What are the Capabilities of Server-Side Mods?

[fathom axle]

I understand server-side mods to be mods that run exclusively on the server, without the need for a mod on the client.

I have found a list of established server-side mods on the Fabric Wiki: https://wiki.fabricmc.net/community:serverside_mods. So, I know it is feasible to make such mods.

I would like to know to what extent can I use Fabric to mod Minecraft on the server side while still allowing players to connect to the server with a "vanilla" client. What are the constraints that have to be applied to a mod in order for it to be server-side?

Are there any resources available for making mods with Fabric that are specifically server-side?

(I already have experience programming with Java.)

[wide basin]

Common sense

But really basically you're limited to everything plugins can do on a Spigot server

It has to be ultimately doable with packets that can be sent to the vanilla client

That's pretty much the only limitaiton

[wild granite]

cant you do mixins in fabric server mods

in spigot its at least a lot harder

[wide basin]

Yes you can, you can also do it in Spigot but like you said its harder (https://github.com/vectrix-space/ignite)

You can get your plugin to attach an agent to the JVM at runtime to apply mixins on Spigot/Paper but its work

[wild granite]

I just discovered this existed

Ive been using spigot for 5 years wtff maan

[dawn beacon]

!!polymer

[wide jewel]

Polymer is a library for creating server-side-only content mods.

https://github.com/Patbox/polymer

[dawn beacon]

!!mr nylon