diff --git a/script/files.lua b/script/files.lua
index 62f011361..7998ceed6 100644
--- a/script/files.lua
+++ b/script/files.lua
@@ -655,6 +655,17 @@ function m.compileStateAsync(uri, callback)
     end)
 end
 
+local function pluginOnTransformAst(uri, state)
+    local plugin   = require 'plugin'
+    ---TODO: maybe deepcopy astNode
+    local suc, result = plugin.dispatch('OnTransformAst', uri, state.ast)
+    if not suc then
+        return state
+    end
+    state.ast = result
+    return state
+end
+
 ---@param uri uri
 ---@return parser.state?
 function m.compileState(uri)
@@ -700,6 +711,12 @@ function m.compileState(uri)
         return nil
     end
 
+    state = pluginOnTransformAst(uri, state)
+    if not state then
+        log.error('pluginOnTransformAst failed! discard the file state')
+        return nil
+    end
+
     m.compileStateThen(state, file)
 
     return state
diff --git a/script/parser/guide.lua b/script/parser/guide.lua
index e7eb3751c..103a8cd5a 100644
--- a/script/parser/guide.lua
+++ b/script/parser/guide.lua
@@ -419,6 +419,22 @@ function m.getParentType(obj, want)
     error('guide.getParentType overstack')
 end
 
+--- 寻找所在父类型
+---@param obj parser.object
+---@return parser.object?
+function m.getParentTypes(obj, wants)
+    for _ = 1, 10000 do
+        obj = obj.parent
+        if not obj then
+            return nil
+        end
+        if wants[obj.type] then
+            return obj
+        end
+    end
+    error('guide.getParentTypes overstack')
+end
+
 --- 寻找根区块
 ---@param obj parser.object
 ---@return parser.object
@@ -1289,4 +1305,22 @@ function m.isParam(source)
     return true
 end
 
+---@param source parser.object
+---@param index integer
+---@return parser.object?
+function m.getParam(source, index)
+    if source.type == 'call' then
+        local args = source.args
+        assert(args.type == 'callargs', 'call.args type is\'t callargs')
+        return args[index]
+    elseif source.type == 'callargs' then
+        return source[index]
+    elseif source.type == 'function' then
+        local args = source.args
+        assert(args.type == 'funcargs', 'function.args type is\'t callargs')
+        return args[index]
+    end
+    return nil
+end
+
 return m
diff --git a/script/parser/init.lua b/script/parser/init.lua
index bc004f770..9848ce00a 100644
--- a/script/parser/init.lua
+++ b/script/parser/init.lua
@@ -2,7 +2,7 @@ local api = {
     compile    = require 'parser.compile',
     lines      = require 'parser.lines',
     guide      = require 'parser.guide',
-    luadoc     = require 'parser.luadoc',
+    luadoc     = require 'parser.luadoc'.luadoc,
 }
 
 return api
diff --git a/script/parser/luadoc.lua b/script/parser/luadoc.lua
index c022adcbf..df47fd943 100644
--- a/script/parser/luadoc.lua
+++ b/script/parser/luadoc.lua
@@ -1921,6 +1921,14 @@ local function bindDocWithSources(sources, binded)
     bindGeneric(binded)
     bindCommentsAndFields(binded)
     bindReturnIndex(binded)
+    
+    -- doc is special node
+    if lastDoc.special then
+        if bindDoc(lastDoc.special, binded) then
+            return
+        end
+    end
+
     local row = guide.rowColOf(lastDoc.finish)
     local suc = bindDocsBetween(sources, binded, guide.positionOf(row, 0), lastDoc.start)
     if not suc then
@@ -1956,7 +1964,8 @@ local function bindDocs(state)
             binded = nil
         else
             local nextDoc = state.ast.docs[i+1]
-            if not isNextLine(doc, nextDoc) then
+            if nextDoc and nextDoc.special
+            or not isNextLine(doc, nextDoc) then
                 bindDocWithSources(sources, binded)
                 binded = nil
             end
@@ -1985,7 +1994,7 @@ local function findTouch(state, doc)
     end
 end
 
-return function (state)
+local function luadoc(state)
     local ast = state.ast
     local comments = state.comms
     table.sort(comments, function (a, b)
@@ -2054,6 +2063,15 @@ return function (state)
             end
         end
     end
+    
+    if ast.state.pluginDocs then
+        for i, doc in ipairs(ast.state.pluginDocs) do
+            insertDoc(doc, doc.originalComment)
+        end
+        table.sort(ast.docs, function (a, b)
+            return a.start < b.start
+        end)
+    end
 
     ast.docs.start  = ast.start
     ast.docs.finish = ast.finish
@@ -2064,3 +2082,19 @@ return function (state)
 
     bindDocs(state)
 end
+
+return {
+    buildAndBindDoc = function (ast, src, comment)
+        local doc = buildLuaDoc(comment)
+        if doc then
+            local pluginDocs = ast.state.pluginDocs or {}
+            pluginDocs[#pluginDocs+1] = doc
+            doc.special = src
+            doc.originalComment = comment
+            ast.state.pluginDocs = pluginDocs
+            return true
+        end
+        return false
+    end,
+    luadoc = luadoc
+}
diff --git a/script/plugins/astHelper.lua b/script/plugins/astHelper.lua
new file mode 100644
index 000000000..6f303c799
--- /dev/null
+++ b/script/plugins/astHelper.lua
@@ -0,0 +1,66 @@
+local luadoc = require 'parser.luadoc'
+local ssub = require 'core.substring'
+local guide = require 'parser.guide'
+local _M = {}
+
+function _M.buildComment(t, value)
+    return {
+        type   = 'comment.short',
+        start  = 1,
+        finish = 1,
+        text   = "-@" .. t .. " " .. value,
+    }
+end
+
+function _M.InsertDoc(ast, comm)
+    local comms = ast.state.comms or {}
+    comms[#comms+1] = comm
+    ast.state.comms = comms
+end
+
+--- give the local/global variable add doc.class
+---@param ast parser.object
+---@param source parser.object local/global variable
+---@param classname string
+function _M.addClassDoc(ast, source, classname)
+    if source.type ~= 'local' and not guide.isGlobal(source) then
+        return false
+    end
+    --TODO fileds
+    --TODO callers
+    local comment = _M.buildComment("class", classname)
+    comment.start = source.start - 1
+    comment.finish = comment.start
+
+    return luadoc.buildAndBindDoc(ast, source, comment)
+end
+
+---remove `ast` function node `index` arg, the variable will be the function local variable
+---@param source parser.object function node
+---@param index integer
+---@return parser.object?
+function _M.removeArg(source, index)
+    if source.type == 'function' then
+        local arg = table.remove(source.args, index)
+        if not arg then
+            return nil
+        end
+        arg.parent = arg.parent.parent
+        return arg
+    end
+    return nil
+end
+
+--- 把特定函数当成构造函数,`index` 参数是self
+---@param classname string
+---@param source parser.object function node
+---@param index integer
+function _M.addClassDocAtParam(ast, classname, source, index)
+    local arg = _M.removeArg(source, index)
+    if arg then
+        return _M.addClassDoc(ast, arg, classname)
+    end
+    return false
+end
+
+return _M
diff --git a/test.lua b/test.lua
index 9e596e880..625710617 100644
--- a/test.lua
+++ b/test.lua
@@ -102,11 +102,12 @@ local function main()
 
         testAll()
     end)
-
+    
     test 'tclient'
     test 'full'
     test 'plugins.ffi.test'
-end
+    test 'plugins.ast'
+    end
 
 loadAllLibs()
 main()
diff --git a/test/full/example.lua b/test/full/example.lua
index de32d60bf..920dcd0d8 100644
--- a/test/full/example.lua
+++ b/test/full/example.lua
@@ -4,7 +4,7 @@ local files  = require 'files'
 local diag   = require 'core.diagnostics'
 local config = require 'config'
 local fs     = require 'bee.filesystem'
-local luadoc = require "parser.luadoc"
+local luadoc = require "parser".luadoc
 
 -- 临时
 ---@diagnostic disable: await-in-sync
diff --git a/test/plugins/ast/init.lua b/test/plugins/ast/init.lua
new file mode 100644
index 000000000..ac2f7079d
--- /dev/null
+++ b/test/plugins/ast/init.lua
@@ -0,0 +1,92 @@
+local config  = require 'config'
+local utility = require 'utility'
+local parser  = require 'parser'
+local luadoc  = require 'parser.luadoc'
+local guide   = require 'parser.guide'
+local vm      = require 'vm'
+local helper  = require 'plugins.astHelper'
+
+---@diagnostic disable: await-in-sync
+local function TestPlugin(script, plugin, checker)
+    config.set(TESTURI, 'Lua.workspace.preloadFileSize', 1000000000)
+    local state = parser.compile(script, "Lua", "Lua 5.4")
+    state.ast = plugin(TESTURI, state.ast) or state.ast
+    parser.luadoc(state)
+    checker(state)
+end
+
+local function isDocClass(ast)
+    return ast.bindDocs[1].type == 'doc.class'
+end
+
+local function TestAIsClass(state, next)
+    assert(isDocClass(state.ast[1]))
+end
+
+--- when call Class
+local function plugin_AddClass(uri, ast)
+    guide.eachSourceType(ast, "call", function (source)
+        local node = source.node
+        if not guide.isGet(node) then
+            return
+        end
+        if not guide.isGlobal(node) then
+            return
+        end
+        if guide.getKeyName(node) ~= 'Class' then
+            return
+        end
+        local wants = {
+            ['local'] = true,
+            ['setglobal'] = true
+        }
+        local classnameNode = guide.getParentTypes(source, wants)
+        if not classnameNode then
+            return
+        end
+        local classname = guide.getKeyName(classnameNode)
+        if classname then
+            helper.addClassDoc(ast, classnameNode, classname)
+        end
+    end)
+end
+
+local function plugin_AddClassAtParam(uri, ast)
+    guide.eachSourceType(ast, "function", function (src)
+        helper.addClassDocAtParam(ast, "A", src, 1)
+    end)
+end
+
+local function TestSelfIsClass(state, next)
+    guide.eachSourceType(state.ast, "local", function (source)
+        if source[1] == 'self' then
+            assert(source.bindDocs)
+            assert(source.parent.type == 'function')
+            assert(#source.parent.args == 0)
+        end
+    end)
+end
+
+local function TestPlugin1(script)
+    TestPlugin(script, plugin_AddClass, TestAIsClass)
+end
+
+local function TestPlugin2(script)
+    TestPlugin(script, plugin_AddClassAtParam, TestSelfIsClass)
+end
+
+TestPlugin1 [[
+    local A = Class(function() end)
+]]
+
+TestPlugin1 [[
+    A = Class(function() end)
+]]
+
+TestPlugin2 [[
+    local function ctor(self) end
+]]
+
+TestPlugin2 [[
+    function ctor(self) end
+]]