ModListObserver

This modification provides server administrators with the unique ability to track which modifications players install when connecting to the server. Information can be obtained in two ways: by using the specially added /modlist command, and by reading system messages (enabled by default) that are displayed in the log every time a user joins the server.

/modlist Command Functionality

• /modlist <target> current - shows the list of mods with which the target player last connected to the server
• /modlist <target> all - displays the complete list of all modifications used by the specified player since the last server restart

Technical Features

Server-side mod - needs to be installed only on the server side, clients can play without this modification.

Platform support - compatible with Forge and NeoForge. A version for Fabric may be developed in the future if there is sufficient demand.

Important Note Regarding Versions

The mod functions perfectly in Minecraft versions up to and including 1.20.1. However, starting with version 1.20.4 in NeoForge, a major network code overhaul was performed, during which the function of automatically sending the mod list from the client to the server was temporarily disabled due to privacy concerns. This means that in NeoForge versions 1.20.4 and above, the original concept of ModListObserver as an exclusively server-side mod is currently not feasible.

Limitations and Purpose

The mod list obtained through ModListObserver is not completely reliable. The absence of any modification in the list does not guarantee that the player doesn't actually have it, just as the presence of a mod record does not confirm its actual existence. Users of illegal clients can artificially change the transmitted mod data to hide unwanted software.

Given these limitations, the mod will never implement a feature for automatically blocking players based on specific mod lists. Its main purpose is to provide administrators with additional information for making informed decisions about the possible use of prohibited mods.