diff --git a/lua/esqueleto/autocmd.lua b/lua/esqueleto/autocmd.lua
index 37dd293..efbb966 100644
--- a/lua/esqueleto/autocmd.lua
+++ b/lua/esqueleto/autocmd.lua
@@ -3,7 +3,7 @@ local utils = require("esqueleto.utils")
 local M = {}
 
 --- Create autocommands for `esqueleto.nvim`
----@param opts table Plugin configuration table
+---@param opts Esqueleto.Config Plugin configuration table
 M.createautocmd = function(opts)
   -- create autocommands for skeleton insertion
   local group = vim.api.nvim_create_augroup("esqueleto", { clear = true })
@@ -13,15 +13,10 @@ M.createautocmd = function(opts)
     desc = "esqueleto.nvim :: Insert template",
     pattern = opts.patterns,
     callback = function()
-      if vim.bo.buftype == "nofile" then
-        return nil
-      end
-
+      if vim.bo.buftype == "nofile" then return nil end
       local filepath = vim.fn.expand("%")
       local emptyfile = vim.fn.getfsize(filepath) < 4
-      if emptyfile then
-        utils.inserttemplate(opts)
-      end
+      if emptyfile then utils.inserttemplate(opts) end
     end,
   })
 end
diff --git a/lua/esqueleto/config.lua b/lua/esqueleto/config.lua
index b9f4697..8a4e0f9 100644
--- a/lua/esqueleto/config.lua
+++ b/lua/esqueleto/config.lua
@@ -1,7 +1,8 @@
+local selector = require("esqueleto.selectors.builtin")
 local utils = require("esqueleto.utils")
-
 local M = {}
 
+---@type Esqueleto.Config
 M.default_config = {
   autouse = true,
   directories = { vim.fn.stdpath("config") .. "/skeletons" },
@@ -17,43 +18,54 @@ M.default_config = {
       ["filetype"] = function() return vim.bo.filetype end,
 
       -- Date and time
-      ["date"] = function() return os.date("%Y%m%d", os.time()) end,
-      ["year"] = function() return os.date("%Y", os.time()) end,
-      ["month"] = function() return os.date("%m", os.time()) end,
-      ["day"] = function() return os.date("%d", os.time()) end,
-      ["time"] = function() return os.date("%T", os.time()) end,
+      ["date"] = function()
+        return os.date("%Y%m%d", os.time()) --[[@as string]]
+      end,
+      ["year"] = function()
+        return os.date("%Y", os.time()) --[[@as string]]
+      end,
+      ["month"] = function()
+        return os.date("%m", os.time()) --[[@as string]]
+      end,
+      ["day"] = function()
+        return os.date("%d", os.time()) --[[@as string]]
+      end,
+      ["time"] = function()
+        return os.date("%T", os.time()) --[[@as string]]
+      end,
 
       -- System
       ["host"] = utils.capture("hostname", false),
-      ["user"] = os.getenv("USER"),
+      ["user"] = os.getenv("USER") or "USER",
 
       -- Github
       ["gh-email"] = utils.capture("git config user.email", false),
       ["gh-user"] = utils.capture("git config user.name", false),
     },
   },
+  selector = selector,
   advanced = {
     ignored = {},
     ignore_os_files = true,
-  }
+  },
 }
 
---- Update default configuration table by merging with user's configuration table
----@param config table user configuration table
----@return table
+---Update default configuration table by merging with user's configuration table
+---@param config Esqueleto.Config user configuration table
+---@return Esqueleto.Config
 M.updateconfig = function(config)
   vim.validate({ config = { config, "table", true } })
   config = vim.tbl_deep_extend("force", M.default_config, config or {})
 
   -- Validate setup
   vim.validate({
-    autouse = { config.autouse, 'boolean' },
-    directories = { config.directories, 'table' },
-    patterns = { config.patterns, 'table' },
+    autouse = { config.autouse, "boolean" },
+    directories = { config.directories, "table" },
+    patterns = { config.patterns, "table" },
     wildcards = { config.wildcards, "table" },
-    advanced = { config.advanced, 'table' },
-    ["advanced.ignored"] = { config.advanced.ignored, { 'table', 'function' } },
-    ["advanced.ignore_os_files"] = { config.advanced.ignore_os_files, 'boolean' },
+    advanced = { config.advanced, "table" },
+    ["advanced.ignored"] = { config.advanced.ignored, { "table", "function" } },
+    ["advanced.ignore_os_files"] = { config.advanced.ignore_os_files, "boolean" },
   })
 
   return config
diff --git a/lua/esqueleto/init.lua b/lua/esqueleto/init.lua
index df6c2af..801fc19 100644
--- a/lua/esqueleto/init.lua
+++ b/lua/esqueleto/init.lua
@@ -1,13 +1,30 @@
 _G.esqueleto_inserted = {}
 
-local autocmd = require('esqueleto.autocmd')
-local excmd = require('esqueleto.excmd')
-local config = require('esqueleto.config')
+local autocmd = require("esqueleto.autocmd")
+local config = require("esqueleto.config")
+local excmd = require("esqueleto.excmd")
+
+---@alias Wildcard { [string] : string | fun():string }
+---@class Wildcards
+---@field lookup Wildcard
+---@field expand boolean Replace ${} with an instance of a wildcards array?
+
+---@class Esqueleto.Advanced
+---@field ignored string[] | fun(file:string):boolean Array of glob file filters
+---@field ignore_os_files boolean To ignore OS files?
+
+---@class Esqueleto.Config
+---@field directories string[]  The list of paths in which the search will be performed
+---@field patterns string[] See: [vim.api.nvim_create_autocmd](lua://vim.api.nvim_create_autocmd)
+---@field autouse boolean Auto-use a template?
+---@field selector fun( templatenames: string[] ):string? Function that choose some of template
+---@field wildcards Wildcards
+---@field advanced Esqueleto.Advanced
 
 local M = {}
 
 --- Setup `esqueleto.nvim`
----@param opts table User configuration table
+---@param opts Esqueleto.Config User configuration table
 M.setup = function(opts)
   -- update defaults
   opts = config.updateconfig(opts)
diff --git a/lua/esqueleto/selectors/builtin.lua b/lua/esqueleto/selectors/builtin.lua
new file mode 100644
index 0000000..7b1d181
--- /dev/null
+++ b/lua/esqueleto/selectors/builtin.lua
@@ -0,0 +1,15 @@
+return function(templates)
+  -- Sync call ui.select
+  -- See: https://github.com/mfussenegger/nvim-dap/blob/66d33b7585b42b7eac20559f1551524287ded353/lua/dap/ui.lua#L55
+  local co = coroutine.running()
+  local choicer = function(choice)
+    if not choice then
+      vim.notify("[esqueleto] No template selected, leaving buffer empty", vim.log.levels.INFO)
+    end
+    coroutine.resume(co, choice)
+  end
+  -- I don't know reason to use that
+  choicer = vim.schedule_wrap(choicer)
+  vim.ui.select(vim.tbl_keys(templates), { prompt = "Select skeleton to use:" }, choicer)
+  return coroutine.yield()
+end
diff --git a/lua/esqueleto/selectors/telescope.lua b/lua/esqueleto/selectors/telescope.lua
new file mode 100644
index 0000000..c428e0d
--- /dev/null
+++ b/lua/esqueleto/selectors/telescope.lua
@@ -0,0 +1,34 @@
+return function(templates)
+  local co = coroutine.running()
+  local pickers = require("telescope.pickers")
+  local finders = require("telescope.finders")
+  local actions = require("telescope.actions")
+  local action_state = require("telescope.actions.state")
+  pickers
+    .new({}, {
+      prompt_title = "Templates",
+      previewer = _TelescopeConfigurationValues.file_previewer({}),
+      finder = finders.new_table({
+        results = vim.tbl_keys(templates),
+        entry_maker = function(entry)
+          return {
+            value = entry,
+            display = entry,
+            ordinal = entry,
+            filename = templates[entry],
+          }
+        end,
+      }),
+      sorter = _TelescopeConfigurationValues.generic_sorter({}),
+      attach_mappings = function(prompt_bufnr)
+        actions.select_default:replace(function()
+          actions.close(prompt_bufnr)
+          local selection = action_state.get_selected_entry()
+          coroutine.resume(co, selection.value)
+        end)
+        return true
+      end,
+    })
+    :find()
+  return coroutine.yield()
+end
diff --git a/lua/esqueleto/utils.lua b/lua/esqueleto/utils.lua
index 4d408c3..481a60b 100644
--- a/lua/esqueleto/utils.lua
+++ b/lua/esqueleto/utils.lua
@@ -31,7 +31,7 @@ end
 
 --- Write template contents to current buffer
 ---@param file string Template file path
----@param opts table Plugin configuration table
+---@param opts Esqueleto.Config Plugin configuration table
 M.writetemplate = function(file, opts)
   if file == nil then
     -- Do an early return if no files are specified
@@ -41,7 +41,7 @@ M.writetemplate = function(file, opts)
   local handler, message = io.open(file, "r")
   if handler == nil then
     -- Print error message and abort if no file handlers are created
-    vim.notify(message, vim.log.levels.ERROR)
+    vim.notify(message --[[@as string]], vim.log.levels.ERROR)
     return
   end
 
@@ -69,17 +69,21 @@ M.writetemplate = function(file, opts)
   end
 end
 
--- List ignored files under a directory, given a list of glob patterns
+---List ignored files under a directory, given a list of glob patterns
+---@param dir string
+---@param ignored_patterns string[]
+---@return string[]
 local listignored = function(dir, ignored_patterns)
-  return vim.tbl_flatten(
-    vim.tbl_map(
-      function(patterns) return vim.fn.globpath(dir, patterns, true, true, true) end,
-      ignored_patterns
-    )
-  )
+  return vim
+    .iter(ignored_patterns)
+    :map(function(patterns) return vim.fn.globpath(dir, patterns, true, true, true) end)
+    :flatten()
+    :totable()
 end
 
--- Returns a ignore checker
+---Returns a ignore checker
+---@param opts Esqueleto.Config
+---@return fun(filepath:string):boolean
 local getignorechecker = function(opts)
   local os_ignore_pats = opts.advanced.ignore_os_files
       and require("esqueleto.constants").ignored_os_patterns
@@ -104,12 +108,13 @@ end
 
 --- Get available templates for current buffer
 ---@param pattern string Pattern to use to find templates
----@param opts table Plugin configuration table
----@return table templates Available templates for current buffer
+---@param opts Esqueleto.Config Plugin configuration table
+---@return {[string]:string} templates Available templates for current buffer
 M.gettemplates = function(pattern, opts)
+  ---@type {[string]:string}
   local templates = {}
   local isignored = getignorechecker(opts)
-
+  ---@type string[]
   local alldirectories = vim.tbl_map(
     function(f) return vim.fn.fnamemodify(f, ":p") end,
     opts.directories
@@ -142,8 +147,8 @@ M.gettemplates = function(pattern, opts)
 end
 
 --- Select template to insert on current buffer
----@param templates table Available template table
----@param opts table Plugin configuration table
+---@param templates {[string]:string} Available template table
+---@param opts Esqueleto.Config Plugin configuration table
 M.selecttemplate = function(templates, opts)
   -- Check if templates exist
   if vim.tbl_isempty(templates) then
@@ -158,24 +163,27 @@ M.selecttemplate = function(templates, opts)
   local templatenames = vim.tbl_keys(templates)
   table.sort(templatenames, function(a, b) return a:lower() < b:lower() end)
 
+  local uv = vim.loop or vim.uv
   -- If only one template, write and return early
   if #templatenames == 1 and opts.autouse then
-    M.writetemplate(vim.loop.fs_realpath(templates[templatenames[1]]), opts)
+    M.writetemplate(uv.fs_realpath(templates[templatenames[1]])--[[@as string]], opts)
     return nil
   end
 
   -- Select template
-  vim.ui.select(templatenames, { prompt = "Select skeleton to use:" }, function(choice)
+
+  -- wrap to coroutine to have possibility to async function
+  ---@see esqueleto.selectors.builtin
+  coroutine.wrap(function()
+    local choice = opts.selector(templates)
     if templates[choice] then
-      M.writetemplate(vim.loop.fs_realpath(templates[choice]), opts)
-    else
-      vim.notify("[esqueleto] No template selected, leaving buffer empty", vim.log.levels.INFO)
+      M.writetemplate(uv.fs_realpath(templates[choice]) --[[@as string]], opts)
     end
-  end)
+  end)()
 end
 
 --- Insert template on current buffer
----@param opts table Plugin configuration table
+---@param opts Esqueleto.Config Plugin configuration table
 M.inserttemplate = function(opts)
   -- Get pattern alternatives for current file
   local filepath = vim.fn.expand("%:p")
@@ -183,7 +191,7 @@ M.inserttemplate = function(opts)
   local filetype = vim.bo.filetype
 
   -- Identify if pattern matches user configuration
-  local pattern = nil
+  local pattern = ""
   if not _G.esqueleto_inserted[filepath] then
     -- match either filename or extension. Filename has priority
     if vim.tbl_contains(opts.patterns, filename) then
@@ -194,6 +202,7 @@ M.inserttemplate = function(opts)
 
     -- Get templates for selected pattern
     local templates = M.gettemplates(pattern, opts)
+    -- Identify if pattern matches user configuration
 
     -- Pop-up selection UI
     M.selecttemplate(templates, opts)
diff --git a/lua/esqueleto/wildcards.lua b/lua/esqueleto/wildcards.lua
index e6d917a..52f6623 100644
--- a/lua/esqueleto/wildcards.lua
+++ b/lua/esqueleto/wildcards.lua
@@ -2,17 +2,23 @@ local M = {}
 
 --- Parse template contents in order to expand wildcards
 ---@param str string String to parse
----@param lookup table Wildcards lookup table
----@return table parsed_str Table containing all lines with wildcards expanded table
----@return table cursor_pos Row-column position tuple of the last cursor wildcard found.
+---@param lookup Wildcard Wildcards lookup table
+---@return string[] parsed_str Table containing all lines with wildcards expanded table
+---@return nil | [integer, integer] cursor_pos Row-column position tuple of the last cursor wildcard found.
 M.parse = function(str, lookup)
+  ---@type string[]
   local parsedstr = {}
   for _, l in ipairs(vim.split(str, "\n", { plain = true })) do
     for wildcard in l:gmatch("${([^{,^}]+)}") do
-      local expansion = nil
-
+      ---@type string
+      local expansion
       if vim.tbl_contains(vim.tbl_keys(lookup), wildcard) then
-        expansion = lookup[wildcard]
+        local wild = lookup[wildcard]
+        if type(wild) == "function" then
+          expansion = wild()
+        else
+          expansion = wild
+        end
       elseif string.find(wildcard, "lua:") then
         local cmdstr = l:gsub(".*${lua:([^{,^}]+)}.*", "%1")
         local cmdout = load("return " .. cmdstr)()
@@ -30,9 +36,7 @@ M.parse = function(str, lookup)
   local cursor_pos = nil
   for row, l in ipairs(parsedstr) do
     local col, _ = string.find(l, "${cursor}")
-    if col ~= nil then
-      cursor_pos = {row, col}
-    end
+    if col ~= nil then cursor_pos = { row, col } end
     parsedstr[row] = parsedstr[row]:gsub("${cursor}", "")
   end