tvOS 12.1.2 (build 16K5534a) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2019-01-07T18:15:35Z. The update package is 68.2 MB. This is a delta (partial) update that requires 12.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 97fba11f76f1f7da96b4f006cd3941ccbae686f8.zip.