diff --git a/default.nix b/default.nix
index 5ede45f76fb..d5e1d099368 100644
--- a/default.nix
+++ b/default.nix
@@ -36,6 +36,17 @@ let dfinity-repo = import (builtins.fetchGit {
   rev = "ab9d9d6ccba33748fc92f6e8d631327f7f25aead";
 }) { system = nixpkgs.system; }; in
 
+let sdk = import (builtins.fetchGit {
+  url = "ssh://git@github.com/dfinity-lab/sdk";
+  ref = "paulyoung/ts-user-library";
+  rev = "42f15621bc5b228c7fd349cb52f265917d33a3a0";
+}) { system = nixpkgs.system; }; in
+
+let esm = builtins.fetchTarball {
+  sha256 = "116k10q9v0yzpng9bgdx3xrjm2kppma2db62mnbilbi66dvrvz9q";
+  url = "https://registry.npmjs.org/esm/-/esm-3.2.25.tgz";
+}; in
+
 let real-dvm =
   if dvm == null
   then dev.dvm
@@ -46,8 +57,7 @@ let real-drun =
   then dfinity-repo.dfinity.drun
   else drun; in
 
-# Include js-client
-let js-client = dev.js-dfinity-client; in
+let js-user-library = sdk.js-user-library; in
 
 let haskellPackages = nixpkgs.haskellPackages.override {
       overrides = self: super: {
@@ -269,11 +279,12 @@ rec {
         nixpkgs.getconf
         nixpkgs.nodejs-10_x
         filecheck
-        js-client
+        js-user-library
         dvm
         drun
         qc-actorscript
         lsp-int
+        esm
       ] ++
       llvmBuildInputs;
 
@@ -283,7 +294,8 @@ rec {
         export ASC=asc
         export AS_LD=as-ld
         export DIDC=didc
-        export JSCLIENT=${js-client}
+        export ESM=${esm}
+        export JS_USER_LIBRARY=${js-user-library}
         asc --version
         make parallel
         qc-actorscript${nixpkgs.lib.optionalString (replay != 0)
@@ -552,8 +564,9 @@ rec {
     ));
 
     shellHook = llvmEnv;
+    ESM=esm;
+    JS_USER_LIBRARY=js-user-library;
     TOMMATHSRC = libtommath;
-    JSCLIENT = js-client;
     NIX_FONTCONFIG_FILE = users-guide.NIX_FONTCONFIG_FILE;
   } else null;
 
diff --git a/src/idllib/compile_js.ml b/src/idllib/compile_js.ml
index ff0f5d8ed34..1e159436d64 100644
--- a/src/idllib/compile_js.ml
+++ b/src/idllib/compile_js.ml
@@ -108,7 +108,7 @@ let rec pp_typ ppf t =
   | OptT t -> str ppf "IDL.Opt("; pp_typ ppf t; str ppf ")";
   | VariantT ts -> str ppf "IDL.Variant({"; concat ppf pp_field "," ts; str ppf "})";
   | FuncT (ms, t1, t2) ->
-     str ppf "IDL.Message(";
+     str ppf "IDL.Func(";
      pp_fields ppf t1;
      kwd ppf ",";
      pp_fields ppf t2;
@@ -169,28 +169,40 @@ let pp_rec ppf x =
   pp_close_box ppf ();
   pp_print_cut ppf ()
 
-let pp_actor ppf actor =
+let pp_actor ppf actor recs =
   pp_open_hovbox ppf 1;
   kwd ppf "const";
   (match actor.it with
    | ActorD (x, t) ->
       let x = ("actor_" ^ x.it) @@ x.at in
-      match t.it with
-      | ServT tp ->
-         id ppf x; space ppf (); kwd ppf "="; kwd ppf "new";
-         str ppf "IDL.ActorInterface({";
-         concat ppf pp_meth "," tp;
-         str ppf "})"
-      | VarT var -> id ppf x; space ppf (); kwd ppf "="; id ppf var
-      | _ -> assert false
+      (match t.it with
+       | ServT tp ->
+          id ppf x; space ppf (); kwd ppf "="; kwd ppf "new";
+          str ppf "IDL.ActorInterface({";
+          concat ppf pp_meth "," tp;
+          str ppf "});"
+       | VarT var ->
+          id ppf x; space ppf (); kwd ppf "=";
+          if TS.mem var.it recs then
+            str ppf (var.it ^ ".__typ;")
+          else
+            str ppf var.it;
+       | _ -> assert false
+      );
+      pp_force_newline ppf ();
+      kwd ppf "return"; id ppf x; str ppf ";"
   );
   pp_close_box ppf ()
 
 let pp_header ppf () =
   pp_open_vbox ppf 0;
-  str ppf "const IDL = require('IDL')";
+  str ppf "export default ({ IDL }) => {";
   pp_close_box ppf ()
-  
+
+let pp_footer ppf () =
+  pp_force_newline ppf ();
+  pp_print_string ppf "};"
+
 let pp_prog ppf env prog =
   match prog.it.actor with
   | None -> ()
@@ -205,8 +217,9 @@ let pp_prog ppf env prog =
      pp_open_vbox ppf 0;
      TS.iter (pp_rec ppf) recs;
      List.iter (pp_dec ppf) env_list;
-     pp_actor ppf actor;
-     pp_close_box ppf ()
+     pp_actor ppf actor recs;
+     pp_close_box ppf ();
+     pp_footer ppf ()
    
 let compile (scope : Typing.scope) (prog : Syntax.prog) =
   let buf = Buffer.create 100 in
diff --git a/test/idl/ok/actor.js.ok b/test/idl/ok/actor.js.ok
index 2225b3b1fd9..36fbe4a2d93 100644
--- a/test/idl/ok/actor.js.ok
+++ b/test/idl/ok/actor.js.ok
@@ -1,9 +1,11 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const o = IDL.Rec()
-const f = IDL.Message(IDL.Obj({'0': IDL.Int8}), IDL.Obj({'0': IDL.Int8}))
-const h = IDL.Message(IDL.Obj({'0': f}), IDL.Obj({'0': f}))
+const f = IDL.Func(IDL.Obj({'0': IDL.Int8}), IDL.Obj({'0': IDL.Int8}))
+const h = IDL.Func(IDL.Obj({'0': f}), IDL.Obj({'0': f}))
 const g = f
 o.fill(IDL.Opt(o))
 const actor_g = new IDL.ActorInterface({
- 'f': IDL.Message(IDL.Obj({'0': IDL.Nat}), IDL.Obj({'0': h})), 'g': f,
- 'h': g, 'o': IDL.Message(IDL.Obj({'0': o}), IDL.Obj({'0': o}))})
+ 'f': IDL.Func(IDL.Obj({'0': IDL.Nat}), IDL.Obj({'0': h})), 'g': f, 'h': g,
+ 'o': IDL.Func(IDL.Obj({'0': o}), IDL.Obj({'0': o}))});
+ return actor_g;
+};
diff --git a/test/idl/ok/cyclic.js.ok b/test/idl/ok/cyclic.js.ok
index f04f438c3ba..6aaa361324b 100644
--- a/test/idl/ok/cyclic.js.ok
+++ b/test/idl/ok/cyclic.js.ok
@@ -1,4 +1,4 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const A = IDL.Rec()
 const C = A
 const B = IDL.Opt(C)
@@ -8,5 +8,7 @@ const Y = Z
 const X = Y
 const actor_S = new IDL.ActorInterface({
  'f':
-  IDL.Message(IDL.Obj({'0': A, '1': B, '2': C, '3': X, '4': Y, '5': Z}),
-   IDL.Obj({}))})
+  IDL.Func(IDL.Obj({'0': A, '1': B, '2': C, '3': X, '4': Y, '5': Z}),
+   IDL.Obj({}))});
+ return actor_S;
+};
diff --git a/test/idl/ok/diamond.js.ok b/test/idl/ok/diamond.js.ok
index 360efbdc716..0570db603c6 100644
--- a/test/idl/ok/diamond.js.ok
+++ b/test/idl/ok/diamond.js.ok
@@ -1,7 +1,10 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const t = IDL.Nat
 const t2 = IDL.Arr(t)
 const t3 = IDL.Opt(t)
 const t1 = IDL.Obj({'0': t2, '1': t3, '2': t})
 const actor_S = new IDL.ActorInterface({
- 'f': IDL.Message(IDL.Obj({'0': t, '1': t2, '2': t3}), IDL.Obj({'0': t1}))})
+ 'f': IDL.Func(IDL.Obj({'0': t, '1': t2, '2': t3}), IDL.Obj({'0': t1}))});
+ 
+ return actor_S;
+};
diff --git a/test/idl/ok/fields.js.ok b/test/idl/ok/fields.js.ok
index 4e2493fcfad..00c249c0f3c 100644
--- a/test/idl/ok/fields.js.ok
+++ b/test/idl/ok/fields.js.ok
@@ -1,4 +1,4 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const A = IDL.Obj({'0': IDL.Nat, '1': IDL.Nat, '2': IDL.Nat})
 const B =
  IDL.Obj({'0': IDL.Arr(IDL.Nat8), '35': IDL.Arr(IDL.Nat8), '36': IDL.Nat,
@@ -15,5 +15,7 @@ const nest_record =
   '5': IDL.Nat, '6': IDL.Nat, '7': A, '8': B, '9': C, '10': IDL.Nat})
 const actor_S = new IDL.ActorInterface({
  'f':
-  IDL.Message(IDL.Obj({'0': A, '1': B, '2': C, '3': nest_record}),
-   IDL.Obj({}))})
+  IDL.Func(IDL.Obj({'0': A, '1': B, '2': C, '3': nest_record}), IDL.Obj({}))
+ });
+ return actor_S;
+};
diff --git a/test/idl/ok/import.js.ok b/test/idl/ok/import.js.ok
index fa9377df38d..daef8d6b5e0 100644
--- a/test/idl/ok/import.js.ok
+++ b/test/idl/ok/import.js.ok
@@ -1,4 +1,4 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const t = IDL.Arr(IDL.Nat8)
 const t1 = t
 const UserId = IDL.Nat
@@ -13,7 +13,10 @@ const IdErr = IDL.Obj({'idErr': OpEntId})
 const Inventory = IDL.Obj({'produce_id': IDL.Nat, 'quantity': IDL.Nat})
 const actor_S = new IDL.ActorInterface({
  'f':
-  IDL.Message(IDL.Obj({'0': t, '1': t1, '2': t2}),
+  IDL.Func(IDL.Obj({'0': t, '1': t1, '2': t2}),
    IDL.Obj({'0': list, '1': IdErr})),
  'getInventory':
-  IDL.Message(IDL.Obj({'producer_id': IDL.Nat}), IDL.Obj({'0': Inventory}))})
+  IDL.Func(IDL.Obj({'producer_id': IDL.Nat}), IDL.Obj({'0': Inventory}))});
+ 
+ return actor_S;
+};
diff --git a/test/idl/ok/import1.js.ok b/test/idl/ok/import1.js.ok
index 23a298b9391..944ff4a8b2b 100644
--- a/test/idl/ok/import1.js.ok
+++ b/test/idl/ok/import1.js.ok
@@ -1,7 +1,9 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const t = IDL.Arr(IDL.Nat8)
 const t1 = t
 const UserId = IDL.Nat
 const t2 = UserId
 const actor_S = new IDL.ActorInterface({
- 'f': IDL.Message(IDL.Obj({'0': t, '1': t1, '2': t2}), IDL.Obj({}))})
+ 'f': IDL.Func(IDL.Obj({'0': t, '1': t1, '2': t2}), IDL.Obj({}))});
+ return actor_S;
+};
diff --git a/test/idl/ok/import3.js.ok b/test/idl/ok/import3.js.ok
index 517f9849fb4..fbd7f269d06 100644
--- a/test/idl/ok/import3.js.ok
+++ b/test/idl/ok/import3.js.ok
@@ -1,16 +1,16 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const B = IDL.Rec()
 const list = IDL.Rec()
 const s = IDL.Rec()
 const stream = IDL.Rec()
 const tree = IDL.Rec()
-const t = IDL.Message(IDL.Obj({'server': s}), IDL.Obj({}))
+const t = IDL.Func(IDL.Obj({'server': s}), IDL.Obj({}))
 const node = IDL.Obj({'head': IDL.Nat, 'tail': list})
 list.fill(IDL.Opt(node))
 stream.fill(
  IDL.Opt(
   IDL.Obj({'head': IDL.Nat,
-   'next': IDL.Message(IDL.Obj({}), IDL.Obj({'0': stream}))}))
+   'next': IDL.Func(IDL.Obj({}), IDL.Obj({'0': stream}))}))
   )
 tree.fill(
  IDL.Variant({
@@ -21,6 +21,8 @@ B.fill(IDL.Opt(A))
 s.fill(
  new IDL.ActorInterface({'f': t,
   'g':
-   IDL.Message(IDL.Obj({'0': list}),
-    IDL.Obj({'2': stream, '1': tree, '0': B}))}))
-const actor_S = s
+   IDL.Func(IDL.Obj({'0': list}), IDL.Obj({'2': stream, '1': tree, '0': B}))
+  }))
+const actor_S = s.__typ;
+ return actor_S;
+};
diff --git a/test/idl/ok/integer.js.ok b/test/idl/ok/integer.js.ok
index 436f404354e..970e4d46cb8 100644
--- a/test/idl/ok/integer.js.ok
+++ b/test/idl/ok/integer.js.ok
@@ -1,5 +1,7 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const actor_num = new IDL.ActorInterface({
- 'f': IDL.Message(IDL.Obj({'0': IDL.Nat8}), IDL.Obj({'0': IDL.Int16})),
- 'g': IDL.Message(IDL.Obj({'0': IDL.Nat64}), IDL.Obj({'0': IDL.Int64})),
- 'h': IDL.Message(IDL.Obj({'0': IDL.Int8}), IDL.Obj({'0': IDL.Nat}))})
+ 'f': IDL.Func(IDL.Obj({'0': IDL.Nat8}), IDL.Obj({'0': IDL.Int16})),
+ 'g': IDL.Func(IDL.Obj({'0': IDL.Nat64}), IDL.Obj({'0': IDL.Int64})),
+ 'h': IDL.Func(IDL.Obj({'0': IDL.Int8}), IDL.Obj({'0': IDL.Nat}))});
+ return actor_num;
+};
diff --git a/test/idl/ok/px.js.ok b/test/idl/ok/px.js.ok
index 06ea8d3f87f..25173a75769 100644
--- a/test/idl/ok/px.js.ok
+++ b/test/idl/ok/px.js.ok
@@ -1,4 +1,4 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const UserId = IDL.Nat
 const RegionId = IDL.Nat
 const ProducerId = IDL.Nat
@@ -14,5 +14,7 @@ const OpEntId = IDL.Opt(EntId)
 const IdErr = IDL.Obj({'idErr': OpEntId})
 const actor_ProduceExchange = new IDL.ActorInterface({
  'getInventory':
-  IDL.Message(IDL.Obj({'producer_id': IDL.Nat, '3667444713': UserInfo}),
-   IDL.Obj({'0': Inventory, '1': IdErr}))})
+  IDL.Func(IDL.Obj({'producer_id': IDL.Nat, '3667444713': UserInfo}),
+   IDL.Obj({'0': Inventory, '1': IdErr}))});
+ return actor_ProduceExchange;
+};
diff --git a/test/idl/ok/recursion.js.ok b/test/idl/ok/recursion.js.ok
index 1b71a15819f..5d828a96773 100644
--- a/test/idl/ok/recursion.js.ok
+++ b/test/idl/ok/recursion.js.ok
@@ -1,16 +1,16 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const B = IDL.Rec()
 const list = IDL.Rec()
 const s = IDL.Rec()
 const stream = IDL.Rec()
 const tree = IDL.Rec()
-const t = IDL.Message(IDL.Obj({'server': s}), IDL.Obj({}))
+const t = IDL.Func(IDL.Obj({'server': s}), IDL.Obj({}))
 const node = IDL.Obj({'head': IDL.Nat, 'tail': list})
 list.fill(IDL.Opt(node))
 stream.fill(
  IDL.Opt(
   IDL.Obj({'head': IDL.Nat,
-   'next': IDL.Message(IDL.Obj({}), IDL.Obj({'0': stream}))}))
+   'next': IDL.Func(IDL.Obj({}), IDL.Obj({'0': stream}))}))
   )
 tree.fill(
  IDL.Variant({
@@ -21,6 +21,8 @@ B.fill(IDL.Opt(A))
 s.fill(
  new IDL.ActorInterface({'f': t,
   'g':
-   IDL.Message(IDL.Obj({'0': list}),
-    IDL.Obj({'2': stream, '1': tree, '0': B}))}))
-const actor_A = s
+   IDL.Func(IDL.Obj({'0': list}), IDL.Obj({'2': stream, '1': tree, '0': B}))
+  }))
+const actor_A = s.__typ;
+ return actor_A;
+};
diff --git a/test/idl/ok/test.js.ok b/test/idl/ok/test.js.ok
index dc13ef34670..178c3c7ff66 100644
--- a/test/idl/ok/test.js.ok
+++ b/test/idl/ok/test.js.ok
@@ -1,23 +1,24 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const my_type = IDL.Nat
 const B = my_type
 const message = IDL.Obj({'25': B, '26': IDL.None, 'name': IDL.Text})
 const broker =
  new IDL.ActorInterface({
   'find':
-   IDL.Message(IDL.Obj({'name': IDL.Text}),
+   IDL.Func(IDL.Obj({'name': IDL.Text}),
     IDL.Obj({
      '0':
-      new IDL.ActorInterface({'up': IDL.Message(IDL.Obj({}), IDL.Obj({})),
-       'current': IDL.Message(IDL.Obj({}), IDL.Obj({'0': IDL.Nat}))})
+      new IDL.ActorInterface({'up': IDL.Func(IDL.Obj({}), IDL.Obj({})),
+       'current': IDL.Func(IDL.Obj({}), IDL.Obj({'0': IDL.Nat}))})
      }))
     })
 const actor_server = new IDL.ActorInterface({
  'addUser':
-  IDL.Message(IDL.Obj({'name': IDL.Text, 'age': IDL.Nat8}),
+  IDL.Func(IDL.Obj({'name': IDL.Text, 'age': IDL.Nat8}),
    IDL.Obj({'id': IDL.Nat64})),
- 'userName':
-  IDL.Message(IDL.Obj({'id': IDL.Nat64}), IDL.Obj({'0': IDL.Text})),
- 'userAge': IDL.Message(IDL.Obj({'id': IDL.Nat64}), IDL.Obj({'0': IDL.Nat8})),
-  'deleteUser': IDL.Message(IDL.Obj({'id': IDL.Nat64}), IDL.Obj({})),
- 'f': IDL.Message(IDL.Obj({'0': message}), IDL.Obj({'0': broker}))})
+ 'userName': IDL.Func(IDL.Obj({'id': IDL.Nat64}), IDL.Obj({'0': IDL.Text})),
+ 'userAge': IDL.Func(IDL.Obj({'id': IDL.Nat64}), IDL.Obj({'0': IDL.Nat8})),
+ 'deleteUser': IDL.Func(IDL.Obj({'id': IDL.Nat64}), IDL.Obj({})),
+ 'f': IDL.Func(IDL.Obj({'0': message}), IDL.Obj({'0': broker}))});
+ return actor_server;
+};
diff --git a/test/idl/ok/unicode.js.ok b/test/idl/ok/unicode.js.ok
index f8f246b20ae..8c6ac0b1ec6 100644
--- a/test/idl/ok/unicode.js.ok
+++ b/test/idl/ok/unicode.js.ok
@@ -1,4 +1,4 @@
-const IDL = require('IDL')
+export default ({ IDL }) => {
 const A =
  IDL.Obj({'': IDL.Nat, '📦🍦': IDL.Nat, '字段名': IDL.Nat,
   '字 段 名2': IDL.Nat})
@@ -6,7 +6,9 @@ const B =
  IDL.Variant({'': IDL.Unit, '空的': IDL.Unit, '  空的  ': IDL.Unit,
   '1⃣️2⃣️3⃣️': IDL.Unit})
 const actor_C = new IDL.ActorInterface({
- '函数名': IDL.Message(IDL.Obj({'0': A}), IDL.Obj({'0': B})),
- '': IDL.Message(IDL.Obj({'0': IDL.Nat}), IDL.Obj({'0': IDL.Nat})),
- '👀': IDL.Message(IDL.Obj({'0': IDL.Nat}), IDL.Obj({'0': IDL.Nat})),
- '✈️  🚗 ⛱️ ': IDL.Message(IDL.Obj({}), IDL.Obj({}))})
+ '函数名': IDL.Func(IDL.Obj({'0': A}), IDL.Obj({'0': B})),
+ '': IDL.Func(IDL.Obj({'0': IDL.Nat}), IDL.Obj({'0': IDL.Nat})),
+ '👀': IDL.Func(IDL.Obj({'0': IDL.Nat}), IDL.Obj({'0': IDL.Nat})),
+ '✈️  🚗 ⛱️ ': IDL.Func(IDL.Obj({}), IDL.Obj({}))});
+ return actor_C;
+};
diff --git a/test/run.sh b/test/run.sh
index 5c4373816ed..edab391f9ae 100755
--- a/test/run.sh
+++ b/test/run.sh
@@ -31,7 +31,6 @@ export AS_LD
 WASM=${WASM:-wasm}
 DVM_WRAPPER=$(realpath $(dirname $0)/dvm.sh)
 DRUN_WRAPPER=$(realpath $(dirname $0)/drun-wrapper.sh)
-JSCLIENT=${JSCLIENT:-$(realpath $(dirname $0)/../../dev/experimental/js-dfinity-client)}
 ECHO=echo
 
 while getopts "a12sir" o; do
@@ -274,10 +273,18 @@ do
       if [ -e $out/$base.js ]
       then
         $ECHO -n " [node]"
-        export NODE_PATH=$NODE_PATH:$JSCLIENT:$JSCLIENT/src
-        node $out/$base.js >& $out/$base.node 2>&1
+        export NODE_PATH=$NODE_PATH:$ESM
+
+        node -r esm $out/$base.js > $out/$base.node 2>&1
         normalize $out/$base.node
         diff_files="$diff_files $base.node"
+
+        node -r esm -e \
+        "import actorInterface from './$out/$base.js';
+        import { makeActor, makeHttpAgent } from '$JS_USER_LIBRARY';
+        const httpAgent = makeHttpAgent({ canisterId: 1 });
+        const actor = makeActor(actorInterface)(httpAgent);
+        assert(Object.entries(actor).length > 0);"
       fi
     fi
   fi