Be Quiet Negotiator

A NeoForge client normally enforces a handshake that confirms both sides agree on modded payloads. When the server does not speak NeoForge, that check fails and the connection drops. This mod quietly suppresses the negotiation step, so the client can reach servers that run no NeoForge at all, including vanilla servers and Fabric servers that carry only server-side mods.

The patches are applied with Mixins to specific NeoForge client methods that cause errors and disconnects when connecting to such servers. Packet decoding errors and unexpected packet sizes are also ignored, so the connection proceeds cleanly. The patches are configurable, which lets users enable or disable individual ones. The author notes that conflicts with other mods may still occur, since the mod hides errors rather than fixing the underlying incompatibility.

The mod is useful for modpack developers and testers who want full-stack NeoForge clients to reach unmodded servers, for LAN play where only the client runs NeoForge, and for players on hybrid proxy networks where an entry point is a vanilla server. It needs no installation on the server. Files are published for NeoForge on 1.21.1, 1.21.2, 1.21.8 and 1.21.11, and the mod is released under the GNU General Public License v3.0 or later, so it is open source.