+/* database.cc */
+
+/* Lookup a prefix value by name.
+ *
+ * XXX: This should really be static inside of message.cc, and we can
+ * do that once we convert database.cc to use the
+ * _notmuch_message_add/remove_term functions. */
+const char *
+_find_prefix (const char *name);
+
+/* thread.cc */
+
+notmuch_thread_t *
+_notmuch_thread_create (const void *talloc_owner,
+ notmuch_database_t *notmuch,
+ const char *thread_id);
+
+void
+_notmuch_thread_add_tag (notmuch_thread_t *thread, const char *tag);
+
+void
+_notmuch_thread_set_subject (notmuch_thread_t *thread, const char *subject);
+