diff --git a/src/main.ml b/src/main.ml
index 238421f..7394498 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -32,7 +32,8 @@ let main () =
           )
         in
         let ty = 400.0 in
-        Mat2A.set (TG.model root.transform) ~tx ~ty ~sx:1.0 ~sy:1.0
+        let tf = TG.model (Scene.transform root) in
+        Mat2A.set tf ~tx ~ty ~sx:1.0 ~sy:1.0
       end;
 
       Renderer.pre_draw ren;
diff --git a/src/n2/n2.mli b/src/n2/n2.mli
new file mode 100644
index 0000000..9af30bd
--- /dev/null
+++ b/src/n2/n2.mli
@@ -0,0 +1,38 @@
+open Adam
+open S2
+module Sexp = Sexplib0.Sexp
+
+module Transform_graph : sig
+  type t
+  type node
+
+  val make : unit -> t
+  val update : t -> unit
+
+  val add : ?parent:node -> t -> node
+  val model : node -> mat2a
+  val world : node -> mat2a
+end
+
+module Sprite_graph : sig
+  type t
+  type node
+
+  val make : unit -> t
+  val render : t -> ren:Renderer.t -> unit
+
+  val add_rect : t -> tf:mat2a -> bb:aabb -> fill:color -> node
+end
+
+module Scene : sig
+  type t
+  type obj
+
+  val load : string ->
+    tg:Transform_graph.t ->
+    sg:Sprite_graph.t ->
+    t
+
+  val get : t -> string -> obj
+  val transform : obj -> Transform_graph.node
+end