diff --git a/lua/cosmic/config/config.lua b/lua/cosmic/config/config.lua
index bd4a83b..4a01795 100644
--- a/lua/cosmic/config/config.lua
+++ b/lua/cosmic/config/config.lua
@@ -9,18 +9,8 @@ config.statusline = {
   main_icon = '★',
 }
 
-config.treesitter = {
-  ensure_installed = {
-    'typescript',
-    'javascript',
-    'tsx',
-    'html',
-    'css',
-    'lua',
-    'json',
-    'scss',
-  },
-}
+See cosmic defaults: cosmic/core/treesitter/init.lua
+config.treesitter = {}
 
 config.lsp = {
 
@@ -31,20 +21,8 @@ config.lsp = {
   rename_notification = false,
 
   -- see :h vim.diagnostic.config for all diagnostic configuration options
+  -- see cosmic defaults: cosmic/lsp/diagnostics.lua
   diagnostic = {
-
-    -- disable diagnostic virtual text
-    virtual_text = false,
-
-    -- disable diagnostic signs
-    signs = false,
-
-    -- enable diagnostic update on insert
-    update_in_insert = true,
-
-    -- disable underline for diagnostic
-    underline = false,
-
   },
 
   servers = {
diff --git a/lua/cosmic/config/init.lua b/lua/cosmic/config/init.lua
index 620d706..b52874c 100644
--- a/lua/cosmic/config/init.lua
+++ b/lua/cosmic/config/init.lua
@@ -15,47 +15,10 @@ local default_config = {
   statusline = {
     main_icon = require('cosmic.core.theme.icons').ghost,
   },
-  treesitter = {
-    ensure_installed = {
-      'typescript',
-      'javascript',
-      'tsx',
-      'html',
-      'css',
-      'lua',
-      'json',
-      'scss',
-    },
-  },
   lsp = {
     format_on_save = true, -- true/false or table of filetypes {'.ts', '.js',}
     rename_notification = true,
     -- vim.diagnostic.config settiings
-    diagnostic = {
-      underline = true,
-      signs = true,
-      update_in_insert = false,
-      severity_sort = true,
-      float = {
-        show_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, ]]
-      },
-    },
     servers = {
       -- enable/disable server + formatting
       -- rust_analyzer = true, -- enable non-default servers
diff --git a/lua/cosmic/core/dashboard/init.lua b/lua/cosmic/core/dashboard/init.lua
index 4a9c172..4b54b01 100644
--- a/lua/cosmic/core/dashboard/init.lua
+++ b/lua/cosmic/core/dashboard/init.lua
@@ -29,11 +29,11 @@ g.dashboard_custom_section = {
     command = 'Telescope find_files',
   },
   file_explorer = {
-    description = { icons.file2 .. ' File Manager        <C-n>    ' },
+    description = { icons.file2 .. ' File Manager        <C-n>     ' },
     command = 'NvimTreeToggle',
   },
   find_string = {
-    description = { icons.word .. '  Grep String         <leader>fs' },
+    description = { icons.word .. ' Grep String         <leader>fs' },
     command = 'Telescope grep_string',
   },
   last_session = {
diff --git a/lua/cosmic/core/session/init.lua b/lua/cosmic/core/session/init.lua
index 5737408..a0b9e20 100644
--- a/lua/cosmic/core/session/init.lua
+++ b/lua/cosmic/core/session/init.lua
@@ -1,6 +1,9 @@
-require('auto-session').setup({
+local config = require('cosmic.config')
+local defaults = {
   pre_save_cmds = { 'NvimTreeClose', 'cclose', 'lua vim.notify.dismiss()' },
   auto_session_enabled = false,
   auto_save_enabled = true,
   auto_restore_enabled = false,
-})
+}
+
+require('auto-session').setup(vim.tbl_deep_extend('force', defaults, config.session or {}))
diff --git a/lua/cosmic/core/statusline/init.lua b/lua/cosmic/core/statusline/init.lua
index 87f1a74..8221685 100644
--- a/lua/cosmic/core/statusline/init.lua
+++ b/lua/cosmic/core/statusline/init.lua
@@ -9,7 +9,12 @@ local highlight = utils.highlight
 local icons = require('cosmic.core.theme.icons')
 local config = require('cosmic.config')
 
-local main_icon = config.statusline.main_icon
+local defaults = vim.tbl_deep_extend('force', {
+  statusline = {
+    main_icon = icons.ghost,
+  },
+}, config.statusline or {})
+local main_icon = defaults.statusline.main_icon
 
 local get_mode = function()
   local mode_colors = {
diff --git a/lua/cosmic/core/theme/icons.lua b/lua/cosmic/core/theme/icons.lua
index 319a87a..7c40246 100644
--- a/lua/cosmic/core/theme/icons.lua
+++ b/lua/cosmic/core/theme/icons.lua
@@ -5,13 +5,13 @@ local icons = {
   arrow_right_filled = '', -- e0b0
   arrow_left = '', -- e0b3
   arrow_right = '', -- e0b1
-  ghost = ' ',
+  ghost = '',
   warn = '',
   info = '',
   error = '',
   hint = '',
   perf = ' ',
-  note = ' ',
+  note = '',
   branch = '',
   file = '',
   dotdotdot = '…',
@@ -22,9 +22,9 @@ local icons = {
   flame = ' ',
   check = ' ',
   trace = '✎',
-  file1 = ' ',
-  file2 = ' ',
-  clock = ' ',
+  file1 = '',
+  file2 = '',
+  clock = '',
   word = '',
   git = {
     unstaged = '✗',
diff --git a/lua/cosmic/core/treesitter/init.lua b/lua/cosmic/core/treesitter/init.lua
index 83abd5e..cbb9cc0 100644
--- a/lua/cosmic/core/treesitter/init.lua
+++ b/lua/cosmic/core/treesitter/init.lua
@@ -1,6 +1,16 @@
 local config = require('cosmic.config')
-require('nvim-treesitter.configs').setup({
-  ensure_installed = config.treesitter.ensure_installed,
+
+local defaults = {
+  ensure_installed = {
+    'typescript',
+    'javascript',
+    'tsx',
+    'html',
+    'css',
+    'lua',
+    'json',
+    'scss',
+  },
   highlight = {
     enable = true,
     use_languagetree = true,
@@ -18,4 +28,6 @@ require('nvim-treesitter.configs').setup({
     highlight_definitions = { enable = true },
     highlight_current_scope = { enable = false },
   },
-})
+}
+
+require('nvim-treesitter.configs').setup(vim.tbl_deep_extend('force', defaults, config.treesitter or {}))
diff --git a/lua/cosmic/lsp/diagnostics.lua b/lua/cosmic/lsp/diagnostics.lua
index 0add56e..04d1857 100644
--- a/lua/cosmic/lsp/diagnostics.lua
+++ b/lua/cosmic/lsp/diagnostics.lua
@@ -1,7 +1,35 @@
 local config = require('cosmic.config')
 local icons = require('cosmic.core.theme.icons')
 
-vim.diagnostic.config(config.lsp.diagnostic)
+local defaults = {
+  underline = true,
+  signs = true,
+  update_in_insert = false,
+  severity_sort = true,
+  float = {
+    show_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 = {