tvOS 12.1 (build 16J5584c) is an official Apple over-the-air update for the Apple TV 4K, released on 2018-10-02T17:18:55Z. The update package is 1.6 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: bc7984c7f0b1c95279879f639d37aeedf4bad097.zip.