diff --git a/mcproto/_types.py b/mcproto/_types.py
index 12c7836..d441411 100644
--- a/mcproto/_types.py
+++ b/mcproto/_types.py
@@ -23,3 +23,156 @@
     "red",
     "black",
 ]
+
+SLOTS: TypeAlias = Literal[
+    "armor.head",
+    "armor.chest",
+    "armor.legs",
+    "armor.feet",
+    "container.0",
+    "container.1",
+    "container.2",
+    "container.3",
+    "container.4",
+    "container.5",
+    "container.6",
+    "container.7",
+    "container.8",
+    "container.9",
+    "container.10",
+    "container.11",
+    "container.12",
+    "container.13",
+    "container.14",
+    "container.15",
+    "container.16",
+    "container.17",
+    "container.18",
+    "container.19",
+    "container.20",
+    "container.21",
+    "container.22",
+    "container.23",
+    "container.24",
+    "container.25",
+    "container.26",
+    "container.27",
+    "container.28",
+    "container.29",
+    "container.30",
+    "container.31",
+    "container.32",
+    "container.33",
+    "container.34",
+    "container.35",
+    "container.36",
+    "container.37",
+    "container.38",
+    "container.39",
+    "container.40",
+    "container.41",
+    "container.42",
+    "container.43",
+    "container.44",
+    "container.45",
+    "container.46",
+    "container.47",
+    "container.48",
+    "container.49",
+    "container.50",
+    "container.51",
+    "container.52",
+    "container.53",
+    "enderchest.0",
+    "enderchest.1",
+    "enderchest.2",
+    "enderchest.3",
+    "enderchest.4",
+    "enderchest.5",
+    "enderchest.6",
+    "enderchest.7",
+    "enderchest.8",
+    "enderchest.9",
+    "enderchest.10",
+    "enderchest.11",
+    "enderchest.12",
+    "enderchest.13",
+    "enderchest.14",
+    "enderchest.15",
+    "enderchest.16",
+    "enderchest.17",
+    "enderchest.18",
+    "enderchest.19",
+    "enderchest.20",
+    "enderchest.21",
+    "enderchest.22",
+    "enderchest.23",
+    "enderchest.24",
+    "enderchest.25",
+    "enderchest.26",
+    "horse.0",
+    "horse.1",
+    "horse.2",
+    "horse.3",
+    "horse.4",
+    "horse.5",
+    "horse.6",
+    "horse.7",
+    "horse.8",
+    "horse.9",
+    "horse.10",
+    "horse.11",
+    "horse.12",
+    "horse.13",
+    "horse.14",
+    "horse.armor",
+    "horse.chest",
+    "horse.saddle",
+    "hotbar.0",
+    "hotbar.1",
+    "hotbar.2",
+    "hotbar.3",
+    "hotbar.4",
+    "hotbar.5",
+    "hotbar.6",
+    "hotbar.7",
+    "hotbar.8",
+    "inventory.0",
+    "inventory.1",
+    "inventory.2",
+    "inventory.3",
+    "inventory.4",
+    "inventory.5",
+    "inventory.6",
+    "inventory.7",
+    "inventory.8",
+    "inventory.9",
+    "inventory.10",
+    "inventory.11",
+    "inventory.12",
+    "inventory.13",
+    "inventory.14",
+    "inventory.15",
+    "inventory.16",
+    "inventory.17",
+    "inventory.18",
+    "inventory.19",
+    "inventory.20",
+    "inventory.21",
+    "inventory.22",
+    "inventory.23",
+    "inventory.24",
+    "inventory.25",
+    "inventory.26",
+    "villager.0",
+    "villager.1",
+    "villager.2",
+    "villager.3",
+    "villager.4",
+    "villager.5",
+    "villager.6",
+    "villager.7",
+    "weapon",
+    "weapon.mainhand",
+    "weapon.offhand"
+]
diff --git a/mcproto/entity.py b/mcproto/entity.py
index 6d10407..4537a7d 100644
--- a/mcproto/entity.py
+++ b/mcproto/entity.py
@@ -4,7 +4,7 @@
 from functools import partial
 
 from ._base import HasStub, _EntityProvider
-from ._types import COLOR
+from ._types import COLOR, SLOTS
 from ._util import ThreadSafeCachedKeyBasedFactory
 from .colors import color_codes
 from .exception import raise_on_error
@@ -126,7 +126,7 @@ def giveEffect(
         pbool = str(not bool(particles)).lower()
         self.runCommand(f"effect give @s {effect} {int(seconds)} {amplifier} {pbool}")
 
-    def replaceItem(self, where: str, item: str, amount: int = 1, nbt: NBT | None = None) -> None:
+    def replaceItem(self, where: SLOTS, item: str, amount: int = 1, nbt: NBT | None = None) -> None:
         if nbt is None:
             self.runCommand(f"item replace entity @s {where} with {item} {amount}")
         else:
diff --git a/mcproto/world.py b/mcproto/world.py
index 5cc3d6b..589a041 100644
--- a/mcproto/world.py
+++ b/mcproto/world.py
@@ -1,8 +1,9 @@
 from __future__ import annotations
 
+from .nbt import NBT
 from . import entity
 from ._base import HasStub, _EntityProvider
-from ._types import CARDINAL, COLOR, DIRECTION
+from ._types import CARDINAL, COLOR, DIRECTION, SLOTS
 from .exception import raise_on_error
 from .mcpb import MinecraftStub
 from .mcpb import minecraft_pb2 as pb
@@ -97,6 +98,12 @@ def setBlockCube(self, blocktype: str, pos1: Vec3, pos2: Vec3) -> None:
             )
         )
         raise_on_error(response)
+    
+    def replaceItem(self, pos: Vec3, slot: SLOTS, item: str, amount: int = 1, nbt: NBT | None = None) -> None:
+        if nbt is None:
+            self.runCommand(f"item replace block {pos.x} {pos.y} {pos.z} {slot} with {item} {amount}")
+        else:
+            self.runCommand(f"item replace block {pos.x} {pos.y} {pos.z} {slot} with {item}{nbt} {amount}")
 
     def __getitem__(
         self,