Logical Replication without Direct Access?

Question

Is there a way to do logical replication from a master to which we cannot directly connect?

I've been able to do physical replication by means of WAL-shipping, but that leaves me with a standby that only allows for basic reads (i.e., no logical replication subscriptions).

Is there software that can read directly from the WALs and emit SQL to a separate, master target DB?