diff --git a/include/patty/kiss.h b/include/patty/kiss.h
index f736284..f01ceca 100644
--- a/include/patty/kiss.h
+++ b/include/patty/kiss.h
@@ -25,8 +25,16 @@ enum patty_kiss_command {
     PATTY_KISS_RETURN      = 0xff
 };
 
-ssize_t patty_kiss_read(int fd, void *buf, size_t len, int *port);
+typedef struct _patty_kiss_tnc patty_kiss_tnc;
 
-ssize_t patty_kiss_write(int fd, const void *buf, size_t len, int port);
+patty_kiss_tnc *patty_kiss_tnc_open(const char *device, size_t bufsize);
+
+void patty_kiss_tnc_close(patty_kiss_tnc *tnc);
+
+ssize_t patty_kiss_read(patty_kiss_tnc *tnc,
+    void *buf, size_t len, int *port);
+
+ssize_t patty_kiss_write(patty_kiss_tnc *tnc,
+    const void *buf, size_t len, int port);
 
 #endif /* _PATTY_KISS_H */