ArmorNotifier

A client-side Forge utility for vanilla armor. It checks the durability of every armor piece every 5 seconds, and when a piece falls below 15% it sends a colored warning message to chat. Each piece is warned about only once until it is repaired, so the chat is not flooded while the same piece stays low. The warning names the piece and shows its remaining durability as a percentage.

Only the player's own client needs the mod, and the server does not have to run it. Single-player worlds and multiplayer servers both work, since the checks happen on the client. The mod covers standard leather, iron, gold, diamond and chainmail armor, and other mods that use the standard durability system on armor slots are handled the same way. Installation requires Minecraft Forge for 1.12.2 at version 14.23.5.2859 or higher, with the mod file placed in the .minecraft/mods folder. Files target 1.12.2 only and are released under the MIT License, which is not open source. Its configuration screen is lightweight and works out of the box without setup.