tvOS 12.1 (build 16J5575c) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2018-09-18T17:26:30Z. The update package is 1.43 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9c4b1eb3e6d6cd83bd879f276d8b41bddccdd2dc.zip.