diff --git a/deployment/data-model-test.nix b/deployment/data-model-test.nix
index 3f24df94..92b20d88 100644
--- a/deployment/data-model-test.nix
+++ b/deployment/data-model-test.nix
@@ -17,52 +17,29 @@ in
   test-eval = {
     expr =
       let
-        example = eval (
+        fediversity = eval (
           { config, ... }:
           {
-            providers.single-ssh-host =
-              { ... }:
-              {
-                system.stateVersion = "25.05";
-              };
-            resources.bar.runtime-environment.single-ssh-host = {
-              ssh = {
-                host = "localhost";
-                username = "root";
-                authentication.password = "";
-              };
+            resources.nixos = {
+
             };
-            applications.foo.module =
-              { pkgs, ... }:
-              {
-                environment.systemPackages = [
-                  pkgs.hello
-                ];
-              };
-            deployments.baz = {
-              module = { };
-              runtime-environment = config.resources.bar.runtime-environment;
+            applications.hello = {
+
             };
-            migrations.boo = {
-              deployment = config.deployments.baz;
-              runtime-environment = config.resources.bar.runtime-environment;
+            environments.single-nixos-vm = {
+
+            };
+            configurations.example = {
+              enable = true;
+              applications.hello.enable = true;
             };
           }
         );
       in
       {
-        has-provider = lib.isAttrs example.providers.single-ssh-host;
-        has-resource = lib.isAttrs example.resources.bar.runtime-environment.single-ssh-host.module;
-        has-application = lib.isAttrs example.applications.foo.module;
-        has-deployment = lib.isAttrs example.deployments.baz.module;
-        has-migration = lib.isAttrs example.migrations.boo.deployment;
+
       };
     expected = {
-      has-provider = true;
-      has-resource = true;
-      has-application = true;
-      has-deployment = true;
-      has-migration = true;
     };
   };
 }
diff --git a/deployment/data-model.nix b/deployment/data-model.nix
index af6eda78..82a1e165 100644
--- a/deployment/data-model.nix
+++ b/deployment/data-model.nix
@@ -5,16 +5,13 @@
   ...
 }:
 let
-  inherit (lib) mkOption;
+  inherit (lib) mkOption types;
   inherit (lib.types)
     attrsOf
     attrTag
     deferredModuleWith
-    mergeTypes
-    nullOr
     submoduleWith
     submodule
-    str
     ;
 
   functionType = import ./interface.nix;
@@ -70,7 +67,7 @@ in
             };
             # TODO: somewhere we still need to
             # - apply = { implementation = config-mapping; input = <application configuration value from operator>; }
-            # - apply.output
+            # - apply.output (applications required by resources)
             function = mkOption {
               description = "Function type for the mapping from application configuration to required resources";
               type = submodule functionType;
@@ -103,8 +100,10 @@ in
             resource-mapping = mkOption {
               description = "Mapping of resources required by applications to available resources; the result can be deployed";
               type = environment.config.function.implementation;
-              # TODO: type = consumer-resources /* same as the output of application.config-mapping, should be in a `let` */ -> nixops4Deployment
             };
+            # TODO: somewhere we still need to
+            # - apply = { implementation = resource-mapping; input = <resource requirements of configured applications>; }
+            # - apply.output (deployment)
             function = mkOption {
               description = "Function type for the mapping from resources to a (NixOps4) deployment";
               type = submodule functionType;
@@ -118,5 +117,17 @@ in
         })
       );
     };
+    configurations = mkOption {
+      description = "Application configurations set by operators";
+      type = attrsOf (submodule {
+        options = {
+          enable = mkOption {
+            description = "Whether to enable the configuration";
+            type = types.bool;
+          };
+          applications = mapAttrs (name: application: submodule application.module) config.applications;
+        };
+      });
+    };
   };
 }