diff --git a/src/gui/game/GameController.cpp b/src/gui/game/GameController.cpp
index f9613b00c..e095c6547 100644
--- a/src/gui/game/GameController.cpp
+++ b/src/gui/game/GameController.cpp
@@ -1729,3 +1729,11 @@ bool GameController::ThreadedRenderingAllowed()
 {
 	return gameModel->GetThreadedRendering() && !commandInterface->HaveSimGraphicsEventHandlers();
 }
+
+void GameController::SetToolIndex(ByteString identifier, std::optional<int> index)
+{
+	if (commandInterface)
+	{
+		commandInterface->SetToolIndex(identifier, index);
+	}
+}
diff --git a/src/gui/game/GameController.h b/src/gui/game/GameController.h
index b3f0ded37..b17b433f8 100644
--- a/src/gui/game/GameController.h
+++ b/src/gui/game/GameController.h
@@ -206,4 +206,6 @@ public:
 	void BeforeSimDraw();
 	void AfterSimDraw();
 	bool ThreadedRenderingAllowed();
+
+	void SetToolIndex(ByteString identifier, std::optional<int> index);
 };
diff --git a/src/gui/game/GameModel.cpp b/src/gui/game/GameModel.cpp
index 79a63c152..43c7e3bfb 100644
--- a/src/gui/game/GameModel.cpp
+++ b/src/gui/game/GameModel.cpp
@@ -598,6 +598,14 @@ Brush *GameModel::GetBrushByID(int i)
 		return nullptr;
 }
 
+int GameModel::GetBrushIndex(const Brush &brush)
+{
+	auto it = std::find_if(brushList.begin(), brushList.end(), [&brush](auto &ptr) {
+		return ptr.get() == &brush;
+	});
+	return int(it - brushList.begin());
+}
+
 int GameModel::GetBrushID()
 {
 	return currentBrush;
@@ -1647,6 +1655,7 @@ void GameModel::AllocTool(std::unique_ptr<Tool> tool)
 		index = int(tools.size());
 		tools.emplace_back();
 	}
+	GameController::Ref().SetToolIndex(tool->Identifier, *index);
 	tools[*index] = std::move(tool);
 }
 
@@ -1659,6 +1668,7 @@ void GameModel::FreeTool(Tool *tool)
 	}
 	auto &ptr = tools[*index];
 	DeselectTool(ptr->Identifier);
+	GameController::Ref().SetToolIndex(ptr->Identifier, std::nullopt);
 	ptr.reset();
 }
 
diff --git a/src/gui/game/GameModel.h b/src/gui/game/GameModel.h
index 068ee5da7..23abf8b0b 100644
--- a/src/gui/game/GameModel.h
+++ b/src/gui/game/GameModel.h
@@ -213,6 +213,7 @@ public:
 	Brush &GetBrush();
 	Brush *GetBrushByID(int i);
 	int GetBrushID();
+	int GetBrushIndex(const Brush &brush);
 	int BrushListSize() const
 	{
 		return int(brushList.size());
diff --git a/src/lua/CommandInterface.h b/src/lua/CommandInterface.h
index 0afa3ad50..1e098ee22 100644
--- a/src/lua/CommandInterface.h
+++ b/src/lua/CommandInterface.h
@@ -5,6 +5,7 @@
 #include "gui/game/GameControllerEvents.h"
 #include "TPTSTypes.h"
 #include <deque>
+#include <optional>
 
 class GameModel;
 class GameController;
@@ -55,5 +56,7 @@ public:
 	AnyType tptS_quit(std::deque<String> * words);
 	ValueType testType(String word);
 
+	void SetToolIndex(ByteString identifier, std::optional<int> index);
+
 	static CommandInterfacePtr Create(GameController *newGameController, GameModel *newGameModel);
 };
diff --git a/src/lua/LuaScriptInterface.cpp b/src/lua/LuaScriptInterface.cpp
index 37ae26776..22b6b4e0c 100644
--- a/src/lua/LuaScriptInterface.cpp
+++ b/src/lua/LuaScriptInterface.cpp
@@ -155,6 +155,7 @@ LuaScriptInterface::LuaScriptInterface(GameController *newGameController, GameMo
 	LuaRenderer::Open(L);
 	LuaSimulation::Open(L);
 	LuaSocket::Open(L);
+	LuaTools::Open(L);
 	{
 		lua_getglobal(L, "os");
 		lua_pushcfunction(L, osExit);
@@ -210,6 +211,12 @@ void CommandInterface::Init()
 	}
 }
 
+void CommandInterface::SetToolIndex(ByteString identifier, std::optional<int> index)
+{
+	auto *lsi = static_cast<LuaScriptInterface *>(this);
+	LuaTools::SetToolIndex(lsi->L, identifier, index);
+}
+
 void LuaGetProperty(lua_State *L, StructProperty property, intptr_t propertyAddress)
 {
 	switch (property.Type)
diff --git a/src/lua/LuaScriptInterface.h b/src/lua/LuaScriptInterface.h
index e6f58fdc0..2519a5c5a 100644
--- a/src/lua/LuaScriptInterface.h
+++ b/src/lua/LuaScriptInterface.h
@@ -58,6 +58,17 @@ struct CustomElement
 	LuaSmartRef changeType;
 };
 
+struct CustomTool
+{
+	LuaSmartRef perform;
+	LuaSmartRef click;
+	LuaSmartRef drag;
+	LuaSmartRef draw;
+	LuaSmartRef drawLine;
+	LuaSmartRef drawRect;
+	LuaSmartRef drawFill;
+};
+
 class LuaScriptInterface : public CommandInterface
 {
 	LuaStatePtr luaState;
@@ -86,6 +97,7 @@ public:
 	}
 
 	std::vector<CustomElement> customElements; // must come after luaState
+	std::vector<CustomTool> customTools;
 
 	EventTraits eventTraits = eventTraitNone;
 
@@ -204,6 +216,12 @@ namespace LuaSocket
 	void OpenTCP(lua_State *L);
 }
 
+namespace LuaTools
+{
+	void Open(lua_State *L);
+	void SetToolIndex(lua_State *L, ByteString identifier, std::optional<int> index);
+}
+
 inline LuaScriptInterface *GetLSI()
 {
 	return static_cast<LuaScriptInterface *>(&CommandInterface::Ref());
diff --git a/src/lua/LuaSimulation.cpp b/src/lua/LuaSimulation.cpp
index d2371d94a..2f72524c1 100644
--- a/src/lua/LuaSimulation.cpp
+++ b/src/lua/LuaSimulation.cpp
@@ -2020,21 +2020,6 @@ void LuaSimulation::Open(lua_State *L)
 		LCONSTAS("NUM_WALLS", UI_WALLCOUNT);
 	}
 
-	{
-		lua_newtable(L);
-		auto &toolList = lsi->gameModel->GetTools();
-		for (int i = 0; i < int(toolList.size()); ++i)
-		{
-			tpt_lua_pushByteString(L, toolList[i]->Identifier);
-			lua_pushinteger(L, i);
-			lua_settable(L, -3);
-			lua_pushinteger(L, i);
-			tpt_lua_pushByteString(L, toolList[i]->Identifier);
-			lua_settable(L, -3);
-		}
-		lua_setfield(L, -2, "tools");
-		LCONSTAS("NUM_TOOLS", UI_WALLCOUNT);
-	}
 #undef LCONSTAS
 #undef LCONSTF
 #undef LCONST
diff --git a/src/lua/LuaTools.cpp b/src/lua/LuaTools.cpp
new file mode 100644
index 000000000..63bd97175
--- /dev/null
+++ b/src/lua/LuaTools.cpp
@@ -0,0 +1,394 @@
+#include "LuaScriptInterface.h"
+#include "gui/game/GameModel.h"
+#include "simulation/SimTool.h"
+#include "simulation/Simulation.h"
+#include <type_traits>
+
+static int allocate(lua_State *L)
+{
+	luaL_checktype(L, 1, LUA_TSTRING);
+	luaL_checktype(L, 2, LUA_TSTRING);
+	auto group = tpt_lua_toByteString(L, 1).ToUpper();
+	auto name = tpt_lua_toByteString(L, 2).ToUpper();
+	if (name.Contains("_"))
+	{
+		return luaL_error(L, "The tool name may not contain '_'.");
+	}
+	if (group.Contains("_"))
+	{
+		return luaL_error(L, "The group name may not contain '_'.");
+	}
+	if (group == "DEFAULT")
+	{
+		return luaL_error(L, "You cannot create tools in the 'DEFAULT' group.");
+	}
+	auto *lsi = GetLSI();
+	auto identifier = group + "_TOOL_" + name;
+	{
+		SimTool tool;
+		tool.Identifier = identifier;
+		lsi->gameModel->AllocTool(std::make_unique<SimTool>(tool));
+	}
+	lsi->gameModel->BuildMenus();
+	auto index = *lsi->gameModel->GetToolIndex(lsi->gameModel->GetToolFromIdentifier(identifier));
+	lsi->customTools.resize(std::max(int(lsi->customTools.size()), index + 1));
+	lua_pushinteger(L, index);
+	return 1;
+}
+
+static bool IsDefault(Tool *tool)
+{
+	return tool->Identifier.BeginsWith("DEFAULT_");
+}
+
+static int ffree(lua_State *L)
+{
+	int index = luaL_checkinteger(L, 1);
+	auto *lsi = GetLSI();
+	auto *tool = lsi->gameModel->GetToolByIndex(index);
+	if (!tool)
+	{
+		return luaL_error(L, "Invalid tool");
+	}
+	if (IsDefault(tool))
+	{
+		return luaL_error(L, "Cannot free default tools");
+	}
+	lsi->customTools[index] = {};
+	lsi->gameModel->FreeTool(tool);
+	lsi->gameModel->BuildMenus();
+	return 0;
+}
+
+static int luaPerformWrapper(SimTool *tool, Simulation *sim, Particle *cpart, int x, int y, int brushX, int brushY, float strength)
+{
+	int ok = 0;
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].perform)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].perform);
+		if (cpart)
+		{
+			lua_pushinteger(L, cpart - &lsi->sim->parts[0]);
+		}
+		else
+		{
+			lua_pushnil(L);
+		}
+		lua_pushinteger(L, x);
+		lua_pushinteger(L, y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		lua_pushinteger(L, brushX);
+		lua_pushinteger(L, brushY);
+		if (tpt_lua_pcall(L, 9, 1, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In perform func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+		if (lua_isboolean(L, -1))
+		{
+			ok = lua_toboolean(L, -1);
+		}
+		lua_pop(L, 1);
+	}
+	return ok;
+}
+
+static void luaClickWrapper(SimTool *tool, Simulation *sim, const Brush &brush, ui::Point position)
+{
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].click)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].click);
+		lua_pushinteger(L, lsi->gameModel->GetBrushIndex(brush));
+		lua_pushinteger(L, position.X);
+		lua_pushinteger(L, position.Y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		if (tpt_lua_pcall(L, 7, 0, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In click func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+	}
+}
+
+static void luaDragWrapper(SimTool *tool, Simulation *sim, const Brush &brush, ui::Point position1, ui::Point position2)
+{
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].drag)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].drag);
+		lua_pushinteger(L, lsi->gameModel->GetBrushIndex(brush));
+		lua_pushinteger(L, position1.X);
+		lua_pushinteger(L, position1.Y);
+		lua_pushinteger(L, position2.X);
+		lua_pushinteger(L, position2.Y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		if (tpt_lua_pcall(L, 9, 0, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In drag func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+	}
+}
+
+static void luaDrawWrapper(SimTool *tool, Simulation *sim, const Brush &brush, ui::Point position)
+{
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].draw)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].draw);
+		lua_pushinteger(L, lsi->gameModel->GetBrushIndex(brush));
+		lua_pushinteger(L, position.X);
+		lua_pushinteger(L, position.Y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		if (tpt_lua_pcall(L, 7, 0, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In draw func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+	}
+}
+
+static void luaDrawLineWrapper(SimTool *tool, Simulation *sim, const Brush &brush, ui::Point position1, ui::Point position2, bool dragging)
+{
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].drawLine)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].drawLine);
+		lua_pushinteger(L, lsi->gameModel->GetBrushIndex(brush));
+		lua_pushinteger(L, position1.X);
+		lua_pushinteger(L, position1.Y);
+		lua_pushinteger(L, position2.X);
+		lua_pushinteger(L, position2.Y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		if (tpt_lua_pcall(L, 9, 0, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In drawLine func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+	}
+}
+
+static void luaDrawRectWrapper(SimTool *tool, Simulation *sim, const Brush &brush, ui::Point position1, ui::Point position2)
+{
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].drawRect)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].drawRect);
+		lua_pushinteger(L, lsi->gameModel->GetBrushIndex(brush));
+		lua_pushinteger(L, position1.X);
+		lua_pushinteger(L, position1.Y);
+		lua_pushinteger(L, position2.X);
+		lua_pushinteger(L, position2.Y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		if (tpt_lua_pcall(L, 9, 0, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In drawRect func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+	}
+}
+
+static void luaDrawFillWrapper(SimTool *tool, Simulation *sim, const Brush &brush, ui::Point position)
+{
+	auto *lsi = GetLSI();
+	auto L = lsi->L;
+	auto index = *lsi->gameModel->GetToolIndex(tool);
+	auto &customTools = lsi->customTools;
+	if (customTools[index].drawFill)
+	{
+		lua_rawgeti(L, LUA_REGISTRYINDEX, customTools[index].drawFill);
+		lua_pushinteger(L, lsi->gameModel->GetBrushIndex(brush));
+		lua_pushinteger(L, position.X);
+		lua_pushinteger(L, position.Y);
+		lua_pushnumber(L, tool->Strength);
+		lua_pushboolean(L, tool->shiftBehaviour);
+		lua_pushboolean(L, tool->ctrlBehaviour);
+		lua_pushboolean(L, tool->altBehaviour);
+		if (tpt_lua_pcall(L, 7, 0, 0, eventTraitNone))
+		{
+			lsi->Log(CommandInterface::LogError, "In drawFill func: " + LuaGetError());
+			lua_pop(L, 1);
+		}
+	}
+}
+
+template <typename T>
+struct DependentFalse : std::false_type
+{
+};
+
+static int property(lua_State *L)
+{
+	auto *lsi = GetLSI();
+	int index = luaL_checkinteger(L, 1);
+	auto *tool = lsi->gameModel->GetToolByIndex(index);
+	if (!tool)
+	{
+		return luaL_error(L, "Invalid tool");
+	}
+	ByteString propertyName = tpt_lua_checkByteString(L, 2);
+	auto handleCallback = [lsi, L, index, tool, &propertyName](
+		auto customToolMember,
+		auto simToolMember,
+		auto wrapper,
+		const char *luaPropertyName
+	) {
+		if (propertyName == luaPropertyName)
+		{
+			if (lua_gettop(L) > 2)
+			{
+				if (IsDefault(tool))
+				{
+					luaL_error(L, "Cannot change callbacks of default tools");
+				}
+				if (lua_type(L, 3) == LUA_TFUNCTION)
+				{
+					(lsi->customTools[index].*customToolMember).Assign(L, 3);
+					(static_cast<SimTool *>(tool)->*simToolMember) = wrapper;
+				}
+				else if (lua_type(L, 3) == LUA_TBOOLEAN && !lua_toboolean(L, 3))
+				{
+					(lsi->customTools[index].*customToolMember).Clear();
+					(static_cast<SimTool *>(tool)->*simToolMember) = SimTool().*simToolMember;
+				}
+				return true;
+			}
+			luaL_error(L, "Invalid tool property");
+		}
+		return false;
+	};
+	if (handleCallback(&CustomTool::perform , &SimTool::Perform        , luaPerformWrapper , "Perform" ) ||
+	    handleCallback(&CustomTool::click   , &SimTool::PerformClick   , luaClickWrapper   , "Click"   ) ||
+	    handleCallback(&CustomTool::drag    , &SimTool::PerformDrag    , luaDragWrapper    , "Drag"    ) ||
+	    handleCallback(&CustomTool::draw    , &SimTool::PerformDraw    , luaDrawWrapper    , "Draw"    ) ||
+	    handleCallback(&CustomTool::drawLine, &SimTool::PerformDrawLine, luaDrawLineWrapper, "DrawLine") ||
+	    handleCallback(&CustomTool::drawRect, &SimTool::PerformDrawRect, luaDrawRectWrapper, "DrawRect") ||
+	    handleCallback(&CustomTool::drawFill, &SimTool::PerformDrawFill, luaDrawFillWrapper, "DrawFill"))
+	{
+		return 0;
+	}
+	int returnValueCount = 0;
+	auto handleProperty = [L, tool, &propertyName, &returnValueCount](auto simToolMember, const char *luaPropertyName) {
+		if (propertyName == luaPropertyName)
+		{
+			auto &thing = tool->*simToolMember;
+			using PropertyType = std::remove_reference_t<decltype(thing)>;
+			if (lua_gettop(L) > 2)
+			{
+				if      constexpr (std::is_same_v<PropertyType, String      >) thing = tpt_lua_checkString(L, 3);
+				else if constexpr (std::is_same_v<PropertyType, RGB<uint8_t>>) thing = RGB<uint8_t>::Unpack(luaL_checkinteger(L, 3));
+				else static_assert(DependentFalse<PropertyType>::value);
+			}
+			else
+			{
+				if      constexpr (std::is_same_v<PropertyType, String      >) tpt_lua_pushString(L, thing);
+				else if constexpr (std::is_same_v<PropertyType, RGB<uint8_t>>) lua_pushinteger(L, thing.Pack());
+				else static_assert(DependentFalse<PropertyType>::value);
+				returnValueCount = 1;
+			}
+			return true;
+		}
+		return false;
+	};
+	if (handleProperty(&SimTool::Name       , "Name"       ) ||
+	    handleProperty(&SimTool::Description, "Description") ||
+	    handleProperty(&SimTool::Colour     , "Colour"     ) ||
+	    handleProperty(&SimTool::Colour     , "Color"      ))
+	{
+		return returnValueCount;
+	}
+	if (propertyName == "Identifier")
+	{
+		tpt_lua_pushByteString(L, tool->Identifier);
+		return 1;
+	}
+	return luaL_error(L, "Invalid tool property");
+}
+
+static int exists(lua_State *L)
+{
+	int index = luaL_checkinteger(L, 1);
+	auto *lsi = GetLSI();
+	lua_pushboolean(L, bool(lsi->gameModel->GetToolByIndex(index)));
+	return 1;
+}
+
+void LuaTools::Open(lua_State *L)
+{
+	auto *lsi = GetLSI();
+	static const luaL_Reg reg[] = {
+#define LFUNC(v) { #v, v }
+		LFUNC(allocate),
+		LFUNC(property),
+		LFUNC(exists),
+#undef LFUNC
+		{ "free", ffree },
+		{ NULL, NULL }
+	};
+	lua_newtable(L);
+	luaL_register(L, NULL, reg);
+	lua_setglobal(L, "tools");
+	auto &toolList = lsi->gameModel->GetTools();
+	for (int i = 0; i < int(toolList.size()); ++i)
+	{
+		if (!toolList[i])
+		{
+			continue;
+		}
+		SetToolIndex(L, toolList[i]->Identifier, i);
+	}
+}
+
+void LuaTools::SetToolIndex(lua_State *L, ByteString identifier, std::optional<int> index)
+{
+	lua_getglobal(L, "tools");
+	tpt_lua_pushByteString(L, identifier);
+	if (index)
+	{
+		lua_pushinteger(L, *index);
+	}
+	else
+	{
+		lua_pushnil(L);
+	}
+	lua_settable(L, -3);
+	lua_pop(L, 1);
+}
diff --git a/src/lua/PlainCommandInterface.cpp b/src/lua/PlainCommandInterface.cpp
index 707af8765..3f29f7925 100644
--- a/src/lua/PlainCommandInterface.cpp
+++ b/src/lua/PlainCommandInterface.cpp
@@ -37,3 +37,7 @@ String CommandInterface::FormatCommand(String command)
 {
 	return PlainFormatCommand(command);
 }
+
+void CommandInterface::SetToolIndex(ByteString identifier, std::optional<int> index)
+{
+}
diff --git a/src/lua/luascripts/compat.lua b/src/lua/luascripts/compat.lua
index 724bf8761..bf1c7a63f 100644
--- a/src/lua/luascripts/compat.lua
+++ b/src/lua/luascripts/compat.lua
@@ -55,15 +55,15 @@ tpt.setfpscap           = tpt.fpsCap
 ui.MOUSE_UP_BLUR        = ui.MOUSEUP_BLUR
 ui.MOUSE_UP_DRAW_END    = ui.MOUSEUP_DRAWEND
 ui.MOUSE_UP_NORMAL      = ui.MOUSEUP_NORMAL
-sim.TOOL_HEAT           = sim.tools.DEFAULT_TOOL_HEAT
-sim.TOOL_COOL           = sim.tools.DEFAULT_TOOL_COOL
-sim.TOOL_VAC            = sim.tools.DEFAULT_TOOL_VAC 
-sim.TOOL_PGRV           = sim.tools.DEFAULT_TOOL_PGRV
-sim.TOOL_AIR            = sim.tools.DEFAULT_TOOL_AIR 
-sim.TOOL_NGRV           = sim.tools.DEFAULT_TOOL_NGRV
-sim.TOOL_MIX            = sim.tools.DEFAULT_TOOL_MIX 
-sim.TOOL_CYCL           = sim.tools.DEFAULT_TOOL_CYCL
-sim.TOOL_WIND           = sim.tools.DEFAULT_TOOL_WIND
+sim.TOOL_HEAT           = tools.DEFAULT_TOOL_HEAT
+sim.TOOL_COOL           = tools.DEFAULT_TOOL_COOL
+sim.TOOL_VAC            = tools.DEFAULT_TOOL_VAC
+sim.TOOL_PGRV           = tools.DEFAULT_TOOL_PGRV
+sim.TOOL_AIR            = tools.DEFAULT_TOOL_AIR
+sim.TOOL_NGRV           = tools.DEFAULT_TOOL_NGRV
+sim.TOOL_MIX            = tools.DEFAULT_TOOL_MIX
+sim.TOOL_CYCL           = tools.DEFAULT_TOOL_CYCL
+sim.TOOL_WIND           = tools.DEFAULT_TOOL_WIND
 if socket then
 	socket.gettime = socket.getTime
 end
diff --git a/src/lua/meson.build b/src/lua/meson.build
index a713fb21c..7446e68bd 100644
--- a/src/lua/meson.build
+++ b/src/lua/meson.build
@@ -21,6 +21,7 @@ luaconsole_files = files(
 	'LuaSocket.cpp',
 	'LuaSmartRef.cpp',
 	'LuaTextbox.cpp',
+	'LuaTools.cpp',
 	'LuaWindow.cpp',
 )
 if lua_variant != 'luajit'