Initial C api

include/zaprus.h

@@ -0,0 +1,24 @@
+// client
+
+int zaprus_init(void);
+
+int zaprus_deinit(void);
+
+int zaprus_send_relay(const char* payload, usize len, char[4] dest);
+
+int zaprus_send_initial_connection(const char* payload, usize len, uint16_t initial_port);
+
+struct SaprusMessage* zaprus_connect(const char* payload, usize len);
+
+// message
+struct SaprusMessage {
+  
+};
+
+// ptr should be freed by the caller.
+int zaprus_message_to_bytes(struct SaprusMessage msg, char** ptr, usize* len);
+
+// Return value should be destroyed with zaprus_message_deinit.
+struct SaprusMessage* zaprus_message_from_bytes(const char* bytes, usize len);
+
+void zaprus_message_deinit(struct SaprusMessage* msg);