You might want to set an AgsFile or AgsSimpleFile instance within your application context. This in view of having your application persisted.
Example 1.4. The application context :file property
#include <glib.h>
#include <glib-object.h>
#include <ags/libags.h>
AgsApplicationContext *application_context;
AgsFile *file;
application_context = ags_application_context_get_instance();
file = ags_file_new();
g_object_set(application_context,
"file", file,
NULL);