As of CouchDB 2.0, Sequence IDs are no longer integers, and can be any valid JSON object. As far as I know, the only place this is exposed in this library is in the ChangesFeed. I suggest changing the SeqID to a json.RawMessage type to accommodate this change.

Another option might be to expose the raw Seq value as a separate field (and set Seq to 0 when it's not an integer). This would allow CouchDB 1.6 users to continue using this library with no changes.