diff --git a/README.md b/README.md
index 8cdeab5..89a383b 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,32 @@
-# My NixOS Configuration
+# Nix Configurations
+
+Repository structure:
+
+- **host/**  
+  One subdirectory per NixOS host, each containing its host-specific configuration.
+
+- **mod/**  
+  NixOS modules.  
+  - **mod/common/**: Modules enabled by default on all hosts.  
+  - **mod/desktop/**: Modules enabled on desktop hosts (i.e. hosts with `hd.desktop.enable = true`).
+
+- **home/**  
+  Home Manager modules. Home Manager is integrated into the system configuration via the `home` option defined in `mod/desktop/default.nix`.
+
+- **bin/**  
+  Helper scripts for generating parts of the configuration.
+
+- **dotfiles/**  
+  Raw configuration files deployed using Home Manager.
+
+- **devshells/**  
+  Nix development shells.
+
+- **pki/**  
+  Certificates used by the configuration.
+
+- **secrets/**  
+  Age-encrypted secrets managed and deployed via agenix.
+
+- **var/**  
+  Shared constants and values used across the configuration.
diff --git a/flake.nix b/flake.nix
index 87d2c79..a2d9d06 100644
--- a/flake.nix
+++ b/flake.nix
@@ -62,53 +62,27 @@
           ;
         secrets = lib'.walk-dir ./secrets;
       };
-      overlays = _: {
-        nixpkgs.overlays = [
-          vscode-extensions.overlays.default
-          colmena.overlay
-        ];
-      };
+
+      mkDesktop =
+        host:
+        nixpkgs.lib.nixosSystem {
+          system = "x86_64-linux";
+          specialArgs = specialArgs // {
+            inherit host;
+          };
+          modules = [
+            (./host + "/${host}")
+            ./home
+            ./mod
+          ];
+        };
     in
     {
       nixosConfigurations = {
-        "solo" = nixpkgs.lib.nixosSystem {
-          system = "x86_64-linux";
-          specialArgs = specialArgs // {
-            host = "solo";
-          };
-          modules = [
-            ./host/solo
-            ./home
-            ./mod
-            overlays
-          ];
-        };
-
-        "c2" = nixpkgs.lib.nixosSystem {
-          system = "x86_64-linux";
-          specialArgs = specialArgs // {
-            host = "c2";
-          };
-          modules = [
-            ./host/c2
-            ./home
-            ./mod
-            overlays
-          ];
-        };
-
-        "fw" = nixpkgs.lib.nixosSystem {
-          system = "x86_64-linux";
-          specialArgs = specialArgs // {
-            host = "fw";
-          };
-          modules = [
-            ./host/fw
-            ./home
-            ./mod
-            overlays
-          ];
-        };
+        # if you add a host, make sure to add it to var/default.nix as well
+        "solo" = mkDesktop "solo";
+        "c2" = mkDesktop "c2";
+        "fw" = mkDesktop "fw";
       };
 
       colmenaHive = colmena.lib.makeHive {
@@ -126,7 +100,6 @@
           imports = [
             ./host/roam
             ./mod
-            overlays
           ];
         };
       };
diff --git a/mod/common/default.nix b/mod/common/default.nix
index fe17135..72c6d87 100644
--- a/mod/common/default.nix
+++ b/mod/common/default.nix
@@ -59,6 +59,7 @@ with lib;
     inputs.agenix.nixosModules.default
     ./locale.nix
     ./nix.nix
+    ./overlays.nix
     ./security.nix
     ./shell.nix
     ./users.nix
diff --git a/mod/common/overlays.nix b/mod/common/overlays.nix
new file mode 100644
index 0000000..83a3175
--- /dev/null
+++ b/mod/common/overlays.nix
@@ -0,0 +1,7 @@
+{ inputs, ... }:
+{
+  nixpkgs.overlays = with inputs; [
+    vscode-extensions.overlays.default
+    colmena.overlay
+  ];
+}
diff --git a/mod/syncthing.nix b/mod/syncthing.nix
index 69364d8..474d6c6 100644
--- a/mod/syncthing.nix
+++ b/mod/syncthing.nix
@@ -13,7 +13,7 @@ let
   is-server = this == "roam";
 
   devices = lib.attrNames var.syncthing.all;
-  desktop-devices = (lib.intersectLists var.desktops devices);
+  desktop-devices = (lib.intersectLists var.nixos-desktops devices);
 
   folders = folders-all // (if config.hd.desktop.enable then folders-desktop else { });
 
diff --git a/var/default.nix b/var/default.nix
index 252d05d..34bd26b 100644
--- a/var/default.nix
+++ b/var/default.nix
@@ -8,19 +8,23 @@ let
     var = outputs;
   };
   load-var = x: import x inputs';
+
   # watch out for cycles
   outputs = rec {
-    "lan-dns" = load-var ./lan-dns.nix;
-    "ssh-keys" = load-var ./ssh-keys.nix;
-    "wg" = load-var ./wg.nix;
-    "syncthing" = load-var ./syncthing.nix;
-    desktops = [
+    # We list the hosts here manually instead of getting them from the flake.
+    # This way, var can be used standalone
+    nixos-desktops = [
       "c2"
       "fw"
       "solo"
     ];
-    servers = [ "roam" ];
-    clients = desktops ++ servers;
+    nixos-servers = [ "roam" ];
+    nixos-hosts = nixos-desktops ++ nixos-servers;
+
+    "lan-dns" = load-var ./lan-dns.nix;
+    "ssh-keys" = load-var ./ssh-keys.nix;
+    "wg" = load-var ./wg.nix;
+    "syncthing" = load-var ./syncthing.nix;
   };
 in
 outputs