diff --git a/etc/api.lua b/etc/api.lua
new file mode 100644
index 0000000..f261c97
--- /dev/null
+++ b/etc/api.lua
@@ -0,0 +1,288 @@
+local make_fs = i3.files.gui()
+
+local S, fmt, reg_items = i3.need("S", "fmt", "reg_items")
+local gmatch, match, split = i3.need("gmatch", "match", "split")
+local sort, concat, copy, insert, remove = i3.need("sort", "concat", "copy", "insert", "remove")
+local true_str, is_str, is_table, clean_name = i3.need("true_str", "is_str", "is_table", "clean_name")
+
+local function err(str)
+	return core.log("error", str)
+end
+
+local function is_func(x)
+	return type(x) == "function"
+end
+
+function i3.register_craft_type(name, def)
+	if not true_str(name) then
+		return err "i3.register_craft_type: name missing"
+	end
+
+	if not is_str(def.description) then
+		def.description = ""
+	end
+
+	i3.craft_types[name] = def
+end
+
+function i3.register_craft(def)
+	local width, c = 0, 0
+
+	if true_str(def.url) then
+		if not i3.http then
+			return err(fmt([[i3.register_craft(): Unable to reach %s.
+				No HTTP support for this mod: add it to the `secure.http_mods` or
+				`secure.trusted_mods` setting.]], def.url))
+		end
+
+		i3.http.fetch({url = def.url}, function(result)
+			if result.succeeded then
+				local t = core.parse_json(result.data)
+				if is_table(t) then
+					return i3.register_craft(t)
+				end
+			end
+		end)
+
+		return
+	end
+
+	if not is_table(def) or not next(def) then
+		return err "i3.register_craft: craft definition missing"
+	end
+
+	if #def > 1 then
+		for _, v in pairs(def) do
+			i3.register_craft(v)
+		end
+		return
+	end
+
+	if def.result then
+		def.output = def.result -- Backward compatibility
+		def.result = nil
+	end
+
+	if not true_str(def.output) then
+		return err "i3.register_craft: output missing"
+	end
+
+	if not is_table(def.items) then
+		def.items = {}
+	end
+
+	if def.grid then
+		if not is_table(def.grid) then
+			def.grid = {}
+		end
+
+		if not is_table(def.key) then
+			def.key = {}
+		end
+
+		local cp = copy(def.grid)
+		sort(cp, function(a, b)
+			return #a > #b
+		end)
+
+		width = #cp[1]
+
+		for i = 1, #def.grid do
+			while #def.grid[i] < width do
+				def.grid[i] = def.grid[i] .. " "
+			end
+		end
+
+		for symbol in gmatch(concat(def.grid), ".") do
+			c = c + 1
+			def.items[c] = def.key[symbol]
+		end
+	else
+		local items, len = def.items, #def.items
+		def.items = {}
+
+		for i = 1, len do
+			local rlen = #split(items[i], ",")
+
+			if rlen > width then
+				width = rlen
+			end
+		end
+
+		for i = 1, len do
+			while #split(items[i], ",") < width do
+				items[i] = fmt("%s,", items[i])
+			end
+		end
+
+		for name in gmatch(concat(items, ","), "[%s%w_:]+") do
+			c = c + 1
+			def.items[c] = clean_name(name)
+		end
+	end
+
+	local item = match(def.output, "%S+")
+	i3.recipes_cache[item] = i3.recipes_cache[item] or {}
+
+	def.custom = true
+	def.width = width
+
+	insert(i3.recipes_cache[item], def)
+end
+
+function i3.add_recipe_filter(name, f)
+	if not true_str(name) then
+		return err "i3.add_recipe_filter: name missing"
+	elseif not is_func(f) then
+		return err "i3.add_recipe_filter: function missing"
+	end
+
+	i3.recipe_filters[name] = f
+end
+
+function i3.set_recipe_filter(name, f)
+	if not is_str(name) then
+		return err "i3.set_recipe_filter: name missing"
+	elseif not is_func(f) then
+		return err "i3.set_recipe_filter: function missing"
+	end
+
+	i3.recipe_filters = {[name] = f}
+end
+
+function i3.add_search_filter(name, f)
+	if not true_str(name) then
+		return err "i3.add_search_filter: name missing"
+	elseif not is_func(f) then
+		return err "i3.add_search_filter: function missing"
+	end
+
+	i3.search_filters[name] = f
+end
+
+function i3.get_recipes(item)
+	return {
+		recipes = i3.recipes_cache[item],
+		usages = i3.usages_cache[item]
+	}
+end
+
+function i3.set_fs(player, _fs)
+	if not player or player.is_fake_player then return end
+	local name = player:get_player_name()
+	local data = i3.data[name]
+	if not data then return end
+
+	local fs = fmt("%s%s", make_fs(player, data), _fs or "")
+	player:set_inventory_formspec(fs)
+end
+
+local set_fs = i3.set_fs
+
+function i3.new_tab(def)
+	if not is_table(def) or not next(def) then
+		return err "i3.new_tab: tab definition missing"
+	end
+
+	if not true_str(def.name) then
+		return err "i3.new_tab: tab name missing"
+	end
+
+	if not true_str(def.description) then
+		return err "i3.new_tab: description missing"
+	end
+
+	if #i3.tabs == 6 then
+		return err(fmt("i3.new_tab: cannot add '%s' tab. Limit reached (6).", def.name))
+	end
+
+	i3.tabs[#i3.tabs + 1] = def
+end
+
+function i3.remove_tab(tabname)
+	if not true_str(tabname) then
+		return err "i3.remove_tab: tab name missing"
+	end
+
+	for i, def in ipairs(i3.tabs) do
+		if tabname == def.name then
+			remove(i3.tabs, i)
+		end
+	end
+end
+
+function i3.get_current_tab(player)
+	local name = player:get_player_name()
+	local data = i3.data[name]
+
+	return data.current_tab
+end
+
+function i3.set_tab(player, tabname)
+	local name = player:get_player_name()
+	local data = i3.data[name]
+
+	if not tabname or tabname == "" then
+		data.current_tab = 0
+		return
+	end
+
+	local found
+
+	for i, def in ipairs(i3.tabs) do
+		if not found and def.name == tabname then
+			data.current_tab = i
+			found = true
+		end
+	end
+
+	if not found then
+		return err(fmt("i3.set_tab: tab name '%s' does not exist", tabname))
+	end
+end
+
+function i3.override_tab(tabname, newdef)
+	if not is_table(newdef) or not next(newdef) then
+		return err "i3.override_tab: tab definition missing"
+	end
+
+	if not true_str(newdef.name) then
+		return err "i3.override_tab: tab name missing"
+	end
+
+	if not true_str(newdef.description) then
+		return err "i3.override_tab: description missing"
+	end
+
+	for i, def in ipairs(i3.tabs) do
+		if def.name == tabname then
+			i3.tabs[i] = newdef
+		end
+	end
+end
+
+i3.register_craft_type("digging", {
+	description = S"Digging",
+	icon = "i3_steelpick.png",
+})
+
+i3.register_craft_type("digging_chance", {
+	description = S"Digging (by chance)",
+	icon = "i3_mesepick.png",
+})
+
+i3.add_search_filter("groups", function(item, groups)
+	local def = reg_items[item]
+	local has_groups = true
+
+	for _, group in ipairs(groups) do
+		if not def.groups[group] then
+			has_groups = nil
+			break
+		end
+	end
+
+	return has_groups
+end)
+
+return set_fs, i3.set_tab
diff --git a/etc/bags.lua b/etc/bags.lua
new file mode 100644
index 0000000..e71f949
--- /dev/null
+++ b/etc/bags.lua
@@ -0,0 +1,97 @@
+local set_fs = i3.files.api()
+local S, fmt, msg, spawn_item = i3.need("S", "fmt", "msg", "spawn_item")
+
+local function init_backpack(player)
+	local name = player:get_player_name()
+	local data = i3.data[name]
+	local inv = player:get_inventory()
+
+	inv:set_size("main", data.bag_size and i3.BAG_SIZES[data.bag_size] or i3.INV_SIZE)
+
+	data.bag = core.create_detached_inventory(fmt("%s_backpack", name), {
+		allow_put = function(_inv, listname, _, stack)
+			local empty = _inv:get_stack(listname, 1):is_empty()
+			local item_group = minetest.get_item_group(stack:get_name(), "bag")
+
+			if empty and item_group > 0 and item_group <= #i3.BAG_SIZES then
+				return 1
+			end
+
+			msg(name, S"This is not a backpack")
+
+			return 0
+		end,
+
+		on_put = function(_, _, _, stack)
+			local stackname = stack:get_name()
+			data.bag_item = stackname
+			data.bag_size = minetest.get_item_group(stackname, "bag")
+
+			inv:set_size("main", i3.BAG_SIZES[data.bag_size])
+			set_fs(player)
+		end,
+
+		on_take = function()
+			for i = i3.INV_SIZE + 1, i3.BAG_SIZES[data.bag_size] do
+				local stack = inv:get_stack("main", i)
+
+				if not stack:is_empty() then
+					spawn_item(player, stack)
+				end
+			end
+
+			data.bag_item = nil
+			data.bag_size = nil
+
+			inv:set_size("main", i3.INV_SIZE)
+			set_fs(player)
+		end,
+	})
+
+	data.bag:set_size("main", 1)
+
+	if data.bag_item then
+		data.bag:set_stack("main", 1, data.bag_item)
+	end
+end
+
+local bag_recipes = {
+	small = {
+		rcp = {
+			{"", "farming:string", ""},
+			{"group:wool", "group:wool", "group:wool"},
+			{"group:wool", "group:wool", "group:wool"},
+		},
+		size = 1,
+	},
+	medium = {
+		rcp = {
+			{"farming:string", "i3:bag_small", "farming:string"},
+			{"farming:string", "i3:bag_small", "farming:string"},
+		},
+		size = 2,
+	},
+	large = {
+		rcp = {
+			{"farming:string", "i3:bag_medium", "farming:string"},
+			{"farming:string", "i3:bag_medium", "farming:string"},
+		},
+		size = 3,
+	},
+}
+
+for size, item in pairs(bag_recipes) do
+	local bagname = fmt("i3:bag_%s", size)
+
+	core.register_craftitem(bagname, {
+		description = fmt("%s Backpack", size:gsub("^%l", string.upper)),
+		inventory_image = fmt("i3_bag_%s.png", size),
+		stack_max = 1,
+		groups = {bag = item.size}
+	})
+
+	core.register_craft {output = bagname, recipe = item.rcp}
+	core.register_craft {type = "fuel", recipe = bagname, burntime = 3}
+end
+
+return init_backpack
diff --git a/etc/common.lua b/etc/common.lua
index ec4a69e..65ff741 100644
--- a/etc/common.lua
+++ b/etc/common.lua
@@ -1,9 +1,8 @@
-local item_compression = core.settings:get_bool("i3_item_compression", true)
-local reg_items, translate = core.registered_items, core.get_translated_string
-
+local translate = core.get_translated_string
 local fmt, find, gmatch, match, sub, split, lower =
-	string.format, string.find, string.gmatch, string.match,
-	string.sub, string.split, string.lower
+	string.format, string.find, string.gmatch, string.match, string.sub, string.split, string.lower
+local reg_items, reg_nodes, reg_craftitems, reg_tools =
+	core.registered_items, core.registered_nodes, core.registered_craftitems, core.registered_tools
 
 local function reset_compression(data)
 	data.alt_items = nil
@@ -156,7 +155,7 @@ local function apply_recipe_filters(recipes, player)
 end
 
 local function compression_active(data)
-	return item_compression and not next(i3.recipe_filters) and data.filter == ""
+	return i3.item_compression and not next(i3.recipe_filters) and data.filter == ""
 end
 
 local function compressible(item, data)
@@ -167,6 +166,10 @@ local function is_str(x)
 	return type(x) == "string"
 end
 
+local function is_table(x)
+	return type(x) == "table"
+end
+
 local function true_str(str)
 	return is_str(str) and str ~= ""
 end
@@ -184,27 +187,147 @@ local function is_fav(favs, query_item)
 	return fav, i
 end
 
+local function sort_by_category(data)
+	reset_compression(data)
+	local items = data.items_raw
+
+	if data.filter ~= "" then
+		search(data)
+		items = data.items
+	end
+
+	local new = {}
+
+	for i = 1, #items do
+		local item = items[i]
+		local to_add = true
+
+		if data.current_itab == 2 then
+			to_add = reg_nodes[item]
+		elseif data.current_itab == 3 then
+			to_add = reg_craftitems[item] or reg_tools[item]
+		end
+
+		if to_add then
+			new[#new + 1] = item
+		end
+	end
+
+	data.items = new
+end
+
+local function clean_name(item)
+	if sub(item, 1, 1) == ":" or sub(item, 1, 1) == " " or sub(item, 1, 1) == "_" then
+		item = sub(item, 2)
+	end
+
+	return item
+end
+
+local function msg(name, str)
+	return core.chat_send_player(name, fmt("[i3] %s", str))
+end
+
+local function spawn_item(player, stack)
+	local dir     = player:get_look_dir()
+	local ppos    = player:get_pos()
+	      ppos.y  = ppos.y + 1.625
+	local look_at = vector.add(ppos, vector.multiply(dir, 1))
+
+	core.add_item(look_at, stack)
+end
+
+local S = core.get_translator "i3"
+local ES = function(...) return core.formspec_escape(S(...)) end
+
 return {
-	init = {
-		is_str,
-		show_item,
-		reset_compression,
+	groups = {
+		is_group = is_group,
+		extract_groups = extract_groups,
+		item_has_groups = item_has_groups,
+		groups_to_items = groups_to_items,
 	},
 
-	progressive = {
-		search,
-		table_merge,
-		is_group,
-		extract_groups,
-		item_has_groups,
-		apply_recipe_filters,
+	compression = {
+		compressible = compressible,
+		compression_active = compression_active,
 	},
 
-	gui = {
-		groups_to_items,
-		compression_active,
-		compressible,
-		true_str,
-		is_fav,
+	sorting = {
+		search = search,
+		sort_by_category = sort_by_category,
+		apply_recipe_filters = apply_recipe_filters,
+	},
+
+	misc = {
+		msg = msg,
+		is_fav = is_fav,
+		show_item = show_item,
+		spawn_item = spawn_item,
+		table_merge = table_merge,
+	},
+
+	core = {
+		clr = core.colorize,
+		ESC = core.formspec_escape,
+		check_privs = core.check_player_privs,
+	},
+
+	reg = {
+		reg_items = core.registered_items,
+		reg_nodes = core.registered_nodes,
+		reg_craftitems = core.registered_craftitems,
+		reg_tools = core.registered_tools,
+		reg_entities = core.registered_entities,
+		reg_aliases = core.registered_aliases,
+	},
+
+	i18n = {
+		S = S,
+		ES = ES,
+		translate = core.get_translated_string,
+	},
+
+	string = {
+		fmt = string.format,
+		find = string.find,
+		gmatch = string.gmatch,
+		match = string.match,
+		sub = string.sub,
+		split = string.split,
+		upper = string.upper,
+		lower = string.lower,
+
+		is_str = is_str,
+		true_str = true_str,
+		clean_name = clean_name,
+	},
+
+	table = {
+		maxn = table.maxn,
+		sort = table.sort,
+		concat = table.concat,
+		copy = table.copy,
+		insert = table.insert,
+		remove = table.remove,
+		indexof = table.indexof,
+
+		is_table = is_table,
+	},
+
+	math = {
+		min = math.min,
+		max = math.max,
+		floor = math.floor,
+		ceil = math.ceil,
+		random = math.random,
+	},
+
+	vec = {
+		vec_new = vector.new,
+		vec_add = vector.add,
+		vec_mul = vector.multiply,
+		vec_eq = vector.equals,
+		vec_round = vector.round,
 	},
 }
diff --git a/etc/compress.lua b/etc/compress.lua
index a61560b..b7cd6c8 100644
--- a/etc/compress.lua
+++ b/etc/compress.lua
@@ -1,4 +1,4 @@
-local fmt, insert, copy, pairs, ipairs = string.format, table.insert, table.copy, pairs, ipairs
+local fmt, copy, insert = i3.need("fmt", "copy", "insert")
 
 local wood_types = {
 	"acacia_wood", "aspen_wood", "junglewood", "pine_wood",
diff --git a/etc/groups.lua b/etc/groups.lua
index ea126e9..32d7297 100644
--- a/etc/groups.lua
+++ b/etc/groups.lua
@@ -1,4 +1,4 @@
-local S = core.get_translator "i3"
+local S = i3.need("S")
 
 local group_stereotypes = {
 	dye = "dye:white",
diff --git a/etc/gui.lua b/etc/gui.lua
index 77f799c..2415170 100644
--- a/etc/gui.lua
+++ b/etc/gui.lua
@@ -1,34 +1,18 @@
 local damage_enabled = core.settings:get_bool "enable_damage"
 
-local reg_items = core.registered_items
-local reg_entities = core.registered_entities
-local reg_tools = core.registered_tools
-
-local pairs, ipairs, next, type, setmetatable, unpack, select =
-	pairs, ipairs, next, type, setmetatable, unpack, select
-
-local sprintf, sub, find, match, upper =
-	string.format, string.sub, string.find, string.match, string.upper
-
-local concat, sort, insert, remove, maxn, copy =
-	table.concat, table.sort, table.insert, table.remove, table.maxn,
-	table.copy
-
-local min, max, floor, ceil = math.min, math.max, math.floor, math.ceil
-
-local clr, ESC, check_privs, translate =
-	core.colorize, core.formspec_escape, core.check_player_privs, core.get_translated_string
-
 local model_aliases = i3.files.model_alias()
 local PNG, styles, fs_elements = i3.files.styles()
-local _, _, is_group, extract_groups, item_has_groups = unpack(i3.files.common().progressive)
-local groups_to_items, compression_active, compressible, true_str, is_fav = unpack(i3.files.common().gui)
 
-local S = i3.S
+local clr, ESC = i3.need("clr", "ESC")
+local S, ES, translate = i3.need("S", "ES", "translate")
+local min, max, floor, ceil = i3.need("min", "max", "floor", "ceil")
+local sprintf, find, match, sub, upper = i3.need("fmt", "find", "match", "sub", "upper")
+local reg_items, reg_tools, reg_entities = i3.need("reg_items", "reg_tools", "reg_entities")
+local maxn, sort, concat, copy, insert, remove = i3.need("maxn", "sort", "concat", "copy", "insert", "remove")
 
-local ES = function(...)
-	return ESC(S(...))
-end
+local is_group, extract_groups, item_has_groups = i3.need("is_group", "extract_groups", "item_has_groups")
+local groups_to_items, compression_active, compressible, true_str, is_fav =
+	i3.need("groups_to_items", "compression_active", "compressible", "true_str", "is_fav")
 
 local function is_num(x)
 	return type(x) == "number"
@@ -306,7 +290,7 @@ local function get_waypoint_fs(fs, data, player, yextra, ctn_len)
 		fs("image_button", ctn_len - 1.5, yi, icon_size, icon_size, "", vsb, "")
 		fs(fmt("tooltip[%s;%s]", vsb, v.hide and ES"Show waypoint" or ES"Hide waypoint"))
 
-		if check_privs(player, {teleport = true}) then
+		if core.check_player_privs(player, {teleport = true}) then
 			local tp = fmt("waypoint_%u_teleport", i)
 
 			fs(fmt("style[%s;fgimg=%s;fgimg_hovered=%s;content_offset=0]",
diff --git a/etc/inventory.lua b/etc/inventory.lua
new file mode 100644
index 0000000..1792b69
--- /dev/null
+++ b/etc/inventory.lua
@@ -0,0 +1,642 @@
+local set_fs, set_tab = i3.files.api()
+local _, get_inventory_fs = i3.files.gui()
+
+local S, clr = i3.need("S", "clr")
+local min, ceil, random = i3.need("min", "ceil", "random")
+local reg_items, reg_aliases = i3.need("reg_items", "reg_aliases")
+local fmt, find, match, sub, lower = i3.need("fmt", "find", "match", "sub", "lower")
+local vec_new, vec_mul, vec_eq, vec_round = i3.need("vec_new", "vec_mul", "vec_eq", "vec_round")
+local sort, copy, insert, remove, indexof = i3.need("sort", "copy", "insert", "remove", "indexof")
+
+local is_group, extract_groups, groups_to_items = i3.need("is_group", "extract_groups", "groups_to_items")
+local search, sort_by_category, apply_recipe_filters = i3.need("search", "sort_by_category", "apply_recipe_filters")
+local msg, is_str, is_fav, show_item, spawn_item, clean_name, compressible =
+	i3.need("msg", "is_str", "is_fav", "show_item", "spawn_item", "clean_name", "compressible")
+
+local old_is_creative_enabled = core.is_creative_enabled
+
+function core.is_creative_enabled(name)
+	if name == "" then
+		return old_is_creative_enabled(name)
+	end
+
+	return core.check_player_privs(name, {creative = true}) or old_is_creative_enabled(name)
+end
+
+local function reset_data(data)
+	data.filter        = ""
+	data.expand        = ""
+	data.pagenum       = 1
+	data.rnum          = 1
+	data.unum          = 1
+	data.scrbar_rcp    = 1
+	data.scrbar_usg    = 1
+	data.query_item    = nil
+	data.recipes       = nil
+	data.usages        = nil
+	data.export_rcp    = nil
+	data.export_usg    = nil
+	data.alt_items     = nil
+	data.confirm_trash = nil
+	data.items         = data.items_raw
+
+	if data.current_itab > 1 then
+		sort_by_category(data)
+	end
+end
+
+local function get_recipes(player, item)
+	local clean_item = reg_aliases[item] or item
+	local recipes = i3.recipes_cache[clean_item]
+	local usages = i3.usages_cache[clean_item]
+
+	if recipes then
+		recipes = apply_recipe_filters(recipes, player)
+	end
+
+	local no_recipes = not recipes or #recipes == 0
+	if no_recipes and not usages then return end
+	usages = apply_recipe_filters(usages, player)
+
+	local no_usages = not usages or #usages == 0
+
+	return not no_recipes and recipes or nil,
+	       not no_usages  and usages  or nil
+end
+
+local function __sort(inv, reverse)
+	sort(inv, function(a, b)
+		if not is_str(a) then
+			a = a:get_name()
+		end
+
+		if not is_str(b) then
+			b = b:get_name()
+		end
+
+		if reverse then
+			return a > b
+		end
+
+		return a < b
+	end)
+end
+
+local function sort_itemlist(player, az)
+	local inv = player:get_inventory()
+	local list = inv:get_list("main")
+	local size = inv:get_size("main")
+	local new_inv, stack_meta = {}, {}
+
+	for i = 1, size do
+		local stack = list[i]
+		local name = stack:get_name()
+		local count = stack:get_count()
+		local empty = stack:is_empty()
+		local meta = stack:get_meta():to_table()
+		local wear = stack:get_wear() > 0
+
+		if not empty then
+			if next(meta.fields) or wear then
+				stack_meta[#stack_meta + 1] = stack
+			else
+				new_inv[#new_inv + 1] = fmt("%s %u", name, count)
+			end
+		end
+	end
+
+	for i = 1, #stack_meta do
+		new_inv[#new_inv + 1] = stack_meta[i]
+	end
+
+	if az then
+		__sort(new_inv)
+	else
+		__sort(new_inv, true)
+	end
+
+	inv:set_list("main", new_inv)
+end
+
+local function compress_items(player)
+	local inv = player:get_inventory()
+	local list = inv:get_list("main")
+	local size = inv:get_size("main")
+	local new_inv, _new_inv, special = {}, {}, {}
+
+	for i = 1, size do
+		local stack = list[i]
+		local name = stack:get_name()
+		local count = stack:get_count()
+		local stackmax = stack:get_stack_max()
+		local empty = stack:is_empty()
+		local meta = stack:get_meta():to_table()
+		local wear = stack:get_wear() > 0
+
+		if not empty then
+			if next(meta.fields) or wear or count >= stackmax then
+				special[#special + 1] = stack
+			else
+				new_inv[name] = new_inv[name] or 0
+				new_inv[name] = new_inv[name] + count
+			end
+		end
+	end
+
+	for name, count in pairs(new_inv) do
+		local stackmax = ItemStack(name):get_stack_max()
+		local iter = ceil(count / stackmax)
+		local leftover = count
+
+		for _ = 1, iter do
+			_new_inv[#_new_inv + 1] = fmt("%s %u", name, min(stackmax, leftover))
+			leftover = leftover - stackmax
+		end
+	end
+
+	for i = 1, #special do
+		_new_inv[#_new_inv + 1] = special[i]
+	end
+
+	__sort(_new_inv)
+	inv:set_list("main", _new_inv)
+end
+
+local function get_stack(player, stack)
+	local inv = player:get_inventory()
+
+	if inv:room_for_item("main", stack) then
+		inv:add_item("main", stack)
+	else
+		spawn_item(player, stack)
+	end
+end
+
+i3.new_tab {
+	name = "inventory",
+	description = S"Inventory",
+	formspec = get_inventory_fs,
+
+	fields = function(player, data, fields)
+		local name = player:get_player_name()
+		local sb_inv = fields.scrbar_inv
+
+		if fields.skins then
+			local id = tonumber(fields.skins)
+			local _skins = skins.get_skinlist_for_player(name)
+			skins.set_player_skin(player, _skins[id])
+		end
+
+		for field in pairs(fields) do
+			if sub(field, 1, 4) == "btn_" then
+				data.subcat = indexof(i3.SUBCAT, sub(field, 5))
+				break
+
+			elseif find(field, "waypoint_%d+") then
+				local id, action = match(field, "_(%d+)_(%w+)$")
+				id = tonumber(id)
+				local waypoint = data.waypoints[id]
+				if not waypoint then return end
+
+				if action == "delete" then
+					player:hud_remove(waypoint.id)
+					remove(data.waypoints, id)
+
+				elseif action == "teleport" then
+					local pos = vec_new(waypoint.pos)
+					pos.y = pos.y + 0.5
+
+					local vel = player:get_velocity()
+					player:add_velocity(vec_mul(vel, -1))
+					player:set_pos(pos)
+
+					msg(name, fmt("Teleported to %s", clr("#ff0", waypoint.name)))
+
+				elseif action == "refresh" then
+					local color = random(0xffffff)
+					waypoint.color = color
+					player:hud_change(waypoint.id, "number", color)
+
+				elseif action == "hide" then
+					if waypoint.hide then
+						local new_id = player:hud_add {
+							hud_elem_type = "waypoint",
+							name = waypoint.name,
+							text = " m",
+							world_pos = waypoint.pos,
+							number = waypoint.color,
+							z_index = -300,
+						}
+
+						waypoint.id = new_id
+						waypoint.hide = nil
+					else
+						player:hud_remove(waypoint.id)
+						waypoint.hide = true
+					end
+				end
+
+				break
+			end
+		end
+
+		if fields.trash then
+			data.confirm_trash = true
+
+		elseif fields.confirm_trash_yes or fields.confirm_trash_no then
+			if fields.confirm_trash_yes then
+				local inv = player:get_inventory()
+				inv:set_list("main", {})
+				inv:set_list("craft", {})
+			end
+
+			data.confirm_trash = nil
+
+		elseif fields.compress then
+			compress_items(player)
+
+		elseif fields.sort_az or fields.sort_za then
+			sort_itemlist(player, fields.sort_az)
+
+		elseif sb_inv and sub(sb_inv, 1, 3) == "CHG" then
+			data.scrbar_inv = tonumber(match(sb_inv, "%d+"))
+			return
+
+		elseif fields.waypoint_add then
+			local pos = player:get_pos()
+
+			for _, v in ipairs(data.waypoints) do
+				if vec_eq(vec_round(pos), vec_round(v.pos)) then
+					return msg(name, "You already set a waypoint at this position")
+				end
+			end
+
+			local waypoint = fields.waypoint_name
+
+			if fields.waypoint_name == "" then
+				waypoint = "Waypoint"
+			end
+
+			local color = random(0xffffff)
+
+			local id = player:hud_add {
+				hud_elem_type = "waypoint",
+				name = waypoint,
+				text = " m",
+				world_pos = pos,
+				number = color,
+				z_index = -300,
+			}
+
+			insert(data.waypoints, {name = waypoint, pos = pos, color = color, id = id})
+			data.scrbar_inv = data.scrbar_inv + 1000
+		end
+
+		return set_fs(player)
+	end,
+}
+
+local function select_item(player, name, data, _f)
+	local item
+
+	for field in pairs(_f) do
+		if find(field, ":") then
+			item = field
+			break
+		end
+	end
+
+	if not item then return end
+
+	if compressible(item, data) then
+		local idx
+
+		for i = 1, #data.items do
+			local it = data.items[i]
+			if it == item then
+				idx = i
+				break
+			end
+		end
+
+		if data.expand ~= "" then
+			data.alt_items = nil
+
+			if item == data.expand then
+				data.expand = nil
+				return
+			end
+		end
+
+		if idx and item ~= data.expand then
+			data.alt_items = copy(data.items)
+			data.expand = item
+
+			if i3.compress_groups[item] then
+				local items = copy(i3.compress_groups[item])
+				insert(items, fmt("_%s", item))
+
+				sort(items, function(a, b)
+					if a:sub(1, 1) == "_" then
+						a = a:sub(2)
+					end
+
+					return a < b
+				end)
+
+				local i = 1
+
+				for _, v in ipairs(items) do
+					if show_item(reg_items[clean_name(v)]) then
+						insert(data.alt_items, idx + i, v)
+						i = i + 1
+					end
+				end
+			end
+		end
+	else
+		if sub(item, 1, 1) == "_" then
+			item = sub(item, 2)
+		elseif sub(item, 1, 6) == "group|" then
+			item = match(item, "([%w:_]+)$")
+		end
+
+		item = reg_aliases[item] or item
+		if not reg_items[item] then return end
+
+		if core.is_creative_enabled(name) then
+			local stack = ItemStack(item)
+			local stackmax = stack:get_stack_max()
+			      stack = fmt("%s %s", item, stackmax)
+
+			return get_stack(player, stack)
+		end
+
+		if item == data.query_item then return end
+		local recipes, usages = get_recipes(player, item)
+
+		data.query_item = item
+		data.recipes    = recipes
+		data.usages     = usages
+		data.rnum       = 1
+		data.unum       = 1
+		data.scrbar_rcp = 1
+		data.scrbar_usg = 1
+		data.export_rcp = nil
+		data.export_usg = nil
+	end
+end
+
+local function craft_stack(player, data, craft_rcp)
+	local inv = player:get_inventory()
+	local rcp_usg = craft_rcp and "recipe" or "usage"
+	local output = craft_rcp and data.recipes[data.rnum].output or data.usages[data.unum].output
+	      output = ItemStack(output)
+	local stackname, stackcount, stackmax = output:get_name(), output:get_count(), output:get_stack_max()
+	local scrbar_val = data[fmt("scrbar_%s", craft_rcp and "rcp" or "usg")] or 1
+
+	for name, count in pairs(data.export_counts[rcp_usg].rcp) do
+		local items = {[name] = count}
+
+		if is_group(name) then
+			items = {}
+			local groups = extract_groups(name)
+			local item_groups = groups_to_items(groups, true)
+			local remaining = count
+
+			for _, item in ipairs(item_groups) do
+			for _name, _count in pairs(data.export_counts[rcp_usg].inv) do
+				if item == _name and remaining > 0 then
+					local c = min(remaining, _count)
+					items[item] = c
+					remaining = remaining - c
+				end
+
+				if remaining == 0 then break end
+			end
+			end
+		end
+
+		for k, v in pairs(items) do
+			inv:remove_item("main", fmt("%s %s", k, v * scrbar_val))
+		end
+	end
+
+	local count = stackcount * scrbar_val
+	local iter = ceil(count / stackmax)
+	local leftover = count
+
+	for _ = 1, iter do
+		local c = min(stackmax, leftover)
+		local stack = ItemStack(fmt("%s %s", stackname, c))
+		get_stack(player, stack)
+		leftover = leftover - stackmax
+	end
+end
+
+local function rcp_fields(player, data, fields)
+	local name = player:get_player_name()
+	local sb_rcp, sb_usg = fields.scrbar_rcp, fields.scrbar_usg
+
+	if fields.cancel then
+		reset_data(data)
+
+	elseif fields.exit then
+		data.query_item = nil
+
+	elseif fields.key_enter_field == "filter" or fields.search then
+		if fields.filter == "" then
+			reset_data(data)
+			return set_fs(player)
+		end
+
+		local str = lower(fields.filter)
+		if data.filter == str then return end
+
+		data.filter = str
+		data.pagenum = 1
+
+		search(data)
+
+		if data.current_itab > 1 then
+			sort_by_category(data)
+		end
+
+	elseif fields.prev_page or fields.next_page then
+		if data.pagemax == 1 then return end
+		data.pagenum = data.pagenum - (fields.prev_page and 1 or -1)
+
+		if data.pagenum > data.pagemax then
+			data.pagenum = 1
+		elseif data.pagenum == 0 then
+			data.pagenum = data.pagemax
+		end
+
+	elseif fields.prev_recipe or fields.next_recipe then
+		local num = data.rnum + (fields.prev_recipe and -1 or 1)
+		data.rnum = data.recipes[num] and num or (fields.prev_recipe and #data.recipes or 1)
+		data.export_rcp = nil
+		data.scrbar_rcp = 1
+
+	elseif fields.prev_usage or fields.next_usage then
+		local num = data.unum + (fields.prev_usage and -1 or 1)
+		data.unum = data.usages[num] and num or (fields.prev_usage and #data.usages or 1)
+		data.export_usg = nil
+		data.scrbar_usg = 1
+
+	elseif fields.fav then
+		local fav, i = is_fav(data.favs, data.query_item)
+		local total = #data.favs
+
+		if total < i3.MAX_FAVS and not fav then
+			data.favs[total + 1] = data.query_item
+		elseif fav then
+			remove(data.favs, i)
+		end
+
+	elseif fields.export_rcp or fields.export_usg then
+		if fields.export_rcp then
+			data.export_rcp = not data.export_rcp
+
+			if not data.export_rcp then
+				data.scrbar_rcp = 1
+			end
+		else
+			data.export_usg = not data.export_usg
+
+			if not data.export_usg then
+				data.scrbar_usg = 1
+			end
+		end
+
+	elseif (sb_rcp and sub(sb_rcp, 1, 3) == "CHG") or (sb_usg and sub(sb_usg, 1, 3) == "CHG") then
+		data.scrbar_rcp = sb_rcp and tonumber(match(sb_rcp, "%d+"))
+		data.scrbar_usg = sb_usg and tonumber(match(sb_usg, "%d+"))
+
+	elseif fields.craft_rcp or fields.craft_usg then
+		craft_stack(player, data, fields.craft_rcp)
+
+		if fields.craft_rcp then
+			data.export_rcp = nil
+			data.scrbar_rcp = 1
+		else
+			data.export_usg = nil
+			data.scrbar_usg = 1
+		end
+	else
+		select_item(player, name, data, fields)
+	end
+end
+
+core.register_on_player_receive_fields(function(player, formname, fields)
+	local name = player:get_player_name()
+
+	if formname == "i3_outdated" then
+		return false, core.kick_player(name, "Come back when your client is up-to-date.")
+	elseif formname ~= "" then
+		return false
+	end
+
+	local data = i3.data[name]
+	if not data then return end
+
+	for f in pairs(fields) do
+		if sub(f, 1, 4) == "tab_" then
+			local tabname = sub(f, 5)
+			set_tab(player, tabname)
+			break
+		elseif sub(f, 1, 5) == "itab_" then
+			data.pagenum = 1
+			data.current_itab = tonumber(f:sub(-1))
+			sort_by_category(data)
+		end
+	end
+
+	rcp_fields(player, data, fields)
+
+	local tab = i3.tabs[data.current_tab]
+
+	if tab and tab.fields then
+		return true, tab.fields(player, data, fields)
+	end
+
+	return true, set_fs(player)
+end)
+
+core.register_on_player_hpchange(function(player, hpchange)
+	local name = player:get_player_name()
+	local data = i3.data[name]
+	if not data then return end
+
+	local hp_max = player:get_properties().hp_max
+	data.hp = min(hp_max, player:get_hp() + hpchange)
+
+	set_fs(player)
+end)
+
+core.register_on_dieplayer(function(player)
+	local name = player:get_player_name()
+	local data = i3.data[name]
+	if not data then return end
+
+	if data.bag_size then
+		data.bag_item = nil
+		data.bag_size = nil
+		data.bag:set_list("main", {})
+
+		local inv = player:get_inventory()
+		inv:set_size("main", i3.INV_SIZE)
+	end
+
+	set_fs(player)
+end)
+
+core.register_on_chatcommand(function(name)
+	local player = core.get_player_by_name(name)
+	core.after(0, set_fs, player)
+end)
+
+core.register_on_priv_grant(function(name, _, priv)
+	if priv == "creative" or priv == "all" then
+		local data = i3.data[name]
+		reset_data(data)
+		data.favs = {}
+
+		local player = core.get_player_by_name(name)
+		core.after(0, set_fs, player)
+	end
+end)
+
+core.register_on_player_inventory_action(function(player, _, _, info)
+	local name = player:get_player_name()
+
+	if not core.is_creative_enabled(name) and
+	  ((info.from_list == "main"  and info.to_list == "craft") or
+	   (info.from_list == "craft" and info.to_list == "main")  or
+	   (info.from_list == "craftresult" and info.to_list == "main")) then
+		set_fs(player)
+	end
+end)
+
+local trash = core.create_detached_inventory("i3_trash", {
+	allow_put = function(_, _, _, stack)
+		return stack:get_count()
+	end,
+	on_put = function(inv, listname, _, _, player)
+		inv:set_list(listname, {})
+
+		local name = player:get_player_name()
+
+		if not core.is_creative_enabled(name) then
+			set_fs(player)
+		end
+	end,
+})
+
+trash:set_size("main", 1)
+
+local output_rcp = core.create_detached_inventory("i3_output_rcp", {})
+output_rcp:set_size("main", 1)
+
+local output_usg = core.create_detached_inventory("i3_output_usg", {})
+output_usg:set_size("main", 1)
diff --git a/etc/progressive.lua b/etc/progressive.lua
index 9f46b60..4fc72fa 100644
--- a/etc/progressive.lua
+++ b/etc/progressive.lua
@@ -1,13 +1,12 @@
+local set_fs = i3.files.api()
+local singleplayer = core.is_singleplayer()
+
+local fmt, search, table_merge, is_group, extract_groups, item_has_groups, apply_recipe_filters =
+	i3.need("fmt", "search", "table_merge", "is_group", "extract_groups", "item_has_groups", "apply_recipe_filters")
+
 local POLL_FREQ = 0.25
 local HUD_TIMER_MAX = 1.5
 
-local search, table_merge, is_group, extract_groups, item_has_groups, apply_recipe_filters =
-	unpack(i3.files.common().progressive)
-
-local singleplayer = core.is_singleplayer()
-local fmt, after, pairs = string.format, core.after, pairs
-local set_fs = i3.set_fs
-
 local function array_diff(t1, t2)
 	local hash = {}
 
@@ -255,7 +254,7 @@ local function poll_new_items()
 		end
 	end
 
-	after(POLL_FREQ, poll_new_items)
+	core.after(POLL_FREQ, poll_new_items)
 end
 
 poll_new_items()
diff --git a/etc/recipes.lua b/etc/recipes.lua
new file mode 100644
index 0000000..1054fde
--- /dev/null
+++ b/etc/recipes.lua
@@ -0,0 +1,314 @@
+local replacements = {fuel = {}}
+
+local fmt, match = i3.need("fmt", "match")
+local reg_items, reg_aliases = i3.need("reg_items", "reg_aliases")
+local maxn, copy, insert, remove = i3.need("maxn", "copy", "insert", "remove")
+
+local true_str, is_table, show_item, table_merge = i3.need("true_str", "is_table", "show_item", "table_merge")
+local is_group, extract_groups, item_has_groups, groups_to_items =
+	i3.need("is_group", "extract_groups", "item_has_groups", "groups_to_items")
+
+local function table_replace(t, val, new)
+	for k, v in pairs(t) do
+		if v == val then
+			t[k] = new
+		end
+	end
+end
+
+local function table_eq(T1, T2)
+	local avoid_loops = {}
+
+	local function recurse(t1, t2)
+		if type(t1) ~= type(t2) then return end
+
+		if not is_table(t1) then
+			return t1 == t2
+		end
+
+		if avoid_loops[t1] then
+			return avoid_loops[t1] == t2
+		end
+
+		avoid_loops[t1] = t2
+		local t2k, t2kv = {}, {}
+
+		for k in pairs(t2) do
+			if is_table(k) then
+				insert(t2kv, k)
+			end
+
+			t2k[k] = true
+		end
+
+		for k1, v1 in pairs(t1) do
+			local v2 = t2[k1]
+			if type(k1) == "table" then
+				local ok
+				for i = 1, #t2kv do
+					local tk = t2kv[i]
+					if table_eq(k1, tk) and recurse(v1, t2[tk]) then
+						remove(t2kv, i)
+						t2k[tk] = nil
+						ok = true
+						break
+					end
+				end
+
+				if not ok then return end
+			else
+				if v2 == nil then return end
+				t2k[k1] = nil
+				if not recurse(v1, v2) then return end
+			end
+		end
+
+		if next(t2k) then return end
+		return true
+	end
+
+	return recurse(T1, T2)
+end
+
+local function get_burntime(item)
+	return core.get_craft_result{method = "fuel", items = {item}}.time
+end
+
+local function cache_fuel(item)
+	local burntime = get_burntime(item)
+	if burntime > 0 then
+		i3.fuel_cache[item] = {
+			type = "fuel",
+			items = {item},
+			burntime = burntime,
+			replacements = replacements.fuel[item],
+		}
+	end
+end
+
+local function get_item_usages(item, recipe, added)
+	local groups = extract_groups(item)
+
+	if groups then
+		for name, def in pairs(reg_items) do
+			if not added[name] and show_item(def) and item_has_groups(def.groups, groups) then
+				local usage = copy(recipe)
+				table_replace(usage.items, item, name)
+
+				i3.usages_cache[name] = i3.usages_cache[name] or {}
+				insert(i3.usages_cache[name], 1, usage)
+
+				added[name] = true
+			end
+		end
+	elseif show_item(reg_items[item]) then
+		i3.usages_cache[item] = i3.usages_cache[item] or {}
+		insert(i3.usages_cache[item], 1, recipe)
+	end
+end
+
+local function get_usages(recipe)
+	local added = {}
+
+	for _, item in pairs(recipe.items) do
+		item = reg_aliases[item] or item
+
+		if not added[item] then
+			get_item_usages(item, recipe, added)
+			added[item] = true
+		end
+	end
+end
+
+local function cache_usages(item)
+	local recipes = i3.recipes_cache[item] or {}
+
+	for i = 1, #recipes do
+		get_usages(recipes[i])
+	end
+
+	if i3.fuel_cache[item] then
+		i3.usages_cache[item] = table_merge(i3.usages_cache[item] or {}, {i3.fuel_cache[item]})
+	end
+end
+
+local function drop_table(name, drop)
+	local count_sure = 0
+	local drop_items = drop.items or {}
+	local max_items = drop.max_items
+
+	for i = 1, #drop_items do
+		local di = drop_items[i]
+		local valid_rarity = di.rarity and di.rarity > 1
+
+		if di.rarity or not max_items or
+				(max_items and not di.rarity and count_sure < max_items) then
+			for j = 1, #di.items do
+				local dstack = ItemStack(di.items[j])
+				local dname  = dstack:get_name()
+				local dcount = dstack:get_count()
+				local empty  = dstack:is_empty()
+
+				if not empty and (dname ~= name or (dname == name and dcount > 1)) then
+					local rarity = valid_rarity and di.rarity
+
+					i3.register_craft {
+						type   = rarity and "digging_chance" or "digging",
+						items  = {name},
+						output = fmt("%s %u", dname, dcount),
+						rarity = rarity,
+						tools  = di.tools,
+					}
+				end
+			end
+		end
+
+		if not di.rarity then
+			count_sure = count_sure + 1
+		end
+	end
+end
+
+local function cache_drops(name, drop)
+	if true_str(drop) then
+		local dstack = ItemStack(drop)
+		local dname  = dstack:get_name()
+		local empty  = dstack:is_empty()
+
+		if not empty and dname ~= name then
+			i3.register_craft {
+				type = "digging",
+				items = {name},
+				output = drop,
+			}
+		end
+	elseif is_table(drop) then
+		drop_table(name, drop)
+	end
+end
+
+local function cache_recipes(item)
+	local recipes = core.get_all_craft_recipes(item)
+
+	if replacements[item] then
+		local _recipes = {}
+
+		for k, v in ipairs(recipes or {}) do
+			_recipes[#recipes + 1 - k] = v
+		end
+
+		local shift = 0
+		local size_rpl = maxn(replacements[item])
+		local size_rcp = #_recipes
+
+		if size_rpl > size_rcp then
+			shift = size_rcp - size_rpl
+		end
+
+		for k, v in pairs(replacements[item]) do
+			k = k + shift
+
+			if _recipes[k] then
+				_recipes[k].replacements = v
+			end
+		end
+
+		recipes = _recipes
+	end
+
+	if recipes then
+		i3.recipes_cache[item] = table_merge(recipes, i3.recipes_cache[item] or {})
+	end
+end
+
+--[[	As `core.get_craft_recipe` and `core.get_all_craft_recipes` do not
+	return the fuel, replacements and toolrepair recipes, we have to
+	override `core.register_craft` and do some reverse engineering.
+	See engine's issues #4901, #5745 and #8920.	]]
+
+local old_register_craft = core.register_craft
+local rcp_num = {}
+
+core.register_craft = function(def)
+	old_register_craft(def)
+
+	if def.type == "toolrepair" then
+		i3.toolrepair = def.additional_wear * -100
+	end
+
+	local output = def.output or (true_str(def.recipe) and def.recipe) or nil
+	if not output then return end
+	output = {match(output, "%S+")}
+
+	local groups
+
+	if is_group(output[1]) then
+		groups = extract_groups(output[1])
+		output = groups_to_items(groups, true)
+	end
+
+	for i = 1, #output do
+		local item = output[i]
+		rcp_num[item] = (rcp_num[item] or 0) + 1
+
+		if def.replacements then
+			if def.type == "fuel" then
+				replacements.fuel[item] = def.replacements
+			else
+				replacements[item] = replacements[item] or {}
+				replacements[item][rcp_num[item]] = def.replacements
+			end
+		end
+	end
+end
+
+local old_clear_craft = core.clear_craft
+
+core.clear_craft = function(def)
+	old_clear_craft(def)
+
+	if true_str(def) then
+		return -- TODO
+	elseif is_table(def) then
+		return -- TODO
+	end
+end
+
+local function resolve_aliases(hash)
+	for oldname, newname in pairs(reg_aliases) do
+		cache_recipes(oldname)
+		local recipes = i3.recipes_cache[oldname]
+
+		if recipes then
+			if not i3.recipes_cache[newname] then
+				i3.recipes_cache[newname] = {}
+			end
+
+			local similar
+
+			for i = 1, #i3.recipes_cache[oldname] do
+				local rcp_old = i3.recipes_cache[oldname][i]
+
+				for j = 1, #i3.recipes_cache[newname] do
+					local rcp_new = copy(i3.recipes_cache[newname][j])
+					rcp_new.output = oldname
+
+					if table_eq(rcp_old, rcp_new) then
+						similar = true
+						break
+					end
+				end
+
+				if not similar then
+					insert(i3.recipes_cache[newname], rcp_old)
+				end
+			end
+		end
+
+		if newname ~= "" and i3.recipes_cache[oldname] and not hash[newname] then
+			i3.init_items[#i3.init_items + 1] = newname
+		end
+	end
+end
+
+return cache_drops, cache_fuel, cache_recipes, cache_usages, resolve_aliases
diff --git a/etc/styles.lua b/etc/styles.lua
index fd3fa10..a083afc 100644
--- a/etc/styles.lua
+++ b/etc/styles.lua
@@ -1,5 +1,3 @@
-local fmt = string.format
-
 local PNG = {
 	bg = "i3_bg.png",
 	bg_full = "i3_bg_full.png",
@@ -62,7 +60,7 @@ local PNG = {
 	exit_hover = "i3_exit.png^\\[brighten",
 }
 
-local styles = fmt([[
+local styles = string.format([[
 	style_type[field;border=false;bgcolor=transparent]
 	style_type[label,field;font_size=16]
 	style_type[button;border=false;content_offset=0]
diff --git a/init.lua b/init.lua
index 16cbcbd..1fe015e 100644
--- a/init.lua
+++ b/init.lua
@@ -6,6 +6,7 @@ end
 
 i3 = {
 	modules = {},
+	http = core.request_http_api(),
 
 	MAX_FAVS = 6,
 	INV_SIZE = 4*9,
@@ -47,146 +48,56 @@ i3 = {
 	tabs           = {},
 
 	files = {
+		api = lf("/etc/api.lua"),
+		bags = lf("/etc/bags.lua"),
 		common = lf("/etc/common.lua"),
 		compress = lf("/etc/compress.lua"),
 		groups = lf("/etc/groups.lua"),
 		gui = lf("/etc/gui.lua"),
+		inventory = lf("/etc/inventory.lua"),
 		model_alias = lf("/etc/model_aliases.lua"),
 		progressive = lf("/etc/progressive.lua"),
+		recipes = lf("/etc/recipes.lua"),
 		styles = lf("/etc/styles.lua"),
-	}
+	},
+
+	progressive_mode = core.settings:get_bool "i3_progressive_mode",
+	item_compression = core.settings:get_bool("i3_item_compression", true),
 }
 
-local http = core.request_http_api()
-local storage = core.get_mod_storage()
+local common = i3.files.common()
 
-i3.S = core.get_translator "i3"
-local S, slz, dslz = i3.S, core.serialize, core.deserialize
+function i3.need(...)
+	local t = {}
+
+	for _, var in ipairs {...} do
+		for _, cat in pairs(common) do
+		for name, func in pairs(cat) do
+			if var == name then
+				t[#t + 1] = func
+				break
+			end
+		end
+		end
+	end
+
+	return unpack(t)
+end
+
+local storage = core.get_mod_storage()
+local slz, dslz = core.serialize, core.deserialize
 
 i3.data = dslz(storage:get_string "data") or {}
 i3.compress_groups, i3.compressed = i3.files.compress()
 i3.group_stereotypes, i3.group_names = i3.files.groups()
 
-local is_str, show_item, reset_compression = unpack(i3.files.common().init)
-local groups_to_items, _, compressible, true_str, is_fav = unpack(i3.files.common().gui)
+local set_fs = i3.files.api()
+local init_backpack = i3.files.bags()
+i3.files.inventory()
+local cache_drops, cache_fuel, cache_recipes, cache_usages, resolve_aliases = i3.files.recipes()
 
-local search, table_merge, is_group, extract_groups, item_has_groups, apply_recipe_filters =
-	unpack(i3.files.common().progressive)
-
-local make_fs, get_inventory_fs = i3.files.gui()
-
-local progressive_mode = core.settings:get_bool "i3_progressive_mode"
-
-local reg_items = core.registered_items
-local reg_nodes = core.registered_nodes
-local reg_craftitems = core.registered_craftitems
-local reg_tools = core.registered_tools
-local reg_aliases = core.registered_aliases
-
-local replacements = {fuel = {}}
-local check_privs = core.check_player_privs
-local after, clr = core.after, core.colorize
-local create_inventory = core.create_detached_inventory
-
-local maxn, sort, concat, copy, insert, remove, indexof =
-	table.maxn, table.sort, table.concat, table.copy,
-	table.insert, table.remove, table.indexof
-
-local fmt, find, gmatch, match, sub, split, upper, lower =
-	string.format, string.find, string.gmatch, string.match,
-	string.sub, string.split, string.upper, string.lower
-
-local min, ceil, random = math.min, math.ceil, math.random
-local pairs, ipairs, next, type, tonum = pairs, ipairs, next, type, tonumber
-
-local vec_new, vec_add, vec_mul, vec_eq, vec_round =
-	vector.new, vector.add, vector.multiply, vector.equals, vector.round
-
-local function err(str)
-	return core.log("error", str)
-end
-
-local function msg(name, str)
-	return core.chat_send_player(name, fmt("[i3] %s", str))
-end
-
-local function is_table(x)
-	return type(x) == "table"
-end
-
-local function is_func(x)
-	return type(x) == "function"
-end
-
-local function clean_name(item)
-	if sub(item, 1, 1) == ":" or sub(item, 1, 1) == " " or sub(item, 1, 1) == "_" then
-		item = sub(item, 2)
-	end
-
-	return item
-end
-
-local function table_replace(t, val, new)
-	for k, v in pairs(t) do
-		if v == val then
-			t[k] = new
-		end
-	end
-end
-
-local function table_eq(T1, T2)
-	local avoid_loops = {}
-
-	local function recurse(t1, t2)
-		if type(t1) ~= type(t2) then return end
-
-		if not is_table(t1) then
-			return t1 == t2
-		end
-
-		if avoid_loops[t1] then
-			return avoid_loops[t1] == t2
-		end
-
-		avoid_loops[t1] = t2
-		local t2k, t2kv = {}, {}
-
-		for k in pairs(t2) do
-			if is_table(k) then
-				insert(t2kv, k)
-			end
-
-			t2k[k] = true
-		end
-
-		for k1, v1 in pairs(t1) do
-			local v2 = t2[k1]
-			if type(k1) == "table" then
-				local ok
-				for i = 1, #t2kv do
-					local tk = t2kv[i]
-					if table_eq(k1, tk) and recurse(v1, t2[tk]) then
-						remove(t2kv, i)
-						t2k[tk] = nil
-						ok = true
-						break
-					end
-				end
-
-				if not ok then return end
-			else
-				if v2 == nil then return end
-				t2k[k1] = nil
-				if not recurse(v1, v2) then return end
-			end
-		end
-
-		if next(t2k) then return end
-		return true
-	end
-
-	return recurse(T1, T2)
-end
+local fmt, sort, copy = i3.need("fmt", "sort", "copy")
+local show_item, reg_items = i3.need("show_item", "reg_items")
 
 local function get_lang_code(info)
 	return info and info.lang_code
@@ -203,728 +114,6 @@ local function outdated(name)
 	core.show_formspec(name, "i3_outdated", fs)
 end
 
-local old_is_creative_enabled = core.is_creative_enabled
-
-function core.is_creative_enabled(name)
-	if name == "" then
-		return old_is_creative_enabled(name)
-	end
-
-	return check_privs(name, {creative = true}) or old_is_creative_enabled(name)
-end
-
-function i3.register_craft_type(name, def)
-	if not true_str(name) then
-		return err "i3.register_craft_type: name missing"
-	end
-
-	if not is_str(def.description) then
-		def.description = ""
-	end
-
-	i3.craft_types[name] = def
-end
-
-function i3.register_craft(def)
-	local width, c = 0, 0
-
-	if true_str(def.url) then
-		if not http then
-			return err(fmt([[i3.register_craft(): Unable to reach %s.
-				No HTTP support for this mod: add it to the `secure.http_mods` or
-				`secure.trusted_mods` setting.]], def.url))
-		end
-
-		http.fetch({url = def.url}, function(result)
-			if result.succeeded then
-				local t = core.parse_json(result.data)
-				if is_table(t) then
-					return i3.register_craft(t)
-				end
-			end
-		end)
-
-		return
-	end
-
-	if not is_table(def) or not next(def) then
-		return err "i3.register_craft: craft definition missing"
-	end
-
-	if #def > 1 then
-		for _, v in pairs(def) do
-			i3.register_craft(v)
-		end
-		return
-	end
-
-	if def.result then
-		def.output = def.result -- Backward compatibility
-		def.result = nil
-	end
-
-	if not true_str(def.output) then
-		return err "i3.register_craft: output missing"
-	end
-
-	if not is_table(def.items) then
-		def.items = {}
-	end
-
-	if def.grid then
-		if not is_table(def.grid) then
-			def.grid = {}
-		end
-
-		if not is_table(def.key) then
-			def.key = {}
-		end
-
-		local cp = copy(def.grid)
-		sort(cp, function(a, b)
-			return #a > #b
-		end)
-
-		width = #cp[1]
-
-		for i = 1, #def.grid do
-			while #def.grid[i] < width do
-				def.grid[i] = def.grid[i] .. " "
-			end
-		end
-
-		for symbol in gmatch(concat(def.grid), ".") do
-			c = c + 1
-			def.items[c] = def.key[symbol]
-		end
-	else
-		local items, len = def.items, #def.items
-		def.items = {}
-
-		for i = 1, len do
-			local rlen = #split(items[i], ",")
-
-			if rlen > width then
-				width = rlen
-			end
-		end
-
-		for i = 1, len do
-			while #split(items[i], ",") < width do
-				items[i] = fmt("%s,", items[i])
-			end
-		end
-
-		for name in gmatch(concat(items, ","), "[%s%w_:]+") do
-			c = c + 1
-			def.items[c] = clean_name(name)
-		end
-	end
-
-	local item = match(def.output, "%S+")
-	i3.recipes_cache[item] = i3.recipes_cache[item] or {}
-
-	def.custom = true
-	def.width = width
-
-	insert(i3.recipes_cache[item], def)
-end
-
-function i3.add_recipe_filter(name, f)
-	if not true_str(name) then
-		return err "i3.add_recipe_filter: name missing"
-	elseif not is_func(f) then
-		return err "i3.add_recipe_filter: function missing"
-	end
-
-	i3.recipe_filters[name] = f
-end
-
-function i3.set_recipe_filter(name, f)
-	if not is_str(name) then
-		return err "i3.set_recipe_filter: name missing"
-	elseif not is_func(f) then
-		return err "i3.set_recipe_filter: function missing"
-	end
-
-	i3.recipe_filters = {[name] = f}
-end
-
-function i3.add_search_filter(name, f)
-	if not true_str(name) then
-		return err "i3.add_search_filter: name missing"
-	elseif not is_func(f) then
-		return err "i3.add_search_filter: function missing"
-	end
-
-	i3.search_filters[name] = f
-end
-
-function i3.remove_search_filter(name)
-	i3.search_filters[name] = nil
-end
-
-local function get_burntime(item)
-	return core.get_craft_result{method = "fuel", items = {item}}.time
-end
-
-local function cache_fuel(item)
-	local burntime = get_burntime(item)
-	if burntime > 0 then
-		i3.fuel_cache[item] = {
-			type = "fuel",
-			items = {item},
-			burntime = burntime,
-			replacements = replacements.fuel[item],
-		}
-	end
-end
-
-local function sort_by_category(data)
-	reset_compression(data)
-	local items = data.items_raw
-
-	if data.filter ~= "" then
-		search(data)
-		items = data.items
-	end
-
-	local new = {}
-
-	for i = 1, #items do
-		local item = items[i]
-		local to_add = true
-
-		if data.current_itab == 2 then
-			to_add = reg_nodes[item]
-		elseif data.current_itab == 3 then
-			to_add = reg_craftitems[item] or reg_tools[item]
-		end
-
-		if to_add then
-			new[#new + 1] = item
-		end
-	end
-
-	data.items = new
-end
-
-local function get_item_usages(item, recipe, added)
-	local groups = extract_groups(item)
-
-	if groups then
-		for name, def in pairs(reg_items) do
-			if not added[name] and show_item(def) and item_has_groups(def.groups, groups) then
-				local usage = copy(recipe)
-				table_replace(usage.items, item, name)
-
-				i3.usages_cache[name] = i3.usages_cache[name] or {}
-				insert(i3.usages_cache[name], 1, usage)
-
-				added[name] = true
-			end
-		end
-	elseif show_item(reg_items[item]) then
-		i3.usages_cache[item] = i3.usages_cache[item] or {}
-		insert(i3.usages_cache[item], 1, recipe)
-	end
-end
-
-local function get_usages(recipe)
-	local added = {}
-
-	for _, item in pairs(recipe.items) do
-		item = reg_aliases[item] or item
-
-		if not added[item] then
-			get_item_usages(item, recipe, added)
-			added[item] = true
-		end
-	end
-end
-
-local function cache_usages(item)
-	local recipes = i3.recipes_cache[item] or {}
-
-	for i = 1, #recipes do
-		get_usages(recipes[i])
-	end
-
-	if i3.fuel_cache[item] then
-		i3.usages_cache[item] = table_merge(i3.usages_cache[item] or {}, {i3.fuel_cache[item]})
-	end
-end
-
-local function drop_table(name, drop)
-	local count_sure = 0
-	local drop_items = drop.items or {}
-	local max_items = drop.max_items
-
-	for i = 1, #drop_items do
-		local di = drop_items[i]
-		local valid_rarity = di.rarity and di.rarity > 1
-
-		if di.rarity or not max_items or
-				(max_items and not di.rarity and count_sure < max_items) then
-			for j = 1, #di.items do
-				local dstack = ItemStack(di.items[j])
-				local dname  = dstack:get_name()
-				local dcount = dstack:get_count()
-				local empty  = dstack:is_empty()
-
-				if not empty and (dname ~= name or (dname == name and dcount > 1)) then
-					local rarity = valid_rarity and di.rarity
-
-					i3.register_craft {
-						type   = rarity and "digging_chance" or "digging",
-						items  = {name},
-						output = fmt("%s %u", dname, dcount),
-						rarity = rarity,
-						tools  = di.tools,
-					}
-				end
-			end
-		end
-
-		if not di.rarity then
-			count_sure = count_sure + 1
-		end
-	end
-end
-
-local function cache_drops(name, drop)
-	if true_str(drop) then
-		local dstack = ItemStack(drop)
-		local dname  = dstack:get_name()
-		local empty  = dstack:is_empty()
-
-		if not empty and dname ~= name then
-			i3.register_craft {
-				type = "digging",
-				items = {name},
-				output = drop,
-			}
-		end
-	elseif is_table(drop) then
-		drop_table(name, drop)
-	end
-end
-
-local function cache_recipes(item)
-	local recipes = core.get_all_craft_recipes(item)
-
-	if replacements[item] then
-		local _recipes = {}
-
-		for k, v in ipairs(recipes or {}) do
-			_recipes[#recipes + 1 - k] = v
-		end
-
-		local shift = 0
-		local size_rpl = maxn(replacements[item])
-		local size_rcp = #_recipes
-
-		if size_rpl > size_rcp then
-			shift = size_rcp - size_rpl
-		end
-
-		for k, v in pairs(replacements[item]) do
-			k = k + shift
-
-			if _recipes[k] then
-				_recipes[k].replacements = v
-			end
-		end
-
-		recipes = _recipes
-	end
-
-	if recipes then
-		i3.recipes_cache[item] = table_merge(recipes, i3.recipes_cache[item] or {})
-	end
-end
-
-function i3.get_recipes(item)
-	return {
-		recipes = i3.recipes_cache[item],
-		usages = i3.usages_cache[item]
-	}
-end
-
-local function get_recipes(player, item)
-	local clean_item = reg_aliases[item] or item
-	local recipes = i3.recipes_cache[clean_item]
-	local usages = i3.usages_cache[clean_item]
-
-	if recipes then
-		recipes = apply_recipe_filters(recipes, player)
-	end
-
-	local no_recipes = not recipes or #recipes == 0
-	if no_recipes and not usages then return end
-	usages = apply_recipe_filters(usages, player)
-
-	local no_usages = not usages or #usages == 0
-
-	return not no_recipes and recipes or nil,
-	       not no_usages  and usages  or nil
-end
-
-local function __sort(inv, reverse)
-	sort(inv, function(a, b)
-		if not is_str(a) then
-			a = a:get_name()
-		end
-
-		if not is_str(b) then
-			b = b:get_name()
-		end
-
-		if reverse then
-			return a > b
-		end
-
-		return a < b
-	end)
-end
-
-local function sort_itemlist(player, az)
-	local inv = player:get_inventory()
-	local list = inv:get_list("main")
-	local size = inv:get_size("main")
-	local new_inv, stack_meta = {}, {}
-
-	for i = 1, size do
-		local stack = list[i]
-		local name = stack:get_name()
-		local count = stack:get_count()
-		local empty = stack:is_empty()
-		local meta = stack:get_meta():to_table()
-		local wear = stack:get_wear() > 0
-
-		if not empty then
-			if next(meta.fields) or wear then
-				stack_meta[#stack_meta + 1] = stack
-			else
-				new_inv[#new_inv + 1] = fmt("%s %u", name, count)
-			end
-		end
-	end
-
-	for i = 1, #stack_meta do
-		new_inv[#new_inv + 1] = stack_meta[i]
-	end
-
-	if az then
-		__sort(new_inv)
-	else
-		__sort(new_inv, true)
-	end
-
-	inv:set_list("main", new_inv)
-end
-
-local function compress_items(player)
-	local inv = player:get_inventory()
-	local list = inv:get_list("main")
-	local size = inv:get_size("main")
-	local new_inv, _new_inv, special = {}, {}, {}
-
-	for i = 1, size do
-		local stack = list[i]
-		local name = stack:get_name()
-		local count = stack:get_count()
-		local stackmax = stack:get_stack_max()
-		local empty = stack:is_empty()
-		local meta = stack:get_meta():to_table()
-		local wear = stack:get_wear() > 0
-
-		if not empty then
-			if next(meta.fields) or wear or count >= stackmax then
-				special[#special + 1] = stack
-			else
-				new_inv[name] = new_inv[name] or 0
-				new_inv[name] = new_inv[name] + count
-			end
-		end
-	end
-
-	for name, count in pairs(new_inv) do
-		local stackmax = ItemStack(name):get_stack_max()
-		local iter = ceil(count / stackmax)
-		local leftover = count
-
-		for _ = 1, iter do
-			_new_inv[#_new_inv + 1] = fmt("%s %u", name, min(stackmax, leftover))
-			leftover = leftover - stackmax
-		end
-	end
-
-	for i = 1, #special do
-		_new_inv[#_new_inv + 1] = special[i]
-	end
-
-	__sort(_new_inv)
-	inv:set_list("main", _new_inv)
-end
-
-local function spawn_item(player, stack)
-	local dir     = player:get_look_dir()
-	local ppos    = player:get_pos()
-	      ppos.y  = ppos.y + 1.625
-	local look_at = vec_add(ppos, vec_mul(dir, 1))
-
-	core.add_item(look_at, stack)
-end
-
-local function get_stack(player, stack)
-	local inv = player:get_inventory()
-
-	if inv:room_for_item("main", stack) then
-		inv:add_item("main", stack)
-	else
-		spawn_item(player, stack)
-	end
-end
-
-local function craft_stack(player, data, craft_rcp)
-	local inv = player:get_inventory()
-	local rcp_usg = craft_rcp and "recipe" or "usage"
-	local output = craft_rcp and data.recipes[data.rnum].output or data.usages[data.unum].output
-	      output = ItemStack(output)
-	local stackname, stackcount, stackmax = output:get_name(), output:get_count(), output:get_stack_max()
-	local scrbar_val = data[fmt("scrbar_%s", craft_rcp and "rcp" or "usg")] or 1
-
-	for name, count in pairs(data.export_counts[rcp_usg].rcp) do
-		local items = {[name] = count}
-
-		if is_group(name) then
-			items = {}
-			local groups = extract_groups(name)
-			local item_groups = groups_to_items(groups, true)
-			local remaining = count
-
-			for _, item in ipairs(item_groups) do
-			for _name, _count in pairs(data.export_counts[rcp_usg].inv) do
-				if item == _name and remaining > 0 then
-					local c = min(remaining, _count)
-					items[item] = c
-					remaining = remaining - c
-				end
-
-				if remaining == 0 then break end
-			end
-			end
-		end
-
-		for k, v in pairs(items) do
-			inv:remove_item("main", fmt("%s %s", k, v * scrbar_val))
-		end
-	end
-
-	local count = stackcount * scrbar_val
-	local iter = ceil(count / stackmax)
-	local leftover = count
-
-	for _ = 1, iter do
-		local c = min(stackmax, leftover)
-		local stack = ItemStack(fmt("%s %s", stackname, c))
-		get_stack(player, stack)
-		leftover = leftover - stackmax
-	end
-end
-
-local function select_item(player, name, data, _f)
-	local item
-
-	for field in pairs(_f) do
-		if find(field, ":") then
-			item = field
-			break
-		end
-	end
-
-	if not item then return end
-
-	if compressible(item, data) then
-		local idx
-
-		for i = 1, #data.items do
-			local it = data.items[i]
-			if it == item then
-				idx = i
-				break
-			end
-		end
-
-		if data.expand ~= "" then
-			data.alt_items = nil
-
-			if item == data.expand then
-				data.expand = nil
-				return
-			end
-		end
-
-		if idx and item ~= data.expand then
-			data.alt_items = copy(data.items)
-			data.expand = item
-
-			if i3.compress_groups[item] then
-				local items = copy(i3.compress_groups[item])
-				insert(items, fmt("_%s", item))
-
-				sort(items, function(a, b)
-					if a:sub(1, 1) == "_" then
-						a = a:sub(2)
-					end
-
-					return a < b
-				end)
-
-				local i = 1
-
-				for _, v in ipairs(items) do
-					if show_item(reg_items[clean_name(v)]) then
-						insert(data.alt_items, idx + i, v)
-						i = i + 1
-					end
-				end
-			end
-		end
-	else
-		if sub(item, 1, 1) == "_" then
-			item = sub(item, 2)
-		elseif sub(item, 1, 6) == "group|" then
-			item = match(item, "([%w:_]+)$")
-		end
-
-		item = reg_aliases[item] or item
-		if not reg_items[item] then return end
-
-		if core.is_creative_enabled(name) then
-			local stack = ItemStack(item)
-			local stackmax = stack:get_stack_max()
-			      stack = fmt("%s %s", item, stackmax)
-
-			return get_stack(player, stack)
-		end
-
-		if item == data.query_item then return end
-		local recipes, usages = get_recipes(player, item)
-
-		data.query_item = item
-		data.recipes    = recipes
-		data.usages     = usages
-		data.rnum       = 1
-		data.unum       = 1
-		data.scrbar_rcp = 1
-		data.scrbar_usg = 1
-		data.export_rcp = nil
-		data.export_usg = nil
-	end
-end
-
-function i3.set_fs(player, _fs)
-	if not player or player.is_fake_player then return end
-	local name = player:get_player_name()
-	local data = i3.data[name]
-	if not data then return end
-
-	local fs = fmt("%s%s", make_fs(player, data), _fs or "")
-	player:set_inventory_formspec(fs)
-end
-
-local set_fs = i3.set_fs
-
-function i3.new_tab(def)
-	if not is_table(def) or not next(def) then
-		return err "i3.new_tab: tab definition missing"
-	end
-
-	if not true_str(def.name) then
-		return err "i3.new_tab: tab name missing"
-	end
-
-	if not true_str(def.description) then
-		return err "i3.new_tab: description missing"
-	end
-
-	if #i3.tabs == 6 then
-		return err(fmt("i3.new_tab: cannot add '%s' tab. Limit reached (6).", def.name))
-	end
-
-	i3.tabs[#i3.tabs + 1] = def
-end
-
-function i3.get_tabs()
-	return i3.tabs
-end
-
-function i3.remove_tab(tabname)
-	if not true_str(tabname) then
-		return err "i3.remove_tab: tab name missing"
-	end
-
-	for i, def in ipairs(i3.tabs) do
-		if tabname == def.name then
-			remove(i3.tabs, i)
-		end
-	end
-end
-
-function i3.get_current_tab(player)
-	local name = player:get_player_name()
-	local data = i3.data[name]
-
-	return data.current_tab
-end
-
-function i3.set_tab(player, tabname)
-	local name = player:get_player_name()
-	local data = i3.data[name]
-
-	if not tabname or tabname == "" then
-		data.current_tab = 0
-		return
-	end
-
-	local found
-
-	for i, def in ipairs(i3.tabs) do
-		if not found and def.name == tabname then
-			data.current_tab = i
-			found = true
-		end
-	end
-
-	if not found then
-		return err(fmt("i3.set_tab: tab name '%s' does not exist", tabname))
-	end
-end
-
-local set_tab = i3.set_tab
-
-function i3.override_tab(tabname, newdef)
-	if not is_table(newdef) or not next(newdef) then
-		return err "i3.override_tab: tab definition missing"
-	end
-
-	if not true_str(newdef.name) then
-		return err "i3.override_tab: tab name missing"
-	end
-
-	if not true_str(newdef.description) then
-		return err "i3.override_tab: description missing"
-	end
-
-	for i, def in ipairs(i3.tabs) do
-		if def.name == tabname then
-			i3.tabs[i] = newdef
-		end
-	end
-end
-
 local function init_data(player, info)
 	local name = player:get_player_name()
 	i3.data[name] = i3.data[name] or {}
@@ -943,283 +132,9 @@ local function init_data(player, info)
 	data.lang_code     = get_lang_code(info)
 	data.fs_version    = info.formspec_version
 
-	after(0, set_fs, player)
+	core.after(0, set_fs, player)
 end
 
-local function reset_data(data)
-	data.filter        = ""
-	data.expand        = ""
-	data.pagenum       = 1
-	data.rnum          = 1
-	data.unum          = 1
-	data.scrbar_rcp    = 1
-	data.scrbar_usg    = 1
-	data.query_item    = nil
-	data.recipes       = nil
-	data.usages        = nil
-	data.export_rcp    = nil
-	data.export_usg    = nil
-	data.alt_items     = nil
-	data.confirm_trash = nil
-	data.items         = data.items_raw
-
-	if data.current_itab > 1 then
-		sort_by_category(data)
-	end
-end
-
-local function rcp_fields(player, data, fields)
-	local name = player:get_player_name()
-	local sb_rcp, sb_usg = fields.scrbar_rcp, fields.scrbar_usg
-
-	if fields.cancel then
-		reset_data(data)
-
-	elseif fields.exit then
-		data.query_item = nil
-
-	elseif fields.key_enter_field == "filter" or fields.search then
-		if fields.filter == "" then
-			reset_data(data)
-			return set_fs(player)
-		end
-
-		local str = lower(fields.filter)
-		if data.filter == str then return end
-
-		data.filter = str
-		data.pagenum = 1
-
-		search(data)
-
-		if data.current_itab > 1 then
-			sort_by_category(data)
-		end
-
-	elseif fields.prev_page or fields.next_page then
-		if data.pagemax == 1 then return end
-		data.pagenum = data.pagenum - (fields.prev_page and 1 or -1)
-
-		if data.pagenum > data.pagemax then
-			data.pagenum = 1
-		elseif data.pagenum == 0 then
-			data.pagenum = data.pagemax
-		end
-
-	elseif fields.prev_recipe or fields.next_recipe then
-		local num = data.rnum + (fields.prev_recipe and -1 or 1)
-		data.rnum = data.recipes[num] and num or (fields.prev_recipe and #data.recipes or 1)
-		data.export_rcp = nil
-		data.scrbar_rcp = 1
-
-	elseif fields.prev_usage or fields.next_usage then
-		local num = data.unum + (fields.prev_usage and -1 or 1)
-		data.unum = data.usages[num] and num or (fields.prev_usage and #data.usages or 1)
-		data.export_usg = nil
-		data.scrbar_usg = 1
-
-	elseif fields.fav then
-		local fav, i = is_fav(data.favs, data.query_item)
-		local total = #data.favs
-
-		if total < i3.MAX_FAVS and not fav then
-			data.favs[total + 1] = data.query_item
-		elseif fav then
-			remove(data.favs, i)
-		end
-
-	elseif fields.export_rcp or fields.export_usg then
-		if fields.export_rcp then
-			data.export_rcp = not data.export_rcp
-
-			if not data.export_rcp then
-				data.scrbar_rcp = 1
-			end
-		else
-			data.export_usg = not data.export_usg
-
-			if not data.export_usg then
-				data.scrbar_usg = 1
-			end
-		end
-
-	elseif (sb_rcp and sub(sb_rcp, 1, 3) == "CHG") or (sb_usg and sub(sb_usg, 1, 3) == "CHG") then
-		data.scrbar_rcp = sb_rcp and tonum(match(sb_rcp, "%d+"))
-		data.scrbar_usg = sb_usg and tonum(match(sb_usg, "%d+"))
-
-	elseif fields.craft_rcp or fields.craft_usg then
-		craft_stack(player, data, fields.craft_rcp)
-
-		if fields.craft_rcp then
-			data.export_rcp = nil
-			data.scrbar_rcp = 1
-		else
-			data.export_usg = nil
-			data.scrbar_usg = 1
-		end
-	else
-		select_item(player, name, data, fields)
-	end
-end
-
-i3.new_tab {
-	name = "inventory",
-	description = S"Inventory",
-	formspec = get_inventory_fs,
-
-	fields = function(player, data, fields)
-		local name = player:get_player_name()
-		local sb_inv = fields.scrbar_inv
-
-		if fields.skins then
-			local id = tonum(fields.skins)
-			local _skins = skins.get_skinlist_for_player(name)
-			skins.set_player_skin(player, _skins[id])
-		end
-
-		for field in pairs(fields) do
-			if sub(field, 1, 4) == "btn_" then
-				data.subcat = indexof(i3.SUBCAT, sub(field, 5))
-				break
-
-			elseif find(field, "waypoint_%d+") then
-				local id, action = match(field, "_(%d+)_(%w+)$")
-				id = tonum(id)
-				local waypoint = data.waypoints[id]
-				if not waypoint then return end
-
-				if action == "delete" then
-					player:hud_remove(waypoint.id)
-					remove(data.waypoints, id)
-
-				elseif action == "teleport" then
-					local pos = vec_new(waypoint.pos)
-					pos.y = pos.y + 0.5
-
-					local vel = player:get_velocity()
-					player:add_velocity(vec_mul(vel, -1))
-					player:set_pos(pos)
-
-					msg(name, fmt("Teleported to %s", clr("#ff0", waypoint.name)))
-
-				elseif action == "refresh" then
-					local color = random(0xffffff)
-					waypoint.color = color
-					player:hud_change(waypoint.id, "number", color)
-
-				elseif action == "hide" then
-					if waypoint.hide then
-						local new_id = player:hud_add {
-							hud_elem_type = "waypoint",
-							name = waypoint.name,
-							text = " m",
-							world_pos = waypoint.pos,
-							number = waypoint.color,
-							z_index = -300,
-						}
-
-						waypoint.id = new_id
-						waypoint.hide = nil
-					else
-						player:hud_remove(waypoint.id)
-						waypoint.hide = true
-					end
-				end
-
-				break
-			end
-		end
-
-		if fields.trash then
-			data.confirm_trash = true
-
-		elseif fields.confirm_trash_yes or fields.confirm_trash_no then
-			if fields.confirm_trash_yes then
-				local inv = player:get_inventory()
-				inv:set_list("main", {})
-				inv:set_list("craft", {})
-			end
-
-			data.confirm_trash = nil
-
-		elseif fields.compress then
-			compress_items(player)
-
-		elseif fields.sort_az or fields.sort_za then
-			sort_itemlist(player, fields.sort_az)
-
-		elseif sb_inv and sub(sb_inv, 1, 3) == "CHG" then
-			data.scrbar_inv = tonum(match(sb_inv, "%d+"))
-			return
-
-		elseif fields.waypoint_add then
-			local pos = player:get_pos()
-
-			for _, v in ipairs(data.waypoints) do
-				if vec_eq(vec_round(pos), vec_round(v.pos)) then
-					return msg(name, "You already set a waypoint at this position")
-				end
-			end
-
-			local waypoint = fields.waypoint_name
-
-			if fields.waypoint_name == "" then
-				waypoint = "Waypoint"
-			end
-
-			local color = random(0xffffff)
-
-			local id = player:hud_add {
-				hud_elem_type = "waypoint",
-				name = waypoint,
-				text = " m",
-				world_pos = pos,
-				number = color,
-				z_index = -300,
-			}
-
-			insert(data.waypoints, {name = waypoint, pos = pos, color = color, id = id})
-			data.scrbar_inv = data.scrbar_inv + 1000
-		end
-
-		return set_fs(player)
-	end,
-}
-
-local trash = create_inventory("i3_trash", {
-	allow_put = function(_, _, _, stack)
-		return stack:get_count()
-	end,
-	on_put = function(inv, listname, _, _, player)
-		inv:set_list(listname, {})
-
-		local name = player:get_player_name()
-
-		if not core.is_creative_enabled(name) then
-			set_fs(player)
-		end
-	end,
-})
-
-trash:set_size("main", 1)
-
-local output_rcp = create_inventory("i3_output_rcp", {})
-output_rcp:set_size("main", 1)
-
-local output_usg = create_inventory("i3_output_usg", {})
-output_usg:set_size("main", 1)
-
-core.register_on_player_inventory_action(function(player, _, _, info)
-	local name = player:get_player_name()
-
-	if not core.is_creative_enabled(name) and
-	  ((info.from_list == "main"  and info.to_list == "craft") or
-	   (info.from_list == "craft" and info.to_list == "main")  or
-	   (info.from_list == "craftresult" and info.to_list == "main")) then
-		set_fs(player)
-	end
-end)
-
 if rawget(_G, "armor") then
 	i3.modules.armor = true
 	armor:register_on_update(set_fs)
@@ -1250,136 +165,6 @@ if rawget(_G, "awards") then
 	end)
 end
 
-core.register_on_chatcommand(function(name)
-	local player = core.get_player_by_name(name)
-	after(0, set_fs, player)
-end)
-
-core.register_on_priv_grant(function(name, _, priv)
-	if priv == "creative" or priv == "all" then
-		local data = i3.data[name]
-		reset_data(data)
-		data.favs = {}
-
-		local player = core.get_player_by_name(name)
-		after(0, set_fs, player)
-	end
-end)
-
-i3.register_craft_type("digging", {
-	description = S"Digging",
-	icon = "i3_steelpick.png",
-})
-
-i3.register_craft_type("digging_chance", {
-	description = S"Digging (by chance)",
-	icon = "i3_mesepick.png",
-})
-
-i3.add_search_filter("groups", function(item, groups)
-	local def = reg_items[item]
-	local has_groups = true
-
-	for _, group in ipairs(groups) do
-		if not def.groups[group] then
-			has_groups = nil
-			break
-		end
-	end
-
-	return has_groups
-end)
-
---[[	As `core.get_craft_recipe` and `core.get_all_craft_recipes` do not
-	return the fuel, replacements and toolrepair recipes, we have to
-	override `core.register_craft` and do some reverse engineering.
-	See engine's issues #4901, #5745 and #8920.	]]
-
-local old_register_craft = core.register_craft
-local rcp_num = {}
-
-core.register_craft = function(def)
-	old_register_craft(def)
-
-	if def.type == "toolrepair" then
-		i3.toolrepair = def.additional_wear * -100
-	end
-
-	local output = def.output or (true_str(def.recipe) and def.recipe) or nil
-	if not output then return end
-	output = {match(output, "%S+")}
-
-	local groups
-
-	if is_group(output[1]) then
-		groups = extract_groups(output[1])
-		output = groups_to_items(groups, true)
-	end
-
-	for i = 1, #output do
-		local item = output[i]
-		rcp_num[item] = (rcp_num[item] or 0) + 1
-
-		if def.replacements then
-			if def.type == "fuel" then
-				replacements.fuel[item] = def.replacements
-			else
-				replacements[item] = replacements[item] or {}
-				replacements[item][rcp_num[item]] = def.replacements
-			end
-		end
-	end
-end
-
-local old_clear_craft = core.clear_craft
-
-core.clear_craft = function(def)
-	old_clear_craft(def)
-
-	if true_str(def) then
-		return -- TODO
-	elseif is_table(def) then
-		return -- TODO
-	end
-end
-
-local function resolve_aliases(hash)
-	for oldname, newname in pairs(reg_aliases) do
-		cache_recipes(oldname)
-		local recipes = i3.recipes_cache[oldname]
-
-		if recipes then
-			if not i3.recipes_cache[newname] then
-				i3.recipes_cache[newname] = {}
-			end
-
-			local similar
-
-			for i = 1, #i3.recipes_cache[oldname] do
-				local rcp_old = i3.recipes_cache[oldname][i]
-
-				for j = 1, #i3.recipes_cache[newname] do
-					local rcp_new = copy(i3.recipes_cache[newname][j])
-					rcp_new.output = oldname
-
-					if table_eq(rcp_old, rcp_new) then
-						similar = true
-						break
-					end
-				end
-
-				if not similar then
-					insert(i3.recipes_cache[newname], rcp_old)
-				end
-			end
-		end
-
-		if newname ~= "" and i3.recipes_cache[oldname] and not hash[newname] then
-			i3.init_items[#i3.init_items + 1] = newname
-		end
-	end
-end
-
 local function get_init_items()
 	local _select, _preselect = {}, {}
 
@@ -1403,13 +188,13 @@ local function get_init_items()
 	resolve_aliases(_select)
 	sort(i3.init_items)
 
-	if http and true_str(i3.export_url) then
+	if i3.http and type(i3.export_url) == "string" then
 		local post_data = {
 			recipes = i3.recipes_cache,
 			usages  = i3.usages_cache,
 		}
 
-		http.fetch_async {
+		i3.http.fetch_async {
 			url = i3.export_url,
 			post_data = core.write_json(post_data),
 		}
@@ -1429,72 +214,6 @@ core.register_on_mods_loaded(function()
 	end
 end)
 
-local function init_backpack(player)
-	local name = player:get_player_name()
-	local data = i3.data[name]
-	local inv = player:get_inventory()
-
-	-- Legacy compat
-	if data.bag_size and type(data.bag_size) == "string" then
-		local convert = {
-			small = 1,
-			medium = 2,
-			large = 3,
-		}
-
-		data.bag_item = fmt("i3:bag_%s", data.bag_size)
-		data.bag_size = convert[data.bag_size]
-	end
-
-	inv:set_size("main", data.bag_size and i3.BAG_SIZES[data.bag_size] or i3.INV_SIZE)
-
-	data.bag = create_inventory(fmt("%s_backpack", name), {
-		allow_put = function(_inv, listname, _, stack)
-			local empty = _inv:get_stack(listname, 1):is_empty()
-			local item_group = minetest.get_item_group(stack:get_name(), "bag")
-
-			if empty and item_group > 0 and item_group <= #i3.BAG_SIZES then
-				return 1
-			end
-
-			msg(name, S"This is not a backpack")
-
-			return 0
-		end,
-
-		on_put = function(_, _, _, stack)
-			local stackname = stack:get_name()
-			data.bag_item = stackname
-			data.bag_size = minetest.get_item_group(stackname, "bag")
-
-			inv:set_size("main", i3.BAG_SIZES[data.bag_size])
-			set_fs(player)
-		end,
-
-		on_take = function()
-			for i = i3.INV_SIZE + 1, i3.BAG_SIZES[data.bag_size] do
-				local stack = inv:get_stack("main", i)
-
-				if not stack:is_empty() then
-					spawn_item(player, stack)
-				end
-			end
-
-			data.bag_item = nil
-			data.bag_size = nil
-
-			inv:set_size("main", i3.INV_SIZE)
-			set_fs(player)
-		end,
-	})
-
-	data.bag:set_size("main", 1)
-
-	if data.bag_item then
-		data.bag:set_stack("main", 1, data.bag_item)
-	end
-end
-
 local function init_waypoints(player)
 	local name = player:get_player_name()
 	local data = i3.data[name]
@@ -1529,29 +248,12 @@ core.register_on_joinplayer(function(player)
 	init_backpack(player)
 	init_waypoints(player)
 
-	after(0, function()
+	core.after(0, function()
 		player:hud_set_hotbar_itemcount(i3.HOTBAR_LEN)
 		player:hud_set_hotbar_image("i3_hotbar.png")
 	end)
 end)
 
-core.register_on_dieplayer(function(player)
-	local name = player:get_player_name()
-	local data = i3.data[name]
-	if not data then return end
-
-	if data.bag_size then
-		data.bag_item = nil
-		data.bag_size = nil
-		data.bag:set_list("main", {})
-
-		local inv = player:get_inventory()
-		inv:set_size("main", i3.INV_SIZE)
-	end
-
-	set_fs(player)
-end)
-
 local function save_data(player_name)
 	local _data = copy(i3.data)
 
@@ -1579,99 +281,14 @@ core.register_on_shutdown(save_data)
 
 local function routine()
 	save_data()
-	after(i3.SAVE_INTERVAL, routine)
+	core.after(i3.SAVE_INTERVAL, routine)
 end
 
-after(i3.SAVE_INTERVAL, routine)
+core.after(i3.SAVE_INTERVAL, routine)
 
-core.register_on_player_receive_fields(function(player, formname, fields)
-	local name = player:get_player_name()
-
-	if formname == "i3_outdated" then
-		return false, core.kick_player(name, "Come back when your client is up-to-date.")
-	elseif formname ~= "" then
-		return false
-	end
-
-	local data = i3.data[name]
-	if not data then return end
-
-	for f in pairs(fields) do
-		if sub(f, 1, 4) == "tab_" then
-			local tabname = sub(f, 5)
-			set_tab(player, tabname)
-			break
-		elseif sub(f, 1, 5) == "itab_" then
-			data.pagenum = 1
-			data.current_itab = tonum(f:sub(-1))
-			sort_by_category(data)
-		end
-	end
-
-	rcp_fields(player, data, fields)
-
-	local tab = i3.tabs[data.current_tab]
-
-	if tab and tab.fields then
-		return true, tab.fields(player, data, fields)
-	end
-
-	return true, set_fs(player)
-end)
-
-core.register_on_player_hpchange(function(player, hpchange)
-	local name = player:get_player_name()
-	local data = i3.data[name]
-	if not data then return end
-
-	local hp_max = player:get_properties().hp_max
-	data.hp = min(hp_max, player:get_hp() + hpchange)
-
-	set_fs(player)
-end)
-
-if progressive_mode then
+if i3.progressive_mode then
 	i3.files.progressive()
 end
 
-local bag_recipes = {
-	small = {
-		rcp = {
-			{"", "farming:string", ""},
-			{"group:wool", "group:wool", "group:wool"},
-			{"group:wool", "group:wool", "group:wool"},
-		},
-		size = 1,
-	},
-	medium = {
-		rcp = {
-			{"farming:string", "i3:bag_small", "farming:string"},
-			{"farming:string", "i3:bag_small", "farming:string"},
-		},
-		size = 2,
-	},
-	large = {
-		rcp = {
-			{"farming:string", "i3:bag_medium", "farming:string"},
-			{"farming:string", "i3:bag_medium", "farming:string"},
-		},
-		size = 3,
-	},
-}
-
-for size, item in pairs(bag_recipes) do
-	local bagname = fmt("i3:bag_%s", size)
-
-	core.register_craftitem(bagname, {
-		description = fmt("%s Backpack", size:gsub("^%l", upper)),
-		inventory_image = fmt("i3_bag_%s.png", size),
-		stack_max = 1,
-		groups = {bag = item.size}
-	})
-
-	core.register_craft {output = bagname, recipe = item.rcp}
-	core.register_craft {type = "fuel", recipe = bagname, burntime = 3}
-end
-
 --dofile(modpath .. "/tests/test_tabs.lua")
 --dofile(modpath .. "/tests/test_custom_recipes.lua")