diff --git a/src/main/kotlin/net/shadowfacts/phycon/network/block/extractor/ExtractorBlockEntity.kt b/src/main/kotlin/net/shadowfacts/phycon/network/block/extractor/ExtractorBlockEntity.kt
index 59fe56f..7d83833 100644
--- a/src/main/kotlin/net/shadowfacts/phycon/network/block/extractor/ExtractorBlockEntity.kt
+++ b/src/main/kotlin/net/shadowfacts/phycon/network/block/extractor/ExtractorBlockEntity.kt
@@ -1,26 +1,31 @@
 package net.shadowfacts.phycon.network.block.extractor
 
 import alexiil.mc.lib.attributes.SearchOptions
-import alexiil.mc.lib.attributes.item.GroupedItemInv
+import alexiil.mc.lib.attributes.Simulation
+import alexiil.mc.lib.attributes.item.FixedItemInv
 import alexiil.mc.lib.attributes.item.ItemAttributes
+import alexiil.mc.lib.attributes.item.filter.ExactItemStackFilter
 import net.minecraft.block.BlockState
+import net.minecraft.item.ItemStack
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.util.math.Direction
 import net.shadowfacts.phycon.api.packet.Packet
-import net.shadowfacts.phycon.api.util.IPAddress
 import net.shadowfacts.phycon.init.PhyBlockEntities
 import net.shadowfacts.phycon.network.DeviceBlockEntity
 import net.shadowfacts.phycon.network.component.ActivationController
+import net.shadowfacts.phycon.network.component.NetworkStackDispatcher
+import net.shadowfacts.phycon.network.component.handleItemStack
 import net.shadowfacts.phycon.network.packet.CapacityPacket
-import net.shadowfacts.phycon.network.packet.CheckCapacityPacket
 import net.shadowfacts.phycon.network.packet.ItemStackPacket
 import net.shadowfacts.phycon.network.packet.RemoteActivationPacket
 import net.shadowfacts.phycon.util.ActivationMode
+import kotlin.properties.Delegates
 
 /**
  * @author shadowfacts
  */
 class ExtractorBlockEntity: DeviceBlockEntity(PhyBlockEntities.EXTRACTOR),
+	NetworkStackDispatcher<ExtractorBlockEntity.PendingInsertion>,
 	ActivationController.ActivatableDevice {
 
 	companion object {
@@ -30,17 +35,18 @@ class ExtractorBlockEntity: DeviceBlockEntity(PhyBlockEntities.EXTRACTOR),
 	private val facing: Direction
 		get() = cachedState[ExtractorBlock.FACING]
 
-	private var inventory: GroupedItemInv? = null
-	private var shouldExtract = false
+	private var inventory: FixedItemInv? = null
+	override val pendingInsertions = mutableListOf<PendingInsertion>()
+	override val dispatchStackTimeout = 40L
 	override val controller = ActivationController(SLEEP_TIME, this)
 
 	fun updateInventory() {
 		val offsetPos = pos.offset(facing)
 		val option = SearchOptions.inDirection(facing)
-		inventory = ItemAttributes.GROUPED_INV.getFirstOrNull(world, offsetPos, option)
+		inventory = ItemAttributes.FIXED_INV.getFirstOrNull(world, offsetPos, option)
 	}
 
-	private fun getInventory(): GroupedItemInv? {
+	private fun getInventory(): FixedItemInv? {
 		if (inventory == null) updateInventory()
 		return inventory
 	}
@@ -48,18 +54,27 @@ class ExtractorBlockEntity: DeviceBlockEntity(PhyBlockEntities.EXTRACTOR),
 	override fun handle(packet: Packet) {
 		when (packet) {
 			is CapacityPacket -> handleCapacity(packet)
+			is ItemStackPacket -> handleItemStack(packet)
 			is RemoteActivationPacket -> controller.handleRemoteActivation(packet)
 		}
 	}
 
-	private fun handleCapacity(packet: CapacityPacket) {
-		if (shouldExtract && packet.capacity > 0) {
-			getInventory()?.also { inv ->
-				shouldExtract = false
-				val extracted = inv.extract(packet.stack, packet.capacity)
-				sendPacket(ItemStackPacket(extracted, ipAddress, packet.stackReceiver.ipAddress))
-			}
-		}
+	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
+		// we can't insert things back into the inventory, so just let them spawn
+		return packet.stack
+	}
+
+	override fun createPendingInsertion(stack: ItemStack) = PendingInsertion(stack, counter)
+
+	override fun finishInsertion(insertion: PendingInsertion): ItemStack {
+		val inventory = getInventory() ?: return insertion.stack
+		// if the inventory has changed, the old slot index is meaningless
+		if (inventory !== insertion.inventory) return insertion.stack
+		val extracted = inventory.extractStack(insertion.inventorySlot, ExactItemStackFilter(insertion.stack), ItemStack.EMPTY, insertion.totalCapacity, Simulation.ACTION)
+		if (extracted.isEmpty) return insertion.stack
+		// if we extracted less than expected, make sure super.finishInsertion doesn't send more than we actually have
+		insertion.stack = extracted
+		return super.finishInsertion(insertion)
 	}
 
 	override fun tick() {
@@ -72,10 +87,16 @@ class ExtractorBlockEntity: DeviceBlockEntity(PhyBlockEntities.EXTRACTOR),
 
 	override fun activate(): Boolean {
 		val inventory = getInventory() ?: return false
-		val stack = inventory.storedStacks.firstOrNull() ?: return false
-		shouldExtract = true
-		sendPacket(CheckCapacityPacket(stack, ipAddress, IPAddress.BROADCAST))
-		return true
+		for (slot in 0 until inventory.slotCount) {
+			val slotStack = inventory.getInvStack(slot)
+			if (slotStack.isEmpty) continue
+			dispatchItemStack(slotStack) { insertion ->
+				insertion.inventory = inventory
+				insertion.inventorySlot = slot
+			}
+			return true
+		}
+		return false
 	}
 
 	override fun toTag(tag: CompoundTag): CompoundTag {
@@ -97,4 +118,9 @@ class ExtractorBlockEntity: DeviceBlockEntity(PhyBlockEntities.EXTRACTOR),
 		super.fromClientTag(tag)
 		controller.activationMode = ActivationMode.valueOf(tag.getString("ActivationMode"))
 	}
+
+	class PendingInsertion(stack: ItemStack, timestamp: Long): NetworkStackDispatcher.PendingInsertion<PendingInsertion>(stack, timestamp) {
+		lateinit var inventory: FixedItemInv
+		var inventorySlot by Delegates.notNull<Int>()
+	}
 }
diff --git a/src/main/kotlin/net/shadowfacts/phycon/network/component/NetworkStackDispatcher.kt b/src/main/kotlin/net/shadowfacts/phycon/network/component/NetworkStackDispatcher.kt
index 1b6d7b8..6d2f3f6 100644
--- a/src/main/kotlin/net/shadowfacts/phycon/network/component/NetworkStackDispatcher.kt
+++ b/src/main/kotlin/net/shadowfacts/phycon/network/component/NetworkStackDispatcher.kt
@@ -33,7 +33,8 @@ interface NetworkStackDispatcher<Insertion: NetworkStackDispatcher.PendingInsert
 		if (insertion != null) {
 			insertion.results.add(packet.capacity to packet.stackReceiver)
 			if (insertion.isFinishable(this)) {
-				finishInsertion(insertion)
+				val remaining = finishInsertion(insertion)
+				// todo: do something with remaining
 			}
 		}
 	}
@@ -43,7 +44,8 @@ interface NetworkStackDispatcher<Insertion: NetworkStackDispatcher.PendingInsert
 
 		// todo: also sort results by interface priority
 		val sortedResults = insertion.results.sortedBy { it.first }.toMutableList()
-		val remaining = insertion.stack
+		// copy the insertion stack so subclasses that override this method can still see the originally dispatched stack after the super call
+		val remaining = insertion.stack.copy()
 		while (!remaining.isEmpty && sortedResults.isNotEmpty()) {
 			val (capacity, receivingInterface) = sortedResults.removeFirst()
 			if (capacity <= 0) continue
@@ -56,7 +58,7 @@ interface NetworkStackDispatcher<Insertion: NetworkStackDispatcher.PendingInsert
 	}
 
 	open class PendingInsertion<Self: PendingInsertion<Self>>(
-		val stack: ItemStack,
+		var stack: ItemStack,
 		val timestamp: Long
 	) {
 		val results = mutableSetOf<Pair<Int, NetworkStackReceiver>>()
@@ -77,5 +79,6 @@ fun <Self, Insertion: NetworkStackDispatcher.PendingInsertion<Insertion>> Self.f
 	val finishable = pendingInsertions.filter { it.isFinishable(this) }
 	// finishInsertion removes the object from pendingInsertions
 	finishable.forEach(::finishInsertion)
+	// todo: do something with remaining?
 	// todo: if a timed-out insertion can't be finished, we should probably retry after some time (exponential backoff?)
 }