diff --git a/res/modules/bit_converter.lua b/res/modules/bit_converter.lua
index 2686c2c2..86afa334 100644
--- a/res/modules/bit_converter.lua
+++ b/res/modules/bit_converter.lua
@@ -68,19 +68,19 @@ local function floatOrDoubleToBytes(val, opt)
       if opt == 'd' then
         val = mantissa
         for i = 1, 6 do
-          table.insert(bytes, math.floor(val) % (2 ^ 8))
+          bytes[#bytes + 1] = math.floor(val) % (2 ^ 8)
           val = math.floor(val / (2 ^ 8))
         end
       else
-        table.insert(bytes, math.floor(mantissa) % (2 ^ 8))
+        bytes[#bytes + 1] = math.floor(mantissa) % (2 ^ 8)
         val = math.floor(mantissa / (2 ^ 8))
-        table.insert(bytes, math.floor(val) % (2 ^ 8))
+        bytes[#bytes + 1] = math.floor(val) % (2 ^ 8)
         val = math.floor(val / (2 ^ 8))
       end
 
-      table.insert(bytes, math.floor(exponent * ((opt == 'd') and 16 or 128) + val) % (2 ^ 8))
+      bytes[#bytes + 1] = math.floor(exponent * ((opt == 'd') and 16 or 128) + val) % (2 ^ 8)
       val = math.floor((exponent * ((opt == 'd') and 16 or 128) + val) / (2 ^ 8))
-      table.insert(bytes, math.floor(sign * 128 + val) % (2 ^ 8))
+      bytes[#bytes + 1] = math.floor(sign * 128 + val) % (2 ^ 8)
       val = math.floor((sign * 128 + val) / (2 ^ 8))
 
       if not endianness then
diff --git a/src/files/files.cpp b/src/files/files.cpp
index 644e8716..8b66fa55 100644
--- a/src/files/files.cpp
+++ b/src/files/files.cpp
@@ -78,6 +78,21 @@ std::unique_ptr<ubyte[]> files::read_bytes(const fs::path& filename, size_t& len
     return data;
 }
 
+std::vector<ubyte> files::read_bytes(const fs::path& filename) {
+    std::ifstream input(filename, std::ios::binary);
+    if (!input.is_open())
+        return {};
+    input.seekg(0, std::ios_base::end);
+    size_t length = input.tellg();
+    input.seekg(0, std::ios_base::beg);
+
+    std::vector<ubyte> data(length);
+    data.resize(length);
+    input.read((char*)data.data(), length);
+    input.close();
+    return data;
+}
+
 std::string files::read_string(const fs::path& filename) {
     size_t size;
     std::unique_ptr<ubyte[]> bytes (read_bytes(filename, size));
diff --git a/src/files/files.hpp b/src/files/files.hpp
index 4e6ad960..1a124b25 100644
--- a/src/files/files.hpp
+++ b/src/files/files.hpp
@@ -57,6 +57,7 @@ namespace files {
 
     bool read(const fs::path&, char* data, size_t size);
     std::unique_ptr<ubyte[]> read_bytes(const fs::path&, size_t& length);
+    std::vector<ubyte> read_bytes(const fs::path&);
     std::string read_string(const fs::path& filename);
 
     /// @brief Read JSON or BJSON file
diff --git a/src/logic/scripting/lua/libfile.cpp b/src/logic/scripting/lua/libfile.cpp
index 87e9af7a..3a00e0dd 100644
--- a/src/logic/scripting/lua/libfile.cpp
+++ b/src/logic/scripting/lua/libfile.cpp
@@ -109,18 +109,8 @@ static int l_file_mkdirs(lua::State* L) {
 static int l_file_read_bytes(lua::State* L) {
     fs::path path = resolve_path(lua::require_string(L, 1));
     if (fs::is_regular_file(path)) {
-        size_t length = static_cast<size_t>(fs::file_size(path));
-
-        auto bytes = files::read_bytes(path, length);
-
-        lua::createtable(L, length, 0);
-        int newTable = lua::gettop(L);
-
-        for(size_t i = 0; i < length; i++) {
-            lua::pushinteger(L, bytes[i]);
-            lua::rawseti(L, i+1, newTable);
-        }
-        return 1;
+        auto bytes = files::read_bytes(path);
+        return lua::newuserdata<lua::Bytearray>(L, std::move(bytes));
     }
     throw std::runtime_error("file does not exists "+util::quote(path.u8string()));   
 }
@@ -151,10 +141,13 @@ static int l_file_write_bytes(lua::State* L) {
 
     fs::path path = resolve_path(lua::require_string(L, pathIndex));
 
+    if (auto bytearray = lua::touserdata<lua::Bytearray>(L, -1)) {
+        auto& bytes = bytearray->data();
+        return lua::pushboolean(L, files::write_bytes(path, bytes.data(), bytes.size()));
+    }
+
     std::vector<ubyte> bytes;
-
     int result = read_bytes_from_table(L, -1, bytes);
-
     if(result != 1) {
         return result;
     } else {
diff --git a/src/logic/scripting/lua/lua_custom_types.cpp b/src/logic/scripting/lua/lua_custom_types.cpp
new file mode 100644
index 00000000..2983e1b1
--- /dev/null
+++ b/src/logic/scripting/lua/lua_custom_types.cpp
@@ -0,0 +1,183 @@
+#include "lua_custom_types.hpp"
+
+#include "lua_util.hpp"
+
+#include <sstream>
+
+using namespace lua;
+
+
+Bytearray::Bytearray(size_t capacity) 
+  : buffer(capacity) {
+    buffer.resize(capacity);
+}
+
+Bytearray::Bytearray(std::vector<ubyte> buffer) : buffer(std::move(buffer)) {
+}
+
+Bytearray::~Bytearray() {
+}
+
+static int l_bytearray_append(lua::State* L) {
+    if (auto buffer = touserdata<Bytearray>(L, 1)) {
+        auto value = tointeger(L, 2);
+        buffer->data().push_back(static_cast<ubyte>(value));
+    }
+    return 0;
+}
+
+static int l_bytearray_insert(lua::State* L) {
+    auto buffer = touserdata<Bytearray>(L, 1);
+    if (buffer == nullptr) {
+        return 0;
+    }
+    auto& data = buffer->data();
+    auto index = tointeger(L, 2)-1;
+    if (static_cast<size_t>(index) > data.size()) {
+        return 0;
+    }
+    auto value = tointeger(L, 3);
+    data.insert(data.begin() + index, static_cast<ubyte>(value));
+    return 0;
+}
+
+static int l_bytearray_remove(lua::State* L) {
+    auto buffer = touserdata<Bytearray>(L, 1);
+    if (buffer == nullptr) {
+        return 0;
+    }
+    auto& data = buffer->data();
+    auto index = tointeger(L, 2)-1;
+    if (static_cast<size_t>(index) > data.size()) {
+        return 0;
+    }
+    data.erase(data.begin()+index);
+    return 0;
+}
+
+static std::unordered_map<std::string, lua_CFunction> bytearray_methods {
+    {"append", lua::wrap<l_bytearray_append>},
+    {"insert", lua::wrap<l_bytearray_insert>},
+    {"remove", lua::wrap<l_bytearray_remove>},
+};
+
+static int l_bytearray_meta_meta_call(lua::State* L) {
+    if (lua_istable(L, 2)) {
+        size_t len = objlen(L, 2);
+        std::vector<ubyte> buffer(len);
+        buffer.resize(len);
+        for (size_t i = 0; i < len; i++) {
+            rawgeti(L, i+1);
+            buffer[i] = static_cast<ubyte>(tointeger(L, -1));
+            pop(L);
+        }
+        return newuserdata<Bytearray>(L, std::move(buffer));
+    }
+    auto size = tointeger(L, 2);
+    if (size < 0) {
+        throw std::runtime_error("size can not be less than 0");
+    }
+    return newuserdata<Bytearray>(L, static_cast<size_t>(size));
+}
+
+static int l_bytearray_meta_index(lua::State* L) {
+    auto buffer = touserdata<Bytearray>(L, 1);
+    if (buffer == nullptr) {
+        return 0;
+    }
+    auto& data = buffer->data();
+    if (isstring(L, 2)) {
+        auto found = bytearray_methods.find(tostring(L, 2));
+        if (found != bytearray_methods.end()) {
+            return pushcfunction(L, found->second);
+        }
+    }
+    auto index = tointeger(L, 2)-1;
+    if (static_cast<size_t>(index) > data.size()) {
+        return 0;
+    }
+    return pushinteger(L, data[index]);
+}
+
+static int l_bytearray_meta_newindex(lua::State* L) {
+    auto buffer = touserdata<Bytearray>(L, 1);
+    if (buffer == nullptr) {
+        return 0;
+    }
+    auto& data = buffer->data();
+    auto index = static_cast<size_t>(tointeger(L, 2)-1);
+    auto value = tointeger(L, 3);
+    if (index >= data.size()) {
+        if (index == data.size()) {
+            data.push_back(static_cast<ubyte>(value));
+        }
+        return 0;
+    }
+    data[index] = static_cast<ubyte>(value);
+    return 0;
+}
+
+static int l_bytearray_meta_len(lua::State* L) {
+    if (auto buffer = touserdata<Bytearray>(L, 1)) {
+        return pushinteger(L, buffer->data().size());
+    }
+    return 0;
+}
+
+static int l_bytearray_meta_tostring(lua::State* L) {
+    auto buffer = touserdata<Bytearray>(L, 1);
+    if (buffer == nullptr) {
+        return 0;
+    }
+    auto& data = buffer->data();
+    if (data.size() > 512) {
+        return pushstring(L, "bytearray["+std::to_string(data.size())+"]{...}");
+    } else {
+        std::stringstream ss;
+        ss << "bytearray[" << std::to_string(data.size()) << "]{";
+        for (size_t i = 0; i < data.size(); i++) {
+            if (i > 0) {
+                ss << " ";
+            }
+            ss << static_cast<uint>(data[i]);
+        }
+        ss << "}";
+        return pushstring(L, ss.str());
+    }
+}
+
+static int l_bytearray_meta_add(lua::State* L) {
+    auto bufferA = touserdata<Bytearray>(L, 1);
+    auto bufferB = touserdata<Bytearray>(L, 2);
+    if (bufferA == nullptr || bufferB == nullptr) {
+        return 0;
+    }
+    auto& dataA = bufferA->data();
+    auto& dataB = bufferB->data();
+
+    std::vector<ubyte> ab;
+    ab.reserve(dataA.size() + dataB.size());
+    ab.insert(ab.end(), dataA.begin(), dataA.end());
+    ab.insert(ab.end(), dataB.begin(), dataB.end());
+    return newuserdata<Bytearray>(L, std::move(ab));
+}
+
+int Bytearray::createMetatable(lua::State* L) {
+    createtable(L, 0, 6);
+    pushcfunction(L, lua::wrap<l_bytearray_meta_index>);
+    setfield(L, "__index");
+    pushcfunction(L, lua::wrap<l_bytearray_meta_newindex>);
+    setfield(L, "__newindex");
+    pushcfunction(L, lua::wrap<l_bytearray_meta_len>);
+    setfield(L, "__len");
+    pushcfunction(L, lua::wrap<l_bytearray_meta_tostring>);
+    setfield(L, "__tostring");
+    pushcfunction(L, lua::wrap<l_bytearray_meta_add>);
+    setfield(L, "__add");
+
+    createtable(L, 0, 1);
+    pushcfunction(L, lua::wrap<l_bytearray_meta_meta_call>);
+    setfield(L, "__call");
+    setmetatable(L);
+    return 1;
+}
diff --git a/src/logic/scripting/lua/lua_custom_types.hpp b/src/logic/scripting/lua/lua_custom_types.hpp
new file mode 100644
index 00000000..c69bd2b0
--- /dev/null
+++ b/src/logic/scripting/lua/lua_custom_types.hpp
@@ -0,0 +1,35 @@
+#ifndef LOGIC_SCRIPTING_LUA_LUA_CUSTOM_TYPES_HPP_
+#define LOGIC_SCRIPTING_LUA_LUA_CUSTOM_TYPES_HPP_
+
+#include "lua_commons.hpp"
+
+#include <string>
+#include <vector>
+
+namespace lua {
+    class Userdata {
+    public:
+        virtual ~Userdata() {};
+        virtual const std::string& getTypeName() const = 0;
+    };
+
+    class Bytearray : public Userdata {
+        std::vector<ubyte> buffer;
+    public:
+        Bytearray(size_t capacity);
+        Bytearray(std::vector<ubyte> buffer);
+        virtual ~Bytearray();
+        
+        const std::string& getTypeName() const override {
+            return TYPENAME;
+        }
+        inline std::vector<ubyte>& data() {
+            return buffer;
+        }
+
+        static int createMetatable(lua::State*);
+        inline static std::string TYPENAME = "bytearray";
+    };
+}
+
+#endif // LOGIC_SCRIPTING_LUA_LUA_CUSTOM_TYPES_HPP_
diff --git a/src/logic/scripting/lua/lua_engine.cpp b/src/logic/scripting/lua/lua_engine.cpp
index 096109df..75ef541f 100644
--- a/src/logic/scripting/lua/lua_engine.cpp
+++ b/src/logic/scripting/lua/lua_engine.cpp
@@ -1,6 +1,7 @@
 #include "lua_engine.hpp"
 
 #include "api_lua.hpp"
+#include "lua_custom_types.hpp"
 #include "../../../debug/Logger.hpp"
 #include "../../../util/stringutil.hpp"
 
@@ -45,7 +46,6 @@ static void create_libs(lua::State* L) {
     addfunc(L, "print", lua::wrap<l_print>);
 }
 
-#include <iostream>
 void lua::initialize() {
     logger.info() << LUA_VERSION;
     logger.info() << LUAJIT_VERSION;
@@ -81,6 +81,8 @@ void lua::initialize() {
 
     createtable(L, 0, 0);
     setglobal(L, LAMBDAS_TABLE);
+
+    newusertype<Bytearray, Bytearray::createMetatable>(L, "bytearray");
 }
 
 void lua::finalize() {
diff --git a/src/logic/scripting/lua/lua_util.cpp b/src/logic/scripting/lua/lua_util.cpp
index 198ba280..745889d2 100644
--- a/src/logic/scripting/lua/lua_util.cpp
+++ b/src/logic/scripting/lua/lua_util.cpp
@@ -9,6 +9,15 @@ using namespace lua;
 
 static int nextEnvironment = 1;
 
+std::unordered_map<std::type_index, std::string> lua::usertypeNames;
+
+int lua::userdata_destructor(lua::State* L) {
+    if (auto obj = touserdata<Userdata>(L, 1)) {
+        obj->~Userdata();
+    }
+    return 0;
+}
+
 std::string lua::env_name(int env) {
     return "_ENV"+util::mangleid(env);
 }
diff --git a/src/logic/scripting/lua/lua_util.hpp b/src/logic/scripting/lua/lua_util.hpp
index 3c705eb3..af58ea11 100644
--- a/src/logic/scripting/lua/lua_util.hpp
+++ b/src/logic/scripting/lua/lua_util.hpp
@@ -2,9 +2,16 @@
 #define LOGIC_SCRIPTING_LUA_UTIL_HPP_
 
 #include "lua_commons.hpp"
+#include "lua_custom_types.hpp"
+
+#include <unordered_map>
+#include <typeindex>
+#include <typeinfo>
 
 namespace lua {
     inline std::string LAMBDAS_TABLE = "$L";
+    extern std::unordered_map<std::type_index, std::string> usertypeNames;
+    int userdata_destructor(lua::State* L);
 
     std::string env_name(int env);
 
@@ -42,6 +49,10 @@ namespace lua {
     inline const char* type_name(lua::State* L, int idx) {
         return lua_typename(L, idx);
     }
+    inline int rawget(lua::State* L, int idx=-2) {
+        lua_rawget(L, idx);
+        return 1;
+    }
     inline int rawgeti(lua::State* L, int n, int idx=-1) {
         lua_rawgeti(L, idx, n);
         return 1;
@@ -230,6 +241,12 @@ namespace lua {
     inline bool isfunction(lua::State* L, int idx) {
         return lua_isfunction(L, idx);
     }
+    inline bool isuserdata(lua::State* L, int idx) {
+        return lua_isuserdata(L, idx);
+    }
+    inline void setfield(lua::State* L, const std::string& name, int idx=-2) {
+        lua_setfield(L, idx, name.c_str());
+    }
     inline bool toboolean(lua::State* L, int idx) {
         return lua_toboolean(L, idx);
     }
@@ -245,7 +262,42 @@ namespace lua {
     inline const void* topointer(lua::State* L, int idx) {
         return lua_topointer(L, idx);
     }
-    inline glm::vec2 tovec2(lua::State* L, int idx) {
+    inline void setglobal(lua::State* L, const std::string& name) {
+        lua_setglobal(L, name.c_str());
+    }
+    template<class T>
+    inline T* touserdata(lua::State* L, int idx) {
+        if (void* rawptr = lua_touserdata(L, idx)) {
+            return static_cast<T*>(rawptr);
+        }
+        return nullptr;
+    }
+    template<class T, typename... Args>
+    inline int newuserdata(lua::State* L, Args&&... args) {
+        const auto& found = usertypeNames.find(typeid(T));
+        void* ptr = lua_newuserdata(L, sizeof(T));
+        new (ptr) T(args...);
+
+        if (found == usertypeNames.end()) {
+            log_error("usertype is not registred: "+std::string(typeid(T).name()));
+        } else if (getglobal(L, found->second)) {
+            setmetatable(L);
+        }
+        return 1;
+    }
+
+    template<class T, lua_CFunction func>
+    inline void newusertype(lua::State* L, const std::string& name) {
+        usertypeNames[typeid(T)] = name;
+        func(L);
+
+        pushcfunction(L, userdata_destructor);
+        setfield(L, "__gc");
+
+        setglobal(L, name);
+    } 
+
+    inline glm::vec2 tovec2(lua::State* L, int idx) { 
         pushvalue(L, idx);
         if (!istable(L, idx) || objlen(L, idx) < 2) {
             throw std::runtime_error("value must be an array of two numbers");
@@ -287,14 +339,6 @@ namespace lua {
         return true;
     }
 
-    inline void setfield(lua::State* L, const std::string& name, int idx=-2) {
-        lua_setfield(L, idx, name.c_str());
-    }
-
-    inline void setglobal(lua::State* L, const std::string& name) {
-        lua_setglobal(L, name.c_str());
-    }
-
     inline const char* require_string(lua::State* L, int idx) {
         if (!isstring(L, idx)) {
             throw luaerror("string expected at "+std::to_string(idx));