diff --git a/.commandcode/taste/taste.md b/.commandcode/taste/taste.md
index 54e4488..4b588b2 100644
--- a/.commandcode/taste/taste.md
+++ b/.commandcode/taste/taste.md
@@ -1,7 +1,6 @@
 # nix
 - For R.nvim in the Nix wrapper, both RNVIM_COMPLDIR (C server compilation) and a writable R_LIBS_USER directory (nvimcom R package installation) must be configured — fixing only one leaves permission errors in the other. Confidence: 0.65
 - For R.nvim writable directories (RNVIM_COMPLDIR, R_LIBS_USER, TMPDIR), prefer project-local paths (e.g., $PWD/.Rlibs) over global cache paths — the cache approach may let the build succeed but still fail at runtime. Confidence: 0.70
-- Do not use lib.mkDefault on values consumed by lib.optionals or other boolean-checking functions — mkDefault wraps values in a priority set that fails "expected a Boolean" at evaluation time. Use plain booleans for inline conditionals, reserving mkDefault for module options resolved by the merge system. Confidence: 0.70
 
 # Taste (Continuously Learned by [CommandCode][cmd])
 
diff --git a/flake.lock b/flake.lock
index 698ccf9..9fbb80f 100644
--- a/flake.lock
+++ b/flake.lock
@@ -126,11 +126,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1779297405,
-        "narHash": "sha256-VFoBwH7ZjVxCnvZTb5ODRXt70sLtWMxstive0N+RS50=",
+        "lastModified": 1779145538,
+        "narHash": "sha256-j2RQqBLYhPuddU6C8n5hGKboXq1tDLCZ7bWe5/LgTHM=",
         "owner": "BirdeeHub",
         "repo": "nix-wrapper-modules",
-        "rev": "e7ed7a1205945befdf2e0d73ba7df91d935e5af1",
+        "rev": "597b35c93dd0ab0ae38758e3193582b2fd259aa1",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 2780328..fa1140a 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,10 +1,11 @@
-# Copyright (c) 2026 Daniel
+# Copyright (c) 2026 BirdeeHub
 # Licensed under the MIT license
 {
   description = "Daniel's NixCats";
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    #nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
     wrappers = {
       url = "github:BirdeeHub/nix-wrapper-modules";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -45,7 +46,7 @@
         gitPlugins = true;
         julia = false;
         lua = true;
-        markdown = true;
+        markdown = false;
         nix = true;
         optional = false;
         python = false;
@@ -53,20 +54,46 @@
       };
       settings = {
         lang_packages = {
-          python = [];
-          r = [];
-          julia = [];
+          python = with pkgs.python3Packages; [
+            duckdb
+            polars
+          ];
+          r = with pkgs.rpkgs.rPackages; [
+            arrow
+            broom
+            data_table
+            janitor
+            languageserver
+            styler
+            pkgs.nvimcom
+          ];
+          julia = ["DataFramesMeta" "QuackIO"];
         };
+        colorscheme = "cyberdream";
+        background = "dark";
+        wrapRc = true;
       };
       binName = "vv";
     };
 
     wrapperSettings = pkgs: let
       cfg = mkWrapperConfig pkgs;
+      def = pkgs.lib.mkDefault;
     in
       wrapper.config.wrap {
         inherit pkgs;
-        inherit (cfg) settings binName;
+        cats = pkgs.lib.mapAttrs (_: v: def v) cfg.cats;
+        settings = {
+          lang_packages = {
+            python = def cfg.settings.lang_packages.python;
+            r = def cfg.settings.lang_packages.r;
+            julia = def cfg.settings.lang_packages.julia;
+          };
+          colorscheme = def cfg.settings.colorscheme;
+          background = def cfg.settings.background;
+          wrapRc = def cfg.settings.wrapRc;
+        };
+        binName = def cfg.binName;
       };
 
     systems = [
@@ -77,39 +104,54 @@
 
     forAllSystems = nixpkgs.lib.genAttrs systems;
 
+    extra_pkg_config = {
+       allowUnfree = true;
+    };
+
     overlayDefs = import ./overlays inputs;
 
+    dependencyOverlays = overlayDefs.dependencyOverlays;
+
+    dependencyOverlay = overlayDefs.dependencyOverlay;
+
     mkPkgs = system:
       import nixpkgs {
         inherit system;
-        config = { allowUnfree = true; };
-        overlays = [ overlayDefs.dependencyOverlay ];
+        config = extra_pkg_config;
+        overlays = [dependencyOverlay];
       };
 
-    module = (import ./modules/neovim.nix) inputs;
+    module = nixpkgs.lib.modules.importApply ./modules/neovim.nix inputs;
     wrapper = wrappers.lib.evalModule module;
   in {
     overlays = {
-      # overlay `vv` wraps the module with default settings only.
-      # For the fully-configured binary (including mkWrapperConfig overrides),
-      # use `packages.<system>.default` instead.
       default = nixpkgs.lib.composeManyExtensions [
-        overlayDefs.dependencyOverlay
+        dependencyOverlay
         (final: prev: {
           vv = wrapper.config.wrap {pkgs = final;};
         })
       ];
-      dependencies = overlayDefs.dependencyOverlay;
+      dependencies = dependencyOverlay;
+      vv = self.overlays.default;
     };
 
-    wrapperModules.default = module;
-    wrapperConfigs.default = wrapper.config;
+    wrapperModules = {
+      default = module;
+      neovim = self.wrapperModules.default;
+    };
+
+    wrappers = {
+      default = wrapper.config;
+      neovim = self.wrappers.default;
+    };
 
     packages = forAllSystems (
       system: let
         pkgs = mkPkgs system;
+        nvimPkg = wrapperSettings pkgs;
       in {
-        default = wrapperSettings pkgs;
+        default = nvimPkg;
+        vv = nvimPkg;
       }
     );
 
@@ -123,29 +165,14 @@
     devShells = forAllSystems (
       system: let
         pkgs = mkPkgs system;
+        cfg = mkWrapperConfig pkgs;
         nvimPkg = wrapperSettings pkgs;
 
-        pythonPkgs = with pkgs.python3Packages; [
-          duckdb
-          polars
-        ];
-
-        rPkgs = (with pkgs.rpkgs.rPackages; [
-          arrow
-          broom
-          data_table
-          janitor
-          languageserver
-          styler
-        ]) ++ [ pkgs.nvimcom ];
-
-        juliaPkgs = ["DataFramesMeta" "QuackIO"];
-
         pythonPackages = let
           python_packages_fn =
             if pkgs ? basePythonPackages
-            then ps: pkgs.basePythonPackages ps ++ pythonPkgs
-            else _: pythonPkgs;
+            then ps: pkgs.basePythonPackages ps ++ cfg.settings.lang_packages.python
+            else _: cfg.settings.lang_packages.python;
         in
           with pkgs; [
             (python3.withPackages python_packages_fn)
@@ -156,7 +183,7 @@
           ];
 
         rPackages = let
-          r_packages = (pkgs.baseRPackages or []) ++ rPkgs;
+          r_packages = (pkgs.baseRPackages or []) ++ cfg.settings.lang_packages.r;
         in
           with pkgs; [
             (rWrapper.override {packages = r_packages;})
@@ -170,7 +197,7 @@
           ];
 
         juliaPackages = let
-          julia_with_packages = pkgs.julia-bin.withPackages juliaPkgs;
+          julia_with_packages = pkgs.julia-bin.withPackages cfg.settings.lang_packages.julia;
         in [julia_with_packages];
 
         markdownPackages = with pkgs; [
@@ -181,15 +208,16 @@
 
         shellPackages =
           [nvimPkg]
-          ++ pkgs.lib.optionals wrapper.config.cats.python pythonPackages
-          ++ pkgs.lib.optionals wrapper.config.cats.r rPackages
-          ++ pkgs.lib.optionals wrapper.config.cats.julia juliaPackages
-          ++ pkgs.lib.optionals wrapper.config.cats.markdown markdownPackages;
+          ++ pkgs.lib.optionals cfg.cats.python pythonPackages
+          ++ pkgs.lib.optionals cfg.cats.r rPackages
+          ++ pkgs.lib.optionals cfg.cats.julia juliaPackages
+          ++ pkgs.lib.optionals cfg.cats.markdown markdownPackages;
       in {
         default = pkgs.mkShell {
           name = "vShell";
           packages = shellPackages;
-          nativeBuildInputs = pkgs.lib.optionals wrapper.config.cats.optional [ pkgs.devenv ];
+          nativeBuildInputs = with pkgs; [] ++ (pkgs.lib.optionals cfg.cats.optional [devenv]);
+          inputsFrom = [];
           shellHook = ''
             echo 'I am a NixShell'
             export R_HOME=$(R RHOME)
@@ -206,11 +234,18 @@
         pkgs = mkPkgs system;
         nvimPkg = wrapperSettings pkgs;
       in {
-        default = pkgs.runCommand "check-vv" {} ''
+        default = nvimPkg;
+        module-eval = let
+          _ = wrapper.config;
+        in
+          pkgs.runCommand "check-module-eval" {} ''
+            echo "Module evaluation successful" > $out
+          '';
+        package-build = pkgs.runCommand "check-vv" {} ''
           BINARY_PATH="${nvimPkg}/bin/vv"
 
           if [ ! -x "$BINARY_PATH" ]; then
-            echo "Error: Binary not found or not executable"
+            echo "Error: Binary n not found or not executable"
             exit 1
           fi
 
@@ -223,11 +258,6 @@
             cat version_output.txt >> $out
           fi
         '';
-        module-eval =
-          let _ = wrapper.config;
-          in pkgs.runCommand "check-module-eval" {} ''
-            echo "Module evaluation successful" > $out
-          '';
       }
     );
 
diff --git a/ftplugin/markdown.lua b/ftplugin/markdown.lua
index db316fc..b673b60 100644
--- a/ftplugin/markdown.lua
+++ b/ftplugin/markdown.lua
@@ -1,35 +1,32 @@
 -- Add the key mappings only for Markdown files in a zk notebook.
-local nix = require("config.nix")
-if nix.get_cat("markdown", false) then
-  if require("zk.util").notebook_root(vim.fn.expand('%:p')) ~= nil then
-    local map = vim.keymap.set
-    -- Open the link under the caret.
-    map("n", "<CR>", "<Cmd>lua vim.lsp.buf.definition()<CR>", { noremap = true, silent = false, buffer = true })
+if require("zk.util").notebook_root(vim.fn.expand('%:p')) ~= nil then
+  local map = vim.keymap.set
+  -- Open the link under the caret.
+  map("n", "<CR>", "<Cmd>lua vim.lsp.buf.definition()<CR>", { noremap = true, silent = false, buffer = true })
 
-    -- Create a new note after asking for its title.
-    -- This overrides the global `<leader>zn` mapping to create the note in the same directory as the current buffer.
-    map("n", "<leader>zhn", "<Cmd>ZkNew { dir = vim.fn.expand('%:p:h'), title = vim.fn.input('Title: ') }<CR>",
-      { noremap = true, silent = false, buffer = true, desc = "Note (here)" })
-    -- Create a new note in the same directory as the current buffer, using the current selection for title.
-    map("v", "<leader>zhnt", ":'<,'>ZkNewFromTitleSelection { dir = vim.fn.expand('%:p:h') }<CR>",
-      { noremap = true, silent = false, buffer = true, desc = "Note from selection (title)" })
-    -- Create a new note in the same directory as the current buffer, using the current selection for note content and asking for its title.
-    map("v", "<leader>zhnc",
-      ":'<,'>ZkNewFromContentSelection { dir = vim.fn.expand('%:p:h'), title = vim.fn.input('Title: ') }<CR>",
-      { noremap = true, silent = false, buffer = true, desc = "Note from selection (content)" })
+  -- Create a new note after asking for its title.
+  -- This overrides the global `<leader>zn` mapping to create the note in the same directory as the current buffer.
+  map("n", "<leader>zhn", "<Cmd>ZkNew { dir = vim.fn.expand('%:p:h'), title = vim.fn.input('Title: ') }<CR>",
+    { noremap = true, silent = false, buffer = true, desc = "Note (here)" })
+  -- Create a new note in the same directory as the current buffer, using the current selection for title.
+  map("v", "<leader>zhnt", ":'<,'>ZkNewFromTitleSelection { dir = vim.fn.expand('%:p:h') }<CR>",
+    { noremap = true, silent = false, buffer = true, desc = "Note from selection (title)" })
+  -- Create a new note in the same directory as the current buffer, using the current selection for note content and asking for its title.
+  map("v", "<leader>zhnc",
+    ":'<,'>ZkNewFromContentSelection { dir = vim.fn.expand('%:p:h'), title = vim.fn.input('Title: ') }<CR>",
+    { noremap = true, silent = false, buffer = true, desc = "Note from selection (content)" })
 
-    -- Open notes linking to the current buffer.
-    map("n", "<leader>zb", "<Cmd>ZkBacklinks<CR>", { noremap = true, silent = false, buffer = true, desc = "Backlinks" })
-    -- Alternative for backlinks using pure LSP and showing the source context.
-    --map('n', '<leader>zb', '<Cmd>lua vim.lsp.buf.references()<CR>', opts)
-    -- Open notes linked by the current buffer.
-    map("n", "<leader>zL", "<Cmd>ZkLinks<CR>", { noremap = true, silent = false, buffer = true, desc = "Links" })
-    map("n", "<leader>zi", "<Cmd>ZkInsertLink<CR>", { noremap = true, silent = false, buffer = true, desc = "Insert link" })
+  -- Open notes linking to the current buffer.
+  map("n", "<leader>zb", "<Cmd>ZkBacklinks<CR>", { noremap = true, silent = false, buffer = true, desc = "Backlinks" })
+  -- Alternative for backlinks using pure LSP and showing the source context.
+  --map('n', '<leader>zb', '<Cmd>lua vim.lsp.buf.references()<CR>', opts)
+  -- Open notes linked by the current buffer.
+  map("n", "<leader>zL", "<Cmd>ZkLinks<CR>", { noremap = true, silent = false, buffer = true, desc = "Links" })
+  map("n", "<leader>zi", "<Cmd>ZkInsertLink<CR>", { noremap = true, silent = false, buffer = true, desc = "Insert link" })
 
-    -- Preview a linked note.
-    -- Open the code actions for a visual selection.
-    map("v", "<leader>za", ":'<,'>lua vim.lsp.buf.range_code_action()<CR>",
-      { noremap = true, silent = false, buffer = true, desc = "Code actions" })
+  -- Preview a linked note.
+  -- Open the code actions for a visual selection.
+  map("v", "<leader>za", ":'<,'>lua vim.lsp.buf.range_code_action()<CR>",
+    { noremap = true, silent = false, buffer = true, desc = "Code actions" })
 
-  end
 end
diff --git a/modules/module/settings/cats.nix b/modules/module/settings/cats.nix
index 13758d4..3da043e 100644
--- a/modules/module/settings/cats.nix
+++ b/modules/module/settings/cats.nix
@@ -14,6 +14,7 @@
 
       Available categories:
       - clickhouse: Clickhouse client and tools
+      - customPlugins: local plugin specs
       - external: external tools and integrations
       - general: core Neovim plugins/features
       - gitPlugins: git-related plugins
@@ -24,6 +25,7 @@
       - optional: optional tools and utilities
       - python: Python tooling and plugins
       - r: R tooling and plugins
+      - test: test-only tooling (disabled by default)
       - treesitterParsers: Treesitter parsers
       - utils: general utilities
     '';
@@ -31,16 +33,18 @@
 
   config.cats = {
     clickhouse = lib.mkDefault false;
+    customPlugins = lib.mkDefault true;
     external = lib.mkDefault true;
     general = lib.mkDefault true;
     gitPlugins = lib.mkDefault true;
     julia = lib.mkDefault false;
     lua = lib.mkDefault true;
-    markdown = lib.mkDefault true;
+    markdown = lib.mkDefault false;
     nix = lib.mkDefault true;
     optional = lib.mkDefault false;
     python = lib.mkDefault false;
     r = lib.mkDefault true;
+    test = lib.mkDefault false;
     treesitterParsers = lib.mkDefault true;
     utils = lib.mkDefault true;
   };
diff --git a/modules/module/settings/core.nix b/modules/module/settings/core.nix
index ec9bb5c..42e9e11 100644
--- a/modules/module/settings/core.nix
+++ b/modules/module/settings/core.nix
@@ -16,7 +16,7 @@
 
   # Lua packages available to neovim (for :lua require())
   config.settings.nvim_lua_env = lp:
-    lib.optionals (config.cats.general or true) [ lp.tiktoken_core ];
+    lib.optionals (config.cats.general or false) [ lp.tiktoken_core ];
 
   # Binary name for the wrapper
   config.binName = lib.mkDefault "vv";
@@ -25,10 +25,10 @@
   config.settings.block_normal_config = true;
 
   # Don't symlink the config (we wrap it instead)
-  config.settings.dont_link = lib.mkDefault false;
+  config.settings.dont_link = false;
 
   # Create additional aliases for the binary
-  config.settings.aliases = lib.mkDefault [ "vvim" ];
+  config.settings.aliases = [ "vvim" ];
 
   # Enable wrapper handling of spec runtimeDeps (template pattern).
   config.settings.autowrapRuntimeDeps = true;
diff --git a/modules/module/settings/env.nix b/modules/module/settings/env.nix
index 2fcab8a..14e0a32 100644
--- a/modules/module/settings/env.nix
+++ b/modules/module/settings/env.nix
@@ -7,11 +7,11 @@
   # Environment variables set for the wrapper.
   # These are available when running neovim.
   config.env = lib.mkMerge [
-    (lib.mkIf (config.cats.python or true) {
+    (lib.mkIf (config.cats.python or false) {
       UV_PYTHON_DOWNLOADS = "never";
       UV_PYTHON = pkgs.python.interpreter;
     })
-    (lib.mkIf (config.cats.r or true) {
+    (lib.mkIf (config.cats.r or false) {
       RNVIM_COMPLDIR = "$PWD/.r-compl";
       R_LIBS_USER = "${pkgs.nvimcom}/library:$PWD/.Rlibs";
       TMPDIR = "$PWD/.r-tmp";
@@ -20,7 +20,7 @@
 
   # Environment variables with defaults (can be overridden by user)
   config.envDefault = lib.mkMerge [
-    (lib.mkIf (config.cats.r or true) {
+    (lib.mkIf (config.cats.r or false) {
       R_LIBS_USER = "${pkgs.nvimcom}/library:$PWD/.Rlibs";
     })
   ];
diff --git a/modules/module/settings/hosts.nix b/modules/module/settings/hosts.nix
index f248a00..0743979 100644
--- a/modules/module/settings/hosts.nix
+++ b/modules/module/settings/hosts.nix
@@ -15,7 +15,7 @@
         nvim-host.enable = true;
         nvim-host.package = "${pkgs.neovide}/bin/neovide";
         nvim-host.argv0 = "neovide";
-        nvim-host.flags."--neovim-bin" = "${builtins.placeholder "out"}/bin/${config.binName}";
+        nvim-host.flags."--neovim-bin" = "${placeholder "out"}/bin/${config.binName}";
       };
 
       m = {
diff --git a/modules/module/settings/lang-packages.nix b/modules/module/settings/lang-packages.nix
index 531b811..3315363 100644
--- a/modules/module/settings/lang-packages.nix
+++ b/modules/module/settings/lang-packages.nix
@@ -26,7 +26,7 @@
     };
     default = { };
     description = ''
-      Language-specific package overrides appended to each language spec's runtimePackages.
+      Language-specific package overrides appended to each language spec's extraPackages.
       Intended for flake.nix overrides via wrapper.config.wrap.
     '';
   };
diff --git a/modules/module/settings/runtime-path.nix b/modules/module/settings/runtime-path.nix
index b321019..96c5d0f 100644
--- a/modules/module/settings/runtime-path.nix
+++ b/modules/module/settings/runtime-path.nix
@@ -10,13 +10,14 @@ let
         let
           is_enabled = if spec ? enable then spec.enable else true;
           has_runtime_deps = (spec.runtimeDeps or false) == runtime_deps_type;
-          packages = spec.runtimePackages or [ ];
+          packages = spec.extraPackages or [ ];
         in
         acc ++ lib.optionals (is_enabled && has_runtime_deps) packages
       )
       [ ];
 
   prefix_packages = collect_runtime_packages "prefix";
+  suffix_packages = collect_runtime_packages "suffix";
 
   to_path_specs = packages: [
     {
@@ -30,4 +31,5 @@ let
 in
 {
   config.prefixVar = lib.optionals (prefix_packages != [ ]) (to_path_specs prefix_packages);
+  config.suffixVar = lib.optionals (suffix_packages != [ ]) (to_path_specs suffix_packages);
 }
diff --git a/modules/module/specs/cats-enable.nix b/modules/module/specs/cats-enable.nix
new file mode 100644
index 0000000..f5a9826
--- /dev/null
+++ b/modules/module/specs/cats-enable.nix
@@ -0,0 +1,51 @@
+{ config, lib, ... }:
+{
+  # This module implements category-based enabling of specs.
+  # It runs early (order 200) so other specMaps can see the enable flags.
+  #
+  # How it works:
+  # 1. For each spec, extract its name (removing -lazy suffix if present)
+  # 2. Check if there's a corresponding cats.<name> toggle
+  # 3. Set spec.value.enable based on the cats toggle (default: true)
+  # 4. This allows specs to be conditionally included based on config.cats settings
+  #
+  # Example: If config.cats.python = false, then specs.python.enable = false
+
+  config.specMaps = lib.mkOrder 200 [
+    {
+      name = "CATS_ENABLE";
+      data =
+        list:
+        map (
+          v:
+          if v.type == "spec" || v.type == "parent" then
+            let
+              # Extract spec name, handling lazy specs (remove -lazy suffix)
+              specName =
+                if v.name == null then
+                  null
+                else if lib.hasSuffix "-lazy" v.name then
+                  lib.removeSuffix "-lazy" v.name
+                else
+                  v.name;
+
+              # Check if this spec has a corresponding cat toggle
+              catEnabled =
+                if specName != null && builtins.hasAttr specName config.cats then
+                  config.cats.${specName}
+                else
+                  true;  # Default to enabled if no cat toggle exists
+            in
+            v
+            // {
+              value = v.value // {
+                # Use explicit enable if set, otherwise use cat toggle
+                enable = if v.value ? enable then v.value.enable else catEnabled;
+              };
+            }
+          else
+            v
+        ) list;
+    }
+  ];
+}
diff --git a/modules/module/specs/deps.nix b/modules/module/specs/deps.nix
index c3a40ea..a8bfaf6 100644
--- a/modules/module/specs/deps.nix
+++ b/modules/module/specs/deps.nix
@@ -5,14 +5,24 @@
   wlib,
   ...
 }: {
+  # ============================================================================
+  # SPEC MODULE DEFAULTS
+  # ============================================================================
+  # Define default options available to all specs
+
   config.specMods = {parentSpec ? null, ...}: {
-    options.runtimePkgs = lib.mkOption {
+    options.extraPackages = lib.mkOption {
       type = lib.types.listOf wlib.types.stringable;
       default = [];
-      description = "a runtimePkgs spec field to put packages to suffix to the PATH";
+      description = "a extraPackages spec field to put packages to suffix to the PATH";
     };
   };
 
+  # ============================================================================
+  # EXTERNAL TOOLS SPEC
+  # ============================================================================
+  # Core system tools and utilities
+
   config.specs.external = {
     data = lib.mkDefault null;
     before = ["INIT_MAIN"];
@@ -20,7 +30,7 @@
       vim.o.shell = "${pkgs.zsh}/bin/zsh"
     '';
     runtimeDeps = "prefix";
-    runtimePkgs = with pkgs; [
+    extraPackages = with pkgs; [
       perl
       ruby
       shfmt
@@ -29,11 +39,15 @@
     ];
   };
 
+  # ============================================================================
+  # OPTIONAL TOOLS SPEC
+  # ============================================================================
+
   config.specs.optional = lib.mkIf (config.cats.optional or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
     before = ["INIT_MAIN"];
-    runtimePkgs = with pkgs; [
+    extraPackages = with pkgs; [
       bat
       broot
       devenv
@@ -62,38 +76,54 @@
     ];
   };
 
+  # ============================================================================
+  # MARKDOWN SPEC
+  # ============================================================================
+
   config.specs.markdown = lib.mkIf (config.cats.markdown or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = with pkgs; [
+    extraPackages = with pkgs; [
       python313Packages.pylatexenc
       quarto
       zk
     ];
   };
 
+  # ============================================================================
+  # NIX SPEC
+  # ============================================================================
+
   config.specs.nix = lib.mkIf (config.cats.nix or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = with pkgs; [
+    extraPackages = with pkgs; [
       alejandra
       nix-doc
       nixd
     ];
   };
 
+  # ============================================================================
+  # LUA SPEC
+  # ============================================================================
+
   config.specs.lua = lib.mkIf (config.cats.lua or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = with pkgs; [
+    extraPackages = with pkgs; [
       lua-language-server
     ];
   };
 
+  # ============================================================================
+  # PYTHON SPEC
+  # ============================================================================
+
   config.specs.python = lib.mkIf (config.cats.python or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = let
+    extraPackages = let
       python_packages_fn =
         if pkgs ? basePythonPackages
         then ps: pkgs.basePythonPackages ps ++ config.settings.lang_packages.python
@@ -109,10 +139,14 @@
       ];
   };
 
+  # ============================================================================
+  # R SPEC
+  # ============================================================================
+
   config.specs.r = lib.mkIf (config.cats.r or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = let
+    extraPackages = let
       r_packages = (pkgs.baseRPackages or []) ++ config.settings.lang_packages.r;
     in
       with pkgs; [
@@ -125,22 +159,30 @@
       ];
   };
 
+  # ============================================================================
+  # JULIA SPEC
+  # ============================================================================
+
   config.specs.julia = lib.mkIf (config.cats.julia or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = let
+    extraPackages = let
       julia_with_packages =
         pkgs.julia-bin.withPackages config.settings.lang_packages.julia;
     in [julia_with_packages];
   };
 
+  # ============================================================================
+  # CLICKHOUSE SPEC
+  # ============================================================================
+
   config.specs.clickhouse = lib.mkIf (config.cats.clickhouse or true) {
     data = lib.mkDefault null;
     runtimeDeps = "prefix";
-    runtimePkgs = with pkgs; [
+    extraPackages = with pkgs; [
       clickhouse-lts
     ];
   };
 
-  config.runtimePkgs = config.specCollect (acc: v: acc ++ (v.runtimePkgs or [])) [];
+  config.extraPackages = config.specCollect (acc: v: acc ++ (v.extraPackages or [])) [];
 }
diff --git a/modules/module/specs/plugins.nix b/modules/module/specs/plugins.nix
index ff00a72..431005d 100644
--- a/modules/module/specs/plugins.nix
+++ b/modules/module/specs/plugins.nix
@@ -4,11 +4,11 @@
   lib,
   ...
 }: {
-  config.specs.gitPlugins = lib.mkIf (config.cats.gitPlugins or true) {
+  config.specs.gitPlugins = {
     data = [];
   };
 
-  config.specs.r = lib.mkIf (config.cats.r or true) {
+  config.specs.r = {
     data = with pkgs.vimPlugins; [
       pkgs.r-nvim
       quarto-nvim
@@ -19,14 +19,14 @@
     ];
   };
 
-  config.specs.markdown-lazy = lib.mkIf (config.cats.markdown or true) {
+  config.specs.markdown-lazy = {
     lazy = true;
     data = [
       config.nvim-lib.neovimPlugins.cmp-pandoc-references
     ];
   };
 
-  config.specs.general = lib.mkIf (config.cats.general or true) {
+  config.specs.general = {
     data = with pkgs.vimPlugins; [
       lze
       lzextras
@@ -79,7 +79,7 @@
     ];
   };
 
-  config.specs.lua = lib.mkIf (config.cats.lua or true) {
+  config.specs.lua = {
     data = with pkgs.vimPlugins; [
       luvit-meta
       {
@@ -89,7 +89,7 @@
     ];
   };
 
-  config.specs.markdown = lib.mkIf (config.cats.markdown or true) {
+  config.specs.markdown = {
     data = with pkgs.vimPlugins; [
       quarto-nvim
       render-markdown-nvim
@@ -104,7 +104,7 @@
     ];
   };
 
-  config.specs.utils = lib.mkIf (config.cats.utils or true) {
+  config.specs.utils = {
     data = with pkgs.vimPlugins; [
       blink-cmp
       nvim-lspconfig
@@ -119,7 +119,7 @@
     ];
   };
 
-  config.specs.treesitterParsers = lib.mkIf (config.cats.treesitterParsers or true) {
+  config.specs.treesitterParsers = {
     data = with pkgs.vimPlugins.nvim-treesitter-parsers; [
       bash
       c
@@ -158,7 +158,7 @@
     ];
   };
 
-  config.specs.utils-lazy = lib.mkIf (config.cats.utils or true) {
+  config.specs.utils-lazy = {
     lazy = true;
     data = with pkgs.vimPlugins; [
       blink-compat
@@ -175,7 +175,7 @@
     ];
   };
 
-  config.specs.gitPlugins-lazy = lib.mkIf (config.cats.gitPlugins or true) {
+  config.specs.gitPlugins-lazy = {
     lazy = true;
     data = [];
   };
diff --git a/modules/neovim.nix b/modules/neovim.nix
index 64d2cda..ba0361c 100644
--- a/modules/neovim.nix
+++ b/modules/neovim.nix
@@ -7,10 +7,16 @@ inputs:
   ...
 }:
 {
+  # ============================================================================
+  # IMPORTS
+  # ============================================================================
+  # Import the base neovim wrapper module and all configuration modules
+
   imports = [
     wlib.wrapperModules.neovim
     ./module/specs/deps.nix
     ./module/specs/plugins.nix
+    ./module/specs/cats-enable.nix
     ./module/settings/core.nix
     ./module/settings/cats.nix
     ./module/settings/env.nix
@@ -19,6 +25,11 @@ inputs:
     ./module/settings/runtime-path.nix
   ];
 
+  # ============================================================================
+  # HELPER FUNCTIONS
+  # ============================================================================
+  # Utilities for working with plugin inputs
+
   options.nvim-lib.neovimPlugins = lib.mkOption {
     readOnly = true;
     type = lib.types.attrsOf wlib.types.stringable;
@@ -47,6 +58,11 @@ inputs:
       ];
   };
 
+  # ============================================================================
+  # CONFIGURATION
+  # ============================================================================
+  # Pass cats configuration to neovim and expose metadata
+
   config.settings.cats = config.cats;
   config.info.cats = config.cats;
   config.info.nixCats_config_location = config.settings.config_directory;
diff --git a/overlays/default.nix b/overlays/default.nix
index 5a4cc6c..ebb6518 100644
--- a/overlays/default.nix
+++ b/overlays/default.nix
@@ -4,8 +4,9 @@ let
 
   rOverlay = import ./r.nix {inherit inputs;};
   rNvimNixOverlay = inputs.r-nvim-nix.overlays.default;
-  pythonOverlay = import ./python.nix {inherit inputs;};
-  pluginsOverlay = import ./plugins.nix {inherit inputs;};
+  franOverlay = inputs.fran.overlays.default;
+  pythonOverlay = import ./python.nix inputs;
+  pluginsOverlay = import ./plugins.nix inputs;
 
   dependencyOverlays = [
     rOverlay
@@ -14,11 +15,6 @@ let
     pluginsOverlay
   ];
   dependencyOverlay = lib.composeManyExtensions dependencyOverlays;
-
-  # franOverlay provides R-specific tooling (radianWrapper, air-formatter).
-  # It is scoped to rixpkgs (via overlays/r.nix) rather than the global
-  # package set, since it only applies to R package derivations.
-  franOverlay = inputs.fran.overlays.default;
 in
 {
   inherit
@@ -30,6 +26,20 @@ in
     dependencyOverlays
     dependencyOverlay;
 
+  # Named exports for downstream composition.
   default = dependencyOverlay;
   dependencies = dependencyOverlays;
+
+  overlays = {
+    inherit
+      rOverlay
+      rNvimNixOverlay
+      franOverlay
+      pythonOverlay
+      pluginsOverlay
+      dependencyOverlays
+      dependencyOverlay;
+    default = dependencyOverlay;
+    dependencies = dependencyOverlays;
+  };
 }
diff --git a/overlays/r.nix b/overlays/r.nix
index 14c02eb..a9961fb 100644
--- a/overlays/r.nix
+++ b/overlays/r.nix
@@ -1,15 +1,55 @@
+# R packages overlay (rix)
+#
+# This overlay provides access to R packages from rstats-on-nix.
+#
+# rstats-on-nix maintains snapshots of CRAN packages built with Nix:
+# - Provides reproducible R package versions
+# - Ensures binary cache availability for faster builds
+# - Maintained by the rstats-on-nix community
+#
+# Available attributes after applying this overlay:
+#   - pkgs.rpkgs: R packages from rstats-on-nix
+#   - pkgs.rpkgs.rPackages: All CRAN packages
+#   - pkgs.rpkgs.quarto: Quarto publishing system
+#   - pkgs.rpkgs.rWrapper: R with package management
+#   - pkgs.rWrapper: R wrapper with standard packages pre-configured
+#   - pkgs.quarto: Quarto with R integration and standard packages
+#
+# Custom R packages and tools (radianWrapper, air-formatter) come from
+# the fran overlay which should be applied separately.
+#
+# To use specific R packages, reference them via:
+#   with pkgs.rpkgs.rPackages; [ package1 package2 ]
+#
+# Update the R snapshot date in flake.nix inputs section:
+#   rixpkgs.url = "github:rstats-on-nix/nixpkgs/YYYY-MM-DD"
 {
   inputs,
   ...
 }: final: prev: let
+  # R packages from rstats-on-nix for the current system
   rpkgs = import inputs.rixpkgs {
     system = prev.stdenv.hostPlatform.system;
     overlays = [inputs.fran.overlays.default];
-  };
+  }; # rixpkgs.legacyPackages.${prev.stdenv.hostPlatform.system};
+
+  # nvimcom and rnvimserver are provided by the r-nvim-nix flake overlay
+  # (inputs.r-nvim-nix.overlays.default)
+
+  # Standard R packages used by default in rWrapper and quarto
+  reqPkgs = with rpkgs.rPackages; [
+    #    languageserver
+  ];
 in {
   inherit rpkgs;
-  baseRPackages = [ ];
-  rWrapper = rpkgs.rWrapper.override {packages = [ ];};
-  quarto = rpkgs.quarto.override {extraRPackages = [ ];};
+  baseRPackages = reqPkgs;
+
+  # R wrapper with standard packages
+  rWrapper = rpkgs.rWrapper.override {packages = reqPkgs;};
+
+  # Quarto with R integration
+  quarto = rpkgs.quarto.override {extraRPackages = reqPkgs;};
+
+  # Update helper for rix
   updateR = import ../scripts/updater.nix {pkgs = final;};
 }
diff --git a/plugin/20_startup.lua b/plugin/20_startup.lua
index 0404b2c..ca18bd8 100644
--- a/plugin/20_startup.lua
+++ b/plugin/20_startup.lua
@@ -390,25 +390,23 @@ end)
 
 -- zk
 now_if_args(function()
-  if nix.get_cat("markdown", false) then
-    require("zk").setup({
-      picker = "minipick",
-      lsp = {
-        -- `config` is passed to `vim.lsp.start_client(config)`
-        config = {
-          cmd = { "zk", "lsp" },
-          name = "zk",
-          -- on_attach = ...
-          -- etc, see `:h vim.lsp.start_client()`
-        },
-
-        -- automatically attach buffers in a zk notebook that match the given filetypes
-        auto_attach = {
-          enabled = true,
-          filetypes = { "markdown" },
-        },
-
+  require("zk").setup({
+    picker = "minipick",
+    lsp = {
+      -- `config` is passed to `vim.lsp.start_client(config)`
+      config = {
+        cmd = { "zk", "lsp" },
+        name = "zk",
+        -- on_attach = ...
+        -- etc, see `:h vim.lsp.start_client()`
       },
-    })
-  end
+
+      -- automatically attach buffers in a zk notebook that match the given filetypes
+      auto_attach = {
+        enabled = true,
+        filetypes = { "markdown" },
+      },
+
+    },
+  })
 end)
diff --git a/plugin/21_datascience.lua b/plugin/21_datascience.lua
index 2e9f86c..62d8f49 100644
--- a/plugin/21_datascience.lua
+++ b/plugin/21_datascience.lua
@@ -71,45 +71,41 @@ end)
 now(function()
   vim.treesitter.language.register("markdown", { "quarto", "rmd" })
 
-  if nix.get_cat({ "r", "markdown" }, false) then
-    vim.api.nvim_create_autocmd("FileType", {
-      pattern = { "quarto" },
-      callback = function()
-        require("otter").activate()
-      end,
-    })
+  vim.api.nvim_create_autocmd("FileType", {
+    pattern = { "quarto" },
+    callback = function()
+      require("otter").activate()
+    end,
+  })
 
-    require("otter").setup({
-      lsp = {
-        diagnostic_update_events = { "BufWritePost", "InsertLeave" },
-      },
-      buffers = {
-        set_filetype = true,
-        write_to_disk = true,
-      },
-    })
-  end
+  require("otter").setup({
+    lsp = {
+      diagnostic_update_events = { "BufWritePost", "InsertLeave" },
+    },
+    buffers = {
+      set_filetype = true,
+      write_to_disk = true,
+    },
+  })
 end)
 
 later(function()
-  if nix.get_cat({ "r", "markdown" }, false) then
-    require("quarto").setup({
-      lspFeatures = {
+  require("quarto").setup({
+    lspFeatures = {
+      enabled = true,
+      chunks = "curly",
+      languages = { "r", "python", "julia" },
+      diagnostics = {
         enabled = true,
-        chunks = "curly",
-        languages = { "r", "python", "julia" },
-        diagnostics = {
-          enabled = true,
-          triggers = { "BufWritePost" },
-        },
-        completion = {
-          enabled = true,
-        },
+        triggers = { "BufWritePost" },
       },
-      codeRunner = {
+      completion = {
         enabled = true,
-        default_method = "slime",
       },
-    })
-  end
+    },
+    codeRunner = {
+      enabled = true,
+      default_method = "slime",
+    },
+  })
 end)
diff --git a/plugin/22_languages.lua b/plugin/22_languages.lua
index ed4682a..1983b25 100644
--- a/plugin/22_languages.lua
+++ b/plugin/22_languages.lua
@@ -1,7 +1,6 @@
 local add = Config.add
 local now_if_args = Config.now_if_args
 local later = MiniDeps.later
-local nix = require('config.nix')
 
 if not Config.isNixCats then
   local m_add = MiniDeps.add
@@ -13,21 +12,19 @@ end
 
 -- lua
 later(function()
-  if nix.get_cat("lua", false) then
-    add("luvit-meta")
-    add("lazydev")
-    require("lazydev").setup({
-      library = {
-        -- See the configuration section for more details
-        -- Load luvit types when the `vim.uv` word is found
-        "lua",
-        "mini.nvim",
-        "MiniDeps",
-        { path = "luvit-meta/library", words = { "vim%.uv" } },
-        { path = "${3rd}/luv/library", words = { "vim%.uv" } },
-      },
-    })
-  end
+  add("luvit-meta")
+  add("lazydev")
+  require("lazydev").setup({
+    library = {
+      -- See the configuration section for more details
+      -- Load luvit types when the `vim.uv` word is found
+      "lua",
+      "mini.nvim",
+      "MiniDeps",
+      { path = "luvit-meta/library", words = { "vim%.uv" } },
+      { path = "${3rd}/luv/library", words = { "vim%.uv" } },
+    },
+  })
 end)
 
 -- Markdown