diff --git a/lua/go.lua b/lua/go.lua
index b00a558..770b909 100644
--- a/lua/go.lua
+++ b/lua/go.lua
@@ -42,6 +42,12 @@ _GO_NVIM_CFG = {
   -- it can be a nulls source name e.g. `golines` or a nulls query table
   lsp_keymaps = true, -- true: use default keymaps defined in go/lsp.lua
   lsp_codelens = true,
+  null_ls = {
+    golangci_lint = {
+      -- disable = {'errcheck', 'staticcheck'}, -- linters to disable empty by default
+      -- enable = {'govet', 'ineffassign','revive', 'gosimple'}, -- linters to enable; empty by default
+    },
+  },
   diagnostic = { -- set diagnostic to false to disable diagnostic
     hdlr = false, -- hook diagnostic handler and send error to quickfix
     underline = true,
diff --git a/lua/go/format.lua b/lua/go/format.lua
index 5d953ca..db354dd 100644
--- a/lua/go/format.lua
+++ b/lua/go/format.lua
@@ -147,7 +147,12 @@ end
 
 M.goimports = function(...)
   local goimports = _GO_NVIM_CFG.goimports or 'gopls'
+  require('go.install').install(goimports)
   local args = { ... }
+  if args[1] == 'goimports' then
+    goimports = 'goimports' -- force goimports
+    table.remove(args, 1)
+  end
   log('imports', args, goimports)
   if goimports == 'gopls' then
     if vfn.empty(args) == 1 then
@@ -159,7 +164,6 @@ M.goimports = function(...)
     end
   end
   local buf = vim.api.nvim_get_current_buf()
-  require('go.install').install(goimports)
   -- specified the pkg name
   if #args > 0 then -- dont use golines
     return run(args, buf, 'goimports')
diff --git a/lua/go/lsp.lua b/lua/go/lsp.lua
index d1cf192..a4eb939 100644
--- a/lua/go/lsp.lua
+++ b/lua/go/lsp.lua
@@ -303,7 +303,13 @@ M.codeaction = function(gopls_cmd, only, hdlr)
       hdlr()
     end
   end
-  local function ca_hdlr(err, result)
+  local function fallback_imports()
+    if only == 'source.organizeImports' then
+      require('go.format').goimports('goimports')
+    end
+  end
+  local function ca_hdlr(err, result, hdl_ctx, config)
+    trace('codeaction', err, result, hdl_ctx, config)
     if err then
       return log('error', err)
     end
@@ -321,20 +327,24 @@ M.codeaction = function(gopls_cmd, only, hdlr)
     end
     if #actions == 0 then
       log('no code actions available')
-      vim.notify('No code actions available', vim.log.levels.INFO)
+      vim.notify('No code actions available, fallback goimports', vim.log.levels.INFO)
+      -- fallback to gofmt/goimports
+      fallback_imports()
       return hdlr()
     end
 
     local action = actions[1]
     -- resolve
-    gopls.request('codeAction/resolve', action, function(_err, resolved_acrtion)
+    gopls.request('codeAction/resolve', action, function(_err, resolved_acrtion, ctx, config)
+      log('codeAction/resolve', _err, resolved_acrtion, ctx, config)
       if _err then
         log('error', _err)
         if action.command then
           apply_action(action)
         else
           log('resolved', resolved_acrtion)
-          vim.notify('No code actions available', vim.log.levels.INFO)
+          vim.notify('No code actions can be resolve fallback goimports', vim.log.levels.INFO)
+          fallback_imports()
           hdlr()
         end
       else
diff --git a/playground/init_packer.lua b/playground/init_packer.lua
deleted file mode 100644
index c528340..0000000
--- a/playground/init_packer.lua
+++ /dev/null
@@ -1,72 +0,0 @@
-vim.cmd([[set runtimepath=$VIMRUNTIME]])
-vim.cmd([[set packpath=/tmp/nvim/site]])
-
-local package_root = '/tmp/nvim/site/pack'
-local install_path = package_root .. '/packer/start/packer.nvim'
-local plugin_folder = function()
-  local host = os.getenv('HOST_NAME')
-  if host and (host:find('Ray') or host:find('ray')) then
-    return [[~/github/]] -- vim.fn.expand("$HOME") .. '/github/'
-  else
-    return ''
-  end
-end
-local function load_plugins()
-  require('packer').startup({
-    function(use)
-      use({ 'wbthomason/packer.nvim' })
-      use({
-        'nvim-treesitter/nvim-treesitter',
-        config = function()
-          require('nvim-treesitter.configs').setup({
-            ensure_installed = { 'go' },
-            highlight = { enable = true },
-          })
-        end,
-        run = ':TSUpdate',
-      })
-      use({ 'neovim/nvim-lspconfig' })
-      use({
-        plugin_folder() .. 'ray-x/go.nvim',
-        requires = {
-          'mfussenegger/nvim-dap', -- Debug Adapter Protocol
-          'rcarriga/nvim-dap-ui',
-          'theHamsta/nvim-dap-virtual-text',
-          'ray-x/guihua.lua',
-        },
-        config = function()
-          require('go').setup({
-            verbose = true,
-            goimports = 'gopls',
-            lsp_cfg = {
-              handlers = {
-                ['textDocument/hover'] = vim.lsp.with(vim.lsp.handlers.hover, { border = 'double' }),
-                ['textDocument/signatureHelp'] = vim.lsp.with(vim.lsp.handlers.signature_help, { border = 'round' }),
-              },
-            }, -- false: do nothing
-            run_in_floaterm = true,
-          })
-        end,
-      })
-    end,
-    config = {
-      package_root = package_root,
-      compile_path = install_path .. '/plugin/packer_compiled.lua',
-    },
-  })
-end
-
-if vim.fn.isdirectory(install_path) == 0 then
-  vim.fn.system({
-    'git',
-    'clone',
-    'https://github.com/wbthomason/packer.nvim',
-    install_path,
-  })
-  load_plugins()
-  require('packer').sync()
-else
-  load_plugins()
-end
-
-vim.cmd('colorscheme murphy')