Community Fluid API

TL;DR: As of Minecraft 26.1, the NeoForged team has officially retired the (Neo)Forge Fluid API... and replaced it with nothing. This mod is a community-developed, from-scratch reimplemention of that API designed to make adding fluids as painless (and collision-free) as it used to be. WIP.

If you don't know what that means, or want some details, here's the longer version:

Wonder why entities are walking through your fluids like they aren't there? Why your fluids don't glow when you tell `em to, they don't push you around, they make mobs path weird, conduits don't work in `em, etc., even though you set everything up in your FluidType class? That's because the (Neo)Forge Fluid API has been discontinued - as of MC 26.1, Neo no longer ships with an implementation*. If you want your fluids to "just work", you're going need something that takes that API and makes the game actually pay attention to it. That's where this API comes in—it's a (more-or-less) drag-`n-drop replacement for the old Forge implementation, written from scratch by community members for MC 26.1.2!

It does make a few changes, and extend on the old functionality:

• isWaterLike is now deprecated. Instead, a variety of more targeted methods have been patched in
• You are now required to tag your fluids (the fallback behavior substitutes water, but reusing a vanilla tag causes most of the Fluid API to be ignored)
• The following methods have been patched in: #getTag, #reducesMiningSpeed, #canSpawnAquaticMobs, #canFish, #getFishingLootTableKey, #entityCanStandOn, #shouldSplash, #createSplashParticleOnClient, #createSplashParticleOnServer, #createWakeParticleOnServer, #makesWet, #hasUnderWaterMusic, #conduitCompatible, #slowsProjectiles, #getInertia, #triggersRipTide, #preventsBurning, #affectsVehicle
• For convenience, colorless, tintable versions of the vanilla splash and wake particles have been provided (by default, these are tinted the same color as your fluid and substituted for their vanilla counterparts)

Documentation is a work in progress; in the meantime, see the community-maintained documentation for the old (Neo)Forge API:

• Example Mod (Now with 26.1.2 version!)
• Wiki

*Well, most of the old API is no longer implemented, and the NeoForged team plans to continue phasing out the rest.