How to make Client must install a mod(which is installed on Server) to join in Server?

I have Reigster a Entity Type(and Renderer, Model for it) and SoundEvent for the new Entity which I make, and a Item.

I remap the jar and put it in my server’s “mods” folder.(It works in client.)

and then I wonder if I can join in the server without installing this mod in my Minecraft Launcher.

the result is that I can join in without installing the mod, and can use summon to spawn the new Entity. But what made me confused is that the new entity’s model is the PigEntityModel(I guess the renderer same).

And then I create the new Item with command “give”.Show the message"给予 玩家xxx xxx".But cannot seen anything in my inventory(but actually the itemstack exists.cannot seen and select or anything.)

I wonder if there exists a way to make sure the client which connect to the server must have installed the specific mod or refuse to connect like forge?

I try to search for some relative message form the english wiki and 中文(Chinese)wiki of fabric. and read about the fabric.mod.json nothing was found but my sadness.(it takes so long time 😦 )

Help me please!Thanks. 😃

[i509VCB]

Hmm, maybe registry sync doesn’t enforce registry mismatches with vanilla clients. Not 100% sure on that. There are plans for a future “mod handshake” system which would give mods control on allowing or denying clients based on missing items, mod versions or other arbitrary things.

[i509VCB]

I think pig was the result since the entity type registry will by default select the Pig entity type. If your server was running in dev, different rules may apply there with connecting clients. A real server (whether integrated or dedicated) with fabric’s registry sync installed should be kicking the client if the client does not understand the registry sync packet.