Uninvited

Uninvited adds a Forge and NeoForge mod that produces fake join messages in the chat. The name shown is picked from three approaches: a subtly distorted version of the player's own name, a generic system-looking placeholder such as an unset account, or an ordinary common name with one small change like a dropped, doubled or swapped letter. The join message copies the formatting of vanilla's real join and leave messages exactly. Each trigger is rare and deliberately quick, and the fake name stays in the list for roughly 10 to 40 minutes before its leave message appears.

The mod runs on the client and on the server, so the server and every player need it, and it depends on Haunted Core, which must be installed alongside it. Purely client-side is not the case here: the fake join is produced through the server side of the connection, though no actual player ever joins. Builds exist for 1.19.2, 1.20.1 and 1.21.1, with 1.0.2 as the latest file for both Forge and NeoForge, and the code is under All rights reserved.