ComputerCraft

Inventory management & item sorting

Connect chests to a computer with peripheral.wrap() and move items between containers automatically — no hoppers required.

Category: ComputerCraft Difficulty: Intermediate Time: ~20 min

What you will end up with

A program that reads the contents of an input chest and distributes each item type into a designated output chest. You define the routing rules in the script — it is simple to expand as your storage grows.

What you need

A Computer (from CC:Tweaked)
At least two Chests (vanilla or modded) placed adjacent to the computer
Items in the input chest to test with

Any inventory that is physically touching the computer (on any of its six sides) can be accessed as a peripheral. The name CC uses for it is the side it is on: "top", "bottom", "left", "right", "front", or "back".

Step 1 — Check what is in a chest

Place a chest on the top of the computer, put some items in it, then open the terminal and run this to inspect its contents:

local chest = peripheral.wrap("top")
local items = chest.list()
for slot, item in pairs(items) do
  print(slot, item.name, item.count)
end

You will see output like 1 minecraft:cobblestone 64. The item.name field is the full item ID you will use for routing rules.

Step 2 — Move items between two chests

Place a second chest on the bottom of the computer. The following moves everything from the top chest to the bottom chest:

local input  = peripheral.wrap("top")
local output = peripheral.wrap("bottom")

local items = input.list()
for slot, item in pairs(items) do
  input.pushItems(peripheral.getName(output), slot)
end
print("Done.")

pushItems(targetName, slot) moves the entire stack in slot from this inventory to the target inventory. Use the optional third argument to limit how many items to move.

Step 3 — Simple item sorter

The sorter below reads the input chest continuously and moves each item to the correct output chest based on its name. Extend the routes table to add more item types.

-- sorter.lua
-- Routes items from input chest to labelled output chests

local input = peripheral.wrap("back")

-- Map item ID → side of the output chest
local routes = {
  ["minecraft:cobblestone"] = "left",
  ["minecraft:iron_ore"]    = "right",
  ["minecraft:coal"]        = "top",
}

local defaultSide = "bottom" -- everything else goes here

while true do
  local items = input.list()
  for slot, item in pairs(items) do
    local side = routes[item.name] or defaultSide
    local target = peripheral.wrap(side)
    if target then
      input.pushItems(peripheral.getName(target), slot)
    end
  end
  os.sleep(1)
end

Useful inventory API methods

chest.list() — returns a table of all items indexed by slot
chest.getItemDetail(slot) — returns detailed info for one slot
chest.size() — returns total number of slots
chest.pushItems(targetName, fromSlot, count, toSlot) — move items out
chest.pullItems(sourceName, fromSlot, count, toSlot) — pull items in
peripheral.getName(wrapped) — get the peripheral name string

Troubleshooting

peripheral.wrap() returns nil — make sure the chest is directly adjacent to the computer on the correct side.
Items not moving — check that the output chest has free slots; a full chest rejects incoming items.
Wrong item name — use the inspect snippet from Step 1 to get the exact item.name string before adding it to the routes table.

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