diff --git a/default.nix b/default.nix
index e851016..1f496c9 100644
--- a/default.nix
+++ b/default.nix
@@ -5,7 +5,7 @@
 , doerg-temml-worker
 , ibm-plex-web
 , test-emacs ? callPackage ./test-emacs.nix {}
-, fake-git
+, fake-git ? null
 , our-tex
 , makeWrapper
 , writeText
@@ -33,7 +33,7 @@ let
   ];
 
   doerg-config = writeText "doerg-extra-config.edn" ''
-    #:net.deertopia.doerg
+    #:net.deertopia.doerg.config
     {:ibm-plex-web "${ibm-plex-web}"
      :latex "${lib.getExe' our-tex "xelatex"}"
      :dvisvgm "${lib.getExe' our-tex "dvisvgm"}"
@@ -74,4 +74,5 @@ in mkCljBin' {
     clojure -M:test
   '';
   passthru = { inherit plex our-tex test-emacs; };
+  meta.mainProgram = "doerg";
 }
diff --git a/flake.nix b/flake.nix
index 2df7f00..f760549 100644
--- a/flake.nix
+++ b/flake.nix
@@ -14,17 +14,18 @@
         "x86_64-linux"
       ];
 
+      overlays = [
+        inputs.sydpkgs.overlays.default
+        clj-nix.overlays.default
+        self.overlays.default
+      ];
+
       each-system = f: nixpkgs.lib.genAttrs supportedSystems (system: f rec {
         pkgs = import nixpkgs {
           inherit system;
-          overlays = [
-            inputs.sydpkgs.overlays.default
-            clj-nix.overlays.default
-            self.overlays.default
-          ];
         };
         inherit (pkgs) lib;
-        inherit system;
+        inherit system overlays;
       });
     in {
       # Exposed as a REPL convenience.
@@ -36,13 +37,17 @@
       });
 
       overlays.default = final: prev:
-        let graal = x: final.mkGraalBin { cljDrv = x; };
+        let
+          # is this really the correct way to satisfy our
+          # dependencies? lmfao
+          final' = final.appendOverlays overlays;
+          graal = x: final'.mkGraalBin { cljDrv = x; };
         in {
-          ibm-plex-web = final.callPackage ./ibm-plex-web.nix {};
-          doerg = final.callPackage ./. {};
-          doerg-parser = final.callPackage ./doerg-parser {};
-          doerg-temml-worker = final.callPackage ./doerg-temml-worker {};
-          our-tex = final.callPackage ./our-tex.nix {};
+          ibm-plex-web = final'.callPackage ./ibm-plex-web.nix {};
+          doerg = final'.callPackage ./. {};
+          doerg-parser = final'.callPackage ./doerg-parser {};
+          doerg-temml-worker = final'.callPackage ./doerg-temml-worker {};
+          our-tex = final'.callPackage ./our-tex.nix {};
         };
 
       checks = each-system ({ pkgs, system, ... }: {
@@ -52,6 +57,8 @@
             (pkgs.lib.attrValues self.packages.${system});
       });
 
+      nixosModules.default = import ./module.nix { inherit self; };
+
       devShells = each-system ({ pkgs, system, ... }: {
         default = pkgs.mkShell {
           inputsFrom = [
diff --git a/module.nix b/module.nix
new file mode 100644
index 0000000..f559c8c
--- /dev/null
+++ b/module.nix
@@ -0,0 +1,64 @@
+{ self, ... }:
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.services.doerg;
+  doerg-config = pkgs.writeText "doerg-config.edn" ''
+    #:net.deertopia.doerg.config
+    {:org-roam-db-path "${cfg.databasePath}"
+     :state-directory "${cfg.stateDir}"}
+  '';
+
+  inherit (lib) types;
+in {
+  options.services.doerg = {
+    enable = lib.mkEnableOption "Doerg";
+    org-roam-db-sync.enable = lib.mkEnableOption "Org-roam db sync";
+    port = lib.mkOption {
+      default = 21984;
+      type = lib.types.port;
+      description = ''
+        The port on which Doerg will listen.
+      '';
+    };
+    stateDir = lib.mkOption {
+      type = types.path;
+      default = "/var/lib/private/doerg";
+      description = "Daemon's state directory.";
+    };
+    orgDir = lib.mkOption {
+      type = types.path;
+      description = "Org roam directory.";
+    };
+    package = lib.mkPackageOption pkgs "doerg" {};
+    databasePath = lib.mkOption {
+      type = types.path;
+      description = "Org roam database path";
+      default = cfg.orgDir + "org-roam.db";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    nixpkgs.overlays = [ self.overlays.default ];
+
+    systemd.services.doerg = {
+      after = [ "network-online.target" ];
+      wants = [ "network-online.target" ];
+      wantedBy = [ "multi-user.target" ];
+      environment.DOERG_CONFIG = doerg-config;
+      serviceConfig = {
+        # WorkingDirectory = cfg.stateDir;
+        StateDirectory = "doerg";
+        ExecStart = lib.getExe cfg.package;
+        DynamicUser = true;
+        ProtectSystem = "strict";
+        PrivateTmp = true;
+        BindReadOnlyPaths = [
+          cfg.orgDir
+          cfg.databasePath
+          "/nix"
+        ];
+      };
+    };
+  };
+}
diff --git a/resources/net/deertopia/doerg/default-config.edn b/resources/net/deertopia/doerg/default-config.edn
index 782ac3b..4d7fad1 100644
--- a/resources/net/deertopia/doerg/default-config.edn
+++ b/resources/net/deertopia/doerg/default-config.edn
@@ -1,9 +1,8 @@
 #:net.deertopia.doerg.config
-{:ibm-plex-web #or [#xdg-data-dir "ibm-plex-web"
-                    #env IBM_PLEX_WEB]
+{:ibm-plex-web #or [#env IBM_PLEX_WEB
+                    #xdg-data-dir "ibm-plex-web"]
  :latex "xelatex"
  :dvisvgm "dvisvgm"
- :debug-unimplemented? #profile {:dev true :default false}
  :doerg-temml-worker
  #profile {:dev #file "../../../../doerg-temml-worker/index.js"
            :default "doerg-temml-worker"}
diff --git a/src/net/deertopia/doerg/cached_file.clj b/src/net/deertopia/doerg/cached_file.clj
index 8dbf9f3..9db42b0 100644
--- a/src/net/deertopia/doerg/cached_file.clj
+++ b/src/net/deertopia/doerg/cached_file.clj
@@ -18,8 +18,10 @@
   calling `compute` with no arguments only if stale? is logical true."
   [& {:keys [file stale? compute]}]
   (when (or (not *use-cache?*) stale?)
-    (let [r (compute)]
+    (let [r (compute)
+          dir (fs/parent file)]
       (assert (string? r))
-      (fs/create-dirs (fs/parent file))
+      (when-not (fs/exists? dir)
+        (fs/create-dirs dir))
       (spit file r)))
   file)
diff --git a/src/net/deertopia/doerg/config.clj b/src/net/deertopia/doerg/config.clj
index 54b9c8e..a17d7e9 100644
--- a/src/net/deertopia/doerg/config.clj
+++ b/src/net/deertopia/doerg/config.clj
@@ -46,7 +46,8 @@
   "Aero tag to search for a directory on $XDG_DATA_DIRS."
   (some #(let [x (fs/path % value)]
            (and (fs/exists? x) x))
-        (fs/split-paths (System/getenv "XDG_DATA_DIRS"))))
+        (some-> (System/getenv "XDG_DATA_DIRS")
+                fs/split-paths)))
 
 (defmethod aero/reader 'file
   [{:keys [source]} tag value]