diff --git a/src/gmser_dyn.erl b/src/gmser_dyn.erl
index a39843c..1acb533 100644
--- a/src/gmser_dyn.erl
+++ b/src/gmser_dyn.erl
@@ -13,12 +13,15 @@
         , decode_typed/3     %% (Type, RLP, Types)       -> Term
         , decode_typed/4 ]). %% (Type, RLP, Vsn, Types)  -> Term
 
--export([ serialize/1
-        , serialize/2
-        , serialize_typed/2
-        , serialize_typed/3
-        , deserialize/1
-        , deserialize/2 ]).
+-export([ serialize/1        %% (Term)                   -> Bin
+        , serialize/2        %% (Term, Types)            -> Bin
+        , serialize/3        %% (Term, Vsn, Types)       -> Bin
+        , serialize_typed/2  %% (Type, Term)             -> Bin
+        , serialize_typed/3  %% (Type, Term, Types)      -> Bin
+        , serialize_typed/4  %% (Type, Term, Vsn, Types) -> Bin
+        , deserialize/1      %% (Bin)                    -> Term
+        , deserialize/2      %% (Bin, Types)             -> Term
+        , deserialize/3 ]).  %% (Bin, Vsn, Types)        -> Term
 
 %% register a type schema, inspect existing schema
 -export([ register_types/1
diff --git a/src/gmser_dyn_types.erl b/src/gmser_dyn_types.erl
index cec7a30..6117d6d 100644
--- a/src/gmser_dyn_types.erl
+++ b/src/gmser_dyn_types.erl
@@ -1,6 +1,8 @@
 -module(gmser_dyn_types).
 
--export([ from_list/2 ]).
+-export([ add_type/4
+        , from_list/2
+        , expand/1 ]).
 -export([ next_code/1 ]).
 
 next_code(#{codes := Codes}) ->
@@ -12,6 +14,18 @@ add_type(Tag, Code, Template, Types) ->
 from_list(L, Types) ->
     lists:foldl(fun elem_to_type/2, Types, L).
 
+expand(#{vsn := V, templates := Templates0} = Types) ->
+    Templates =
+        maps:map(
+          fun(_, F) when is_function(F, 0) ->
+                  F();
+             (_, F) when is_function(F, 1) ->
+                  F(V);
+             (_, T) ->
+                  T
+          end, Templates0),
+    Types#{templates := Templates}.
+
 elem_to_type({Tag, Code, Template}, Acc) when is_atom(Tag), is_integer(Code) ->
     #{codes := Codes, rev := Rev, templates := Temps} = Acc,
     case {is_map_key(Tag, Rev), is_map_key(Code, Codes)} of