tvOS 12.1.2 (build 16K534) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2019-01-22T18:13:52Z. The update package is 819.23 MB. This is a delta (partial) update that requires 11.2.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a3423d70e779a8868dfeb5efb66735aea230b830.zip.