diff --git a/craft.lua b/craft.lua
index 59ba4b2..cfb397a 100644
--- a/craft.lua
+++ b/craft.lua
@@ -2,24 +2,13 @@ local component = require("component")
 local robot = require("robot")
 local sides = require("sides")
 
+local recipes = require('recipes')
+
 local crafting = component.crafting
 local inventory = component.inventory_controller
 
 RESULT_SLOT = 4
 
-local iron_pickaxe_recipe = {
-    result = {
-        item = { 'minecraft:iron_pickaxe', 0 },
-        count = 1,
-    },
-    ingredients = {
-        -- pair of name (string id) and damage separated by ';'
-        'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0',
-        nil, 'minecraft:stick;0', nil,
-        nil, 'minecraft:stick;0', nil,
-    }
-}
-
 -- robots inventory is 4 wide and crafting uses the top left portion
 local slot_map = {
     1, 2, 3,
@@ -36,9 +25,32 @@ local slot_map = {
 local function parse_item(str, delimiter)
     local pos = string.find(str, delimiter)
     if not pos then
-        return nil,nil
+        return nil, nil
+    end
+    return string.sub(str, 1, pos - 1), tonumber(string.sub(str, pos + 1))
+end
+
+---add count to the selected key, or create it if it doesn't exist
+---@param dict table
+---@param key string
+---@param count number
+local function add(dict, key, count)
+    if dict[key] then
+        dict[key] = dict[key] + count
+    else
+        dict[key] = count
+    end
+end
+
+---append the array b to the end of array a
+---@param a table
+---@param b table
+---@return table
+local function append(a, b)
+    for i = 1, #b do
+        a[#a + 1] = b[i]
     end
-    return string.sub(str, 1, pos-1), tonumber(string.sub(str, pos+1))
+    return a
 end
 
 ---read the facing inventory and return a table of item names and their count or nil if not facing an inventory
@@ -53,11 +65,7 @@ local function read_chest_contents()
         local stack = inventory.getStackInSlot(sides.forward, slot)
         if stack then
             local name = stack.name .. ";" .. stack.damage
-            if contents[name] then
-                contents[name] = contents[name] + stack.size
-            else
-                contents[name] = stack.size
-            end
+            add(contents, name, stack.size)
         end
     end
     return contents
@@ -139,12 +147,12 @@ end
 ---accepts a recipe table containing result and ingredients
 ---@param recipe table
 ---@return boolean
-local function craft_recipe(recipe)
+local function craft_single_recipe(recipe)
     if inventory.getStackInInternalSlot(RESULT_SLOT) then
         print('Cannot craft - output slot occupied')
         return false
     end
-    for i, ingredient in pairs(recipe.ingredients) do
+    for i, ingredient in pairs(recipe.shape) do
         print('Fetching ' .. ingredient)
         fetch_item(ingredient, slot_map[i])
     end
@@ -162,6 +170,111 @@ local function craft_recipe(recipe)
     return store_item()
 end
 
+---comment
+---@param recipe table
+---@param available_items table
+---@return boolean success
+---@return table total_required_items
+---@return table recipe_crafting_order array of recipes
+local function craft_recipe_recursion(recipe, available_items)
+    local total_required_items = {}
+    local total_crafting_order = { recipe }
+
+    for item, count in pairs(recipe.requires) do
+        local available = available_items[item]
+        if not available then
+            available = 0
+        end
+        if available >= count then
+            print('I have ' .. count .. ' ' .. item)
+            -- don't have to craft anything
+            add(total_required_items, item, count)
+            -- remove it from tracked available items so if other recipe requires it, it needs to craft it
+            available_items[item] = available_items[item] - count
+        else
+            local required_count = count - available
+            print('Missing ' .. required_count .. ' ' .. item)
+
+            -- check if I can craft it
+            local sub_recipe = recipes[item]
+            if sub_recipe then
+                print('Trying to craft ' .. item)
+                local number_of_crafting_operations = math.ceil(required_count / sub_recipe.count)
+                local excess = required_count % sub_recipe.count
+                print('  Will make ' .. number_of_crafting_operations .. ' crafting operations')
+                print('  That will produce ' .. excess .. ' items I can use later')
+
+                local current_crafting_order = {}
+                for _ = 1, number_of_crafting_operations do
+                    local success, required_items, crafting_order = craft_recipe_recursion(sub_recipe, available_items)
+                    if not success then
+                        return false, {}, {}
+                    end
+                    for k, v in pairs(required_items) do
+                        add(total_required_items, k, v)
+                    end
+                    -- append
+                    current_crafting_order = append(current_crafting_order, crafting_order)
+                end
+                -- prepend
+                total_crafting_order = append(current_crafting_order, total_crafting_order)
+                if excess > 0 then
+                    add(available_items, item, excess)
+                end
+            else
+                print('Need ' .. required_count .. ' more ' .. item)
+                return false, {}, {}
+            end
+        end
+    end
+    return true, total_required_items, total_crafting_order
+end
+
+---accepts a recipe table
+---@param item string
+---@return boolean
+local function craft_recipe(item)
+    print('Trying to craft ' .. item)
+    local recipe = recipes[item]
+    if not recipe then
+        print('Cannot craft ' .. item)
+        return false
+    end
+
+    local available_items = read_chest_contents()
+    if not available_items then
+        print('Not facing a chest')
+        return false
+    end
+
+    local success, required_items, crafting_order = craft_recipe_recursion(recipe, available_items)
+    if not success then
+        print('Failed')
+        return false
+    end
+    print('\nRequires these items:')
+    for k, v in pairs(required_items) do
+        print(k, v)
+    end
+
+    print('\nCrafting in order:')
+    for i, rec in ipairs(crafting_order) do
+        print(i, rec.result)
+    end
+
+
+    -- proceed to crafting the things
+    for i, rec in ipairs(crafting_order) do
+        print('Step #' .. i .. ' - ' .. rec.result)
+        if not craft_single_recipe(rec) then
+            print('Unexpected error')
+            return false
+        end
+    end
+
+    return true
+end
+
 -- local target = ...
 
 -- if not target then
@@ -169,7 +282,8 @@ end
 --     return
 -- end
 
-craft_recipe(iron_pickaxe_recipe)
+-- craft_recipe('minecraft:iron_pickaxe;0')
+craft_recipe('opencomputers:keyboard;0')
 
 -- store_item()
 
diff --git a/recipes.lua b/recipes.lua
new file mode 100644
index 0000000..3b8c0d1
--- /dev/null
+++ b/recipes.lua
@@ -0,0 +1,253 @@
+-- template:
+-- pair of name (string id) and damage separated by ';'
+-- Iron Pickaxe
+-- ['minecraft:iron_pickaxe;0'] = {
+--     result      = 'minecraft:iron_pickaxe;0',
+--     count       = 1,
+--     ingredients = {
+--         'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0',
+--         nil, 'minecraft:stick;0', nil,
+--         nil, 'minecraft:stick;0', nil,
+--     }
+-- },
+
+return {
+    -- Oak planks
+    ['minecraft:planks;0'] = {
+        result   = 'minecraft:planks;0',
+        count    = 4,
+        requires = {
+            ['minecraft:log;0'] = 1,
+        },
+        shape    = {
+            nil, nil, nil,
+            nil, 'minecraft:log;0', nil,
+            nil, nil, nil,
+        }
+    },
+    -- Sticks
+    ['minecraft:stick;0'] = {
+        result   = 'minecraft:stick;0',
+        count    = 4,
+        requires = {
+            ['minecraft:planks;0'] = 2,
+        },
+        shape    = {
+            nil, 'minecraft:planks;0', nil,
+            nil, 'minecraft:planks;0', nil,
+            nil, nil, nil,
+        }
+    },
+    -- Iron Pickaxe
+    ['minecraft:iron_pickaxe;0'] = {
+        result   = 'minecraft:iron_pickaxe;0',
+        count    = 1,
+        requires = {
+            ['minecraft:iron_ingot;0'] = 3,
+            ['minecraft:stick;0'] = 5,
+        },
+        shape    = {
+            'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0',
+            nil, 'minecraft:stick;0', nil,
+            nil, 'minecraft:stick;0', nil,
+        }
+    },
+    -- Iron nugget
+    ['minecraft:iron_nugget;0'] = {
+        result   = 'minecraft:iron_nugget;0',
+        count    = 9,
+        requires = {
+            ['minecraft:iron_ingot;0'] = 1,
+        },
+        shape    = {
+            'minecraft:iron_ingot;0', nil, nil,
+            nil, nil, nil,
+            nil, nil, nil,
+        }
+    },
+    -- gold nugget
+    ['minecraft:gold_nugget;0'] = {
+        result   = 'minecraft:gold_nugget;0',
+        count    = 9,
+        requires = {
+            ['minecraft:gold_ingot;0'] = 1,
+        },
+        shape    = {
+            'minecraft:gold_ingot;0', nil, nil,
+            nil, nil, nil,
+            nil, nil, nil,
+        }
+    },
+    -- Paper
+    ['minecraft:paper;0'] = {
+        result   = 'minecraft:paper;0',
+        count    = 3,
+        requires = {
+            ['minecraft:reeds;0'] = 3,
+        },
+        shape    = {
+            nil, nil, nil,
+            'minecraft:reeds;0', 'minecraft:reeds;0', 'minecraft:reeds;0',
+            nil, nil, nil,
+        }
+    },
+    -- Clock
+    ['minecraft:clock;0'] = {
+        result   = 'minecraft:clock;0',
+        count    = 1,
+        requires = {
+            ['minecraft:gold_ingot;0'] = 4,
+            ['minecraft:redstone;0'] = 1,
+        },
+        shape    = {
+            nil, 'minecraft:gold_ingot;0', nil,
+            'minecraft:gold_ingot;0', 'minecraft:redstone;0', 'minecraft:gold_ingot;0',
+            nil, 'minecraft:gold_ingot;0', nil,
+        }
+    },
+    -- Button
+    ['minecraft:stone_button;0'] = {
+        result   = 'minecraft:stone_button;0',
+        count    = 1,
+        requires = {
+            ['minecraft:stone;0'] = 1,
+        },
+        shape    = {
+            nil, nil, nil,
+            nil, 'minecraft:stone;0', nil,
+            nil, nil, nil,
+        }
+    },
+    -- Transistor
+    ['opencomputers:material;6'] = {
+        result   = 'opencomputers:material;6',
+        count    = 8,
+        requires = {
+            ['minecraft:iron_ingot;0'] = 3,
+            ['minecraft:gold_nugget;0'] = 2,
+            ['minecraft:paper;0'] = 1,
+            ['minecraft:redstone;0'] = 1,
+        },
+        shape    = {
+            'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0', 'minecraft:iron_ingot;0',
+            'minecraft:gold_nugget;0', 'minecraft:paper;0', 'minecraft:gold_nugget;0',
+            nil, 'minecraft:redstone;0', nil,
+        }
+    },
+    -- Microchip (Tier 1)
+    ['opencomputers:material;7'] = {
+        result   = 'opencomputers:material;7',
+        count    = 8,
+        requires = {
+            ['minecraft:iron_nugget;0'] = 6,
+            ['minecraft:redstone;0'] = 2,
+            ['opencomputers:material;6'] = 1, -- Transistor
+        },
+        shape    = {
+            'minecraft:iron_nugget;0', 'minecraft:iron_nugget;0', 'minecraft:iron_nugget;0',
+            'minecraft:redstone;0', 'opencomputers:material;6', 'minecraft:redstone;0',
+            'minecraft:iron_nugget;0', 'minecraft:iron_nugget;0', 'minecraft:iron_nugget;0',
+        }
+    },
+    -- Microchip (Tier 2)
+    ['opencomputers:material;8'] = {
+        result   = 'opencomputers:material;8',
+        count    = 4,
+        requires = {
+            ['minecraft:gold_nugget;0'] = 6,
+            ['minecraft:redstone;0'] = 2,
+            ['opencomputers:material;6'] = 1, -- Transistor
+        },
+        shape    = {
+            'minecraft:gold_nugget;0', 'minecraft:gold_nugget;0', 'minecraft:gold_nugget;0',
+            'minecraft:redstone;0', 'opencomputers:material;6', 'minecraft:redstone;0',
+            'minecraft:gold_nugget;0', 'minecraft:gold_nugget;0', 'minecraft:gold_nugget;0',
+        }
+    },
+    -- Arithmetic Logic Unit (ALU)
+    ['opencomputers:material;10'] = {
+        result   = 'opencomputers:material;10',
+        count    = 1,
+        requires = {
+            ['minecraft:iron_nugget;0'] = 4,
+            ['opencomputers:material;6'] = 3, -- Transistor
+            ['minecraft:redstone;0'] = 1,
+            ['opencomputers:material;7'] = 1, -- Microchip (Tier 1)
+        },
+        shape    = {
+            'minecraft:iron_nugget;0', 'minecraft:redstone;0', 'minecraft:iron_nugget;0',
+            'opencomputers:material;6', 'opencomputers:material;7', 'opencomputers:material;6',
+            'minecraft:iron_nugget;0', 'opencomputers:material;6', 'minecraft:iron_nugget;0',
+        }
+    },
+    -- Control Unit (CU)
+    ['opencomputers:material;11'] = {
+        result   = 'opencomputers:material;11',
+        count    = 1,
+        requires = {
+            ['minecraft:gold_nugget;0'] = 4,
+            ['opencomputers:material;6'] = 3, -- Transistor
+            ['minecraft:redstone;0'] = 1,
+            ['minecraft:clock;0'] = 1,
+        },
+        shape    = {
+            'minecraft:gold_nugget;0', 'minecraft:redstone;0', 'minecraft:gold_nugget;0',
+            'opencomputers:material;6', 'minecraft:clock;0', 'opencomputers:material;6',
+            'minecraft:gold_nugget;0', 'opencomputers:material;6', 'minecraft:gold_nugget;0',
+        }
+    },
+    -- Button Group
+    ['opencomputers:material;14'] = {
+        result   = 'opencomputers:material;14',
+        count    = 1,
+        requires = {
+            ['minecraft:stone_button;0'] = 6,
+        },
+        shape    = {
+            nil, nil, nil,
+            'minecraft:stone_button;0', 'minecraft:stone_button;0', 'minecraft:stone_button;0',
+            'minecraft:stone_button;0', 'minecraft:stone_button;0', 'minecraft:stone_button;0',
+        }
+    },
+    -- Arrow Keys
+    ['opencomputers:material;15'] = {
+        result   = 'opencomputers:material;15',
+        count    = 1,
+        requires = {
+            ['minecraft:stone_button;0'] = 4,
+        },
+        shape    = {
+            nil, nil, nil,
+            nil, 'minecraft:stone_button;0', nil,
+            'minecraft:stone_button;0', 'minecraft:stone_button;0', 'minecraft:stone_button;0',
+        }
+    },
+    -- Numeric Keypad
+    ['opencomputers:material;16'] = {
+        result   = 'opencomputers:material;16',
+        count    = 1,
+        requires = {
+            ['minecraft:stone_button;0'] = 9,
+        },
+        shape    = {
+            'minecraft:stone_button;0', 'minecraft:stone_button;0', 'minecraft:stone_button;0',
+            'minecraft:stone_button;0', 'minecraft:stone_button;0', 'minecraft:stone_button;0',
+            'minecraft:stone_button;0', 'minecraft:stone_button;0', 'minecraft:stone_button;0',
+        }
+    },
+    -- Keyboard
+    ['opencomputers:keyboard;0'] = {
+        result   = 'opencomputers:material;0',
+        count    = 1,
+        requires = {
+            ['opencomputers:material;14'] = 4,
+            ['opencomputers:material;15'] = 1,
+            ['opencomputers:material;16'] = 1,
+        },
+        shape    = {
+            nil, nil, nil,
+            'opencomputers:material;14', 'opencomputers:material;14', 'opencomputers:material;14',
+            'opencomputers:material;14', 'opencomputers:material;15', 'opencomputers:material;16',
+        }
+    },
+}