diff --git a/src/main/kotlin/cc/modlabs/kpaper/extensions/InventoryExtensions.kt b/src/main/kotlin/cc/modlabs/kpaper/extensions/InventoryExtensions.kt
index dce10a3..35d1166 100644
--- a/src/main/kotlin/cc/modlabs/kpaper/extensions/InventoryExtensions.kt
+++ b/src/main/kotlin/cc/modlabs/kpaper/extensions/InventoryExtensions.kt
@@ -1,6 +1,8 @@
 package cc.modlabs.kpaper.extensions
 
 import cc.modlabs.kpaper.consts.NAMESPACE_GUI_IDENTIFIER
+import cc.modlabs.kpaper.consts.NAMESPACE_ITEM_IDENTIFIER
+import cc.modlabs.kpaper.inventory.ItemBuilder
 import cc.modlabs.kpaper.inventory.toItemBuilder
 import dev.fruxz.stacked.text
 import org.bukkit.Material
@@ -103,4 +105,84 @@ fun Inventory.isIdentifiedAs(identifier: String): Boolean {
         NAMESPACE_GUI_IDENTIFIER,
         PersistentDataType.STRING
     ) == identifier
+}
+
+val Inventory.identifier: String?
+    get() = this.getItem(0)?.itemMeta?.persistentDataContainer?.get(
+        NAMESPACE_GUI_IDENTIFIER,
+        PersistentDataType.STRING
+    )
+
+fun Inventory.identifier(namespacedKey: NamespacedKey): String? {
+    return this.getItem(0)?.itemMeta?.persistentDataContainer?.get(
+        namespacedKey,
+        PersistentDataType.STRING
+    )
+}
+
+fun ItemStack.isIdentifiedAs(identifier: String): Boolean {
+    return this.itemMeta?.persistentDataContainer?.get(
+        NAMESPACE_ITEM_IDENTIFIER,
+        PersistentDataType.STRING
+    ) == identifier
+}
+
+val ItemStack.identifier: String?
+    get() = this.itemMeta?.persistentDataContainer?.get(
+        NAMESPACE_ITEM_IDENTIFIER,
+        PersistentDataType.STRING
+    )
+
+fun ItemStack.identifier(namespacedKey: NamespacedKey): String? {
+    return this.itemMeta?.persistentDataContainer?.get(
+        namespacedKey,
+        PersistentDataType.STRING
+    )
+}
+
+fun ItemStack.hasKey(namespacedKey: NamespacedKey): Boolean {
+    return this.itemMeta?.persistentDataContainer?.has(
+        namespacedKey,
+        PersistentDataType.STRING
+    ) == true
+}
+
+fun ItemStack.getKey(namespacedKey: NamespacedKey): String? {
+    return this.itemMeta?.persistentDataContainer?.get(
+        namespacedKey,
+        PersistentDataType.STRING
+    )
+}
+
+val PLACEHOLDER_GRAY = ItemBuilder(Material.GRAY_STAINED_GLASS_PANE) {
+    display(" ")
+}.build()
+
+fun Inventory.setItem(range: IntProgression, item: ItemStack) {
+    range.forEach { this.setItem(it, item) }
+}
+
+fun fillEmptyAndOpenInventory(player: Player, inv: Inventory, identifier: String? = null, vararg identifiers: Map<NamespacedKey, String>? = arrayOf()) {
+    fillEmpty(inv)
+    if (identifier != null) inv.identify(identifier, *identifiers)
+    player.openInventory(inv)
+}
+
+fun Inventory.fillEmpty(filler: ItemStack, identifier: String? = null, vararg identifiers: Map<NamespacedKey, String>? = arrayOf()) {
+    for (i in 0 until this.size) {
+        if (this.getItem(i) == null || this.getItem(i)!!.type == Material.AIR) {
+            this.setItem(i, filler)
+        }
+    }
+    if (identifier != null) this.identify(identifier, *identifiers)
+}
+
+fun fillEmpty(inventory: Inventory, identifier: String? = null, vararg identifiers: Map<NamespacedKey, String>? = arrayOf()) {
+    val item = PLACEHOLDER_GRAY
+    for (i in 0 until inventory.size) {
+        if (inventory.getItem(i) == null || inventory.getItem(i)!!.type == Material.AIR) {
+            inventory.setItem(i, item)
+        }
+    }
+    if (identifier != null) inventory.identify(identifier, *identifiers)
 }
\ No newline at end of file
diff --git a/src/main/kotlin/cc/modlabs/kpaper/main/KPlugin.kt b/src/main/kotlin/cc/modlabs/kpaper/main/KPlugin.kt
index 3c6184d..802d6f3 100644
--- a/src/main/kotlin/cc/modlabs/kpaper/main/KPlugin.kt
+++ b/src/main/kotlin/cc/modlabs/kpaper/main/KPlugin.kt
@@ -2,14 +2,10 @@
 
 import org.bukkit.plugin.java.JavaPlugin
 
-val PluginMainInstance: KPlugin get() = PluginInstance
-
 /**
  * The main plugin instance. Less complicated name for internal usage.
  */
-@PublishedApi
-internal lateinit var PluginInstance: KPlugin
-    private set
+lateinit var PluginInstance: KPlugin
 
 
 abstract class KPlugin : JavaPlugin() {