diff --git a/lua/cosmic/core/pluginsInit.lua b/lua/cosmic/core/pluginsInit.lua
index f795a7f..ec54e33 100644
--- a/lua/cosmic/core/pluginsInit.lua
+++ b/lua/cosmic/core/pluginsInit.lua
@@ -80,24 +80,20 @@ return packer.startup(function()
       require('cosmic.lsp')
     end,
     requires = {
-      {
-        'ray-x/lsp_signature.nvim',
-        config = function()
-          -- must happen after servers are set up
-          require('lsp_signature').setup({
-            bind = true, -- This is mandatory, otherwise border config won't get registered.
-            handler_opts = {
-              border = 'rounded',
-            },
-          })
-        end,
-        after = 'nvim-lspconfig',
-      },
       { 'jose-elias-alvarez/nvim-lsp-ts-utils' },
       { 'williamboman/nvim-lsp-installer' },
     },
   })
 
+  use({
+    'CosmicNvim/cosmic-ui',
+    requires = { 'MunifTanjim/nui.nvim', 'nvim-lua/plenary.nvim', 'ray-x/lsp_signature.nvim' },
+    config = function()
+      require('cosmic-ui').setup({})
+    end,
+    after = 'nvim-lspconfig',
+  })
+
   use({
     'jose-elias-alvarez/null-ls.nvim',
     config = function()
diff --git a/lua/cosmic/lsp/autocomplete.lua b/lua/cosmic/lsp/autocomplete.lua
index a760f5e..9b70033 100644
--- a/lua/cosmic/lsp/autocomplete.lua
+++ b/lua/cosmic/lsp/autocomplete.lua
@@ -59,7 +59,7 @@ M.init = function()
       }),
     },
     documentation = {
-      border = 'single',
+      border = 'rounded',
       winhighlight = 'FloatBorder:FloatBorder,Normal:Normal',
     },
     experimental = {
diff --git a/lua/cosmic/lsp/diagnostics.lua b/lua/cosmic/lsp/diagnostics.lua
deleted file mode 100644
index 76b02d0..0000000
--- a/lua/cosmic/lsp/diagnostics.lua
+++ /dev/null
@@ -1,68 +0,0 @@
-local config = require('cosmic.config')
-local icons = require('cosmic.theme.icons')
-
-local defaults = {
-  underline = true,
-  signs = true,
-  update_in_insert = false,
-  severity_sort = true,
-  float = {
-    header = false,
-    source = 'always',
-    border = 'single',
-  },
-  virtual_text = {
-    spacing = 4,
-    source = 'always',
-    severity = {
-      min = vim.diagnostic.severity.HINT,
-    },
-    -- todo: icons for diagnostics?
-    --[[ format = function(diagnostic)
-          if diagnostic.severity == vim.diagnostic.severity.ERROR then
-            return ('E: %s'):format(diagnostic.message)
-          end
-          return diagnostic.message
-        end, ]]
-  },
-}
-
-local opts = vim.tbl_deep_extend('force', defaults, config.lsp.diagnostic or {})
-
-vim.diagnostic.config(opts)
-
-local function do_diagnostic_signs()
-  local signs = {
-    Error = icons.error .. ' ',
-    Warn = icons.warn .. ' ',
-    Hint = icons.hint .. ' ',
-    Info = icons.info .. ' ',
-  }
-
-  local t = vim.fn.sign_getdefined('DiagnosticSignWarn')
-  if vim.tbl_isempty(t) then
-    for type, icon in pairs(signs) do
-      local hl = 'DiagnosticSign' .. type
-      vim.fn.sign_define(hl, { text = icon, texthl = hl, numhl = '' })
-    end
-  end
-end
-
-local function do_legacy_diagnostic_signs()
-  local signs = {
-    Error = icons.error .. ' ',
-    Warning = icons.warn .. ' ',
-    Hint = icons.hint .. ' ',
-    Information = icons.info .. ' ',
-  }
-  local h = vim.fn.sign_getdefined('LspDiagnosticsSignWarn')
-  if vim.tbl_isempty(h) then
-    for type, icon in pairs(signs) do
-      local hl = 'LspDiagnosticsSign' .. type
-      vim.fn.sign_define(hl, { text = icon, texthl = hl, numhl = '' })
-    end
-  end
-end
-
-do_diagnostic_signs()
-do_legacy_diagnostic_signs()
diff --git a/lua/cosmic/lsp/init.lua b/lua/cosmic/lsp/init.lua
index 4905687..e3eca7c 100644
--- a/lua/cosmic/lsp/init.lua
+++ b/lua/cosmic/lsp/init.lua
@@ -1,7 +1,4 @@
-require('cosmic.lsp.providers')
-require('cosmic.lsp.diagnostics')
+-- local config = require('cosmic.config')
 
-vim.lsp.handlers['textDocument/signatureHelp'] = vim.lsp.with(vim.lsp.handlers.signature_help, { border = 'single' })
-vim.lsp.handlers['textDocument/hover'] = vim.lsp.with(vim.lsp.handlers.hover, {
-  border = 'single',
-})
+-- set up lsp servers
+require('cosmic.lsp.providers')
diff --git a/lua/cosmic/lsp/mappings.lua b/lua/cosmic/lsp/mappings.lua
index 7283bf6..a07adf7 100644
--- a/lua/cosmic/lsp/mappings.lua
+++ b/lua/cosmic/lsp/mappings.lua
@@ -8,7 +8,7 @@ map('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>')
 map('n', 'gi', '<cmd>lua require("telescope.builtin").lsp_implementations()<cr>')
 map('n', 'gt', '<cmd>lua require("telescope.builtin").lsp_type_definitions()<cr>')
 map('n', 'gr', '<cmd>lua require("telescope.builtin").lsp_references()<cr>')
-map('n', 'gn', '<cmd>lua require("cosmic.theme.ui").rename()<cr>')
+map('n', 'gn', '<cmd>lua require("cosmic-ui").rename()<cr>')
 
 -- diagnostics
 map('n', '[g', '<cmd>lua vim.diagnostic.goto_prev()<cr>')
diff --git a/lua/cosmic/modules/statusline/init.lua b/lua/cosmic/modules/statusline/init.lua
index 82b79d3..1aba5d6 100644
--- a/lua/cosmic/modules/statusline/init.lua
+++ b/lua/cosmic/modules/statusline/init.lua
@@ -5,7 +5,7 @@ local condition = require('galaxyline.condition')
 local fileinfo = require('galaxyline.providers.fileinfo')
 local utils = require('cosmic.utils')
 local colors = require('cosmic.theme.colors')
-local highlight = utils.highlight
+local highlight = require('cosmic.theme.highlight')
 local icons = require('cosmic.theme.icons')
 local config = require('cosmic.config')
 
diff --git a/lua/cosmic/packer.lua b/lua/cosmic/packer.lua
index 4a23f7d..ae4c722 100644
--- a/lua/cosmic/packer.lua
+++ b/lua/cosmic/packer.lua
@@ -33,9 +33,9 @@ end
 packer.init({
   display = {
     open_fn = function()
-      return require('packer.util').float({ border = 'single' })
+      return require('packer.util').float({ border = 'rounded' })
     end,
-    prompt_border = 'single',
+    prompt_border = 'rounded',
   },
   git = {
     clone_timeout = 800, -- Timeout, in seconds, for git clones
diff --git a/lua/cosmic/theme/highlight.lua b/lua/cosmic/theme/highlight.lua
new file mode 100644
index 0000000..6eb182a
--- /dev/null
+++ b/lua/cosmic/theme/highlight.lua
@@ -0,0 +1,9 @@
+return function(group, bg, fg, gui)
+  if gui ~= nil and gui ~= '' then
+    vim.api.nvim_command(('hi %s guibg=%s guifg=%s gui=%s'):format(group, bg, fg, gui))
+  elseif bg == nil then
+    vim.api.nvim_command(('hi %s guifg=%s'):format(group, fg))
+  else
+    vim.api.nvim_command(('hi %s guibg=%s guifg=%s'):format(group, bg, fg))
+  end
+end
diff --git a/lua/cosmic/theme/init.lua b/lua/cosmic/theme/init.lua
index d3b2af5..94323b7 100644
--- a/lua/cosmic/theme/init.lua
+++ b/lua/cosmic/theme/init.lua
@@ -2,7 +2,7 @@ local _, colors = pcall(require, 'cosmic.theme.colors')
 if not colors then
   return
 end
-local highlight = require('cosmic.utils').highlight
+local highlight = require('cosmic.theme.highlight')
 
 -- diagnostic virtual text highlights
 highlight('DiagnosticVirtualTextError', 'None', colors.error)
@@ -32,7 +32,7 @@ highlight('LspDiagnosticsSignInformation', 'None', colors.info)
 highlight('LspDiagnosticsSignHint', 'None', colors.hint)
 
 -- signature highlight color
-highlight('LspSignatureActiveParameter', 'None', colors.orange)
+-- highlight('LspSignatureActiveParameter', 'None', colors.orange)
 
 -- currently not working?
 highlight('TelescopeSelectionCaret', 'None', colors.selection_caret)
diff --git a/lua/cosmic/theme/ui.lua b/lua/cosmic/theme/ui.lua
deleted file mode 100644
index e5bb56f..0000000
--- a/lua/cosmic/theme/ui.lua
+++ /dev/null
@@ -1,99 +0,0 @@
-local M = {}
-
-local api = vim.api
-local lsp = vim.lsp
-local buf, win
-
-function M.rename()
-  local icons = require('cosmic.theme.icons')
-  local utils = require('cosmic.utils')
-  local config = require('cosmic.config')
-  local Logger = require('cosmic.utils.logger')
-  local highlight = utils.highlight
-  local prompt_str = ' ' .. icons.folder.arrow_closed .. ' '
-  local map_opts = { noremap = true, silent = true }
-  local opts = {
-    style = 'minimal',
-    border = 'single',
-    relative = 'cursor',
-    width = 25,
-    height = 1,
-    row = 1,
-    col = 1,
-  }
-  buf, win = api.nvim_create_buf(false, true)
-  api.nvim_buf_set_option(buf, 'bufhidden', 'wipe')
-
-  api.nvim_open_win(buf, true, opts)
-  api.nvim_win_set_option(win, 'scrolloff', 0)
-  api.nvim_win_set_option(win, 'sidescrolloff', 0)
-  api.nvim_buf_set_option(buf, 'modifiable', true)
-  api.nvim_buf_set_option(buf, 'buftype', 'prompt')
-
-  local _, colors = pcall(require, 'cosmic.theme.colors')
-  if colors then
-    api.nvim_buf_add_highlight(buf, -1, 'LspRenamePrompt', 0, 0, #prompt_str)
-    highlight('LspRenamePrompt', 'None', colors.selection_caret)
-  end
-
-  vim.fn.prompt_setprompt(buf, prompt_str)
-
-  vim.api.nvim_command('startinsert!')
-  api.nvim_buf_set_keymap(buf, 'i', '<esc>', '<CMD>stopinsert <BAR> q!<CR>', map_opts)
-  api.nvim_buf_set_keymap(
-    buf,
-    'i',
-    '<CR>',
-    "<CMD>stopinsert <BAR> lua require('cosmic.theme.ui')._rename()<CR>",
-    map_opts
-  )
-
-  local function handler(...)
-    local result
-    local method
-    local err = select(1, ...)
-    local is_new = not select(4, ...) or type(select(4, ...)) ~= 'number'
-    if is_new then
-      method = select(3, ...).method
-      result = select(2, ...)
-    else
-      method = select(2, ...)
-      result = select(3, ...)
-    end
-
-    if config.lsp.rename_notification then
-      if err then
-        Logger:error(("Error running LSP query '%s': %s"):format(method, err))
-        return
-      end
-
-      -- echo the resulting changes
-      local new_word = ''
-      if result and result.changes then
-        local msg = {}
-        for f, c in pairs(result.changes) do
-          new_word = c[1].newText
-          table.insert(msg, ('%d changes -> %s'):format(#c, utils.get_relative_path(f)))
-        end
-        local currName = vim.fn.expand('<cword>')
-        Logger:log(msg, { title = ('Rename: %s -> %s'):format(currName, new_word) })
-      end
-    end
-
-    vim.lsp.handlers[method](...)
-  end
-
-  function M._rename()
-    local new_name = vim.trim(vim.fn.getline('.'):sub(5, -1))
-    vim.cmd([[q!]])
-    local params = lsp.util.make_position_params()
-    local curr_name = vim.fn.expand('<cword>')
-    if not (new_name and #new_name > 0) or new_name == curr_name then
-      return
-    end
-    params.newName = new_name
-    lsp.buf_request(0, 'textDocument/rename', params, handler)
-  end
-end
-
-return M
diff --git a/lua/cosmic/utils/init.lua b/lua/cosmic/utils/init.lua
index e431322..ba71ac0 100644
--- a/lua/cosmic/utils/init.lua
+++ b/lua/cosmic/utils/init.lua
@@ -19,24 +19,6 @@ function M.split(str, sep)
   return res
 end
 
-function M.highlight(group, bg, fg, gui)
-  if gui ~= nil and gui ~= '' then
-    vim.api.nvim_command(('hi %s guibg=%s guifg=%s gui=%s'):format(group, bg, fg, gui))
-  elseif bg == nil then
-    vim.api.nvim_command(('hi %s guifg=%s'):format(group, fg))
-  else
-    vim.api.nvim_command(('hi %s guibg=%s guifg=%s'):format(group, bg, fg))
-  end
-end
-
-function M.get_relative_path(file_path)
-  local plenary_path = require('plenary.path')
-  local parsed_path, _ = file_path:gsub('file://', '')
-  local path = plenary_path:new(parsed_path)
-  local relative_path = path:make_relative(vim.fn.getcwd())
-  return './' .. relative_path
-end
-
 function M.get_active_lsp_client_names()
   local active_clients = vim.lsp.get_active_clients()
   local client_names = {}