tvOS 12.1 (build 16J5593c) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2018-10-09T17:15:36Z. The update package is 91.78 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 3c515007607dc41af2f82f4d152ad82576266326.zip.