diff --git a/res/content/base/items/bazalt_breaker.json b/res/content/base/items/bazalt_breaker.json
index 59aeabdb..9e70fa55 100644
--- a/res/content/base/items/bazalt_breaker.json
+++ b/res/content/base/items/bazalt_breaker.json
@@ -1,4 +1,5 @@
 {
     "icon-type": "sprite",
-    "icon": "items:bazalt_breaker"
+    "icon": "items:bazalt_breaker",
+    "uses": 100
 }
diff --git a/res/content/base/modules/util.lua b/res/content/base/modules/util.lua
index d12337fb..b1a97ad0 100644
--- a/res/content/base/modules/util.lua
+++ b/res/content/base/modules/util.lua
@@ -1,12 +1,13 @@
 local util = {}
 
-function util.drop(ppos, itemid, count, pickup_delay)
+function util.drop(ppos, itemid, count, data, pickup_delay)
     if itemid == 0 or not itemid then
         return nil
     end
     return entities.spawn("base:drop", ppos, {base__drop={
         id=itemid,
         count=count,
+        data=data,
         pickup_delay=pickup_delay
     }})
 end
diff --git a/res/content/base/scripts/bazalt_breaker.lua b/res/content/base/scripts/bazalt_breaker.lua
index 78b872b2..8869eca5 100644
--- a/res/content/base/scripts/bazalt_breaker.lua
+++ b/res/content/base/scripts/bazalt_breaker.lua
@@ -1,3 +1,6 @@
-function on_block_break_by(x, y, z, p)
+function on_block_break_by(x, y, z, pid)
     block.set(x, y, z, 0, 0)
+    if not player.is_infinite_items(pid) then
+        inventory.use(player.get_inventory(pid))
+    end
 end
diff --git a/res/content/base/scripts/components/drop.lua b/res/content/base/scripts/components/drop.lua
index 7aa8babb..cf57f72f 100644
--- a/res/content/base/scripts/components/drop.lua
+++ b/res/content/base/scripts/components/drop.lua
@@ -14,6 +14,7 @@ end
 if SAVED_DATA.item then
     dropitem.id = item.index(SAVED_DATA.item)
     dropitem.count = SAVED_DATA.count
+    dropitem.data = SAVED_DATA.data
 end
 
 local DROP_SCALE = 0.3
@@ -25,6 +26,7 @@ local rotation = mat4.rotate({
 function on_save()
     SAVED_DATA.item = item.name(dropitem.id)
     SAVED_DATA.count = dropitem.count
+    SAVED_DATA.data = dropitem.data
 end
 
 do -- setup visuals
@@ -59,11 +61,10 @@ function on_sensor_enter(index, oid)
     if pid == -1 then
         -- other is base:drop too
         if index == 0 and other:def_index() == def_index then
-            local odrop = other:get_component("base:drop")
-            if odrop.dropitem.id == dropitem.id then
-                -- // TODO: replace combination logic with item.* function
+            local odrop = other:get_component("base:drop").dropitem
+            if odrop.id == dropitem.id and not odrop.data then
                 local stack = item.stack_size(dropitem.id)
-                local sum = dropitem.count + odrop.dropitem.count
+                local sum = dropitem.count + odrop.count
                 if sum <= stack then
                     dropitem.count = sum
                     other:despawn()
@@ -75,7 +76,7 @@ function on_sensor_enter(index, oid)
 
     if timer < 0.0 and index == 0 then
         entity:despawn()
-        inventory.add(player.get_inventory(pid), dropitem.id, dropitem.count)
+        inventory.add(player.get_inventory(pid), dropitem.id, dropitem.count, dropitem.data)
         audio.play_sound_2d("events/pickup", 0.5, 0.8 + math.random() * 0.4, "regular")
     end
     if index == 1 then
diff --git a/res/content/base/scripts/hud.lua b/res/content/base/scripts/hud.lua
index 31125631..00f6bdc6 100644
--- a/res/content/base/scripts/hud.lua
+++ b/res/content/base/scripts/hud.lua
@@ -14,12 +14,13 @@ function on_hud_open()
         if itemid == 0 then
             return
         end
+        local data = inventory.get_all_data(invid, slot)
         inventory.set(invid, slot, itemid, itemcount-1)
 
         local pvel = {player.get_vel(pid)}
         local ppos = vec3.add({player.get_pos(pid)}, {0, 0.7, 0})
         local throw_force = vec3.mul(player.get_dir(pid), DROP_FORCE)
-        local drop = base_util.drop(ppos, itemid, 1, 1.5)
+        local drop = base_util.drop(ppos, itemid, 1, data, 1.5)
         local velocity = vec3.add(throw_force, vec3.add(pvel, DROP_INIT_VEL))
         drop.rigidbody:set_vel(velocity)
     end)
diff --git a/res/scripts/stdlib.lua b/res/scripts/stdlib.lua
index 6d458584..8a5f66eb 100644
--- a/res/scripts/stdlib.lua
+++ b/res/scripts/stdlib.lua
@@ -94,6 +94,31 @@ elseif __vc_app then
     complete_app_lib(__vc_app)
 end
 
+function inventory.get_uses(invid, slot)
+    local uses = inventory.get_data(invid, slot, "uses")
+    if uses == nil then
+        return item.uses(inventory.get(invid, slot))
+    end
+    return uses
+end
+
+
+function inventory.use(invid, slot)
+    local itemid, count = inventory.get(invid, slot)
+    if itemid == nil then
+        return
+    end
+    local item_uses = inventory.get_uses(invid, slot)
+    if item_uses == nil then
+        return
+    end
+    if item_uses == 1 then
+        inventory.set(invid, slot, itemid, count - 1)
+    elseif item_uses > 1 then
+        inventory.set_data(invid, slot, "uses", item_uses - 1)
+    end
+end
+
 ------------------------------------------------
 ------------------- Events ---------------------
 ------------------------------------------------
diff --git a/src/content/ContentLoader.cpp b/src/content/ContentLoader.cpp
index 64d4f69b..b2457cf4 100644
--- a/src/content/ContentLoader.cpp
+++ b/src/content/ContentLoader.cpp
@@ -429,15 +429,29 @@ void ContentLoader::loadItem(
     } else if (iconTypeStr == "sprite") {
         def.iconType = ItemIconType::SPRITE;
     } else if (iconTypeStr.length()) {
-        logger.error() << name << ": unknown icon type" << iconTypeStr;
+        logger.error() << name << ": unknown icon type - " << iconTypeStr;
     }
     root.at("icon").get(def.icon);
     root.at("placing-block").get(def.placingBlock);
     root.at("script-name").get(def.scriptName);
     root.at("model-name").get(def.modelName);
     root.at("stack-size").get(def.stackSize);
+    root.at("uses").get(def.uses);
+
+    std::string usesDisplayStr = "";
+    root.at("uses-display").get(usesDisplayStr);
+    if (usesDisplayStr == "none") {
+        def.usesDisplay = ItemUsesDisplay::NONE;
+    } else if (usesDisplayStr == "number") {
+        def.usesDisplay = ItemUsesDisplay::NUMBER;
+    } else if (usesDisplayStr == "relation") {
+        def.usesDisplay = ItemUsesDisplay::RELATION;
+    } else if (usesDisplayStr == "vbar") {
+        def.usesDisplay = ItemUsesDisplay::VBAR;
+    } else if (usesDisplayStr.length()) {
+        logger.error() << name << ": unknown uses display mode - " << usesDisplayStr;
+    }
 
-    // item light emission [r, g, b] where r,g,b in range [0..15]
     if (auto found = root.at("emission")) {
         const auto& emissionarr = *found;
         def.emission[0] = emissionarr[0].asNumber();
diff --git a/src/frontend/hud.cpp b/src/frontend/hud.cpp
index 1f062240..1684799f 100644
--- a/src/frontend/hud.cpp
+++ b/src/frontend/hud.cpp
@@ -70,7 +70,7 @@ std::shared_ptr<UINode> create_debug_panel(
 );
 
 HudElement::HudElement(
-    hud_element_mode mode, 
+    HudElementMode mode, 
     UiDocument* document, 
     std::shared_ptr<UINode> node, 
     bool debug
@@ -83,16 +83,16 @@ void HudElement::update(bool pause, bool inventoryOpen, bool debugMode) {
         return;
     }
     switch (mode) {
-        case hud_element_mode::permanent:
+        case HudElementMode::PERMANENT:
             node->setVisible(true);
             break;
-        case hud_element_mode::ingame:
+        case HudElementMode::INGAME:
             node->setVisible(!pause && !inventoryOpen);
             break;
-        case hud_element_mode::inventory_any:
+        case HudElementMode::INVENTORY_ANY:
             node->setVisible(inventoryOpen);
             break;
-        case hud_element_mode::inventory_bound:
+        case HudElementMode::INVENTORY:
             removed = !inventoryOpen;
             break;
     }
@@ -108,21 +108,21 @@ std::shared_ptr<UINode> HudElement::getNode() const {
 
 std::shared_ptr<InventoryView> Hud::createContentAccess() {
     auto& content = frontend.getLevel().content;
-    auto indices = content.getIndices();
+    auto& indices = *content.getIndices();
     auto inventory = player.getInventory();
     
-    size_t itemsCount = indices->items.count();
+    size_t itemsCount = indices.items.count();
     auto accessInventory = std::make_shared<Inventory>(0, itemsCount);
     for (size_t id = 1; id < itemsCount; id++) {
         accessInventory->getSlot(id-1).set(ItemStack(id, 1));
     }
 
     SlotLayout slotLayout(-1, glm::vec2(), false, true, nullptr,
-    [=](uint, ItemStack& item) {
+    [inventory, &indices](uint, ItemStack& item) {
         auto copy = ItemStack(item);
         inventory->move(copy, indices);
     }, 
-    [=](uint, ItemStack& item) {
+    [this, inventory](uint, ItemStack& item) {
         inventory->getSlot(player.getChosenSlot()).set(item);
     });
 
@@ -192,7 +192,7 @@ Hud::Hud(Engine& engine, LevelFrontend& frontend, Player& player)
     auto dplotter = std::make_shared<Plotter>(350, 250, 2000, 16);
     dplotter->setGravity(Gravity::bottom_right);
     dplotter->setInteractive(false);
-    add(HudElement(hud_element_mode::permanent, nullptr, dplotter, true));
+    add(HudElement(HudElementMode::PERMANENT, nullptr, dplotter, true));
 
     assets.store(Texture::from(debugImgWorldGen.get()), DEBUG_WORLDGEN_IMAGE);
 
@@ -200,7 +200,7 @@ Hud::Hud(Engine& engine, LevelFrontend& frontend, Player& player)
             "<image src='"+DEBUG_WORLDGEN_IMAGE+
             "' pos='0' size='256' gravity='top-right' margin='0,20,0,0'/>"
         );
-    add(HudElement(hud_element_mode::permanent, nullptr, debugMinimap, true));
+    add(HudElement(HudElementMode::PERMANENT, nullptr, debugMinimap, true));
 }
 
 Hud::~Hud() {
@@ -372,8 +372,8 @@ void Hud::openInventory() {
     auto inventoryDocument = assets.get<UiDocument>("core:inventory");
     inventoryView = std::dynamic_pointer_cast<InventoryView>(inventoryDocument->getRoot());
     inventoryView->bind(inventory, &content);
-    add(HudElement(hud_element_mode::inventory_bound, inventoryDocument, inventoryView, false));
-    add(HudElement(hud_element_mode::inventory_bound, nullptr, exchangeSlot, false));
+    add(HudElement(HudElementMode::INVENTORY, inventoryDocument, inventoryView, false));
+    add(HudElement(HudElementMode::INVENTORY, nullptr, exchangeSlot, false));
 }
 
 std::shared_ptr<Inventory> Hud::openInventory(
@@ -401,7 +401,7 @@ std::shared_ptr<Inventory> Hud::openInventory(
         inv = level.inventories->createVirtual(secondInvView->getSlotsCount());
     }
     secondInvView->bind(inv, &content);
-    add(HudElement(hud_element_mode::inventory_bound, doc, secondUI, false));
+    add(HudElement(HudElementMode::INVENTORY, doc, secondUI, false));
     scripting::on_inventory_open(&player, *inv);
     return inv;
 }
@@ -436,7 +436,7 @@ void Hud::openInventory(
     blockUI->bind(blockinv, &content);
     blockPos = block;
     currentblockid = chunks.require(block.x, block.y, block.z).id;
-    add(HudElement(hud_element_mode::inventory_bound, doc, blockUI, false));
+    add(HudElement(HudElementMode::INVENTORY, doc, blockUI, false));
 
     scripting::on_inventory_open(&player, *blockinv);
 }
@@ -468,8 +468,7 @@ void Hud::showOverlay(
         showExchangeSlot();
         inventoryOpen = true;
     }
-    add(HudElement(hud_element_mode::inventory_bound, doc, secondUI, false),
-        args);
+    add(HudElement(HudElementMode::INVENTORY, doc, secondUI, false), args);
 }
 
 void Hud::openPermanent(UiDocument* doc) {
@@ -480,7 +479,7 @@ void Hud::openPermanent(UiDocument* doc) {
     if (invview) {
         invview->bind(player.getInventory(), &frontend.getLevel().content);
     }
-    add(HudElement(hud_element_mode::permanent, doc, doc->getRoot(), false));
+    add(HudElement(HudElementMode::PERMANENT, doc, doc->getRoot(), false));
 }
 
 void Hud::dropExchangeSlot() {
@@ -494,12 +493,12 @@ void Hud::dropExchangeSlot() {
     
     auto indices = frontend.getLevel().content.getIndices();
     if (auto invView = std::dynamic_pointer_cast<InventoryView>(blockUI)) {
-        invView->getInventory()->move(stack, indices);
+        invView->getInventory()->move(stack, *indices);
     }
     if (stack.isEmpty()) {
         return;
     }
-    player.getInventory()->move(stack, indices);
+    player.getInventory()->move(stack, *indices);
     if (!stack.isEmpty()) {
         logger.warning() << "discard item [" << stack.getItemId() << ":"
                          << stack.getCount();
diff --git a/src/frontend/hud.hpp b/src/frontend/hud.hpp
index 07affc66..a978e282 100644
--- a/src/frontend/hud.hpp
+++ b/src/frontend/hud.hpp
@@ -30,26 +30,26 @@ namespace gui {
     class SlotView;
 }
 
-enum class hud_element_mode {
+enum class HudElementMode {
     // element is hidden if menu or inventory open
-    ingame,
+    INGAME,
     // element is visible if hud is visible
-    permanent,
+    PERMANENT,
     // element is visible in inventory mode
-    inventory_any,
+    INVENTORY_ANY,
     // element will be removed on inventory close
-    inventory_bound
+    INVENTORY
 };
 
 class HudElement {
-    hud_element_mode mode;
+    HudElementMode mode;
     UiDocument* document;
     std::shared_ptr<gui::UINode> node;
 
     bool debug;
     bool removed = false;
 public:
-    HudElement(hud_element_mode mode, UiDocument* document, std::shared_ptr<gui::UINode> node, bool debug);
+    HudElement(HudElementMode mode, UiDocument* document, std::shared_ptr<gui::UINode> node, bool debug);
 
     void update(bool pause, bool inventoryOpen, bool debug);
 
@@ -57,7 +57,7 @@ public:
     std::shared_ptr<gui::UINode> getNode() const;
 
     bool isInventoryBound() const {
-        return mode == hud_element_mode::inventory_bound;
+        return mode == HudElementMode::INVENTORY;
     }
 
     void setRemoved() {
diff --git a/src/graphics/core/Batch2D.hpp b/src/graphics/core/Batch2D.hpp
index 6bfdb14d..5610f603 100644
--- a/src/graphics/core/Batch2D.hpp
+++ b/src/graphics/core/Batch2D.hpp
@@ -48,10 +48,15 @@ public:
     void sprite(float x, float y, float w, float h, float skew, int atlasRes, int index, glm::vec4 tint);
     void point(float x, float y, float r, float g, float b, float a);
     
-    inline void setColor(glm::vec4 color) {
+    void setColor(glm::vec4 color) {
         this->color = color;
     }
-    inline glm::vec4 getColor() const {
+
+    void resetColor() {
+        this->color = glm::vec4(1.0f);
+    }
+
+    glm::vec4 getColor() const {
         return color;
     }
     
diff --git a/src/graphics/ui/elements/InventoryView.cpp b/src/graphics/ui/elements/InventoryView.cpp
index 22e1b82a..a5a2c8a5 100644
--- a/src/graphics/ui/elements/InventoryView.cpp
+++ b/src/graphics/ui/elements/InventoryView.cpp
@@ -8,7 +8,6 @@
 #include "items/Inventories.hpp"
 #include "items/Inventory.hpp"
 #include "items/ItemDef.hpp"
-#include "items/ItemStack.hpp"
 #include "logic/scripting/scripting.hpp"
 #include "maths/voxmaths.hpp"
 #include "objects/Player.hpp"
@@ -115,26 +114,73 @@ SlotView::SlotView(
     setTooltipDelay(0.0f);
 }
 
+void SlotView::refreshTooltip(const ItemStack& stack, const ItemDef& item) {
+    itemid_t itemid = stack.getItemId();
+    if (itemid == cache.stack.getItemId()) {
+        return;
+    }
+    if (itemid) {
+        tooltip = util::pascal_case(
+            langs::get(util::str2wstr_utf8(item.caption))
+        );
+    } else {
+        tooltip.clear();
+    }
+}
+
+void SlotView::drawItemIcon(
+    Batch2D& batch,
+    const ItemStack& stack,
+    const ItemDef& item,
+    const Assets& assets,
+    const glm::vec4& tint,
+    const glm::vec2& pos
+) {
+    const int SLOT_SIZE = InventoryView::SLOT_SIZE;
+    const auto& previews = assets.require<Atlas>("block-previews");
+    batch.setColor(glm::vec4(1.0f));
+    switch (item.iconType) {
+        case ItemIconType::NONE:
+            break;
+        case ItemIconType::BLOCK: {
+            const Block& block = content->blocks.require(item.icon);
+            batch.texture(previews.getTexture());
+
+            UVRegion region = previews.get(block.name);
+            batch.rect(
+                pos.x, pos.y, SLOT_SIZE, SLOT_SIZE, 
+                0, 0, 0, region, false, true, tint
+            );
+            break;
+        }
+        case ItemIconType::SPRITE: {
+            auto textureRegion =
+                util::get_texture_region(assets, item.icon, "blocks:notfound");
+            
+            batch.texture(textureRegion.texture);
+            batch.rect(
+                pos.x, pos.y, SLOT_SIZE, SLOT_SIZE, 
+                0, 0, 0, textureRegion.region, false, true, tint
+            );
+            break;
+        }
+    }
+}
+
 void SlotView::draw(const DrawContext& pctx, const Assets& assets) {
     if (bound == nullptr) {
         return;
     }
-    itemid_t itemid = bound->getItemId();
-    if (itemid != prevItem) {
-        if (itemid) {
-            auto& def = content->getIndices()->items.require(itemid);
-            tooltip = util::pascal_case(
-                langs::get(util::str2wstr_utf8(def.caption))
-            );
-        } else {
-            tooltip.clear();
-        }
-    }
-    prevItem = itemid;
-
-    const int slotSize = InventoryView::SLOT_SIZE;
-
+    const auto& indices = *content->getIndices();
     const ItemStack& stack = *bound;
+    const ItemDef& item = indices.items.require(stack.getItemId());
+
+    if (cache.stack.getCount() != stack.getCount()) {
+        cache.countStr = std::to_wstring(stack.getCount());
+    }
+    refreshTooltip(stack, item);
+    cache.stack.set(ItemStack(stack.getItemId(), stack.getCount()));
+
     glm::vec4 tint(1, 1, 1, isEnabled() ? 1 : 0.5f);
     glm::vec2 pos = calcPos();
     glm::vec4 color = getColor();
@@ -144,59 +190,84 @@ void SlotView::draw(const DrawContext& pctx, const Assets& assets) {
         color = glm::vec4(1, 1, 1, 0.2f);
     }
 
-    auto batch = pctx.getBatch2D();
-    batch->setColor(color);
+    auto& batch = *pctx.getBatch2D();
+
     if (color.a > 0.0) {
-        batch->texture(nullptr);
+        batch.setColor(color);
+        batch.texture(nullptr);
+
+        const int size = InventoryView::SLOT_SIZE;
         if (highlighted) {
-            batch->rect(pos.x-4, pos.y-4, slotSize+8, slotSize+8);
+            batch.rect(pos.x - 4, pos.y - 4, size + 8, size + 8);
         } else {
-            batch->rect(pos.x, pos.y, slotSize, slotSize);
-        }
-    }
-    
-    batch->setColor(glm::vec4(1.0f));
-
-    auto previews = assets.get<Atlas>("block-previews");
-    auto indices = content->getIndices();
-
-    auto& item = indices->items.require(stack.getItemId());
-    switch (item.iconType) {
-        case ItemIconType::NONE:
-            break;
-        case ItemIconType::BLOCK: {
-            const Block& cblock = content->blocks.require(item.icon);
-            batch->texture(previews->getTexture());
-
-            UVRegion region = previews->get(cblock.name);
-            batch->rect(
-                pos.x, pos.y, slotSize, slotSize, 
-                0, 0, 0, region, false, true, tint);
-            break;
-        }
-        case ItemIconType::SPRITE: {
-            auto textureRegion =
-                util::get_texture_region(assets, item.icon, "blocks:notfound");
-            
-            batch->texture(textureRegion.texture);
-            batch->rect(
-                pos.x, pos.y, slotSize, slotSize, 
-                0, 0, 0, textureRegion.region, false, true, tint);
-            break;
+            batch.rect(pos.x, pos.y, size, size);
         }
     }
 
+    drawItemIcon(batch, stack, item, assets, tint, pos);
+
+    if (stack.getCount() > 1 || stack.getFields() != nullptr) {
+        const auto& font = assets.require<Font>("normal");
+        drawItemInfo(batch, stack, item, font, pos);
+    }
+}
+
+static void draw_shaded_text(
+    Batch2D& batch, const Font& font, const std::wstring& text, int x, int y
+) {
+    batch.setColor({0, 0, 0, 1.0f});
+    font.draw(batch, text, x + 1, y + 1, nullptr, 0);
+    batch.resetColor();
+    font.draw(batch, text, x, y, nullptr, 0);
+}
+
+void SlotView::drawItemInfo(
+    Batch2D& batch,
+    const ItemStack& stack,
+    const ItemDef& item,
+    const Font& font,
+    const glm::vec2& pos
+) {
+    const int SLOT_SIZE = InventoryView::SLOT_SIZE;
     if (stack.getCount() > 1) {
-        auto font = assets.get<Font>("normal");
-        std::wstring text = std::to_wstring(stack.getCount());
+        const auto& countStr = cache.countStr;
+        int x = pos.x + SLOT_SIZE - countStr.length() * 8;
+        int y = pos.y + SLOT_SIZE - 16;
+        draw_shaded_text(batch, font, countStr, x, y);
+    }
 
-        int x = pos.x+slotSize-text.length()*8;
-        int y = pos.y+slotSize-16;
-
-        batch->setColor({0, 0, 0, 1.0f});
-        font->draw(*batch, text, x+1, y+1, nullptr, 0);
-        batch->setColor(glm::vec4(1.0f));
-        font->draw(*batch, text, x, y, nullptr, 0);
+    auto usesPtr = stack.getField("uses");
+    if (usesPtr == nullptr || !usesPtr->isInteger()) {
+        return;
+    }
+    int16_t uses = usesPtr->asInteger();
+    if (uses < 0) {
+        return;
+    }
+    switch (item.usesDisplay) {
+        case ItemUsesDisplay::NONE:
+            break;
+        case ItemUsesDisplay::RELATION:
+            draw_shaded_text(
+                batch, font, std::to_wstring(item.uses), pos.x - 3, pos.y + 9
+            );
+            [[fallthrough]];
+        case ItemUsesDisplay::NUMBER:
+            draw_shaded_text(
+                batch, font, std::to_wstring(uses), pos.x - 3, pos.y - 3
+            );
+            break;
+        case ItemUsesDisplay::VBAR: {
+            batch.untexture();
+            batch.setColor({0, 0, 0, 0.75f});
+            batch.rect(pos.x - 2, pos.y - 2, 6, SLOT_SIZE + 4);
+            float t = static_cast<float>(uses) / item.uses;
+            
+            int height = SLOT_SIZE * t;
+            batch.setColor({(1.0f - t * 0.8f), 0.4f, t * 0.8f + 0.2f, 1.0f});
+            batch.rect(pos.x, pos.y + SLOT_SIZE - height, 2, height);
+            break;
+        }
     }
 }
 
@@ -219,7 +290,7 @@ void SlotView::performLeftClick(ItemStack& stack, ItemStack& grabbed) {
         return;
     }
     if (!layout.itemSource && stack.accepts(grabbed) && layout.placing) {
-        stack.move(grabbed, content->getIndices());
+        stack.move(grabbed, *content->getIndices());
     } else {
         if (layout.itemSource) {
             if (grabbed.isEmpty()) {
@@ -249,10 +320,11 @@ void SlotView::performRightClick(ItemStack& stack, ItemStack& grabbed) {
         return;
     if (grabbed.isEmpty()) {
         if (!stack.isEmpty() && layout.taking) {
-            grabbed.set(stack);
+            grabbed.set(std::move(stack));
             int halfremain = stack.getCount() / 2;
             grabbed.setCount(stack.getCount() - halfremain);
-            stack.setCount(halfremain);
+            // reset all data in the origin slot
+            stack = ItemStack(stack.getItemId(), halfremain);
         }
         return;
     }
@@ -261,9 +333,14 @@ void SlotView::performRightClick(ItemStack& stack, ItemStack& grabbed) {
         return;
     }
     if (stack.isEmpty()) {
-        stack.set(grabbed);
+        itemcount_t count = grabbed.getCount();
+        stack.set(std::move(grabbed));
         stack.setCount(1);
-        grabbed.setCount(grabbed.getCount() - 1);
+        if (count == 1) {
+            grabbed = {};
+        } else {
+            grabbed = ItemStack(stack.getItemId(), count - 1);
+        }
     } else if (stack.accepts(grabbed) && stack.getCount() < stackDef.stackSize) {
         stack.setCount(stack.getCount() + 1);
         grabbed.setCount(grabbed.getCount() - 1);
diff --git a/src/graphics/ui/elements/InventoryView.hpp b/src/graphics/ui/elements/InventoryView.hpp
index f98bb20c..c43d48fe 100644
--- a/src/graphics/ui/elements/InventoryView.hpp
+++ b/src/graphics/ui/elements/InventoryView.hpp
@@ -4,15 +4,18 @@
 #include "Container.hpp"
 #include "typedefs.hpp"
 #include "constants.hpp"
+#include "items/ItemStack.hpp"
 
 #include <vector>
 #include <functional>
 #include <glm/glm.hpp>
 
+class Font;
 class Assets;
+class ItemDef;
+class Batch2D;
 class DrawContext;
 class Content;
-class ItemStack;
 class ContentIndices;
 class LevelFrontend;
 class Inventory;
@@ -49,6 +52,11 @@ namespace gui {
     };
 
     class SlotView : public gui::UINode {
+        struct {
+            ItemStack stack {};
+            std::wstring countStr;
+        } cache;
+    
         const Content* content = nullptr;
         SlotLayout layout;
         bool highlighted = false;
@@ -56,11 +64,27 @@ namespace gui {
         int64_t inventoryid = 0;
         ItemStack* bound = nullptr;
 
-        std::wstring tooltip;
-        itemid_t prevItem = 0;
-
         void performLeftClick(ItemStack& stack, ItemStack& grabbed);
         void performRightClick(ItemStack& stack, ItemStack& grabbed);
+
+        void drawItemIcon(
+            Batch2D& batch,
+            const ItemStack& stack,
+            const ItemDef& item,
+            const Assets& assets,
+            const glm::vec4& tint,
+            const glm::vec2& pos
+        );
+
+        void drawItemInfo(
+            Batch2D& batch,
+            const ItemStack& stack,
+            const ItemDef& item,
+            const Font& font,
+            const glm::vec2& pos
+        );
+
+        void refreshTooltip(const ItemStack& stack, const ItemDef& item);
     public:
         SlotView(SlotLayout layout);
 
diff --git a/src/items/Inventory.cpp b/src/items/Inventory.cpp
index 9797a15e..5978f283 100644
--- a/src/items/Inventory.cpp
+++ b/src/items/Inventory.cpp
@@ -37,7 +37,7 @@ size_t Inventory::findSlotByItem(
 }
 
 void Inventory::move(
-    ItemStack& item, const ContentIndices* indices, size_t begin, size_t end
+    ItemStack& item, const ContentIndices& indices, size_t begin, size_t end
 ) {
     end = std::min(slots.size(), end);
     for (size_t i = begin; i < end && !item.isEmpty(); i++) {
@@ -72,8 +72,12 @@ void Inventory::deserialize(const dv::value& src) {
         if (item.has("count")){
             count = item["count"].asInteger();
         }
+        dv::value fields = nullptr;
+        if (item.has("fields")) {
+            fields = item["fields"];
+        }
         auto& slot = slots[i];
-        slot.set(ItemStack(id, count));
+        slot.set(ItemStack(id, count, fields));
     }
 }
 
@@ -92,6 +96,10 @@ dv::value Inventory::serialize() const {
         if (count) {
             slotmap["count"] = count;
         }
+        const auto& fields = item.getFields();
+        if (fields != nullptr) {
+            slotmap["fields"] = fields;
+        }
     }
     return map;
 }
@@ -110,5 +118,3 @@ void Inventory::convert(dv::value& data, const ContentReport* report) {
     inventory.convert(report);
     data = inventory.serialize();
 }
-
-const size_t Inventory::npos = -1;
diff --git a/src/items/Inventory.hpp b/src/items/Inventory.hpp
index 49560523..29205640 100644
--- a/src/items/Inventory.hpp
+++ b/src/items/Inventory.hpp
@@ -26,13 +26,9 @@ public:
         itemid_t id, size_t begin = 0, size_t end = -1, size_t minCount = 1
     );
 
-    inline size_t size() const {
-        return slots.size();
-    }
-
     void move(
         ItemStack& item,
-        const ContentIndices* indices,
+        const ContentIndices& indices,
         size_t begin = 0,
         size_t end = -1
     );
@@ -46,17 +42,21 @@ public:
     void convert(const ContentReport* report);
     static void convert(dv::value& data, const ContentReport* report);
 
-    inline void setId(int64_t id) {
+    size_t size() const {
+        return slots.size();
+    }
+
+    void setId(int64_t id) {
         this->id = id;
     }
 
-    inline int64_t getId() const {
+    int64_t getId() const {
         return id;
     }
 
-    inline bool isVirtual() const {
+    bool isVirtual() const {
         return id < 0;
     }
 
-    static const size_t npos;
+    static constexpr size_t npos = -1;
 };
diff --git a/src/items/ItemDef.cpp b/src/items/ItemDef.cpp
index 8d0cdd66..e2b54b81 100644
--- a/src/items/ItemDef.cpp
+++ b/src/items/ItemDef.cpp
@@ -15,4 +15,6 @@ void ItemDef::cloneTo(ItemDef& dst) {
     dst.placingBlock = placingBlock;
     dst.scriptName = scriptName;
     dst.modelName = modelName;
+    dst.uses = uses;
+    dst.usesDisplay = usesDisplay;
 }
diff --git a/src/items/ItemDef.hpp b/src/items/ItemDef.hpp
index f6d61208..db4ff9f3 100644
--- a/src/items/ItemDef.hpp
+++ b/src/items/ItemDef.hpp
@@ -19,6 +19,14 @@ enum class ItemIconType {
     BLOCK,   // block preview: icon is string block id
 };
 
+enum class ItemUsesDisplay {
+    NONE,     // uses count is not displayed
+    NUMBER,   // uses count is displayed as number
+    RELATION, // uses count is displayed as `remain/default` relation
+    VBAR,     // uses count is displayed as vertical bar without counter
+    DEFAULT = VBAR,
+};
+
 struct ItemDef {
     /// @brief Item string id (with prefix included)
     std::string const name;
@@ -28,10 +36,21 @@ struct ItemDef {
 
     dv::value properties = nullptr;
 
+    /// @brief Item max stack size
     itemcount_t stackSize = 64;
+
+    /// @brief Item is generated for other content unit (like block)
     bool generated = false;
+    
+    /// @brief Item light emission [r, g, b] where r,g,b in range [0..15]
     uint8_t emission[4] {0, 0, 0, 0};
 
+    /// @brief Default item uses count
+    int16_t uses = -1;
+
+    /// @brief Item uses count display mode
+    ItemUsesDisplay usesDisplay = ItemUsesDisplay::DEFAULT;
+
     ItemIconType iconType = ItemIconType::SPRITE;
     std::string icon = "blocks:notfound";
 
diff --git a/src/items/ItemStack.cpp b/src/items/ItemStack.cpp
index 99cb0a0e..f99d8700 100644
--- a/src/items/ItemStack.cpp
+++ b/src/items/ItemStack.cpp
@@ -3,16 +3,18 @@
 #include "content/Content.hpp"
 #include "ItemDef.hpp"
 
-ItemStack::ItemStack() : item(ITEM_EMPTY), count(0) {
-}
-
-ItemStack::ItemStack(itemid_t item, itemcount_t count)
-    : item(item), count(count) {
+ItemStack::ItemStack(itemid_t item, itemcount_t count, dv::value data)
+    : item(item), count(count), fields(std::move(data)) {
 }
 
 void ItemStack::set(const ItemStack& item) {
+    set(ItemStack(item));
+}
+
+void ItemStack::set(ItemStack&& item) {
     this->item = item.item;
     this->count = item.count;
+    this->fields = std::move(item.fields);
     if (count == 0) {
         this->item = 0;
     }
@@ -25,14 +27,14 @@ bool ItemStack::accepts(const ItemStack& other) const {
     if (isEmpty()) {
         return true;
     }
-    return item == other.getItemId();
+    return item == other.getItemId() && other.fields == nullptr;
 }
 
-void ItemStack::move(ItemStack& item, const ContentIndices* indices) {
-    auto& def = indices->items.require(item.getItemId());
-    int count = std::min(item.count, def.stackSize - this->count);
+void ItemStack::move(ItemStack& item, const ContentIndices& indices) {
+    auto& def = indices.items.require(item.getItemId());
+    itemcount_t count = std::min(item.count, def.stackSize - this->count);
     if (isEmpty()) {
-        set(ItemStack(item.getItemId(), count));
+        set(ItemStack(item.getItemId(), count, std::move(item.fields)));
     } else {
         setCount(this->count + count);
     }
@@ -42,6 +44,30 @@ void ItemStack::move(ItemStack& item, const ContentIndices* indices) {
 void ItemStack::setCount(itemcount_t count) {
     this->count = count;
     if (count == 0) {
-        item = 0;
+        clear();
     }
 }
+
+void ItemStack::setField(std::string_view name, dv::value value) {
+    if (fields == nullptr) {
+        if (value == nullptr) {
+            return;
+        }
+        fields = dv::object();
+    }
+    if (value == nullptr) {
+        fields.erase(std::string(name));
+        if (fields.empty()) {
+            fields = nullptr;
+        }
+        return;
+    }
+    fields[std::string(name)] = std::move(value);
+}
+
+dv::value* ItemStack::getField(const std::string& name) const {
+    if (fields == nullptr) {
+        return nullptr;
+    }
+    return fields.at(name).ptr;
+}
diff --git a/src/items/ItemStack.hpp b/src/items/ItemStack.hpp
index 1a8e191d..91f2d3e7 100644
--- a/src/items/ItemStack.hpp
+++ b/src/items/ItemStack.hpp
@@ -2,36 +2,60 @@
 
 #include "constants.hpp"
 #include "typedefs.hpp"
+#include "data/dv.hpp"
 
 class ContentIndices;
 
 class ItemStack {
-    itemid_t item;
-    itemcount_t count;
+    itemid_t item = ITEM_EMPTY;
+    itemcount_t count = 0;
+    dv::value fields = nullptr;
 public:
-    ItemStack();
+    ItemStack() = default;
 
-    ItemStack(itemid_t item, itemcount_t count);
+    ItemStack(itemid_t item, itemcount_t count, dv::value data=nullptr);
 
     void set(const ItemStack& item);
+    void set(ItemStack&& item);
     void setCount(itemcount_t count);
 
-    bool accepts(const ItemStack& item) const;
-    void move(ItemStack& item, const ContentIndices* indices);
+    /// @brief Set a field in the item stack data.
+    void setField(std::string_view name, dv::value value);
 
-    inline void clear() {
+    /// @brief Get a field from the item stack data.
+    /// @param name field name
+    /// @return value pointer or nullptr if the field does not exist.
+    dv::value* getField(const std::string& name) const;
+
+    bool accepts(const ItemStack& item) const;
+
+    /// @brief Move items from one stack to another. 
+    /// If the target stack is completely filled, the source stack will be reduced.
+    /// @param item source stack
+    /// @param indices content indices
+    void move(ItemStack& item, const ContentIndices& indices);
+
+    void clear() {
         set(ItemStack(0, 0));
     }
 
-    inline bool isEmpty() const {
+    bool isEmpty() const {
         return item == ITEM_EMPTY;
     }
 
-    inline itemid_t getItemId() const {
+    itemid_t getItemId() const {
         return item;
     }
 
-    inline itemcount_t getCount() const {
+    itemcount_t getCount() const {
         return count;
     }
+
+    const dv::value& getFields() const {
+        return fields;
+    }
+
+    bool hasFields() const {
+        return fields != nullptr;
+    }
 };
diff --git a/src/logic/scripting/lua/libs/libinventory.cpp b/src/logic/scripting/lua/libs/libinventory.cpp
index 65f0dd7c..3e2d390e 100644
--- a/src/logic/scripting/lua/libs/libinventory.cpp
+++ b/src/logic/scripting/lua/libs/libinventory.cpp
@@ -7,68 +7,73 @@
 
 using namespace scripting;
 
-static void validate_itemid(itemid_t id) {
-    if (id >= indices->items.count()) {
-        throw std::runtime_error("invalid item id");
+namespace {
+    void validate_itemid(itemid_t id) {
+        if (id >= indices->items.count()) {
+            throw std::runtime_error("invalid item id");
+        }
+    }
+
+    Inventory& get_inventory(int64_t id) {
+        auto inv = level->inventories->get(id);
+        if (inv == nullptr) {
+            throw std::runtime_error("inventory not found: " + std::to_string(id));
+        }
+        return *inv;
+    }
+
+    Inventory& get_inventory(int64_t id, int arg) {
+        auto inv = level->inventories->get(id);
+        if (inv == nullptr) {
+            throw std::runtime_error(
+                "inventory not found: " + std::to_string(id) + " argument " +
+                std::to_string(arg)
+            );
+        }
+        return *inv;
+    }
+    
+    void validate_slotid(int slotid, const Inventory& inv) {
+        if (static_cast<size_t>(slotid) >= inv.size()) {
+            throw std::runtime_error(
+                "slot index is out of range [0..inventory.size(invid)]"
+            );
+        }
+    }
+
+    using SlotFunc = int(lua::State*, ItemStack&);
+
+    template <SlotFunc func>
+    int wrap_slot(lua::State* L) {
+        auto invid = lua::tointeger(L, 1);
+        auto slotid = lua::tointeger(L, 2);
+        auto& inv = get_inventory(invid);
+        validate_slotid(slotid, inv);
+        auto& item = inv.getSlot(slotid);
+        return func(L, item);
     }
 }
 
-static Inventory& get_inventory(int64_t id) {
-    auto inv = level->inventories->get(id);
-    if (inv == nullptr) {
-        throw std::runtime_error("inventory not found: " + std::to_string(id));
-    }
-    return *inv;
-}
-
-static Inventory& get_inventory(int64_t id, int arg) {
-    auto inv = level->inventories->get(id);
-    if (inv == nullptr) {
-        throw std::runtime_error(
-            "inventory not found: " + std::to_string(id) + " argument " +
-            std::to_string(arg)
-        );
-    }
-    return *inv;
-}
-
-static void validate_slotid(int slotid, const Inventory& inv) {
-    if (static_cast<size_t>(slotid) >= inv.size()) {
-        throw std::runtime_error(
-            "slot index is out of range [0..inventory.size(invid)]"
-        );
-    }
-}
-
-static int l_get(lua::State* L) {
-    auto invid = lua::tointeger(L, 1);
-    auto slotid = lua::tointeger(L, 2);
-    auto inv = get_inventory(invid);
-    validate_slotid(slotid, inv);
-    const ItemStack& item = inv.getSlot(slotid);
+static int l_get(lua::State* L, ItemStack& item) {
     lua::pushinteger(L, item.getItemId());
     lua::pushinteger(L, item.getCount());
     return 2;
 }
 
-static int l_set(lua::State* L) {
-    auto invid = lua::tointeger(L, 1);
-    auto slotid = lua::tointeger(L, 2);
+static int l_set(lua::State* L, ItemStack& item) {
     auto itemid = lua::tointeger(L, 3);
     auto count = lua::tointeger(L, 4);
-    validate_itemid(itemid);
-
-    auto& inv = get_inventory(invid);
-
-    validate_slotid(slotid, inv);
-    ItemStack& item = inv.getSlot(slotid);
-    item.set(ItemStack(itemid, count));
+    auto data = lua::tovalue(L, 5);
+    if (!data.isObject() && data != nullptr) {
+        throw std::runtime_error("invalid data argument type (table expected)");
+    }
+    item.set(ItemStack(itemid, count, std::move(data)));
     return 0;
 }
 
 static int l_size(lua::State* L) {
     auto invid = lua::tointeger(L, 1);
-    auto& inv = get_inventory(invid);
+    const auto& inv = get_inventory(invid);
     return lua::pushinteger(L, inv.size());
 }
 
@@ -76,11 +81,16 @@ static int l_add(lua::State* L) {
     auto invid = lua::tointeger(L, 1);
     auto itemid = lua::tointeger(L, 2);
     auto count = lua::tointeger(L, 3);
+    auto data = lua::tovalue(L, 4);
+
     validate_itemid(itemid);
+    if (!data.isObject() && data != nullptr) {
+        throw std::runtime_error("invalid data argument type (table expected)");
+    }
 
     auto& inv = get_inventory(invid);
-    ItemStack item(itemid, count);
-    inv.move(item, indices);
+    ItemStack item(itemid, count, std::move(data));
+    inv.move(item, *indices);
     return lua::pushinteger(L, item.getCount());
 }
 
@@ -144,9 +154,9 @@ static int l_move(lua::State* L) {
     auto& invB = get_inventory(invBid, 3);
     auto& slot = invA.getSlot(slotAid);
     if (slotBid == -1) {
-        invB.move(slot, content->getIndices());
+        invB.move(slot, *content->getIndices());
     } else {
-        invB.move(slot, content->getIndices(), slotBid, slotBid + 1);
+        invB.move(slot, *content->getIndices(), slotBid, slotBid + 1);
     }
     return 0;
 }
@@ -163,9 +173,9 @@ static int l_move_range(lua::State* L) {
     auto invB = get_inventory(invBid, 3);
     auto& slot = invA.getSlot(slotAid);
     if (slotBegin == -1) {
-        invB.move(slot, content->getIndices());
+        invB.move(slot, *content->getIndices());
     } else {
-        invB.move(slot, content->getIndices(), slotBegin, slotEnd);
+        invB.move(slot, *content->getIndices(), slotBegin, slotEnd);
     }
     return 0;
 }
@@ -184,9 +194,38 @@ static int l_find_by_item(lua::State* L) {
     return lua::pushinteger(L, index);
 }
 
+static int l_get_data(lua::State* L, ItemStack& stack) {
+    auto key = lua::require_string(L, 3);
+    auto value = stack.getField(key);
+    if (value == nullptr) {
+        return 0;
+    }
+    return lua::pushvalue(L, *value);
+}
+
+static int l_get_all_data(lua::State* L, ItemStack& stack) {
+    return lua::pushvalue(L, stack.getFields());
+}
+
+static int l_has_data(lua::State* L, ItemStack& stack) {
+    auto key = lua::tostring(L, 3);
+    if (key == nullptr) {
+        return lua::pushboolean(L, stack.hasFields());
+    }
+    return lua::pushboolean(L, stack.getField(key) != nullptr);
+}
+
+static int l_set_data(lua::State* L, ItemStack& stack) {
+    auto key = lua::require_string(L, 3);
+    auto value = lua::tovalue(L, 4);
+    auto& fields = stack.getFields();
+    stack.setField(key, std::move(value));
+    return 0;
+}
+
 const luaL_Reg inventorylib[] = {
-    {"get", lua::wrap<l_get>},
-    {"set", lua::wrap<l_set>},
+    {"get", wrap_slot<l_get>},
+    {"set", wrap_slot<l_set>},
     {"size", lua::wrap<l_size>},
     {"add", lua::wrap<l_add>},
     {"move", lua::wrap<l_move>},
@@ -195,7 +234,12 @@ const luaL_Reg inventorylib[] = {
     {"get_block", lua::wrap<l_get_block>},
     {"bind_block", lua::wrap<l_bind_block>},
     {"unbind_block", lua::wrap<l_unbind_block>},
+    {"get_data", wrap_slot<l_get_data>},
+    {"set_data", wrap_slot<l_set_data>},
+    {"get_all_data", wrap_slot<l_get_all_data>},
+    {"has_data", wrap_slot<l_has_data>},
     {"create", lua::wrap<l_create>},
     {"remove", lua::wrap<l_remove>},
     {"clone", lua::wrap<l_clone>},
-    {NULL, NULL}};
+    {NULL, NULL}
+};
diff --git a/src/logic/scripting/lua/libs/libitem.cpp b/src/logic/scripting/lua/libs/libitem.cpp
index c4ac49ec..b905f1d9 100644
--- a/src/logic/scripting/lua/libs/libitem.cpp
+++ b/src/logic/scripting/lua/libs/libitem.cpp
@@ -80,6 +80,13 @@ static int l_emission(lua::State* L) {
     return 0;
 }
 
+static int l_uses(lua::State* L) {
+    if (auto def = get_item_def(L, 1)) {
+        return lua::pushinteger(L, def->uses);
+    }
+    return 0;
+}
+
 const luaL_Reg itemlib[] = {
     {"index", lua::wrap<l_index>},
     {"name", lua::wrap<l_name>},
@@ -90,4 +97,6 @@ const luaL_Reg itemlib[] = {
     {"placing_block", lua::wrap<l_placing_block>},
     {"model_name", lua::wrap<l_model_name>},
     {"emission", lua::wrap<l_emission>},
-    {NULL, NULL}};
+    {"uses", lua::wrap<l_uses>},
+    {NULL, NULL}
+};