ModVerifier

When a player connects, ModVerifier intercepts the login event during the handshake and checks the client's mod list against the server's rules, so a server can keep players on an agreed set of client-side mods. Its checks run in the network login pipeline, where it also identifies whether a connection comes from a Java or a Bedrock client, so Bedrock players can join immediately without the mod check.

The mod is meant for a private survival server, an SMP or a community hub where friends play together on both Java and Bedrock. Servers that use Geyser and Floodgate for cross-play can run it alongside those mods, and the mod is built to avoid sending extra data packets that could cause a player to lose the connection. Installing it means placing the mod in the server's mods folder, with Fabric API and Floodgate running for cross-play, and starting the server once so it can generate its configuration files.

The files cover 26.1 – 26.1.2 on Fabric only, and the environment is client and server, so both the server and every Java player need the mod. It is released under the Creative Commons Attribution Non Commercial No Derivatives 4.0 license and is not open source.