1 files changed, 9 insertions, 0 deletions
diff --git a/docs/application/interface.md b/docs/application/interface.md
index 3f270bd..5042bb4 100644
--- a/docs/application/interface.md
+++ b/docs/application/interface.md
@@ -33,6 +33,15 @@ typedef int32_t kpl_any_print_fn(const kpl_any a, FILE *file, size_t idnt, uint3
 typedef void kpl_any_free_fn(kpl_any a);
 
 typedef struct {
+    // TODO
+} kpl_interface;
+
+typedef struct {
+    kpl_any *any;
+    kpl_interface *interflace;
+} kpl_class;
+
+typedef struct {
     any value, info;
 } kpl_result;
 ```