A plugin for Minecraft 1.12 that turns Noteblocks and Jukeboxes into snitches that record player entries and actions.
Reinforce a Noteblock with a Citadel reinforcement to create an entry snitch. The snitch will send a notification to everyone on the Citadel group its reinforced to when other players enter its field - an 11 block cube centered on the snitch.
Reinforce a Jukebox with a Citadel reinforcement to create a snitch. The snitch will send a notification to everyone on the Citadel group its reinforced to when other players enter its field - an 11 block cube centered on the snitch. It will also record player actions that occur within the field, e.g. block placement and destruction. Type /jainfo to check what players did in the snitched area while you were gone.
Wiki: https://github.com/CivClassic/JukeAlert/wiki