There are three endpoints for fetching replication packets:
Hourly:
GET https://metabrainz.org/api/musicbrainz/replication-<PACKET_NUMBER>.tar.bz2?token=<ACCESS_TOKEN>
Daily:
GET https://metabrainz.org/api/musicbrainz/replication-daily-<PACKET_NUMBER>.tar.bz2?token=<ACCESS_TOKEN>
Weekly:
GET https://metabrainz.org/api/musicbrainz/replication-weekly-<PACKET_NUMBER>.tar.bz2?token=<ACCESS_TOKEN>
It is possible to get a signature for each replication packet. Just replace
.tar.bz2 with .asc.
You can find the latest replication packet numbers from this endpoint:
GET https://metabrainz.org/api/musicbrainz/replication-info?token=<ACCESS_TOKEN>