diff --git a/data/computercraft/lua/packages/example-pkg/1.0.0/package.json b/data/computercraft/lua/packages/example-pkg/1.0.0/package.json
index 7bcd2e6..ca743fb 100644
--- a/data/computercraft/lua/packages/example-pkg/1.0.0/package.json
+++ b/data/computercraft/lua/packages/example-pkg/1.0.0/package.json
@@ -4,6 +4,7 @@
   "description": "An example package for LeonOS",
   "author": "LeonMMcoset",
   "license": "MIT",
+  "type": "app",
   "dependencies": {},
   "files": [
     "example.lua"
diff --git a/data/computercraft/lua/rom/apis/appgui.lua b/data/computercraft/lua/rom/apis/appgui.lua
new file mode 100644
index 0000000..6404c08
--- /dev/null
+++ b/data/computercraft/lua/rom/apis/appgui.lua
@@ -0,0 +1,94 @@
+-- appgui API for LeonOS
+-- Provides simple topbar and downbar drawing functions
+
+local term = require("term")
+local colors = require("colors")
+local expect = require("cc.expect").expect
+
+local appgui = {}
+
+--- Draws a top bar with the specified text centered
+--- @param text string The text to display in the top bar
+--- @param fgColor number Optional foreground color (default: white)
+--- @param bgColor number Optional background color (default: blue)
+function appgui.topbar(text, fgColor, bgColor)
+  expect(1, text, "string")
+  expect(2, fgColor, "number", "nil")
+  expect(3, bgColor, "number", "nil")
+  
+  -- Default colors
+  fgColor = fgColor or colors.white
+  bgColor = bgColor or colors.blue
+  
+  -- Save current colors
+  local oldFg = term.getTextColor()
+  local oldBg = term.getBackgroundColor()
+  
+  -- Get terminal size
+  local w, h = term.getSize()
+  
+  -- Set colors and position
+  term.setTextColor(fgColor)
+  term.setBackgroundColor(bgColor)
+  term.setCursorPos(1, 1)
+  
+  -- Clear the top line
+  term.clearLine()
+  
+  -- Calculate padding for centered text
+  local padding = math.floor((w - #text) / 2)
+  
+  -- Draw the top bar with centered text
+  term.write(string.rep(" ", padding) .. text .. string.rep(" ", padding))
+  
+  -- Restore original colors
+  term.setTextColor(oldFg)
+  term.setBackgroundColor(oldBg)
+  
+  -- Move cursor below the top bar
+  term.setCursorPos(1, 2)
+end
+
+--- Draws a bottom bar with the specified text centered
+--- @param text string The text to display in the bottom bar
+--- @param fgColor number Optional foreground color (default: white)
+--- @param bgColor number Optional background color (default: blue)
+function appgui.downbar(text, fgColor, bgColor)
+  expect(1, text, "string")
+  expect(2, fgColor, "number", "nil")
+  expect(3, bgColor, "number", "nil")
+  
+  -- Default colors
+  fgColor = fgColor or colors.white
+  bgColor = bgColor or colors.blue
+  
+  -- Save current colors
+  local oldFg = term.getTextColor()
+  local oldBg = term.getBackgroundColor()
+  
+  -- Get terminal size
+  local w, h = term.getSize()
+  
+  -- Set colors and position
+  term.setTextColor(fgColor)
+  term.setBackgroundColor(bgColor)
+  term.setCursorPos(1, h)
+  
+  -- Clear the bottom line
+  term.clearLine()
+  
+  -- Calculate padding for centered text
+  local padding = math.floor((w - #text) / 2)
+  
+  -- Draw the bottom bar with centered text
+  term.write(string.rep(" ", padding) .. text .. string.rep(" ", padding))
+  
+  -- Restore original colors
+  term.setTextColor(oldFg)
+  term.setBackgroundColor(oldBg)
+  
+  -- Move cursor to a safe position
+  term.setCursorPos(1, 1)
+end
+
+return appgui
\ No newline at end of file
diff --git a/data/computercraft/lua/rom/help/appgui.hlp b/data/computercraft/lua/rom/help/appgui.hlp
new file mode 100644
index 0000000..a4c99d3
--- /dev/null
+++ b/data/computercraft/lua/rom/help/appgui.hlp
@@ -0,0 +1,103 @@
+=== appgui API ===
+
+The `appgui` API provides simple functions for drawing top bars and bottom bars in LeonOS applications, making it easy to create consistent user interfaces.
+
+== Introduction ==
+
+The appgui API is designed to simplify the process of adding professional-looking UI elements to your applications. It provides two main functions for drawing centered text bars at the top or bottom of the screen.
+
+== Available Functions ==
+
+- **appgui.topbar(text, [fgColor], [bgColor])**: Draws a top bar with centered text
+- **appgui.downbar(text, [fgColor], [bgColor])**: Draws a bottom bar with centered text
+
+== Function Parameters ==
+
+Both functions accept the following parameters:
+
+- **text**: (string) The text to display in the bar
+- **fgColor**: (number, optional) The foreground color (default: white)
+- **bgColor**: (number, optional) The background color (default: blue)
+
+== Usage Examples ==
+
+=== Basic Usage ===
+
+First, you need to import the appgui module:
+
+>>color yellow
+local appgui = require("appgui")
+>>color white
+
+Then you can use the functions to draw bars:
+
+1. Draw a top bar with default colors (white text on blue background):
+>>color yellow
+appgui.topbar("My Application Title")
+>>color white
+
+2. Draw a bottom bar with default colors:
+>>color yellow
+appgui.downbar("Status: Ready")
+>>color white
+
+=== Custom Colors ===
+
+You can specify custom colors using the `colors` module:
+
+>>color yellow
+local colors = require("colors")
+
+-- Red text on yellow background
+appgui.topbar("Warning Message", colors.red, colors.yellow)
+
+-- Green text on black background
+appgui.downbar("Success", colors.green, colors.black)
+>>color white
+
+=== Complete Example ===
+
+Here's a complete example showing how to use both top and bottom bars in an application:
+
+>>color yellow
+local appgui = require("appgui")
+local term = require("term")
+local colors = require("colors")
+
+-- Clear the screen
+term.clear()
+
+-- Draw top and bottom bars
+appgui.topbar("My Application")
+appgui.downbar("Press Q to quit")
+
+-- Add some content
+print()
+print("Welcome to my application!")
+print()
+print("This is a demonstration of the appgui API.")
+print()
+
+-- Wait for 'Q' key to exit
+while true do
+  local event, key = os.pullEvent("key")
+  if key == 16 then -- Q key
+    break
+  end
+end
+>>color white
+
+== Notes ==
+
+- The text will be automatically centered in the bar
+- The functions will preserve the original terminal colors by saving and restoring them
+- After drawing a top bar, the cursor will be positioned below the bar
+- After drawing a bottom bar, the cursor will be positioned at the top of the screen
+- You can use any colors available in the `colors` module
+- If the text is longer than the terminal width, it will be truncated
+
+== See Also ==
+
+- **colors**: For available color values
+- **term**: For other terminal manipulation functions
+- **appgui_demo**: A demonstration program showing the appgui API in action
\ No newline at end of file
diff --git a/data/computercraft/lua/rom/help/create_package.hlp b/data/computercraft/lua/rom/help/create_package.hlp
index c3bbacb..8528fd7 100644
--- a/data/computercraft/lua/rom/help/create_package.hlp
+++ b/data/computercraft/lua/rom/help/create_package.hlp
@@ -52,10 +52,33 @@ The package.json file contains metadata about your package. Here's an example:
 - **version**: The package version (semantic versioning recommended)
 - **author**: Your name or username
 - **description**: A short description of what the package does
+- **type**: The type of your package ("app" for applications, "api" for libraries)
 - **main**: The main Lua file to load
 - **dependencies**: Other packages your package depends on
 - **exports**: Functions or variables to export for other programs to use
 
+== Package Type Field ==
+
+The `type` field in package.json determines where your package files will be installed:
+
+- **app**: Files will be installed in the `/app` directory (default behavior)
+- **api**: Files will be installed in the `/leonos/apis` directory
+
+Example of a package.json with type field:
+
+>>color yellow
+{
+  "name": "example-api",
+  "version": "1.0.0",
+  "author": "Your Name",
+  "description": "An example API package",
+  "type": "api",
+  "main": "example-api.lua",
+  "dependencies": {},
+  "exports": {}
+}
+>>color white
+
 == Writing Package Code ==
 
 Edit the `<package_name>.lua` file to add your code. Here's a simple example:
diff --git a/data/computercraft/lua/rom/programs/appgui_demo.lua b/data/computercraft/lua/rom/programs/appgui_demo.lua
new file mode 100644
index 0000000..cd0707b
--- /dev/null
+++ b/data/computercraft/lua/rom/programs/appgui_demo.lua
@@ -0,0 +1,64 @@
+-- appgui_demo.lua
+-- Demonstration of the appgui API for drawing top and bottom bars
+
+local appgui = require("appgui")
+local term = require("term")
+local colors = require("colors")
+
+-- Clear the screen before starting
+term.clear()
+
+-- Draw the top bar with default colors (white text on blue background)
+appgui.topbar("LeonOS App GUI Demo")
+
+-- Add some content in the middle
+print()
+print("This is a demonstration of the appgui API.")
+print()
+print("The top bar shows the application title.")
+print("The bottom bar shows the status information.")
+print()
+print("Press any key to see custom colors...")
+
+-- Wait for a key press
+os.pullEvent("key")
+
+-- Clear the screen and redraw with custom colors
+term.clear()
+appgui.topbar("Custom Colored Top Bar", colors.yellow, colors.red)
+
+-- Add some content
+print()
+print("Now with custom colors!")
+print()
+print("Top bar: Yellow text on Red background")
+print()
+print("Press any key to continue...")
+
+-- Wait for a key press
+os.pullEvent("key")
+
+-- Clear the screen and draw both top and bottom bars
+term.clear()
+appgui.topbar("Complete GUI Demo")
+appgui.downbar("Status: Running - Press Q to quit")
+
+-- Add some content in the middle
+print()
+print("Now you can see both top and bottom bars.")
+print()
+print("Try resizing the terminal window to see how the text stays centered.")
+print()
+print("Press Q to exit this demo.")
+
+-- Main loop to handle key presses
+while true do
+  local event, key = os.pullEvent("key")
+  if key == 16 then -- Q key
+    break
+  end
+end
+
+-- Clear the screen before exiting
+term.clear()
+print("AppGUI Demo has ended.")
\ No newline at end of file
diff --git a/data/computercraft/lua/rom/programs/pkg.lua b/data/computercraft/lua/rom/programs/pkg.lua
index a66e2b4..e8941fb 100644
--- a/data/computercraft/lua/rom/programs/pkg.lua
+++ b/data/computercraft/lua/rom/programs/pkg.lua
@@ -54,6 +54,7 @@ local function create_package(pkg_name)
     description = "A new package for LeonOS",
     author = "LeonOS User",
     license = "MIT",
+    type = "app", -- 默认类型为app
     dependencies = {},
     files = {
       pkg_name .. ".lua"
@@ -288,18 +289,25 @@ local function install_github_package(repo_path, options)
   meta_file:write(textutils.serializeJSON(meta, false))
   meta_file:close()
   
-  -- 下载并安装文件
+  -- 根据package类型确定安装目录
   print("Installing version: " .. pkg_version)
-  local app_dir = "/app"
-  if not fs.exists(app_dir) then
-    fs.makeDir(app_dir)
+  local install_dir
+  if meta.type and meta.type == "api" then
+    install_dir = "/leonos/apis"
+  else
+    install_dir = "/app" -- 默认安装到app目录
+  end
+  
+  -- 确保安装目录存在
+  if not fs.exists(install_dir) then
+    fs.makeDir(install_dir)
   end
   
   local success_count = 0
   local fail_count = 0
   
   for _, file_path in ipairs(meta.files or {}) do
-    local dest = fs.combine(app_dir, file_path)
+    local dest = fs.combine(install_dir, file_path)
     
     if download_github_package_file(repo_path, file_path, dest) then
       print("Installed: " .. file_path)
@@ -386,17 +394,23 @@ local function install_package(pkg_name, options)
     return false
   end
 
-  -- 安装文件
+  -- 根据package类型确定安装目录
   print("Installing version: " .. latest_version)
-  -- 确保app目录存在
-  local app_dir = "/app"
-  if not fs.exists(app_dir) then
-    fs.makeDir(app_dir)
+  local install_dir
+  if meta.type and meta.type == "api" then
+    install_dir = "/leonos/apis"
+  else
+    install_dir = "/app" -- 默认安装到app目录
+  end
+  
+  -- 确保安装目录存在
+  if not fs.exists(install_dir) then
+    fs.makeDir(install_dir)
   end
   
   for _, file_path in ipairs(meta.files or {}) do
     local src = fs.combine(version_path, file_path)
-    local dest = fs.combine(app_dir, file_path)
+    local dest = fs.combine(install_dir, file_path)
     
     -- 确保目标目录存在
     local dest_dir = fs.getDir(dest)
@@ -508,9 +522,14 @@ local function remove_package(pkg_name)
     file:close()
     local ok, meta = pcall(textutils.unserializeJSON, meta_content)
     if ok and meta then
-      -- 删除包文件
+      -- 移除包文件
       for _, file_path in ipairs(meta.files or {}) do
-        local dest = fs.combine("/rom", file_path)
+        local dest
+        if meta.type and meta.type == "api" then
+          dest = fs.combine("/leonos/apis", file_path)
+        else
+          dest = fs.combine("/app", file_path)
+        end
         if fs.exists(dest) then
           fs.delete(dest)
           print("Removed: " .. file_path)
diff --git a/installer.lua b/installer.lua
index f2120ef..5b5aa1a 100644
--- a/installer.lua
+++ b/installer.lua
@@ -1,5 +1,5 @@
 -- LeonOS installer
-local INSTALLER_VERSION = "1.0.3 Beta 1"
+local INSTALLER_VERSION = "1.0.3 Beta 2"
 local DEFAULT_ROM_DIR = "/leonos"
 
 print("Start loading LeonOS installer ("..INSTALLER_VERSION..")...")
@@ -69,25 +69,28 @@ term.write("[Installer] Loading done.\n")
 local term = require("term")
 local colors = require("colors")
 local rc = require("rc")
--- 保存当前颜色设置
-local old_fg = term.getTextColor()
-local old_bg = term.getBackgroundColor()
+local appgui = require("appgui")
+-- -- 保存当前颜色设置
+-- local old_fg = term.getTextColor()
+-- local old_bg = term.getBackgroundColor()
 
--- 设置名称栏颜色并显示
-term.setTextColor(colors.white)
-term.setBackgroundColor(colors.cyan)
-term.at(1, 1).clearLine()
-term.at(1, 1).write("=== LeonOS Installer ===")
+-- -- 设置名称栏颜色并显示
+-- term.setTextColor(colors.white)
+-- term.setBackgroundColor(colors.cyan)
+-- term.at(1, 1).clearLine()
+-- term.at(1, 1).write("=== LeonOS Installer ===")
+
+-- -- 恢复颜色设置
+-- term.setTextColor(old_fg)
+-- term.setBackgroundColor(old_bg)
+-- term.at(1, 2)
+-- -- 只清除顶栏以下的区域
+-- for y=2, term.getSize() do
+--   term.at(1, y).clearLine()
+-- end
+-- term.at(1, 2)
+appgui.topbar("=== LeonOS Installer ===")
 
--- 恢复颜色设置
-term.setTextColor(old_fg)
-term.setBackgroundColor(old_bg)
-term.at(1, 2)
--- 只清除顶栏以下的区域
-for y=2, term.getSize() do
-  term.at(1, y).clearLine()
-end
-term.at(1, 2)
 tu.coloredPrint(colors.yellow,
   "LeonOS Installer (v"..INSTALLER_VERSION..")\n=======================")
 tu.coloredPrint("You are going to install LeonOS "..INSTALLER_VERSION.." to your computer.")
@@ -96,10 +99,13 @@ tu.coloredPrint("If you want to keep the existing files, please backup them firs
 tu.coloredPrint(colors.yellow, "Are you sure? (y/n)")
 local confirm = read()
 if confirm ~= "y" then
+  term.at(1, y).clearLine()
   print("Installation cancelled.")
   return
 end
-
+for y=2, term.getSize() do
+  term.at(1, y).clearLine()
+end
 local ROM_DIR
 -- tu.coloredPrint("Enter installation directory ", colors.yellow, "[",
 --   colors.lightBlue, DEFAULT_ROM_DIR, colors.yellow, "]")
@@ -200,7 +206,10 @@ assert(io.open(
    "https://gh.catmak.name/https://raw.githubusercontent.com/CCLeonOS/LeonOS/refs/heads/main/unbios.lua"
   )):close()
 ok()
-
+os.sleep(0.5)
+for y=2, term.getSize() do
+  term.at(1, y).clearLine()
+end
 tu.coloredPrint(colors.yellow, "Your computer will restart in 3 seconds.")
 local _, y = term.getCursorPos()