diff --git a/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala b/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala
index d38f9ae79..050967bd1 100644
--- a/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala
+++ b/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala
@@ -2,6 +2,7 @@ package li.cil.oc.server.component
 
 import java.util
 
+import com.google.common.base.Strings
 import com.google.common.hash.Hashing
 import li.cil.oc.Constants
 import li.cil.oc.api.driver.DeviceInfo.DeviceAttribute
@@ -12,19 +13,19 @@ import li.cil.oc.api.internal
 import li.cil.oc.api.machine.Arguments
 import li.cil.oc.api.machine.Callback
 import li.cil.oc.api.machine.Context
-import li.cil.oc.api.network.Visibility
+import li.cil.oc.api.network.{Node, Visibility}
 import li.cil.oc.api.prefab
 import li.cil.oc.util.DatabaseAccess
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.ExtendedNBT._
 import net.minecraft.inventory.IInventory
-import net.minecraft.item.ItemStack
-import net.minecraft.nbt.CompressedStreamTools
+import net.minecraft.item.{Item, ItemStack}
+import net.minecraft.nbt.{CompressedStreamTools, JsonToNBT, NBTTagCompound}
 
 import scala.collection.convert.WrapAsJava._
 
 class UpgradeDatabase(val data: IInventory) extends prefab.ManagedEnvironment with internal.Database with DeviceInfo {
-  override val node = Network.newNode(this, Visibility.Network).
+  override val node: Node = Network.newNode(this, Visibility.Network).
     withComponent("database").
     create()
 
@@ -38,17 +39,19 @@ class UpgradeDatabase(val data: IInventory) extends prefab.ManagedEnvironment wi
 
   override def getDeviceInfo: util.Map[String, String] = deviceInfo
 
-  override def size = data.getSizeInventory
+  override def size: Int = data.getSizeInventory
 
-  override def getStackInSlot(slot: Int) = Option(data.getStackInSlot(slot)).map(_.copy()).orNull
+  override def getStackInSlot(slot: Int): ItemStack = Option(data.getStackInSlot(slot)).map(_.copy()).orNull
 
-  override def setStackInSlot(slot: Int, stack: ItemStack) = data.setInventorySlotContents(slot, stack)
+  override def setStackInSlot(slot: Int, stack: ItemStack): Unit = data.setInventorySlotContents(slot, stack)
 
-  override def findStackWithHash(needle: String) = indexOf(needle)
+  override def findStackWithHash(needle: String): Int = indexOf(needle)
 
+  //noinspection ScalaUnusedSymbol
   @Callback(doc = "function(slot:number):table -- Get the representation of the item stack stored in the specified slot.")
   def get(context: Context, args: Arguments): Array[AnyRef] = result(data.getStackInSlot(args.checkSlot(data, 0)))
 
+  //noinspection ScalaUnusedSymbol
   @Callback(doc = "function(slot:number):string -- Computes a hash value for the item stack in the specified slot.")
   def computeHash(context: Context, args: Arguments): Array[AnyRef] = {
     data.getStackInSlot(args.checkSlot(data, 0)) match {
@@ -59,9 +62,11 @@ class UpgradeDatabase(val data: IInventory) extends prefab.ManagedEnvironment wi
     }
   }
 
+  //noinspection ScalaUnusedSymbol
   @Callback(doc = "function(hash:string):number -- Get the index of an item stack with the specified hash. Returns a negative value if no such stack was found.")
   def indexOf(context: Context, args: Arguments): Array[AnyRef] = result(indexOf(args.checkString(0), 1))
 
+  //noinspection ScalaUnusedSymbol
   @Callback(doc = "function(slot:number):boolean -- Clears the specified slot. Returns true if there was something in the slot before.")
   def clear(context: Context, args: Arguments): Array[AnyRef] = {
     val slot = args.checkSlot(data, 0)
@@ -70,6 +75,7 @@ class UpgradeDatabase(val data: IInventory) extends prefab.ManagedEnvironment wi
     result(nonEmpty)
   }
 
+  //noinspection ScalaUnusedSymbol
   @Callback(doc = "function(fromSlot:number, toSlot:number[, address:string]):boolean -- Copies an entry to another slot, optionally to another database. Returns true if something was overwritten.")
   def copy(context: Context, args: Arguments): Array[AnyRef] = {
     val fromSlot = args.checkSlot(data, 0)
@@ -84,6 +90,7 @@ class UpgradeDatabase(val data: IInventory) extends prefab.ManagedEnvironment wi
     else set(data)
   }
 
+  //noinspection ScalaUnusedSymbol
   @Callback(doc = "function(address:string):number -- Copies the data stored in this database to another database with the specified address.")
   def clone(context: Context, args: Arguments): Array[AnyRef] = {
     DatabaseAccess.withDatabase(node, args.checkString(0), database => {
@@ -96,6 +103,22 @@ class UpgradeDatabase(val data: IInventory) extends prefab.ManagedEnvironment wi
     })
   }
 
+  //noinspection ScalaUnusedSymbol
+  @Callback(doc = """function(slot:number, id:string, damage:number, nbt:string):boolean - Set an item into the specified database slot. NBT tag is expected in JSON format.""")
+  def set(context: Context, args: Arguments): Array[AnyRef] = {
+    val slot = args.checkSlot(data, 0)
+    val item = Item.itemRegistry.getObject(args.checkString(1)).asInstanceOf[Item]
+    if (item == null)
+      return result(false, "invalid item id")
+    val damage = args.checkInteger(2)
+    val tagJson = args.optString(3, "")
+    val tag = if (Strings.isNullOrEmpty(tagJson)) null else JsonToNBT.func_150315_a(tagJson).asInstanceOf[NBTTagCompound]
+    val stack = new ItemStack(item, 1, damage)
+    stack.setTagCompound(tag)
+    data.setInventorySlotContents(slot, stack)
+    result(true)
+  }
+
   private def indexOf(needle: String, offset: Int = 0): Int = {
     for (slot <- 0 until data.getSizeInventory) data.getStackInSlot(slot) match {
       case stack: ItemStack =>