --git a/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java b/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java
index 0374cac..5221d74 100644
--- a/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java
+++ b/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java
@@ -1,6 +1,6 @@
 package de.studiocode.invui.window.impl;
 
-import de.studiocode.inventoryaccess.api.version.InventoryAccess;
+import de.studiocode.inventoryaccess.version.InventoryAccess;
 import de.studiocode.invui.InvUI;
 import de.studiocode.invui.gui.GUI;
 import de.studiocode.invui.gui.SlotElement;
diff --git a/InvUI/src/main/java/de/studiocode/invui/window/impl/merged/split/AnvilSplitWindow.java b/InvUI/src/main/java/de/studiocode/invui/window/impl/merged/split/AnvilSplitWindow.java
index f6968b4..886bb80 100644
--- a/InvUI/src/main/java/de/studiocode/invui/window/impl/merged/split/AnvilSplitWindow.java
+++ b/InvUI/src/main/java/de/studiocode/invui/window/impl/merged/split/AnvilSplitWindow.java
@@ -1,7 +1,7 @@
 package de.studiocode.invui.window.impl.merged.split;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
-import de.studiocode.inventoryaccess.api.version.InventoryAccess;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.version.InventoryAccess;
 import de.studiocode.invui.gui.GUI;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.api.chat.TextComponent;
diff --git a/InvUI/src/main/java/de/studiocode/invui/window/impl/single/AnvilWindow.java b/InvUI/src/main/java/de/studiocode/invui/window/impl/single/AnvilWindow.java
index d7ccb74..2761241 100644
--- a/InvUI/src/main/java/de/studiocode/invui/window/impl/single/AnvilWindow.java
+++ b/InvUI/src/main/java/de/studiocode/invui/window/impl/single/AnvilWindow.java
@@ -1,7 +1,7 @@
 package de.studiocode.invui.window.impl.single;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
-import de.studiocode.inventoryaccess.api.version.InventoryAccess;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.version.InventoryAccess;
 import de.studiocode.invui.gui.GUI;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.api.chat.TextComponent;
diff --git a/InventoryAccess/1_14_R1/pom.xml b/InventoryAccess/1_14_R1/pom.xml
index ef11e60..1519fc8 100644
--- a/InventoryAccess/1_14_R1/pom.xml
+++ b/InventoryAccess/1_14_R1/pom.xml
@@ -26,7 +26,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/inventory/AnvilInventoryImpl.java
index 9a29cec..12f54ea 100644
--- a/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/inventory/AnvilInventoryImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_14_R1.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import de.studiocode.inventoryaccess.v1_14_R1.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.server.v1_14_R1.*;
@@ -46,9 +46,9 @@ public class AnvilInventoryImpl extends ContainerAnvil implements AnvilInventory
         this.renameHandler = renameHandler;
         this.player = player;
         
-        repairInventory = ReflectionUtils.getValueOfField(REPAIR_INVENTORY_FIELD, this);
-        resultInventory = ReflectionUtils.getValueOfField(RESULT_INVENTORY_FIELD, this);
-        ContainerAccess containerAccess = ReflectionUtils.getValueOfField(CONTAINER_ACCESS_FIELD, this);
+        repairInventory = ReflectionUtils.getFieldValue(REPAIR_INVENTORY_FIELD, this);
+        resultInventory = ReflectionUtils.getFieldValue(RESULT_INVENTORY_FIELD, this);
+        ContainerAccess containerAccess = ReflectionUtils.getFieldValue(CONTAINER_ACCESS_FIELD, this);
         
         CraftInventoryAnvil inventory = new CraftInventoryAnvil(containerAccess.getLocation(),
             repairInventory, resultInventory, this);
diff --git a/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/InventoryUtilsImpl.java b/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/InventoryUtilsImpl.java
index 516b031..04535a6 100644
--- a/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_14_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.server.v1_14_R1.*;
diff --git a/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/ItemUtilsImpl.java b/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/ItemUtilsImpl.java
index 149b3e4..ff2d416 100644
--- a/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_14_R1/src/main/java/de/studiocode/inventoryaccess/v1_14_R1/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_14_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.server.v1_14_R1.ItemStack;
 import net.minecraft.server.v1_14_R1.NBTCompressedStreamTools;
 import net.minecraft.server.v1_14_R1.NBTTagCompound;
diff --git a/InventoryAccess/1_15_R1/pom.xml b/InventoryAccess/1_15_R1/pom.xml
index 021634f..9652c97 100644
--- a/InventoryAccess/1_15_R1/pom.xml
+++ b/InventoryAccess/1_15_R1/pom.xml
@@ -26,7 +26,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/inventory/AnvilInventoryImpl.java
index dba23fd..3f96618 100644
--- a/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/inventory/AnvilInventoryImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_15_R1.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import de.studiocode.inventoryaccess.v1_15_R1.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.server.v1_15_R1.*;
@@ -46,9 +46,9 @@ public class AnvilInventoryImpl extends ContainerAnvil implements AnvilInventory
         this.renameHandler = renameHandler;
         this.player = player;
         
-        repairInventory = ReflectionUtils.getValueOfField(REPAIR_INVENTORY_FIELD, this);
-        resultInventory = ReflectionUtils.getValueOfField(RESULT_INVENTORY_FIELD, this);
-        ContainerAccess containerAccess = ReflectionUtils.getValueOfField(CONTAINER_ACCESS_FIELD, this);
+        repairInventory = ReflectionUtils.getFieldValue(REPAIR_INVENTORY_FIELD, this);
+        resultInventory = ReflectionUtils.getFieldValue(RESULT_INVENTORY_FIELD, this);
+        ContainerAccess containerAccess = ReflectionUtils.getFieldValue(CONTAINER_ACCESS_FIELD, this);
         
         CraftInventoryAnvil inventory = new CraftInventoryAnvil(containerAccess.getLocation(),
             repairInventory, resultInventory, this);
diff --git a/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/InventoryUtilsImpl.java b/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/InventoryUtilsImpl.java
index d3c610d..4dc93e8 100644
--- a/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_15_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.server.v1_15_R1.*;
diff --git a/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/ItemUtilsImpl.java b/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/ItemUtilsImpl.java
index 2fac3c4..f0c0e3b 100644
--- a/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_15_R1/src/main/java/de/studiocode/inventoryaccess/v1_15_R1/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_15_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.server.v1_15_R1.ItemStack;
 import net.minecraft.server.v1_15_R1.NBTCompressedStreamTools;
 import net.minecraft.server.v1_15_R1.NBTTagCompound;
diff --git a/InventoryAccess/1_16_R1/pom.xml b/InventoryAccess/1_16_R1/pom.xml
index b894d7f..a1a55e9 100644
--- a/InventoryAccess/1_16_R1/pom.xml
+++ b/InventoryAccess/1_16_R1/pom.xml
@@ -26,7 +26,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/inventory/AnvilInventoryImpl.java
index a1da112..3f9d299 100644
--- a/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/inventory/AnvilInventoryImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_16_R1.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
 import de.studiocode.inventoryaccess.v1_16_R1.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.server.v1_16_R1.*;
diff --git a/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/InventoryUtilsImpl.java b/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/InventoryUtilsImpl.java
index 8ece690..c57391c 100644
--- a/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_16_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.server.v1_16_R1.*;
diff --git a/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/ItemUtilsImpl.java b/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/ItemUtilsImpl.java
index 9fb8352..217e2af 100644
--- a/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_16_R1/src/main/java/de/studiocode/inventoryaccess/v1_16_R1/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_16_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.server.v1_16_R1.ItemStack;
 import net.minecraft.server.v1_16_R1.NBTCompressedStreamTools;
 import net.minecraft.server.v1_16_R1.NBTTagCompound;
diff --git a/InventoryAccess/1_16_R2/pom.xml b/InventoryAccess/1_16_R2/pom.xml
index 7505d5e..d16811e 100644
--- a/InventoryAccess/1_16_R2/pom.xml
+++ b/InventoryAccess/1_16_R2/pom.xml
@@ -26,7 +26,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/inventory/AnvilInventoryImpl.java
index 2b91d97..a54c996 100644
--- a/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/inventory/AnvilInventoryImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_16_R2.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
 import de.studiocode.inventoryaccess.v1_16_R2.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.server.v1_16_R2.*;
diff --git a/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/InventoryUtilsImpl.java b/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/InventoryUtilsImpl.java
index c33a542..95f2428 100644
--- a/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_16_R2.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.server.v1_16_R2.*;
diff --git a/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/ItemUtilsImpl.java b/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/ItemUtilsImpl.java
index 35c2976..8db8c0c 100644
--- a/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_16_R2/src/main/java/de/studiocode/inventoryaccess/v1_16_R2/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_16_R2.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.server.v1_16_R2.ItemStack;
 import net.minecraft.server.v1_16_R2.NBTCompressedStreamTools;
 import net.minecraft.server.v1_16_R2.NBTTagCompound;
diff --git a/InventoryAccess/1_16_R3/pom.xml b/InventoryAccess/1_16_R3/pom.xml
index e700327..82696b6 100644
--- a/InventoryAccess/1_16_R3/pom.xml
+++ b/InventoryAccess/1_16_R3/pom.xml
@@ -26,7 +26,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/inventory/AnvilInventoryImpl.java
index 94994f9..4136d52 100644
--- a/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/inventory/AnvilInventoryImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_16_R3.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
 import de.studiocode.inventoryaccess.v1_16_R3.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.server.v1_16_R3.*;
diff --git a/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/InventoryUtilsImpl.java b/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/InventoryUtilsImpl.java
index 3b4a29a..16df54e 100644
--- a/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_16_R3.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.server.v1_16_R3.*;
diff --git a/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/ItemUtilsImpl.java b/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/ItemUtilsImpl.java
index 897c318..a4c369e 100644
--- a/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_16_R3/src/main/java/de/studiocode/inventoryaccess/v1_16_R3/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_16_R3.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.server.v1_16_R3.ItemStack;
 import net.minecraft.server.v1_16_R3.NBTCompressedStreamTools;
 import net.minecraft.server.v1_16_R3.NBTTagCompound;
diff --git a/InventoryAccess/1_17_R1/pom.xml b/InventoryAccess/1_17_R1/pom.xml
index 97bb9c7..b16efd1 100644
--- a/InventoryAccess/1_17_R1/pom.xml
+++ b/InventoryAccess/1_17_R1/pom.xml
@@ -28,7 +28,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/inventory/AnvilInventoryImpl.java
index b276e19..caf639f 100644
--- a/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/inventory/AnvilInventoryImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_17_R1.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
 import de.studiocode.inventoryaccess.v1_17_R1.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.core.BlockPos;
diff --git a/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/InventoryUtilsImpl.java b/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/InventoryUtilsImpl.java
index d04c798..9acb739 100644
--- a/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_17_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.network.chat.Component;
diff --git a/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/ItemUtilsImpl.java b/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/ItemUtilsImpl.java
index e193356..98b2941 100644
--- a/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_17_R1/src/main/java/de/studiocode/inventoryaccess/v1_17_R1/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_17_R1.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.NbtIo;
 import net.minecraft.world.item.ItemStack;
diff --git a/InventoryAccess/1_17_R2/pom.xml b/InventoryAccess/1_17_R2/pom.xml
index ab24c4f..838900a 100644
--- a/InventoryAccess/1_17_R2/pom.xml
+++ b/InventoryAccess/1_17_R2/pom.xml
@@ -28,7 +28,7 @@
         </dependency>
         <dependency>
             <groupId>de.studiocode.invui</groupId>
-            <artifactId>api</artifactId>
+            <artifactId>abstraction</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
     </dependencies>
diff --git a/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/inventory/AnvilInventoryImpl.java b/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/inventory/AnvilInventoryImpl.java
index 410f55f..2804158 100644
--- a/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/inventory/AnvilInventoryImpl.java
+++ b/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/inventory/AnvilInventoryImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_17_R2.inventory;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
 import de.studiocode.inventoryaccess.v1_17_R2.util.InventoryUtilsImpl;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.minecraft.core.BlockPos;
diff --git a/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/InventoryUtilsImpl.java b/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/InventoryUtilsImpl.java
index 855aadf..7254dcd 100644
--- a/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/InventoryUtilsImpl.java
+++ b/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/InventoryUtilsImpl.java
@@ -1,6 +1,6 @@
 package de.studiocode.inventoryaccess.v1_17_R2.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import net.minecraft.network.chat.Component;
diff --git a/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/ItemUtilsImpl.java b/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/ItemUtilsImpl.java
index eba8316..5e58ff3 100644
--- a/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/ItemUtilsImpl.java
+++ b/InventoryAccess/1_17_R2/src/main/java/de/studiocode/inventoryaccess/v1_17_R2/util/ItemUtilsImpl.java
@@ -1,7 +1,7 @@
 package de.studiocode.inventoryaccess.v1_17_R2.util;
 
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
-import de.studiocode.inventoryaccess.api.version.ReflectionUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.NbtIo;
 import net.minecraft.world.item.ItemStack;
diff --git a/InventoryAccess/api/pom.xml b/InventoryAccess/abstraction/pom.xml
similarity index 95%
rename from InventoryAccess/api/pom.xml
rename to InventoryAccess/abstraction/pom.xml
index b533194..9e25dfa 100644
--- a/InventoryAccess/api/pom.xml
+++ b/InventoryAccess/abstraction/pom.xml
@@ -10,13 +10,13 @@
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
-    <artifactId>api</artifactId>
+    <artifactId>abstraction</artifactId>
 
     <properties>
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>
     </properties>
-    
+
     <dependencies>
         <dependency>
             <groupId>org.spigotmc</groupId>
diff --git a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/inventory/AnvilInventory.java b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/inventory/AnvilInventory.java
similarity index 93%
rename from InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/inventory/AnvilInventory.java
rename to InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/inventory/AnvilInventory.java
index 82914e2..3b47e5e 100644
--- a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/inventory/AnvilInventory.java
+++ b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/inventory/AnvilInventory.java
@@ -1,4 +1,4 @@
-package de.studiocode.inventoryaccess.api.abstraction.inventory;
+package de.studiocode.inventoryaccess.abstraction.inventory;
 
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
diff --git a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/util/InventoryUtils.java b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/util/InventoryUtils.java
similarity index 96%
rename from InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/util/InventoryUtils.java
rename to InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/util/InventoryUtils.java
index 3c6b836..dfe07ea 100644
--- a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/util/InventoryUtils.java
+++ b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/util/InventoryUtils.java
@@ -1,4 +1,4 @@
-package de.studiocode.inventoryaccess.api.abstraction.util;
+package de.studiocode.inventoryaccess.abstraction.util;
 
 import net.md_5.bungee.api.chat.BaseComponent;
 import org.bukkit.entity.Player;
diff --git a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/util/ItemUtils.java b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/util/ItemUtils.java
similarity index 96%
rename from InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/util/ItemUtils.java
rename to InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/util/ItemUtils.java
index 2ce08c6..d3b05c9 100644
--- a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/abstraction/util/ItemUtils.java
+++ b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/abstraction/util/ItemUtils.java
@@ -1,4 +1,4 @@
-package de.studiocode.inventoryaccess.api.abstraction.util;
+package de.studiocode.inventoryaccess.abstraction.util;
 
 import org.bukkit.inventory.ItemStack;
 
diff --git a/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/util/ReflectionRegistry.java b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/util/ReflectionRegistry.java
new file mode 100644
index 0000000..efc24b2
--- /dev/null
+++ b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/util/ReflectionRegistry.java
@@ -0,0 +1,30 @@
+package de.studiocode.inventoryaccess.util;
+
+import java.lang.reflect.Field;
+
+import static de.studiocode.inventoryaccess.util.ReflectionUtils.*;
+
+
+public class ReflectionRegistry {
+    
+    public static final int VERSION = getVersionNumber();
+    public static final String INV_ACCESS_VERSION = getInventoryAccessVersion();
+    
+    public static final String CRAFT_BUKKIT_PACKAGE_PATH = getCB();
+    public static final String BUKKIT_PACKAGE_PATH = "org.bukkit.";
+    
+    // Classes
+    public static final Class<?> CB_CRAFT_META_SKULL_CLASS = getCBClass("inventory.CraftMetaSkull");
+    public static final Class<?> PLUGIN_CLASS_LOADER_CLASS = getBukkitClass("plugin.java.PluginClassLoader");
+    public static final Class<?> CB_CRAFT_META_ITEM_CLASS = getCBClass("inventory.CraftMetaItem");
+    public static final Class<?> CB_CRAFT_ITEM_STACK_CLASS = getCBClass("inventory.CraftItemStack");
+    
+    // Fields
+    public static final Field CB_CRAFT_META_SKULL_PROFILE_FIELD = getField(CB_CRAFT_META_SKULL_CLASS, true, "profile");
+    public static final Field PLUGIN_CLASS_LOADER_PLUGIN_FIELD = getField(PLUGIN_CLASS_LOADER_CLASS, true, "plugin");
+    public static final Field CB_CRAFT_META_ITEM_INTERNAL_TAG_FIELD = getField(CB_CRAFT_META_ITEM_CLASS, true, "internalTag");
+    public static final Field CB_CRAFT_META_ITEM_DISPLAY_NAME_FIELD = getField(CB_CRAFT_META_ITEM_CLASS, true, "displayName");
+    public static final Field CB_CRAFT_META_ITEM_LORE_FIELD = getField(CB_CRAFT_META_ITEM_CLASS, true, "lore");
+    public static final Field CB_CRAFT_ITEM_STACK_HANDLE_FIELD = ReflectionUtils.getField(CB_CRAFT_ITEM_STACK_CLASS, true, "handle");
+    
+}
diff --git a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/version/ReflectionUtils.java b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/util/ReflectionUtils.java
similarity index 64%
rename from InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/version/ReflectionUtils.java
rename to InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/util/ReflectionUtils.java
index 7d57c63..24a91c5 100644
--- a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/version/ReflectionUtils.java
+++ b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/util/ReflectionUtils.java
@@ -1,4 +1,4 @@
-package de.studiocode.inventoryaccess.api.version;
+package de.studiocode.inventoryaccess.util;
 
 import org.bukkit.Bukkit;
 
@@ -7,12 +7,24 @@ import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 
-@SuppressWarnings({"unchecked", "UnusedReturnValue"})
+import static de.studiocode.inventoryaccess.util.ReflectionRegistry.*;
+
+@SuppressWarnings({"unchecked", "unused"})
 public class ReflectionUtils {
     
-    private static final String VERSION = getVersion();
+    protected static String getCB() {
+        String path = Bukkit.getServer().getClass().getPackage().getName();
+        String version = path.substring(path.lastIndexOf(".") + 1);
+        return "org.bukkit.craftbukkit." + version + ".";
+    }
     
-    private static String getVersion() {
+    protected static int getVersionNumber() {
+        String version = Bukkit.getVersion();
+        version = version.substring(version.indexOf("MC: "), version.length() - 1).substring(4);
+        return Integer.parseInt(version.split("\\.")[1]);
+    }
+    
+    protected static String getInventoryAccessVersion() {
         String version = Bukkit.getVersion();
         version = version.substring(version.indexOf("MC: "), version.length() - 1).substring(4);
         
@@ -26,12 +38,20 @@ public class ReflectionUtils {
     
     public static <T> Class<T> getImplClass(String path) {
         try {
-            return (Class<T>) Class.forName("de.studiocode.inventoryaccess." + VERSION + "." + path);
+            return (Class<T>) Class.forName("de.studiocode.inventoryaccess." + INV_ACCESS_VERSION + "." + path);
         } catch (ClassNotFoundException e) {
-            throw new UnsupportedOperationException("Your version (" + VERSION + ") is not supported by InventoryAccess");
+            throw new UnsupportedOperationException("Your version (" + INV_ACCESS_VERSION + ") is not supported by InventoryAccess");
         }
     }
     
+    public static <T> Class<T> getBukkitClass(String path) {
+        return getClass(BUKKIT_PACKAGE_PATH + path);
+    }
+    
+    public static <T> Class<T> getCBClass(String path) {
+        return getClass(CRAFT_BUKKIT_PACKAGE_PATH + path);
+    }
+    
     public static <T> Class<T> getClass(String path) {
         try {
             return (Class<T>) Class.forName(path);
@@ -42,9 +62,21 @@ public class ReflectionUtils {
         return null;
     }
     
-    public static <T> Constructor<T> getConstructor(Class<T> clazz, Class<?>... parameterTypes) {
+    public static Field getField(Class<?> clazz, boolean declared, String name) {
         try {
-            return clazz.getConstructor(parameterTypes);
+            Field field = declared ? clazz.getDeclaredField(name) : clazz.getField(name);
+            if (declared) field.setAccessible(true);
+            return field;
+        } catch (NoSuchFieldException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
+    public static <T> Constructor<T> getConstructor(Class<T> clazz, boolean declared, Class<?>... parameterTypes) {
+        try {
+            return declared ? clazz.getDeclaredConstructor(parameterTypes) : clazz.getConstructor(parameterTypes);
         } catch (NoSuchMethodException e) {
             e.printStackTrace();
         }
@@ -72,33 +104,9 @@ public class ReflectionUtils {
         return null;
     }
     
-    public static Field getField(Class<?> clazz, boolean declared, String name) {
-        try {
-            Field field = declared ? clazz.getDeclaredField(name) : clazz.getField(name);
-            if (declared) field.setAccessible(true);
-            return field;
-        } catch (NoSuchFieldException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
-    public static <T> T getValueOfField(Field field, Object obj) {
-        try {
-            return (T) field.get(obj);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        }
-        
-        return null;
-    }
-    
     public static Method getMethod(Class<?> clazz, boolean declared, String name, Class<?>... parameterTypes) {
         try {
-            Method method = declared ? clazz.getDeclaredMethod(name, parameterTypes) : clazz.getMethod(name, parameterTypes);
-            if (declared) method.setAccessible(true);
-            return method;
+            return declared ? clazz.getDeclaredMethod(name, parameterTypes) : clazz.getMethod(name, parameterTypes);
         } catch (NoSuchMethodException e) {
             e.printStackTrace();
         }
@@ -116,4 +124,23 @@ public class ReflectionUtils {
         return null;
     }
     
+    public static void setFieldValue(Field field, Object obj, Object value) {
+        try {
+            field.set(obj, value);
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
+    }
+    
+    @SuppressWarnings("unchecked")
+    public static <T> T getFieldValue(Field field, Object obj) {
+        try {
+            return (T) field.get(obj);
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
 }
diff --git a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/version/InventoryAccess.java b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/version/InventoryAccess.java
similarity index 84%
rename from InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/version/InventoryAccess.java
rename to InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/version/InventoryAccess.java
index ac3a6b5..b55f211 100644
--- a/InventoryAccess/api/src/main/java/de/studiocode/inventoryaccess/api/version/InventoryAccess.java
+++ b/InventoryAccess/abstraction/src/main/java/de/studiocode/inventoryaccess/version/InventoryAccess.java
@@ -1,8 +1,9 @@
-package de.studiocode.inventoryaccess.api.version;
+package de.studiocode.inventoryaccess.version;
 
-import de.studiocode.inventoryaccess.api.abstraction.inventory.AnvilInventory;
-import de.studiocode.inventoryaccess.api.abstraction.util.InventoryUtils;
-import de.studiocode.inventoryaccess.api.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.abstraction.inventory.AnvilInventory;
+import de.studiocode.inventoryaccess.abstraction.util.InventoryUtils;
+import de.studiocode.inventoryaccess.abstraction.util.ItemUtils;
+import de.studiocode.inventoryaccess.util.ReflectionUtils;
 import net.md_5.bungee.api.chat.BaseComponent;
 import org.bukkit.entity.Player;
 
@@ -16,7 +17,7 @@ public class InventoryAccess {
     private static final Class<AnvilInventory> ANVIL_INVENTORY_CLASS = ReflectionUtils.getImplClass("inventory.AnvilInventoryImpl");
     
     private static final Constructor<AnvilInventory> ANVIL_INVENTORY_CONSTRUCTOR
-        = ReflectionUtils.getConstructor(ANVIL_INVENTORY_CLASS, Player.class, BaseComponent[].class, Consumer.class);
+        = ReflectionUtils.getConstructor(ANVIL_INVENTORY_CLASS, false, Player.class, BaseComponent[].class, Consumer.class);
     
     private static final InventoryUtils INVENTORY_UTILS = ReflectionUtils.constructEmpty(INVENTORY_UTILS_CLASS);
     private static final ItemUtils ITEM_UTILS = ReflectionUtils.constructEmpty(ITEM_UTILS_CLASS);
diff --git a/pom.xml b/pom.xml
index 82b688d..3e2b334 100644
--- a/pom.xml
+++ b/pom.xml
@@ -36,8 +36,8 @@
         <module>InventoryAccess/1_16_R3</module>
         <module>InventoryAccess/1_17_R1</module>
         <module>InventoryAccess/1_17_R2</module>
-        <module>InventoryAccess/api</module>
         <module>InvUI</module>
+        <module>InventoryAccess/abstraction</module>
     </modules>
 
     <build>