Tempora

Tempora is a logging tool for server admins, built for GTNH. It records detailed events that took place, for example, blocks broken, placed and changed, explosions, deaths, mob spawns, items moving in and out of inventories, items picked up and dropped, commands, where players and mobs went, and server-wide events such as players joining and leaving, weather and TPS. When something goes wrong (a base griefed, a chest emptied, a machine blown up, the server lagging) you can find out who did what, where and when. This mod is designed for the GTNH ecosystem, outside support may be provided depending on the request but is not actively maintained for that purpose.

Each kind of event is stored in its own SQLite database in the world folder. Admins search it in game: /tempora lookup shows what happened around you, the Tempora wand shows a single block's history, and /tempora player follows one player wherever they went. Results are listed in chat with coordinates you can click to teleport to, and drawn in the world for a few seconds as the blocks, mobs and players involved. For anything the commands don't cover, /tempora sql runs a read-only query on the data directly.

This mod should also work in singleplayer, if enabled in config. Though primary support is for servers due to the nature of the mod, but some tooks like e.g. stacktrace logging may be of use in diagnostics.