Adding more structure.

modules/metanix-core.nix

@@ -0,0 +1,71 @@
+{ lib, meta, addressing, ... }:
+
+let
+  inherit (lib) mkOption types;
+in
+{
+  options.metanix = {
+    # Raw world spec, straight from meta.nix
+    meta = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      default = { };
+      description = "Raw Metanix world spec loaded from meta.nix.";
+    };
+
+    domain = mkOption {
+      type = types.str;
+      readOnly = true;
+      description = "Base DNS domain for this Metanix world.";
+    };
+
+    locations = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Location tree from meta.nix.";
+    };
+
+    systems = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "System definitions from meta.nix.";
+    };
+
+    # Computed addressing
+    network = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Computed addressing (hosts, subnets, etc.) from meta.nix.";
+    };
+
+    hosts = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Shortcut for metanix.network.hosts.";
+    };
+
+    subnets = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Shortcut for metanix.network.subnets.";
+    };
+  };
+
+  config.metanix =
+    let
+      world = meta;
+      network = addressing.mkNetworkFromSpec world;
+    in
+    {
+      meta = world;
+
+      domain = world.domain;
+      locations = world.locations or { };
+      systems = world.systems or { };
+      policy = world.policy or { };
+
+      inherit network;
+      hosts = network.hosts;
+      subnets = network.subnets;
+    };
+}