How to Run Fabric Mods on a NeoForge Server with Forgified Fabric API

Running Fabric mods on a NeoForge server is the trickiest use case, because both sides must agree on registries and networking.

Match Client and Server

Install Forgified Fabric API on both the server and every client that connects. Registry synchronization is one of its core features, and mismatched registries between client and server cause disconnects or missing content. Keep the same set of Fabric-dependent mods on both sides unless a mod is explicitly client-only.

Verify Registry Sync

After starting the server, watch the startup log for registry synchronization messages. When a player joins, the client receives synchronized registry data. If a player is kicked immediately on join, suspect a registry mismatch — usually a mod present on one side but not the other.

Test Before Opening the Server

Start the server, connect with a single test client, and confirm the Fabric-dependent mod's content is present and usable. Place or use one of its blocks or items to confirm both sides registered it. Only then invite other players.

Expect Limits

Some Fabric mods use client-side rendering hooks or Fabric Loader features that have no server equivalent. Those will fail even with Forgified Fabric API installed. If the server log names a missing class from the Fabric mod itself, that mod needs a native NeoForge version for server use.