diff --git a/src/gen_json.erl b/src/gen_json.erl
index f9d9399..d9818ee 100644
--- a/src/gen_json.erl
+++ b/src/gen_json.erl
@@ -28,6 +28,29 @@
 -export([handle_event/2, init/1]).
 
 
+-type events() :: [event()].
+-type event() :: start_object
+    | end_object
+    | start_array
+    | end_array
+    | end_json
+    | {key, list()}
+    | {string, list()}
+    | {integer, integer()}
+    | {float, float()}
+    | {literal, true}
+    | {literal, false}
+    | {literal, null}.
+
+-type opts() :: [opt()].
+-type opt() :: loose_unicode
+        | escape_forward_slashes
+        | explicit_end
+        | {parser, auto} | {parser, encoder} | {parser, decoder} | {parser, function()}.
+
+-export_type([events/0, event/0, opts/0, opt/0]).
+
+
 behaviour_info(callbacks) -> [{init, 0}, {handle_event, 2}];
 behaviour_info(_) -> undefined.
 
@@ -41,13 +64,13 @@ parser(Mod, Args) -> parser(Mod, Args, []).
 parser(Mod, Args, Opts) when is_atom(Mod), is_list(Opts) ->
     case proplists:get_value(parser, Opts, auto) of
         auto ->
-            fun(Input) when is_list(Input) -> (jsx:encoder(Mod, Args, Opts))(Input)
-                ; (Input) when is_binary(Input) -> (jsx:decoder(Mod, Args, Opts))(Input)
+            fun(Input) when is_list(Input) -> (jsx_encoder:encoder(Mod, Mod:init(Args), Opts))(Input)
+                ; (Input) when is_binary(Input) -> (jsx_decoder:decoder(Mod, Mod:init(Args), Opts))(Input)
             end
         ; encoder ->
-            fun(Input) -> (jsx:encoder(Mod, Args, Opts))(Input) end
+            fun(Input) -> (jsx_encoder:encoder(Mod, Mod:init(Args), Opts))(Input) end
         ; decoder ->
-            fun(Input) -> (jsx:decoder(Mod, Args, Opts))(Input) end
+            fun(Input) -> (jsx_decoder:decoder(Mod, Mod:init(Args), Opts))(Input) end
     end.
 
 
diff --git a/src/jsx.erl b/src/jsx.erl
index e15209d..6d37ae9 100644
--- a/src/jsx.erl
+++ b/src/jsx.erl
@@ -36,29 +36,6 @@
 -endif.
 
 
-%% various semi-useful types with nowhere else to hang out
-
--type events() :: [event()].
--type event() :: start_object
-    | end_object
-    | start_array
-    | end_array
-    | end_json
-    | {key, list()}
-    | {string, list()}
-    | {integer, integer()}
-    | {float, float()}
-    | {literal, true}
-    | {literal, false}
-    | {literal, null}.
-
--type opts() :: [opt()].
--type opt() :: loose_unicode
-        | escape_forward_slashes
-        | explicit_end
-        | {parser, auto} | {parser, encoder} | {parser, decoder} | {parser, function()}.
-
-
 
 -spec to_json(Source::any()) -> binary().
 -spec to_json(Source::any(), Opts::jsx_to_json:opts()) -> binary().
@@ -115,9 +92,9 @@ jsx_decoder_test_() ->
 encoder_decoder_equiv_test_() ->
     [
         {"encoder/decoder equivalency",
-            ?_assert((jsx:decoder(?MODULE, []))(
+            ?_assert((jsx_decoder:decoder(?MODULE, [], []))(
                     <<"[\"a\", 17, 3.14, true, {\"k\":false}, []]">>
-                ) =:= (jsx:encoder(?MODULE, []))([<<"a">>, 17, 3.14, true, [{<<"k">>, false}], []])
+                ) =:= (jsx_encoder:encoder(?MODULE, [], []))([<<"a">>, 17, 3.14, true, [{<<"k">>, false}], []])
             )
         }
     ].
diff --git a/src/jsx_decoder.erl b/src/jsx_decoder.erl
index 6d31e74..38ee72e 100644
--- a/src/jsx_decoder.erl
+++ b/src/jsx_decoder.erl
@@ -26,10 +26,10 @@
 -export([decoder/3]).
 
 
--spec decoder(Mod::module(), Args::any(), Opts::jsx:opts()) -> jsx:decoder().
+-spec decoder(Handler::module(), State::any(), Opts::jsx:opts()) -> jsx:decoder().
 
-decoder(Mod, Args, Opts) ->
-    fun(JSON) -> value(JSON, {Mod, Mod:init(Args)}, [], jsx_utils:parse_opts(Opts)) end.
+decoder(Handler, State, Opts) ->
+    fun(JSON) -> value(JSON, {Handler, State}, [], jsx_utils:parse_opts(Opts)) end.
 
 
 
diff --git a/src/jsx_encoder.erl b/src/jsx_encoder.erl
index 50db861..07c18f8 100644
--- a/src/jsx_encoder.erl
+++ b/src/jsx_encoder.erl
@@ -26,10 +26,10 @@
 -export([encoder/3]).
 
 
--spec encoder(Mod::module(), Args::any(), Opts::jsx:opts()) -> jsx:encoder().
+-spec encoder(Handler::module(), State::any(), Opts::jsx:opts()) -> jsx:encoder().
 
-encoder(Mod, Args, Opts) ->
-    fun(JSON) -> start(JSON, {Mod, Mod:init(Args)}, jsx_utils:parse_opts(Opts)) end.
+encoder(Handler, State, Opts) ->
+    fun(JSON) -> start(JSON, {Handler, State}, jsx_utils:parse_opts(Opts)) end.