diff --git a/deployment/data-model.nix b/deployment/data-model.nix
index 24e90284..59f907f3 100644
--- a/deployment/data-model.nix
+++ b/deployment/data-model.nix
@@ -15,7 +15,6 @@ let
     functionTo
     ;
 
-  functionType = import ./function.nix;
   application-resources = submodule {
     options.resources = mkOption {
       # TODO: maybe transpose, and group the resources by type instead
@@ -124,24 +123,16 @@ in
               );
             };
             implementation = mkOption {
-              description = "Mapping of resources required by applications to available resources; the result can be deployed";
-              type = environment.config.resource-mapping.function-type;
-            };
-            resource-mapping = mkOption {
-              description = "Function type for the mapping from resources to a (NixOps4) deployment";
-              type = submodule functionType;
-              readOnly = true;
-              default = {
-                input-type = application-resources;
-                output-type = nixops4Deployment;
-              };
+              description = "Mapping from resources required by applications to available resources to a deployment";
+              # input: application-resources
+              type = functionTo nixops4Deployment;
             };
             # TODO(@fricklerhandwerk): maybe this should be a separate thing such as `fediversity-setup`,
             # which makes explicit which applications and environments are available.
             # then the deployments can simply be the result of the function application baked into this module.
             deployment = mkOption {
               description = "Generate a deployment from a configuration, by applying an environment's resource policies to the applications' resource mappings";
-              type = functionTo (environment.config.resource-mapping.output-type);
+              type = functionTo nixops4Deployment;
               readOnly = true;
               default =
                 cfg: