diff --git a/src/gui/server/public-api-structs.lisp b/src/gui/server/public-api-structs.lisp
new file mode 100644
index 0000000..7523b46
--- /dev/null
+++ b/src/gui/server/public-api-structs.lisp
@@ -0,0 +1,21 @@
+;; tinmop: an humble gemini and pleroma client
+;; Copyright (C) 2022  cage
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.
+;; If not, see [[http://www.gnu.org/licenses/][http://www.gnu.org/licenses/]].
+
+(in-package :json-rpc-communication)
+
+(defstruct box
+  (payload))
diff --git a/src/gui/server/public-api.lisp b/src/gui/server/public-api.lisp
index 2dd29f0..d1f8185 100644
--- a/src/gui/server/public-api.lisp
+++ b/src/gui/server/public-api.lisp
@@ -17,6 +17,9 @@
 
 (in-package :json-rpc-communication)
 
+(defstruct box
+  (payload))
+
 (defun make-rpc-parameters (&rest params)
   (loop for (a b) on params by 'cddr collect (cons a b)))
 
diff --git a/tinmop.asd b/tinmop.asd
index 63a642d..2929988 100644
--- a/tinmop.asd
+++ b/tinmop.asd
@@ -149,6 +149,7 @@
                (:module gui-server
                 :pathname    "gui/server"
                 :components ((:file "main-window-server-side")
+                             (:file "public-api-structs")
                              (:file "public-api-gemini-stream")
                              (:file "public-api-gemini-certificates")
                              (:file "public-api-gemini-tour-links")