From aa5aacf7b2b98135cf7cc70c4e1f7a5756bb7437 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Sat, 17 Jan 2026 22:08:04 -0700
Subject: [PATCH 1/9] initial commit, includes cache optimizations

---
 control.lua                               |   1 +
 scripts/slaughterhouse/slaughterhouse.lua | 260 ++++++++++++++++++++++
 2 files changed, 261 insertions(+)
 create mode 100644 scripts/slaughterhouse/slaughterhouse.lua

diff --git a/control.lua b/control.lua
index 64acbb73..1e819116 100644
--- a/control.lua
+++ b/control.lua
@@ -22,6 +22,7 @@ require "scripts.ocula.ocula"
 require "scripts.farming.farming"
 require "scripts.smart-farm.smart-farm"
 require "scripts.smart-farm.mega-farm"
+require "scripts.slaughterhouse.slaughterhouse"
 require "scripts.worm.worm"
 require "scripts.turd.turd"
 require "scripts.vatbrain.vatbrain"
diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
new file mode 100644
index 00000000..214058b1
--- /dev/null
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -0,0 +1,260 @@
+local animals = {
+	"auog",
+	"ulric",
+	"mukmoux",
+	"arthurian",
+	"cottongut",
+	"dhilmos",
+	"scrondrix",
+	"phadai",
+	"fish",
+	"phagnot",
+	"kmauts",
+	"dingrits",
+	"xeno",
+	"arqad",
+	"cridren",
+	"antelope",
+	"trits",
+	"vonix",
+	"vrauks",
+	"xyhiphoe",
+	"zipir",
+	"korlex",
+	"simik",
+}
+if script.active_mods["pyalternativeenergy"] then
+	table.insert(animals, "zungror")
+	table.insert(animals, "numal")
+end
+if script.active_mods["pystellarexpedition"] then
+	--table.insert(animals, 'tuls')
+	--table.insert(animals, 'riga')
+	table.insert(animals, "kakkalakki")
+end
+
+--TODO circuit connections, parameters, quality
+
+local machines_with_gui = {
+	["slaughterhouse-mk01"] = true,
+	["slaughterhouse-mk02"] = true,
+	["slaughterhouse-mk03"] = true,
+	["slaughterhouse-mk04"] = true,
+	["rc-mk01"] = true,
+	["rc-mk02"] = true,
+	["rc-mk03"] = true,
+	["rc-mk04"] = true,
+}
+
+-- cache crafting categories
+local permitted_recipes = {}
+for machine in pairs(machines_with_gui) do
+  for category in pairs(prototypes.entity[machine].crafting_categories) do
+    permitted_recipes[category] = {}
+  end
+end
+-- ignore parameters
+permitted_recipes.parameters = nil
+
+-- cache permitted recipes
+for category in pairs(permitted_recipes) do
+  for r, recipe in pairs(prototypes.get_recipe_filtered{{filter = "category", category = category}}) do
+    permitted_recipes[category][r] = recipe.subgroup.name
+  end
+end
+
+py.on_event(defines.events.on_object_destroyed, function(event)
+	local unit_number = event.useful_id
+	if not unit_number or not storage.opened_slaughterhouses[unit_number] then return end
+
+	storage.opened_slaughterhouses[unit_number] = nil
+	for _, player in pairs(game.players) do
+		local gui = player.gui.screen.slaughterhouse
+		if gui and gui.tags.entity == unit_number then gui.destroy() end
+	end
+end)
+
+local alt_animals = {
+  zipir = "zipir1",
+  kakkalakki = "kakkalakki-f"
+}
+
+local function get_animal_item(animal)
+	return alt_animals[animal] or animal
+end
+
+local function build_animal_table(content_frame, player)
+	content_frame.clear()
+	local main_frame = content_frame.parent
+	main_frame.caption = main_frame.tags.caption
+	local animal_table = content_frame.add {type = "table", name = "s_table", column_count = 6}
+  for category in pairs(main_frame.tags.categories) do
+    for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
+      if player.force.recipes[recipe].enabled then
+        for _, animal in pairs(animals) do
+          if subgroup:match(animal, 1, true) then
+            local name = "py_slaughterhouse_animal_" .. animal
+            if not animal_table[name] then
+              animal_table.add {
+                type = "choose-elem-button",
+                name = name,
+                elem_type = "item",
+                item = get_animal_item(animal),
+                style = "image_tab_slot",
+                tags = {animal = animal},
+								locked = true
+              }
+            end
+            goto continue
+          end
+        end
+        game.print('ERROR: Recipe "' .. recipe .. '" has crafting category "' .. category .. '" but is unselectable in the GUI')
+        ::continue::
+      end
+    end
+  end
+end
+
+local function create_slaughterhouse_gui(player_index)
+	local player = game.get_player(player_index)
+	if not player then return end
+	local entity = player.opened
+	if not entity then return end
+  local name = entity.name == "entity-ghost" and entity.ghost_name or entity.name
+  if not machines_with_gui[name] or entity.get_recipe() then return end
+	local main_frame = player.gui.screen.add {
+		type = "frame",
+		name = "slaughterhouse",
+		direction = "vertical",
+		tags = {entity = entity.unit_number, categories = entity.prototype.crafting_categories, caption = {"slaughterhouse-gui." .. name}}
+	}
+	main_frame.force_auto_center()
+	player.opened = main_frame
+	local content_frame = main_frame.add {type = "frame", name = "content_frame", direction = "vertical", style = "inside_shallow_frame_with_padding"}
+	content_frame.style.vertically_stretchable = true
+	build_animal_table(content_frame, player)
+	storage.opened_slaughterhouses[entity.unit_number] = entity
+	script.register_on_object_destroyed(entity)
+	storage.watched_slaughterhouses[player_index] = nil
+	storage.watch_slaughterhouse = not not next(storage.watched_slaughterhouses)
+end
+
+py.on_event(py.events.on_gui_opened(), function(event)
+	local entity = event.entity
+	if not entity then return end
+	if not string.match(entity.name, "slaughterhouse%-") and not string.match(entity.name, "rc%-") then return end
+
+	if entity.get_recipe() then
+		storage.watched_slaughterhouses[event.player_index] = entity
+		storage.watch_slaughterhouse = true
+	else
+		create_slaughterhouse_gui(event.player_index)
+	end
+end)
+
+py.on_event(defines.events.on_gui_closed, function(event)
+	-- if not storage.watched_slaughterhouses then return end
+	local player = game.get_player(event.player_index)
+	if event.gui_type == defines.gui_type.custom then
+		local gui = player.gui.screen.slaughterhouse
+		if gui then gui.destroy() end
+	end
+	storage.watched_slaughterhouses[event.player_index] = nil
+	storage.watch_slaughterhouse = not not next(storage.watched_slaughterhouses)
+end)
+
+local function set_recipe(player, entity, recipe)
+	for item, count in pairs(entity.set_recipe(recipe)) do
+		count = count - player.insert {name = item, count = count}
+		if count > 0 then
+			player.surface.spill_item_stack {position = player.position, stack = {name = item, count = count}, enable_looted = true}
+		end
+	end
+	player.opened = entity
+end
+
+gui_events[defines.events.on_gui_click]["py_slaughterhouse_animal_.+"] = function(event)
+	local player = game.get_player(event.player_index)
+	local element = event.element
+	local content_frame = element.parent.parent
+	local main_frame = content_frame.parent
+	local animal = element.tags.animal
+	content_frame.clear()
+	main_frame.caption = {"slaughterhouse-gui.select-recipe"}
+	local recipe_flow = content_frame.add {type = "flow", direction = "horizontal"}
+	recipe_flow.add {type = "sprite-button", name = "py_slaughterhouse_back", sprite = "utility/left_arrow"}
+	local recipe_table = recipe_flow.add {type = "table", column_count = 5}
+	local recipe_count, avalible_recipe = 0, nil
+	for category in pairs(main_frame.tags.categories) do
+		for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
+			if subgroup:match(animal) and player.force.recipes[recipe].enabled then
+				recipe_count, avalible_recipe = recipe_count + 1, recipe
+				recipe_table.add {
+					type = "choose-elem-button",
+					name = "py_slaughterhouse_recipe_" .. recipe,
+					elem_type = "recipe",
+					recipe = recipe,
+					style = "slot_button",
+					tags = {recipe = recipe},
+					locked = true
+				}
+			end
+		end
+	end
+	-- for _, recipe in pairs(player.force.recipes) do
+	-- 	if main_frame.tags.categories[recipe.category] and string.match(recipe.subgroup.name, animal) and recipe.enabled then
+	-- 		recipe_count, avalible_recipe = recipe_count + 1, recipe.name
+	-- 		recipe_table.add {
+	-- 			type = "choose-elem-button",
+	-- 			name = "py_slaughterhouse_recipe_" .. recipe.name,
+	-- 			elem_type = "recipe",
+	-- 			recipe = recipe.name,
+	-- 			style = "slot_button",
+	-- 			tags = {recipe = recipe.name},
+	-- 			locked = true
+	-- 		}
+	-- 	end
+	-- end
+
+	if recipe_count == 1 then
+		local entity = storage.opened_slaughterhouses[main_frame.tags.entity]
+		if not entity or not entity.valid then return end
+		set_recipe(player, entity, avalible_recipe)
+	end
+end
+
+gui_events[defines.events.on_gui_click]["py_slaughterhouse_back"] = function(event)
+	local player = game.players[event.player_index]
+	local content_frame = event.element.parent.parent
+	build_animal_table(content_frame, player)
+end
+
+gui_events[defines.events.on_gui_click]["py_slaughterhouse_recipe_.+"] = function(event)
+	local player = game.get_player(event.player_index)
+	local element = event.element
+	local main_frame = element.parent.parent.parent.parent
+	local entity = storage.opened_slaughterhouses[main_frame.tags.entity]
+	local recipe = element.tags.recipe
+	if not entity or not entity.valid then return end
+	set_recipe(player, entity, recipe)
+end
+
+py.on_event(py.events.on_init(), function()
+	storage.watched_slaughterhouses = storage.watched_slaughterhouses or {}
+	storage.opened_slaughterhouses = storage.opened_slaughterhouses or {}
+end)
+
+py.on_event(defines.events.on_tick, function()
+	if not storage.watch_slaughterhouse then return end
+
+	for player_index, entity in pairs(storage.watched_slaughterhouses) do
+		if not entity.valid then
+			storage.watched_slaughterhouses[player_index] = nil
+			return
+		end
+
+		if not entity.get_recipe() then
+			create_slaughterhouse_gui(player_index, entity)
+		end
+	end
+end)
\ No newline at end of file

From 728774a9dfb7eb666add891fc7ddfa508fa0243b Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Sat, 17 Jan 2026 22:14:17 -0700
Subject: [PATCH 2/9] allow normal assembler GUI if circuit set recipe is
 enabled

---
 scripts/slaughterhouse/slaughterhouse.lua | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index 214058b1..e5cd3005 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -148,7 +148,10 @@ py.on_event(py.events.on_gui_opened(), function(event)
 		storage.watched_slaughterhouses[event.player_index] = entity
 		storage.watch_slaughterhouse = true
 	else
-		create_slaughterhouse_gui(event.player_index)
+		local control_behavior = entity.get_control_behavior()
+		if not control_behavior or not control_behavior.circuit_set_recipe then
+			create_slaughterhouse_gui(event.player_index)
+		end
 	end
 end)
 

From e0482be4f38b3b2345ad6ed210de22c52911393a Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Sat, 17 Jan 2026 22:20:31 -0700
Subject: [PATCH 3/9] generalize control behaviour check

---
 scripts/slaughterhouse/slaughterhouse.lua | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index e5cd3005..ef15283c 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -121,7 +121,8 @@ local function create_slaughterhouse_gui(player_index)
 	local entity = player.opened
 	if not entity then return end
   local name = entity.name == "entity-ghost" and entity.ghost_name or entity.name
-  if not machines_with_gui[name] or entity.get_recipe() then return end
+	local control_behavior = entity.get_control_behavior()
+  if not machines_with_gui[name] or entity.get_recipe() or (control_behavior and control_behavior.circuit_set_recipe) then return end
 	local main_frame = player.gui.screen.add {
 		type = "frame",
 		name = "slaughterhouse",
@@ -143,15 +144,13 @@ py.on_event(py.events.on_gui_opened(), function(event)
 	local entity = event.entity
 	if not entity then return end
 	if not string.match(entity.name, "slaughterhouse%-") and not string.match(entity.name, "rc%-") then return end
+	local control_behavior = entity.get_control_behavior()
 
-	if entity.get_recipe() then
+	if entity.get_recipe() or control_behavior and control_behavior.circuit_set_recipe then
 		storage.watched_slaughterhouses[event.player_index] = entity
 		storage.watch_slaughterhouse = true
 	else
-		local control_behavior = entity.get_control_behavior()
-		if not control_behavior or not control_behavior.circuit_set_recipe then
-			create_slaughterhouse_gui(event.player_index)
-		end
+		create_slaughterhouse_gui(event.player_index)
 	end
 end)
 

From 2817b1f8634ee6a4a1510040e1125c20f6621132 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Sat, 17 Jan 2026 22:31:50 -0700
Subject: [PATCH 4/9] formatting

---
 scripts/slaughterhouse/slaughterhouse.lua | 316 +++++++++++-----------
 1 file changed, 151 insertions(+), 165 deletions(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index ef15283c..5d19f774 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -1,49 +1,49 @@
+-- for full history reference: https://github.com/pyanodon/pyalienlife/commit/ed87228489c87e6c68993d78f09e76e21970302a
+
 local animals = {
-	"auog",
-	"ulric",
-	"mukmoux",
-	"arthurian",
-	"cottongut",
-	"dhilmos",
-	"scrondrix",
-	"phadai",
-	"fish",
-	"phagnot",
-	"kmauts",
-	"dingrits",
-	"xeno",
-	"arqad",
-	"cridren",
-	"antelope",
-	"trits",
-	"vonix",
-	"vrauks",
-	"xyhiphoe",
-	"zipir",
-	"korlex",
-	"simik",
+  "auog",
+  "ulric",
+  "mukmoux",
+  "arthurian",
+  "cottongut",
+  "dhilmos",
+  "scrondrix",
+  "phadai",
+  "fish",
+  "phagnot",
+  "kmauts",
+  "dingrits",
+  "xeno",
+  "arqad",
+  "cridren",
+  "antelope",
+  "trits",
+  "vonix",
+  "vrauks",
+  "xyhiphoe",
+  "zipir",
+  "korlex",
+  "simik",
 }
 if script.active_mods["pyalternativeenergy"] then
-	table.insert(animals, "zungror")
-	table.insert(animals, "numal")
+  table.insert(animals, "zungror")
+  table.insert(animals, "numal")
 end
 if script.active_mods["pystellarexpedition"] then
-	--table.insert(animals, 'tuls')
-	--table.insert(animals, 'riga')
-	table.insert(animals, "kakkalakki")
+  --table.insert(animals, 'tuls')
+  --table.insert(animals, 'riga')
+  table.insert(animals, "kakkalakki")
 end
 
---TODO circuit connections, parameters, quality
-
 local machines_with_gui = {
-	["slaughterhouse-mk01"] = true,
-	["slaughterhouse-mk02"] = true,
-	["slaughterhouse-mk03"] = true,
-	["slaughterhouse-mk04"] = true,
-	["rc-mk01"] = true,
-	["rc-mk02"] = true,
-	["rc-mk03"] = true,
-	["rc-mk04"] = true,
+  ["slaughterhouse-mk01"] = true,
+  ["slaughterhouse-mk02"] = true,
+  ["slaughterhouse-mk03"] = true,
+  ["slaughterhouse-mk04"] = true,
+  ["rc-mk01"] = true,
+  ["rc-mk02"] = true,
+  ["rc-mk03"] = true,
+  ["rc-mk04"] = true,
 }
 
 -- cache crafting categories
@@ -64,14 +64,14 @@ for category in pairs(permitted_recipes) do
 end
 
 py.on_event(defines.events.on_object_destroyed, function(event)
-	local unit_number = event.useful_id
-	if not unit_number or not storage.opened_slaughterhouses[unit_number] then return end
+  local unit_number = event.useful_id
+  if not unit_number or not storage.opened_slaughterhouses[unit_number] then return end
 
-	storage.opened_slaughterhouses[unit_number] = nil
-	for _, player in pairs(game.players) do
-		local gui = player.gui.screen.slaughterhouse
-		if gui and gui.tags.entity == unit_number then gui.destroy() end
-	end
+  storage.opened_slaughterhouses[unit_number] = nil
+  for _, player in pairs(game.players) do
+    local gui = player.gui.screen.slaughterhouse
+    if gui and gui.tags.entity == unit_number then gui.destroy() end
+  end
 end)
 
 local alt_animals = {
@@ -80,14 +80,14 @@ local alt_animals = {
 }
 
 local function get_animal_item(animal)
-	return alt_animals[animal] or animal
+  return alt_animals[animal] or animal
 end
 
 local function build_animal_table(content_frame, player)
-	content_frame.clear()
-	local main_frame = content_frame.parent
-	main_frame.caption = main_frame.tags.caption
-	local animal_table = content_frame.add {type = "table", name = "s_table", column_count = 6}
+  content_frame.clear()
+  local main_frame = content_frame.parent
+  main_frame.caption = main_frame.tags.caption
+  local animal_table = content_frame.add {type = "table", name = "s_table", column_count = 6}
   for category in pairs(main_frame.tags.categories) do
     for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
       if player.force.recipes[recipe].enabled then
@@ -102,7 +102,7 @@ local function build_animal_table(content_frame, player)
                 item = get_animal_item(animal),
                 style = "image_tab_slot",
                 tags = {animal = animal},
-								locked = true
+                locked = true
               }
             end
             goto continue
@@ -116,147 +116,133 @@ local function build_animal_table(content_frame, player)
 end
 
 local function create_slaughterhouse_gui(player_index)
-	local player = game.get_player(player_index)
-	if not player then return end
-	local entity = player.opened
-	if not entity then return end
+  local player = game.get_player(player_index)
+  if not player then return end
+  local entity = player.opened
+  if not entity then return end
   local name = entity.name == "entity-ghost" and entity.ghost_name or entity.name
-	local control_behavior = entity.get_control_behavior()
+  local control_behavior = entity.get_control_behavior()
   if not machines_with_gui[name] or entity.get_recipe() or (control_behavior and control_behavior.circuit_set_recipe) then return end
-	local main_frame = player.gui.screen.add {
-		type = "frame",
-		name = "slaughterhouse",
-		direction = "vertical",
-		tags = {entity = entity.unit_number, categories = entity.prototype.crafting_categories, caption = {"slaughterhouse-gui." .. name}}
-	}
-	main_frame.force_auto_center()
-	player.opened = main_frame
-	local content_frame = main_frame.add {type = "frame", name = "content_frame", direction = "vertical", style = "inside_shallow_frame_with_padding"}
-	content_frame.style.vertically_stretchable = true
-	build_animal_table(content_frame, player)
-	storage.opened_slaughterhouses[entity.unit_number] = entity
-	script.register_on_object_destroyed(entity)
-	storage.watched_slaughterhouses[player_index] = nil
-	storage.watch_slaughterhouse = not not next(storage.watched_slaughterhouses)
+  local main_frame = player.gui.screen.add {
+    type = "frame",
+    name = "slaughterhouse",
+    direction = "vertical",
+    tags = {entity = entity.unit_number, categories = entity.prototype.crafting_categories, caption = {"slaughterhouse-gui." .. name}}
+  }
+  main_frame.force_auto_center()
+  player.opened = main_frame
+  local content_frame = main_frame.add {type = "frame", name = "content_frame", direction = "vertical", style = "inside_shallow_frame_with_padding"}
+  content_frame.style.vertically_stretchable = true
+  build_animal_table(content_frame, player)
+  storage.opened_slaughterhouses[entity.unit_number] = entity
+  script.register_on_object_destroyed(entity)
+  storage.watched_slaughterhouses[player_index] = nil
+  storage.watch_slaughterhouse = not not next(storage.watched_slaughterhouses)
 end
 
 py.on_event(py.events.on_gui_opened(), function(event)
-	local entity = event.entity
-	if not entity then return end
-	if not string.match(entity.name, "slaughterhouse%-") and not string.match(entity.name, "rc%-") then return end
-	local control_behavior = entity.get_control_behavior()
-
-	if entity.get_recipe() or control_behavior and control_behavior.circuit_set_recipe then
-		storage.watched_slaughterhouses[event.player_index] = entity
-		storage.watch_slaughterhouse = true
-	else
-		create_slaughterhouse_gui(event.player_index)
-	end
+  local entity = event.entity
+  if not entity then return end
+  if not string.match(entity.name, "slaughterhouse%-") and not string.match(entity.name, "rc%-") then return end
+  local control_behavior = entity.get_control_behavior()
+
+  if entity.get_recipe() or control_behavior and control_behavior.circuit_set_recipe then
+    storage.watched_slaughterhouses[event.player_index] = entity
+    storage.watch_slaughterhouse = true
+  else
+    create_slaughterhouse_gui(event.player_index)
+  end
 end)
 
 py.on_event(defines.events.on_gui_closed, function(event)
-	-- if not storage.watched_slaughterhouses then return end
-	local player = game.get_player(event.player_index)
-	if event.gui_type == defines.gui_type.custom then
-		local gui = player.gui.screen.slaughterhouse
-		if gui then gui.destroy() end
-	end
-	storage.watched_slaughterhouses[event.player_index] = nil
-	storage.watch_slaughterhouse = not not next(storage.watched_slaughterhouses)
+  -- if not storage.watched_slaughterhouses then return end
+  local player = game.get_player(event.player_index)
+  if event.gui_type == defines.gui_type.custom then
+    local gui = player.gui.screen.slaughterhouse
+    if gui then gui.destroy() end
+  end
+  storage.watched_slaughterhouses[event.player_index] = nil
+  storage.watch_slaughterhouse = not not next(storage.watched_slaughterhouses)
 end)
 
 local function set_recipe(player, entity, recipe)
-	for item, count in pairs(entity.set_recipe(recipe)) do
-		count = count - player.insert {name = item, count = count}
-		if count > 0 then
-			player.surface.spill_item_stack {position = player.position, stack = {name = item, count = count}, enable_looted = true}
-		end
-	end
-	player.opened = entity
+  for item, count in pairs(entity.set_recipe(recipe)) do
+    count = count - player.insert {name = item, count = count}
+    if count > 0 then
+      player.surface.spill_item_stack {position = player.position, stack = {name = item, count = count}, enable_looted = true}
+    end
+  end
+  player.opened = entity
 end
 
 gui_events[defines.events.on_gui_click]["py_slaughterhouse_animal_.+"] = function(event)
-	local player = game.get_player(event.player_index)
-	local element = event.element
-	local content_frame = element.parent.parent
-	local main_frame = content_frame.parent
-	local animal = element.tags.animal
-	content_frame.clear()
-	main_frame.caption = {"slaughterhouse-gui.select-recipe"}
-	local recipe_flow = content_frame.add {type = "flow", direction = "horizontal"}
-	recipe_flow.add {type = "sprite-button", name = "py_slaughterhouse_back", sprite = "utility/left_arrow"}
-	local recipe_table = recipe_flow.add {type = "table", column_count = 5}
-	local recipe_count, avalible_recipe = 0, nil
-	for category in pairs(main_frame.tags.categories) do
-		for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
-			if subgroup:match(animal) and player.force.recipes[recipe].enabled then
-				recipe_count, avalible_recipe = recipe_count + 1, recipe
-				recipe_table.add {
-					type = "choose-elem-button",
-					name = "py_slaughterhouse_recipe_" .. recipe,
-					elem_type = "recipe",
-					recipe = recipe,
-					style = "slot_button",
-					tags = {recipe = recipe},
-					locked = true
-				}
-			end
-		end
-	end
-	-- for _, recipe in pairs(player.force.recipes) do
-	-- 	if main_frame.tags.categories[recipe.category] and string.match(recipe.subgroup.name, animal) and recipe.enabled then
-	-- 		recipe_count, avalible_recipe = recipe_count + 1, recipe.name
-	-- 		recipe_table.add {
-	-- 			type = "choose-elem-button",
-	-- 			name = "py_slaughterhouse_recipe_" .. recipe.name,
-	-- 			elem_type = "recipe",
-	-- 			recipe = recipe.name,
-	-- 			style = "slot_button",
-	-- 			tags = {recipe = recipe.name},
-	-- 			locked = true
-	-- 		}
-	-- 	end
-	-- end
+  local player = game.get_player(event.player_index)
+  local element = event.element
+  local content_frame = element.parent.parent
+  local main_frame = content_frame.parent
+  local animal = element.tags.animal
+  content_frame.clear()
+  main_frame.caption = {"slaughterhouse-gui.select-recipe"}
+  local recipe_flow = content_frame.add {type = "flow", direction = "horizontal"}
+  recipe_flow.add {type = "sprite-button", name = "py_slaughterhouse_back", sprite = "utility/left_arrow"}
+  local recipe_table = recipe_flow.add {type = "table", column_count = 5}
+  local recipe_count, avalible_recipe = 0, nil
+  for category in pairs(main_frame.tags.categories) do
+    for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
+      if subgroup:match(animal) and player.force.recipes[recipe].enabled then
+        recipe_count, avalible_recipe = recipe_count + 1, recipe
+        recipe_table.add {
+          type = "choose-elem-button",
+          name = "py_slaughterhouse_recipe_" .. recipe,
+          elem_type = "recipe",
+          recipe = recipe,
+          style = "slot_button",
+          tags = {recipe = recipe},
+          locked = true
+        }
+      end
+    end
+  end
 
-	if recipe_count == 1 then
-		local entity = storage.opened_slaughterhouses[main_frame.tags.entity]
-		if not entity or not entity.valid then return end
-		set_recipe(player, entity, avalible_recipe)
-	end
+  if recipe_count == 1 then
+    local entity = storage.opened_slaughterhouses[main_frame.tags.entity]
+    if not entity or not entity.valid then return end
+    set_recipe(player, entity, avalible_recipe)
+  end
 end
 
 gui_events[defines.events.on_gui_click]["py_slaughterhouse_back"] = function(event)
-	local player = game.players[event.player_index]
-	local content_frame = event.element.parent.parent
-	build_animal_table(content_frame, player)
+  local player = game.players[event.player_index]
+  local content_frame = event.element.parent.parent
+  build_animal_table(content_frame, player)
 end
 
 gui_events[defines.events.on_gui_click]["py_slaughterhouse_recipe_.+"] = function(event)
-	local player = game.get_player(event.player_index)
-	local element = event.element
-	local main_frame = element.parent.parent.parent.parent
-	local entity = storage.opened_slaughterhouses[main_frame.tags.entity]
-	local recipe = element.tags.recipe
-	if not entity or not entity.valid then return end
-	set_recipe(player, entity, recipe)
+  local player = game.get_player(event.player_index)
+  local element = event.element
+  local main_frame = element.parent.parent.parent.parent
+  local entity = storage.opened_slaughterhouses[main_frame.tags.entity]
+  local recipe = element.tags.recipe
+  if not entity or not entity.valid then return end
+  set_recipe(player, entity, recipe)
 end
 
 py.on_event(py.events.on_init(), function()
-	storage.watched_slaughterhouses = storage.watched_slaughterhouses or {}
-	storage.opened_slaughterhouses = storage.opened_slaughterhouses or {}
+  storage.watched_slaughterhouses = storage.watched_slaughterhouses or {}
+  storage.opened_slaughterhouses = storage.opened_slaughterhouses or {}
 end)
 
 py.on_event(defines.events.on_tick, function()
-	if not storage.watch_slaughterhouse then return end
+  if not storage.watch_slaughterhouse then return end
 
-	for player_index, entity in pairs(storage.watched_slaughterhouses) do
-		if not entity.valid then
-			storage.watched_slaughterhouses[player_index] = nil
-			return
-		end
+  for player_index, entity in pairs(storage.watched_slaughterhouses) do
+    if not entity.valid then
+      storage.watched_slaughterhouses[player_index] = nil
+      return
+    end
 
-		if not entity.get_recipe() then
-			create_slaughterhouse_gui(player_index, entity)
-		end
-	end
+    if not entity.get_recipe() then
+      create_slaughterhouse_gui(player_index, entity)
+    end
+  end
 end)
\ No newline at end of file

From 6d77c7f71f248def6cfe75ceccbde4e4ace83652 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Sat, 17 Jan 2026 22:42:24 -0700
Subject: [PATCH 5/9] cache animal instead of subgroup

---
 scripts/slaughterhouse/slaughterhouse.lua | 47 +++++++++++------------
 1 file changed, 23 insertions(+), 24 deletions(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index 5d19f774..acd43830 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -59,7 +59,15 @@ permitted_recipes.parameters = nil
 -- cache permitted recipes
 for category in pairs(permitted_recipes) do
   for r, recipe in pairs(prototypes.get_recipe_filtered{{filter = "category", category = category}}) do
-    permitted_recipes[category][r] = recipe.subgroup.name
+		for _, animal in pairs(animals) do
+			if recipe.subgroup.name:match(animal) then
+				permitted_recipes[category][r] = animal
+				break
+			end
+		end
+		if not permitted_recipes[category][r] then
+			error("Could not find associated animal for recipe: " .. r)
+		end
   end
 end
 
@@ -89,27 +97,18 @@ local function build_animal_table(content_frame, player)
   main_frame.caption = main_frame.tags.caption
   local animal_table = content_frame.add {type = "table", name = "s_table", column_count = 6}
   for category in pairs(main_frame.tags.categories) do
-    for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
-      if player.force.recipes[recipe].enabled then
-        for _, animal in pairs(animals) do
-          if subgroup:match(animal, 1, true) then
-            local name = "py_slaughterhouse_animal_" .. animal
-            if not animal_table[name] then
-              animal_table.add {
-                type = "choose-elem-button",
-                name = name,
-                elem_type = "item",
-                item = get_animal_item(animal),
-                style = "image_tab_slot",
-                tags = {animal = animal},
-                locked = true
-              }
-            end
-            goto continue
-          end
-        end
-        game.print('ERROR: Recipe "' .. recipe .. '" has crafting category "' .. category .. '" but is unselectable in the GUI')
-        ::continue::
+    for recipe, animal in pairs(permitted_recipes[category] or {}) do
+			local name = "py_slaughterhouse_animal_" .. animal
+      if not animal_table[name] and player.force.recipes[recipe].enabled then
+				animal_table.add {
+					type = "choose-elem-button",
+					name = name,
+					elem_type = "item",
+					item = get_animal_item(animal),
+					style = "image_tab_slot",
+					tags = {animal = animal},
+					locked = true
+				}
       end
     end
   end
@@ -188,8 +187,8 @@ gui_events[defines.events.on_gui_click]["py_slaughterhouse_animal_.+"] = functio
   local recipe_table = recipe_flow.add {type = "table", column_count = 5}
   local recipe_count, avalible_recipe = 0, nil
   for category in pairs(main_frame.tags.categories) do
-    for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
-      if subgroup:match(animal) and player.force.recipes[recipe].enabled then
+    for recipe, recipe_animal in pairs(permitted_recipes[category] or {}) do
+      if recipe_animal == animal and player.force.recipes[recipe].enabled then
         recipe_count, avalible_recipe = recipe_count + 1, recipe
         recipe_table.add {
           type = "choose-elem-button",

From 00654b90a983f0af0cc5c28b00b1f3d601d398f6 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Mon, 19 Jan 2026 18:42:30 -0700
Subject: [PATCH 6/9] remove logging, remove string.match uses, generalize
 naming such that it's easier to read out of context

---
 scripts/slaughterhouse/slaughterhouse.lua | 75 ++++++++++++-----------
 1 file changed, 38 insertions(+), 37 deletions(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index acd43830..427f8428 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -1,6 +1,6 @@
 -- for full history reference: https://github.com/pyanodon/pyalienlife/commit/ed87228489c87e6c68993d78f09e76e21970302a
 
-local animals = {
+local subgroups = {
   "auog",
   "ulric",
   "mukmoux",
@@ -26,13 +26,13 @@ local animals = {
   "simik",
 }
 if script.active_mods["pyalternativeenergy"] then
-  table.insert(animals, "zungror")
-  table.insert(animals, "numal")
+  subgroups[#subgroups+1] = "zungror"
+  subgroups[#subgroups+1] = "numal"
 end
 if script.active_mods["pystellarexpedition"] then
-  --table.insert(animals, 'tuls')
-  --table.insert(animals, 'riga')
-  table.insert(animals, "kakkalakki")
+  -- subgroups[#subgroups+1] = "tuls"
+  -- subgroups[#subgroups+1] = "riga"
+  subgroups[#subgroups+1] = "kakkalakki"
 end
 
 local machines_with_gui = {
@@ -59,14 +59,14 @@ permitted_recipes.parameters = nil
 -- cache permitted recipes
 for category in pairs(permitted_recipes) do
   for r, recipe in pairs(prototypes.get_recipe_filtered{{filter = "category", category = category}}) do
-		for _, animal in pairs(animals) do
-			if recipe.subgroup.name:match(animal) then
-				permitted_recipes[category][r] = animal
+		for _, subgroup in pairs(subgroups) do
+			if recipe.subgroup.name:match(subgroup) then
+				permitted_recipes[category][r] = subgroup
 				break
 			end
 		end
 		if not permitted_recipes[category][r] then
-			error("Could not find associated animal for recipe: " .. r)
+			error("Could not find associated subgroup for recipe: " .. r)
 		end
   end
 end
@@ -82,31 +82,31 @@ py.on_event(defines.events.on_object_destroyed, function(event)
   end
 end)
 
-local alt_animals = {
+local alt_items = {
   zipir = "zipir1",
   kakkalakki = "kakkalakki-f"
 }
 
-local function get_animal_item(animal)
-  return alt_animals[animal] or animal
+local function get_item_from_subgroup(subgroup)
+  return alt_items[subgroup] or subgroup
 end
 
-local function build_animal_table(content_frame, player)
+local function build_subgroup_table(content_frame, player)
   content_frame.clear()
   local main_frame = content_frame.parent
   main_frame.caption = main_frame.tags.caption
-  local animal_table = content_frame.add {type = "table", name = "s_table", column_count = 6}
+  local subgroup_table = content_frame.add {type = "table", name = "s_table", column_count = 6}
   for category in pairs(main_frame.tags.categories) do
-    for recipe, animal in pairs(permitted_recipes[category] or {}) do
-			local name = "py_slaughterhouse_animal_" .. animal
-      if not animal_table[name] and player.force.recipes[recipe].enabled then
-				animal_table.add {
+    for recipe, subgroup in pairs(permitted_recipes[category] or {}) do
+			local name = "py_recipe_gui_subgroup_" .. subgroup
+      if not subgroup_table[name] and player.force.recipes[recipe].enabled then
+				subgroup_table.add {
 					type = "choose-elem-button",
 					name = name,
 					elem_type = "item",
-					item = get_animal_item(animal),
+					item = get_item_from_subgroup(subgroup),
 					style = "image_tab_slot",
-					tags = {animal = animal},
+					tags = {subgroup = subgroup},
 					locked = true
 				}
       end
@@ -114,7 +114,7 @@ local function build_animal_table(content_frame, player)
   end
 end
 
-local function create_slaughterhouse_gui(player_index)
+local function create_gui(player_index)
   local player = game.get_player(player_index)
   if not player then return end
   local entity = player.opened
@@ -126,13 +126,13 @@ local function create_slaughterhouse_gui(player_index)
     type = "frame",
     name = "slaughterhouse",
     direction = "vertical",
-    tags = {entity = entity.unit_number, categories = entity.prototype.crafting_categories, caption = {"slaughterhouse-gui." .. name}}
+    tags = {entity = entity.unit_number, categories = entity.prototype.crafting_categories, caption = {"py-recipe-gui." .. name}}
   }
   main_frame.force_auto_center()
   player.opened = main_frame
   local content_frame = main_frame.add {type = "frame", name = "content_frame", direction = "vertical", style = "inside_shallow_frame_with_padding"}
   content_frame.style.vertically_stretchable = true
-  build_animal_table(content_frame, player)
+  build_subgroup_table(content_frame, player)
   storage.opened_slaughterhouses[entity.unit_number] = entity
   script.register_on_object_destroyed(entity)
   storage.watched_slaughterhouses[player_index] = nil
@@ -142,14 +142,15 @@ end
 py.on_event(py.events.on_gui_opened(), function(event)
   local entity = event.entity
   if not entity then return end
-  if not string.match(entity.name, "slaughterhouse%-") and not string.match(entity.name, "rc%-") then return end
+  local name = entity.name == "entity-ghost" and entity.ghost_name or entity.name
+  if not machines_with_gui[name] then return end
   local control_behavior = entity.get_control_behavior()
 
   if entity.get_recipe() or control_behavior and control_behavior.circuit_set_recipe then
     storage.watched_slaughterhouses[event.player_index] = entity
     storage.watch_slaughterhouse = true
   else
-    create_slaughterhouse_gui(event.player_index)
+    create_gui(event.player_index)
   end
 end)
 
@@ -174,25 +175,25 @@ local function set_recipe(player, entity, recipe)
   player.opened = entity
 end
 
-gui_events[defines.events.on_gui_click]["py_slaughterhouse_animal_.+"] = function(event)
+gui_events[defines.events.on_gui_click]["py_recipe_gui_subgroup_.+"] = function(event)
   local player = game.get_player(event.player_index)
   local element = event.element
   local content_frame = element.parent.parent
   local main_frame = content_frame.parent
-  local animal = element.tags.animal
+  local subgroup = element.tags.subgroup
   content_frame.clear()
-  main_frame.caption = {"slaughterhouse-gui.select-recipe"}
+  main_frame.caption = {"py-recipe-gui.select-recipe"}
   local recipe_flow = content_frame.add {type = "flow", direction = "horizontal"}
-  recipe_flow.add {type = "sprite-button", name = "py_slaughterhouse_back", sprite = "utility/left_arrow"}
+  recipe_flow.add {type = "sprite-button", name = "py_recipe_gui_back", sprite = "utility/left_arrow"}
   local recipe_table = recipe_flow.add {type = "table", column_count = 5}
   local recipe_count, avalible_recipe = 0, nil
   for category in pairs(main_frame.tags.categories) do
-    for recipe, recipe_animal in pairs(permitted_recipes[category] or {}) do
-      if recipe_animal == animal and player.force.recipes[recipe].enabled then
+    for recipe, recipe_subgroup in pairs(permitted_recipes[category] or {}) do
+      if recipe_subgroup == subgroup and player.force.recipes[recipe].enabled then
         recipe_count, avalible_recipe = recipe_count + 1, recipe
         recipe_table.add {
           type = "choose-elem-button",
-          name = "py_slaughterhouse_recipe_" .. recipe,
+          name = "py_recipe_gui_recipe_" .. recipe,
           elem_type = "recipe",
           recipe = recipe,
           style = "slot_button",
@@ -210,13 +211,13 @@ gui_events[defines.events.on_gui_click]["py_slaughterhouse_animal_.+"] = functio
   end
 end
 
-gui_events[defines.events.on_gui_click]["py_slaughterhouse_back"] = function(event)
+gui_events[defines.events.on_gui_click]["py_recipe_gui_back"] = function(event)
   local player = game.players[event.player_index]
   local content_frame = event.element.parent.parent
-  build_animal_table(content_frame, player)
+  build_subgroup_table(content_frame, player)
 end
 
-gui_events[defines.events.on_gui_click]["py_slaughterhouse_recipe_.+"] = function(event)
+gui_events[defines.events.on_gui_click]["py_recipe_gui_recipe_.+"] = function(event)
   local player = game.get_player(event.player_index)
   local element = event.element
   local main_frame = element.parent.parent.parent.parent
@@ -241,7 +242,7 @@ py.on_event(defines.events.on_tick, function()
     end
 
     if not entity.get_recipe() then
-      create_slaughterhouse_gui(player_index, entity)
+      create_gui(player_index, entity)
     end
   end
 end)
\ No newline at end of file

From 17cbf09aaf3676bac253a382b8a1d2bb93b38827 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Mon, 19 Jan 2026 18:55:26 -0700
Subject: [PATCH 7/9] fix locale references

---
 locale/de/extras.cfg         | 2 +-
 locale/en/extras.cfg         | 2 +-
 locale/es-ES/extras.cfg      | 2 +-
 locale/nl/extras.cfg         | 2 +-
 locale/pl/extras.cfg         | 2 +-
 locale/ru/extras.cfg         | 2 +-
 locale/uk/extras.cfg         | 2 +-
 locale/zh-CN/pyalienlife.cfg | 2 +-
 8 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/locale/de/extras.cfg b/locale/de/extras.cfg
index e83d7a75..a916e5e0 100644
--- a/locale/de/extras.cfg
+++ b/locale/de/extras.cfg
@@ -2,7 +2,7 @@
 
 [gui-game-finished]
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Wähle das nächste Opfer
 slaughterhouse-mk02=Wähle das nächste Opfer
 slaughterhouse-mk03=Wähle das nächste Opfer
diff --git a/locale/en/extras.cfg b/locale/en/extras.cfg
index 5680c065..b1827708 100644
--- a/locale/en/extras.cfg
+++ b/locale/en/extras.cfg
@@ -1,6 +1,6 @@
 [gui-game-finished]
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Choose your next victim
 slaughterhouse-mk02=Choose your next victim
 slaughterhouse-mk03=Choose your next victim
diff --git a/locale/es-ES/extras.cfg b/locale/es-ES/extras.cfg
index 0684e808..0e9fc0e3 100644
--- a/locale/es-ES/extras.cfg
+++ b/locale/es-ES/extras.cfg
@@ -1,6 +1,6 @@
 [gui-game-finished]
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Elige a tu próxima víctima
 slaughterhouse-mk02=Elige a tu próxima víctima
 slaughterhouse-mk03=Elige a tu próxima víctima
diff --git a/locale/nl/extras.cfg b/locale/nl/extras.cfg
index bc00f115..7faa9b4c 100644
--- a/locale/nl/extras.cfg
+++ b/locale/nl/extras.cfg
@@ -1,6 +1,6 @@
 [gui-game-finished]
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Kies je volgende slachtoffer
 slaughterhouse-mk02=Kies je volgende slachtoffer
 slaughterhouse-mk03=Kies je volgende slachtoffer
diff --git a/locale/pl/extras.cfg b/locale/pl/extras.cfg
index 4c611a64..8bbfc532 100644
--- a/locale/pl/extras.cfg
+++ b/locale/pl/extras.cfg
@@ -1,6 +1,6 @@
 [gui-game-finished]
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Wybierz swoją następną ofiarę
 slaughterhouse-mk02=Wybierz swoją następną ofiarę
 slaughterhouse-mk03=Wybierz swoją następną ofiarę
diff --git a/locale/ru/extras.cfg b/locale/ru/extras.cfg
index ab6927a6..900eb714 100644
--- a/locale/ru/extras.cfg
+++ b/locale/ru/extras.cfg
@@ -1,4 +1,4 @@
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Выберите следующую жертву
 slaughterhouse-mk02=Выберите следующую жертву
 slaughterhouse-mk03=Выберите следующую жертву
diff --git a/locale/uk/extras.cfg b/locale/uk/extras.cfg
index e65e7d54..1f6959a4 100644
--- a/locale/uk/extras.cfg
+++ b/locale/uk/extras.cfg
@@ -1,6 +1,6 @@
 [gui-game-finished]
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=Виберіть наступну жертву
 slaughterhouse-mk02=Виберіть наступну жертву
 slaughterhouse-mk03=Виберіть наступну жертву
diff --git a/locale/zh-CN/pyalienlife.cfg b/locale/zh-CN/pyalienlife.cfg
index 5ac997e7..b33bff7f 100644
--- a/locale/zh-CN/pyalienlife.cfg
+++ b/locale/zh-CN/pyalienlife.cfg
@@ -161,7 +161,7 @@ requestor_info=需求箱信息
 provider=供应箱
 provider_info=供应箱信息
 
-[slaughterhouse-gui]
+[py-recipe-gui]
 slaughterhouse-mk01=有请下一位受害者
 slaughterhouse-mk02=有请下一位受害者
 slaughterhouse-mk03=有请下一位受害者

From fd5ecfd5df06db05e630a6ca89c6fcce03955f68 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Mon, 19 Jan 2026 19:00:42 -0700
Subject: [PATCH 8/9] ghost support

---
 scripts/slaughterhouse/slaughterhouse.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index 427f8428..785da4b1 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -126,7 +126,7 @@ local function create_gui(player_index)
     type = "frame",
     name = "slaughterhouse",
     direction = "vertical",
-    tags = {entity = entity.unit_number, categories = entity.prototype.crafting_categories, caption = {"py-recipe-gui." .. name}}
+    tags = {entity = entity.unit_number, categories = (entity.name == "entity-ghost" and entity.ghost_prototype or entity.prototype).crafting_categories, caption = {"py-recipe-gui." .. name}}
   }
   main_frame.force_auto_center()
   player.opened = main_frame

From 3880a82a53e740f73e8a6260609ec0a16ae3ab65 Mon Sep 17 00:00:00 2001
From: protocol_1903 <67478786+protocol-1903@users.noreply.github.com>
Date: Mon, 19 Jan 2026 20:11:34 -0700
Subject: [PATCH 9/9] remote interface

---
 scripts/slaughterhouse/slaughterhouse.lua | 83 +++++++++++++++++------
 1 file changed, 63 insertions(+), 20 deletions(-)

diff --git a/scripts/slaughterhouse/slaughterhouse.lua b/scripts/slaughterhouse/slaughterhouse.lua
index 785da4b1..63ffdb00 100644
--- a/scripts/slaughterhouse/slaughterhouse.lua
+++ b/scripts/slaughterhouse/slaughterhouse.lua
@@ -46,30 +46,78 @@ local machines_with_gui = {
   ["rc-mk04"] = true,
 }
 
--- cache crafting categories
+local alt_items = {
+  zipir = "zipir1",
+  kakkalakki = "kakkalakki-f"
+}
+
 local permitted_recipes = {}
+
+local function update_recipes()
+  for category in pairs(permitted_recipes) do
+    for r, recipe in pairs(prototypes.get_recipe_filtered{{filter = "category", category = category}}) do
+      for _, subgroup in pairs(subgroups) do
+        if recipe.subgroup.name:match(subgroup) then
+          permitted_recipes[category][r] = subgroup
+          break
+        end
+      end
+      if not permitted_recipes[category][r] then
+        error("Could not find associated subgroup for recipe: " .. r)
+      end
+    end
+  end
+end
+
+remote.add_interface("py-recipe-gui", {
+  ---add a machine to use the custom recipe viewer. requires subgroups to be registered
+  ---@param machine data.EntityID
+  add_machine = function (machine)
+    local update = not machines_with_gui
+    machines_with_gui[machine] = true
+    for category in pairs(update and prototypes.entity[machine].crafting_categories or {}) do
+      permitted_recipes[category] = {}
+    end
+    permitted_recipes.parameters = nil
+  end,
+  ---remove a machine from the whitelist for the custom recipe viewer
+  ---@param machine data.EntityID
+  remove_machine = function (machine)
+    machines_with_gui[machine] = nil
+  end,
+  ---add a subgroup to use the custom recipe viewer. requires a compatible crafting machine
+  ---@param subgroup data.EntityID
+  add_subgroup = function (subgroup)
+    local update = not subgroups[subgroup]
+    subgroups[subgroup] = true
+    if update then update_recipes() end
+  end,
+  ---add a subgroup to use the custom recipe viewer
+  ---@param subgroup data.EntityID
+  remove_subgroup = function (subgroup)
+    subgroups[subgroup] = nil
+  end,
+  ---use an alternative item for the subgroup header icon. set to nil to remove
+  ---@param subgroup data.ItemSubGroupID
+  ---@param item data.ItemID
+  set_alt_item = function (subgroup, item)
+    alt_items[subgroup] = item
+  end,
+})
+
+-- TODO have AE/SE use remote interface
+
+-- cache crafting categories
 for machine in pairs(machines_with_gui) do
   for category in pairs(prototypes.entity[machine].crafting_categories) do
     permitted_recipes[category] = {}
   end
 end
+
 -- ignore parameters
 permitted_recipes.parameters = nil
 
--- cache permitted recipes
-for category in pairs(permitted_recipes) do
-  for r, recipe in pairs(prototypes.get_recipe_filtered{{filter = "category", category = category}}) do
-		for _, subgroup in pairs(subgroups) do
-			if recipe.subgroup.name:match(subgroup) then
-				permitted_recipes[category][r] = subgroup
-				break
-			end
-		end
-		if not permitted_recipes[category][r] then
-			error("Could not find associated subgroup for recipe: " .. r)
-		end
-  end
-end
+update_recipes()
 
 py.on_event(defines.events.on_object_destroyed, function(event)
   local unit_number = event.useful_id
@@ -82,11 +130,6 @@ py.on_event(defines.events.on_object_destroyed, function(event)
   end
 end)
 
-local alt_items = {
-  zipir = "zipir1",
-  kakkalakki = "kakkalakki-f"
-}
-
 local function get_item_from_subgroup(subgroup)
   return alt_items[subgroup] or subgroup
 end