diff --git a/flake.nix b/flake.nix
index 7d629db8..e077d377 100644
--- a/flake.nix
+++ b/flake.nix
@@ -72,7 +72,7 @@
             });
 
           devShell = import ./shell {
-            inherit pkgs nixos;
+            inherit self system;
           };
 
           legacyPackages.hmActivationPackages =
diff --git a/shell/default.nix b/shell/default.nix
index e693f765..22ce384a 100644
--- a/shell/default.nix
+++ b/shell/default.nix
@@ -1,50 +1,19 @@
-{ pkgs ? (import ./compat).defaultNix.nixosConfigurations.NixOS.config.nixpkgs.pkgs
-, nixos ? (import ./compat).defaultNix.inputs.nixos
-, ...
+{ self ? (import ../compat).defaultNix
+, system ? builtins.currentSystem
 }:
 let
-  build = "config.system.build";
+  pkgs = (self.lib.genPkgs { inherit self; }).${system};
 
-  installPkgs = (import "${nixos}/nixos" {
-    configuration = { };
-    system = pkgs.system;
+  inherit (pkgs) lib;
+
+  installPkgs = (lib.nixosSystem {
+    inherit system;
+    modules = [ ];
   }).config.system.build;
 
-  flk = pkgs.writeShellScriptBin "flk" ''
-    if [[ -z "$1" ]]; then
-      echo "Usage: $(basename $0) [ up | get [core|community] {dest} | iso {host} | install {host} | {host} [switch|boot|test] | home {host} {user} [switch] ]"
-    elif [[ "$1" == "up" ]]; then
-      mkdir -p "$DEVSHELL_ROOT/up"
-      hostname="$(hostname)"
-      nixos-generate-config --dir "$DEVSHELL_ROOT/up/$hostname"
-      echo \
-      "{
-      imports = [ ../up/$hostname/configuration.nix ];
-    }" > "$DEVSHELL_ROOT/hosts/up-$hostname.nix"
-    git add -f "$DEVSHELL_ROOT/up/$hostname"
-    git add -f "$DEVSHELL_ROOT/hosts/up-$hostname.nix"
-    elif [[ "$1" == "iso" ]]; then
-      nix build "$DEVSHELL_ROOT#nixosConfigurations.$2.${build}.iso" "${"\${@:3}"}"
-    elif [[ "$1" == "install" ]]; then
-      sudo nixos-install --flake "$DEVSHELL_ROOT#$2" "${"\${@:3}"}"
-    elif [[ "$1" == "home" ]]; then
-      nix build "./#hmActivationPackages.$2.$3"  "${"\${@:4}"}"
-      if [[ "$4" == "switch" ]]; then
-        ./result/activate && unlink result
-      fi
-    elif [[ "$1" == "get" ]]; then
-      if [[ "$2" == "core" || "$2" == "community" ]]; then
-        nix flake new -t "github:nrdxp/nixflk/$2" "${"\${3:-flk}"}"
-      else
-        echo "flk get [core|community] {dest}"
-        exit 1
-      fi
-    else
-      sudo nixos-rebuild --flake "$DEVSHELL_ROOT#$1" "${"\${@:2}"}"
-    fi
-  '';
+  flk = pkgs.callPackage ./flk.nix { };
 
-  name = "flk";
+  inherit (flk) name;
 in
 pkgs.devshell.mkShell {
   inherit name;
@@ -59,71 +28,31 @@ pkgs.devshell.mkShell {
 
   env = { inherit name; };
 
-  git.hooks = with pkgs; {
+  git.hooks = {
     enable = true;
-    pre-commit.text = ''
-      #!/usr/bin/env bash
-
-      if ${git}/bin/git rev-parse --verify HEAD >/dev/null 2>&1
-      then
-        against=HEAD
-      else
-        # Initial commit: diff against an empty tree object
-        against=$(${git}/bin/git hash-object -t tree /dev/null)
-      fi
-
-      diff="${git}/bin/git diff-index --name-only --cached $against --diff-filter d"
-
-      nix_files=($($diff -- '*.nix'))
-
-      all_files=($($diff))
-
-      # Format staged nix files.
-      ${nixpkgs-fmt}/bin/nixpkgs-fmt "${"\${nix_files[@]}"}" \
-      && git add "${"\${nix_files[@]}"}"
-
-      # check editorconfig
-      ${editorconfig-checker}/bin/editorconfig-checker -- "${"\${all_files[@]}"}"
-      if [[ $? != '0' ]]; then
-        {
-          echo -e "\nCode is not aligned with .editorconfig"
-          echo "Review the output and commit your fixes"
-        } >&2
-        exit 1
-      fi
-    '';
+    pre-commit.text = lib.fileContents ./pre-commit.sh;
   };
 
-  commands = with pkgs; [
-    {
-      name = nixpkgs-fmt.pname;
-      package = nixpkgs-fmt;
-      help = nixpkgs-fmt.meta.description;
-      category = "linters";
-    }
-    {
-      name = flk.name;
-      help = "Build, deploy, and install nixflk";
-      category = "main";
-      package = flk;
-    }
-    {
-      name = "grip";
-      help = python38Packages.grip.meta.description;
-      category = "servers";
-      package = python38Packages.grip;
-    }
-    {
-      name = git.pname;
-      help = git.meta.description;
-      category = "vcs";
-      package = git;
-    }
+  commands = with pkgs; let
+    mkCommand = category: package: {
+      inherit package category;
+      name = package.pname or package.name;
+      help = package.meta.description;
+    };
+
+    mapCmd = category: map (mkCommand category);
+  in
+  mapCmd "main" [ flk cachix git ] ++
+  mapCmd "linters" [ nixpkgs-fmt editorconfig-checker ] ++
+  mapCmd "documentation" [ python3Packages.grip mdbook ] ++ [
     {
       name = "nix";
       help = nixFlakes.meta.description;
       category = "main";
-      command = ''${nixFlakes}/bin/nix --option experimental-features "nix-command flakes ca-references" "$@"'';
+      command = ''
+        ${nixFlakes}/bin/nix --option experimental-features \
+          "nix-command flakes ca-references" "$@"
+      '';
     }
   ];
 
diff --git a/shell/flk.nix b/shell/flk.nix
new file mode 100644
index 00000000..ff9c59e7
--- /dev/null
+++ b/shell/flk.nix
@@ -0,0 +1,23 @@
+{ stdenv }:
+let
+  name = "flk";
+in
+stdenv.mkDerivation {
+  inherit name;
+
+  src = ./flk.sh;
+
+  dontUnpack = true;
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p $out/bin
+    install $src $out/bin/${name}
+  '';
+
+  checkPhase = ''
+    ${stdenv.shell} -n -O extglob $out/bin/${name}
+  '';
+
+  meta.description = "Build, deploy, and install NixOS";
+}
diff --git a/shell/flk.sh b/shell/flk.sh
new file mode 100755
index 00000000..07a08d69
--- /dev/null
+++ b/shell/flk.sh
@@ -0,0 +1,82 @@
+[[ -d "$DEVSHELL_ROOT" ]] ||
+  {
+    echo "This script must be run from nixflk's devshell" >&2
+    exit 1
+  }
+
+shopt -s extglob
+
+HOSTNAME="$(hostname)"
+
+usage () {
+  printf "%b\n" \
+    "\e[4mUsage\e[0m: $(basename $0) COMMAND [ARGS]\n" \
+    "\e[4mCommands\e[0m:"
+
+  printf "  %-30s %s\n\n" \
+  "up" "Generate $DEVSHELL_ROOT/hosts/up-$HOSTNAME.nix" \
+  "update" "Update and commit the lock file" \
+  "get [core|community] DEST" "Copy the desired template to DEST" \
+  "iso HOST" "Generate an ISO image of HOST" \
+  "install HOST [ARGS]" "Shortcut for nixos-install" \
+  "home HOST USER [switch]" "Home-manager config of USER from HOST" \
+  "HOST [switch|boot|test]" "Shortcut for nixos-rebuild"
+}
+
+case "$1" in
+  ""|"-h"|"help"|*(-)"help")
+    usage
+    ;;
+
+  "up")
+    mkdir -p "$DEVSHELL_ROOT/up"
+
+    nixos-generate-config --dir "$DEVSHELL_ROOT/up/$HOSTNAME"
+
+    printf "{ imports = [ ../up/$HOSTNAME/configuration.nix ]; }" \
+      > "$DEVSHELL_ROOT/hosts/up-$HOSTNAME.nix"
+
+    git add -f \
+      "$DEVSHELL_ROOT/up/$HOSTNAME" \
+      "$DEVSHELL_ROOT/hosts/up-$HOSTNAME.nix"
+    ;;
+
+  "update")
+    nix flake update --recreate-lock-file --commit-lock-file "$DEVSHELL_ROOT"
+    ;;
+
+  "get")
+    if [[ "$2" == "core" || "$2" == "community" ]]; then
+      nix flake new -t "github:nrdxp/nixflk/$2" "${3:-flk}"
+    else
+      echo "flk get [core|community] {dest}"
+      exit 1
+    fi
+    ;;
+
+  "iso")
+    nix build \
+      "$DEVSHELL_ROOT#nixosConfigurations.$2.config.system.build.iso" \
+      "${@:3}"
+    ;;
+
+  "install")
+    sudo nixos-install --flake "$DEVSHELL_ROOT#$2" "${@:3}"
+    ;;
+
+  "home")
+    ref="$DEVSHELL_ROOT/#hmActivationPackages.$2.$3"
+
+    if [[ "$4" == "switch" ]]; then
+      nix build "$ref" && result/activate &&
+        unlink result
+
+    else
+      nix build "$ref" "${@:4}"
+    fi
+    ;;
+
+  *)
+    sudo nixos-rebuild --flake "$DEVSHELL_ROOT#$1" "${@:2}"
+    ;;
+esac
diff --git a/shell/pre-commit.sh b/shell/pre-commit.sh
new file mode 100755
index 00000000..985d3b40
--- /dev/null
+++ b/shell/pre-commit.sh
@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+if git rev-parse --verify HEAD >/dev/null 2>&1
+then
+  against=HEAD
+else
+  # Initial commit: diff against an empty tree object
+  against=$(${git}/bin/git hash-object -t tree /dev/null)
+fi
+
+diff="git diff-index --name-only --cached $against --diff-filter d"
+
+nix_files=($($diff -- '*.nix'))
+all_files=($($diff))
+
+# Format staged nix files.
+if [[ -n "${nix_files[@]}" ]]; then
+  nixpkgs-fmt "${nix_files[@]}" \
+  && git add "${nix_files[@]}"
+fi
+
+# check editorconfig
+editorconfig-checker -- "${all_files[@]}"
+if [[ $? != '0' ]]; then
+  printf "%b\n" \
+    "\nCode is not aligned with .editorconfig" \
+    "Review the output and commit your fixes" >&2
+  exit 1
+fi