feat: configuring shell & add fish shell

devshells/default.nix

@@ -1,8 +1,50 @@
 { pkgs, ... }:
 
-pkgs.mkShell {
+let
+  # MCP wrapper script that ensures Python is available for GUI apps
+  mcpNixosWrapper = pkgs.writeShellScriptBin "mcp-nixos-wrapper" ''
+    export PATH="${pkgs.python3}/bin:${pkgs.uv}/bin:$PATH"
+    exec ${pkgs.uv}/bin/uvx mcp-nixos "$@"
+  '';
+
+  # Generate MCP configs for GUI applications
+  mcpConfigForGUI = pkgs.writeText "mcp_settings.json" (builtins.toJSON {
+    mcpServers = {
+      nixos = {
+        type = "stdio";
+        command = "${mcpNixosWrapper}/bin/mcp-nixos-wrapper";
+        args = [ ];
+      };
+    };
+  });
+
+  # Script to install MCP configs for Claude Code and Codex
+  installMcpConfigs = pkgs.writeShellScriptBin "install-mcp-configs" ''
+    set -e
+    echo "Installing MCP configurations..."
+
+    mkdir -p "$HOME/.config/claude-code"
+    mkdir -p "$HOME/.config/codex"
+
+    cp ${mcpConfigForGUI} "$HOME/.config/claude-code/mcp_settings.json"
+    cp ${mcpConfigForGUI} "$HOME/.config/codex/mcp_settings.json"
+
+    echo "✓ Installed MCP config to ~/.config/claude-code/mcp_settings.json"
+    echo "✓ Installed MCP config to ~/.config/codex/mcp_settings.json"
+    echo ""
+    echo "Restart Claude Code and Codex to apply changes."
+  '';
+
+in pkgs.mkShell {
   name = "default";
-  packages = with pkgs; [ git nixfmt-classic uv ];
+  packages = with pkgs; [
+    git
+    nixfmt-classic
+    uv
+    python3
+    mcpNixosWrapper
+    installMcpConfigs
+  ];
   shellHook = ''
     export DOTFILES_ROOT="$PWD"
     export XDG_CACHE_HOME="$DOTFILES_ROOT/.cache"
@@ -18,5 +60,8 @@ pkgs.mkShell {
 
     echo "Loaded default shell for dotfiles development"
     echo "MCP helper alias ready: mcp-nixos"
+    echo ""
+    echo "To install MCP configs for Claude Code and Codex, run:"
+    echo "  install-mcp-configs"
   '';
 }

flake.nix

@@ -28,7 +28,9 @@
       inherit (nixpkgs.lib) genAttrs;
       lib = nixpkgs.lib;
 
-      systems = [ "aarch64-darwin" "x86_64-darwin" ];
+      darwinSystems = [ "aarch64-darwin" "x86_64-darwin" ];
+      linuxSystems = [ "x86_64-linux" "aarch64-linux" ];
+      systems = darwinSystems ++ linuxSystems;
 
       forEachSystem = f: genAttrs systems (system: f system);
 
@@ -46,7 +48,8 @@
           config.allowUnfree = true;
         };
 
-      sharedModules = [ ./modules/darwin/system.nix ];
+      sharedDarwinModules = [ ./modules/darwin/system.nix ];
+      sharedNixosModules = [ ./modules/nixos/system.nix ];
 
       user = "rasyidanakbar";
 
@@ -56,14 +59,12 @@
         in darwin.lib.darwinSystem {
           inherit system pkgs;
           specialArgs = { inherit inputs overlaysList user; };
-          modules = sharedModules ++ extraModules ++ [
+          modules = sharedDarwinModules ++ extraModules ++ [
             home-manager.darwinModules.home-manager
             {
               nix.registry.self.flake = self;
               nixpkgs.overlays = overlaysList;
 
-              users.users.${user}.home = "/Users/${user}";
-
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
               home-manager.backupFileExtension = "backup";
@@ -72,8 +73,28 @@
             }
           ];
         };
+      mkNixos = { system ? "x86_64-linux", extraModules ? [ ]
+        , homeFile ? ./modules/nixos/home/default.nix }:
+        let pkgs = mkPkgs system;
+        in lib.nixosSystem {
+          inherit system pkgs;
+          specialArgs = { inherit inputs overlaysList user; };
+          modules = sharedNixosModules ++ extraModules ++ [
+            home-manager.nixosModules.home-manager
+            {
+              nix.registry.self.flake = self;
+              nixpkgs.overlays = overlaysList;
+
+              home-manager.useGlobalPkgs = true;
+              home-manager.useUserPackages = true;
+              home-manager.extraSpecialArgs = { inherit inputs user; };
+              home-manager.users.${user} = import homeFile;
+            }
+          ];
+        };
     in {
       darwinConfigurations = { macbook-pro = mkDarwin { }; };
+      nixosConfigurations = { };
 
       devShells = forEachSystem (system:
         let

modules/darwin/home/default.nix

@@ -1,5 +1,9 @@
 { config, pkgs, lib, ... }: {
   # Import shared cross-platform home configuration
-  imports =
+  imports = [
-    [ ../../home/rsydn/base.nix ./programs/aerospace ./programs/ghostty.nix ];
+    ../../home/rsydn/base.nix
+    ../../home/rsydn/shell/nushell.nix
+    ./programs/aerospace
+    ./programs/ghostty.nix
+  ];
 }

modules/darwin/system.nix

@@ -25,7 +25,10 @@
 
   environment.shells = [ pkgs.nushell ];
 
-  users.users.${user}.shell = pkgs.nushell;
+  users.users.${user} = {
+    home = lib.mkDefault "/Users/${user}";
+    shell = pkgs.nushell;
+  };
 
   system = {
     primaryUser = user;

modules/home/rsydn/base.nix

@@ -4,7 +4,6 @@
   imports = [
     ./programs/helix.nix
     ./programs/neovim.nix
-    ./shell/nushell.nix
     ./shell/tmux.nix
     ./devtools/ai-tools.nix
     ./devtools/languages.nix
@@ -57,7 +56,7 @@
     node.enable = true;
   };
 
-  rsydn.secrets = {
+  rsydn.secrets = lib.mkIf pkgs.stdenv.hostPlatform.isDarwin {
     enable = lib.mkDefault true;
     defaultSopsFile = ../../../secrets/local-ai-tokens.sops.yaml;
     secrets = {

modules/home/rsydn/shell/fish.nix

@@ -0,0 +1,17 @@
+{ config, pkgs, lib, ... }: {
+  imports = [ ./oh-my-posh ];
+
+  programs.fish = {
+    enable = true;
+    interactiveShellInit = ''
+      set -g fish_greeting ""
+      set -gx EDITOR nvim
+      set -gx VISUAL nvim
+    '';
+  };
+
+  programs.oh-my-posh.enableFishIntegration = lib.mkDefault true;
+
+  # Ensure fish is available for login shells on Linux hosts.
+  home.packages = lib.mkAfter [ pkgs.fish ];
+}

modules/home/rsydn/shell/nushell.nix

@@ -1,8 +1,5 @@
 { config, pkgs, lib, ... }:
 let
-  themeName = "capr4n.omp.json";
-  themeSource = ./oh-my-posh/capr4n.omp.json;
-  themeConfigPath = "${config.xdg.configHome}/oh-my-posh/${themeName}";
   profileBin = "${config.home.profileDirectory}/bin";
   systemBin = "/run/current-system/sw/bin";
   defaultBin = "/nix/var/nix/profiles/default/bin";
@@ -28,6 +25,8 @@ let
   formatPathList = paths:
     lib.concatMapStrings (path: "      \"${path}\"\n") paths;
 in {
+  imports = [ ./oh-my-posh ];
+
   programs.nushell.enable = lib.mkDefault true;
 
   programs.nushell.extraConfig = ''
@@ -115,11 +114,5 @@ in {
         load-secret "firecrawl-api-key" "FIRECRAWL_API_KEY"
   '';
 
-  programs.oh-my-posh = {
+  programs.oh-my-posh.enableNushellIntegration = lib.mkDefault true;
-    enable = lib.mkDefault true;
-    enableNushellIntegration = lib.mkDefault true;
-    configFile = themeConfigPath;
-  };
-
-  xdg.configFile."oh-my-posh/${themeName}".source = themeSource;
 }

modules/home/rsydn/shell/oh-my-posh/default.nix

@@ -0,0 +1,13 @@
+{ config, lib, ... }:
+let
+  themeName = "capr4n.omp.json";
+  themeSource = ./capr4n.omp.json;
+  themeConfigPath = "${config.xdg.configHome}/oh-my-posh/${themeName}";
+in {
+  programs.oh-my-posh = {
+    enable = lib.mkDefault true;
+    configFile = themeConfigPath;
+  };
+
+  xdg.configFile."oh-my-posh/${themeName}".source = themeSource;
+}

modules/nixos/home/default.nix

@@ -0,0 +1,3 @@
+{ config, pkgs, lib, ... }: {
+  imports = [ ../../home/rsydn/base.nix ../../home/rsydn/shell/fish.nix ];
+}

modules/nixos/system.nix

@@ -0,0 +1,10 @@
+{ config, pkgs, lib, user, ... }: {
+  users.users.${user} = {
+    isNormalUser = lib.mkDefault true;
+    extraGroups = lib.mkDefault [ "wheel" "networkmanager" ];
+    home = lib.mkDefault "/home/${user}";
+    shell = lib.mkDefault pkgs.fish;
+  };
+
+  programs.fish.enable = lib.mkDefault true;
+}