@dinosaur I'm not quite sure how this is any different from moving the type into the metadata. A message cypherlink currently points to a tuple of (feed id, seqnum, ..., content) (pretend I filled in all the metadata and the order magically matches). By moving the type into the metadata, we get a tuple (feed id, seqnum, ..., type, content), which is exactly the same as (feed id, seqnum, ..., (type, content)).