diff --git a/configuration.nix b/configuration.nix
index 250fafd..515b715 100644
--- a/configuration.nix
+++ b/configuration.nix
@@ -185,6 +185,7 @@ inputs: let
       };
 
       vim.ui = {
+        borders.enable = true;
         noice.enable = true;
         colorizer.enable = true;
         modes-nvim.enable = false; # the theme looks terrible with catppuccin
diff --git a/modules/completion/nvim-cmp/config.nix b/modules/completion/nvim-cmp/config.nix
index 52e8972..e7ab3ac 100644
--- a/modules/completion/nvim-cmp/config.nix
+++ b/modules/completion/nvim-cmp/config.nix
@@ -193,12 +193,14 @@ in {
 
       local cmp = require'cmp'
       cmp.setup({
+        ${optionalString (config.vim.ui.borders.enable) ''
+        -- explicitly enabled by setting ui.borders.enable = true
+        -- TODO: try to get nvim-cmp to follow global border style
         window = {
-          -- TODO: at some point, those need to be optional
-          -- but first nvim cmp module needs to be detached from "cfg.autocomplete"
           completion = cmp.config.window.bordered(),
           documentation = cmp.config.window.bordered(),
         },
+      ''}
 
         snippet = {
           expand = function(args)
diff --git a/modules/lsp/lsp-signature/config.nix b/modules/lsp/lsp-signature/config.nix
index 738dcb5..1e73476 100644
--- a/modules/lsp/lsp-signature/config.nix
+++ b/modules/lsp/lsp-signature/config.nix
@@ -14,7 +14,14 @@ in {
 
     vim.luaConfigRC.lsp-signature = nvim.dag.entryAnywhere ''
       -- Enable lsp signature viewer
-      require("lsp_signature").setup()
+      require("lsp_signature").setup({
+        ${optionalString (config.vim.ui.borders.plugins.lsp-signature.enable) ''
+        bind = true, -- This is mandatory, otherwise border config won't get registered.
+        handler_opts = {
+          border = "${config.vim.ui.borders.plugins.lsp-signature.style}"
+        }
+      ''}
+      })
     '';
   };
 }
diff --git a/modules/lsp/lspconfig/config.nix b/modules/lsp/lspconfig/config.nix
index 70485be..e9d7b3c 100644
--- a/modules/lsp/lspconfig/config.nix
+++ b/modules/lsp/lspconfig/config.nix
@@ -16,6 +16,13 @@ in {
 
       vim.luaConfigRC.lspconfig = nvim.dag.entryAfter ["lsp-setup"] ''
         local lspconfig = require('lspconfig')
+
+        ${
+          # TODO: make border style configurable
+          optionalString (config.vim.ui.borders.enable) ''
+            require('lspconfig.ui.windows').default_options.border = '${config.vim.ui.borders.globalStyle}'
+          ''
+        }
       '';
     }
     {
diff --git a/modules/lsp/lspsaga/config.nix b/modules/lsp/lspsaga/config.nix
index 3b7ea26..74b91fc 100644
--- a/modules/lsp/lspsaga/config.nix
+++ b/modules/lsp/lspsaga/config.nix
@@ -39,7 +39,11 @@ in {
     vim.luaConfigRC.lspsage = nvim.dag.entryAnywhere ''
       -- Enable lspsaga
       local saga = require 'lspsaga'
-      saga.init_lsp_saga()
+      saga.init_lsp_saga({
+        ${optionalString (config.vim.ui.borders.plugins.lspsaga.enable) ''
+        border_style = '${config.vim.ui.borders.plugins.lspsaga.style}',
+      ''}
+      })
     '';
   };
 }
diff --git a/modules/minimap/codewindow/config.nix b/modules/minimap/codewindow/config.nix
index 1025e63..ac82829 100644
--- a/modules/minimap/codewindow/config.nix
+++ b/modules/minimap/codewindow/config.nix
@@ -27,7 +27,7 @@ in {
     vim.luaConfigRC.codewindow = nvim.dag.entryAnywhere ''
       local codewindow = require('codewindow')
       codewindow.setup({
-        exclude_filetypes = { 'NvimTree', 'orgagenda'},
+        exclude_filetypes = { 'NvimTree', 'orgagenda', 'Alpha'},
       })
     '';
   };
diff --git a/modules/ui/borders/borders.nix b/modules/ui/borders/borders.nix
new file mode 100644
index 0000000..179de44
--- /dev/null
+++ b/modules/ui/borders/borders.nix
@@ -0,0 +1,43 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkOption mkEnableOption types;
+
+  cfg = config.vim.ui.borders;
+
+  defaultStyles = ["none" "single" "double" "rounded"];
+in {
+  options.vim.ui.borders = {
+    enable = mkEnableOption "visible borders for most windows";
+
+    globalStyle = mkOption {
+      type = types.enum defaultStyles;
+      default = "rounded";
+      description = ''
+        global border style to use
+      '';
+    };
+
+    # TODO: make per-plugin borders configurable
+    plugins = let
+      mkPluginStyleOption = name: {
+        enable = mkEnableOption "whether to enable borders for the ${name} plugin" // {default = cfg.enable;};
+
+        style = mkOption {
+          type = types.enum (defaultStyles ++ lib.optionals (name != "which-key") ["shadow"]);
+          default = cfg.globalStyle;
+          description = "border style to use for the ${name} plugin";
+        };
+      };
+    in {
+      # despite not having it listed in example configuration, which-key does support the rounded type
+      # additionall, it supports a "shadow" type that is similar to none but is of higher contrast
+      which-key = mkPluginStyleOption "which-key";
+      lspsaga = mkPluginStyleOption "lspsaga";
+      nvim-cmp = mkPluginStyleOption "nvim-cmp";
+      lsp-signature = mkPluginStyleOption "lsp-signature";
+    };
+  };
+}
diff --git a/modules/ui/borders/default.nix b/modules/ui/borders/default.nix
new file mode 100644
index 0000000..526ac4e
--- /dev/null
+++ b/modules/ui/borders/default.nix
@@ -0,0 +1,5 @@
+_: {
+  imports = [
+    ./borders.nix
+  ];
+}
diff --git a/modules/ui/default.nix b/modules/ui/default.nix
index 980a04a..757dd46 100644
--- a/modules/ui/default.nix
+++ b/modules/ui/default.nix
@@ -6,5 +6,6 @@ _: {
     ./smartcolumn
     ./colorizer
     ./illuminate
+    ./borders
   ];
 }
diff --git a/modules/ui/noice/config.nix b/modules/ui/noice/config.nix
index 705256b..d12ebf0 100644
--- a/modules/ui/noice/config.nix
+++ b/modules/ui/noice/config.nix
@@ -32,7 +32,7 @@ in {
           command_palette = true, -- position the cmdline and popupmenu together
           long_message_to_split = true, -- long messages will be sent to a split
           inc_rename = false, -- enables an input dialog for inc-rename.nvim
-          lsp_doc_border = false, -- add a border to hover docs and signature help
+          lsp_doc_border = ${boolToString (config.vim.ui.borders.enable)}, -- add a border to hover docs and signature help
         },
 
         format = {
diff --git a/modules/utility/binds/which-key/config.nix b/modules/utility/binds/which-key/config.nix
index a5c1569..8b0fa6c 100644
--- a/modules/utility/binds/which-key/config.nix
+++ b/modules/utility/binds/which-key/config.nix
@@ -18,7 +18,13 @@ in {
           ["<leader>"] = "SPACE",
           ["<cr>"] = "RETURN",
           ["<tab>"] = "TAB",
-        }
+        },
+
+        ${lib.optionalString (config.vim.ui.borders.plugins.which-key.enable) ''
+        window = {
+          border = "${config.vim.ui.borders.plugins.which-key.style}",
+        },
+      ''}
       })
 
       wk.register({