CurseForge · Minecraft mod
Fluidlogged API
A library mod that adds highly customizable fluidlogging to 1.12.2!
Quick answer
Which Fluidlogged API release should I use?
Fluidlogged API Fluidlogged-API-v3.3.3-mc1.12.2.jar targets 1.12.2 with Forge. The project page does not say whether this file belongs on the client, dedicated server, or both. No extra mods listed for this file.
Where it goes
Is Fluidlogged API required on the client, server, or both?
The project page does not say whether this file belongs on the client, dedicated server, or both.
The source does not explicitly classify this release as client-only or server-only.
What else does Fluidlogged API Fluidlogged-API-v3.3.3-mc1.12.2.jar need?
Fluidlogged-API-v3.3.3-mc1.12.2.jar. Change the file and its required mods may change too.
This file does not list any required mods. Do not add a library just because a different file uses it.
This file does not list any required or optional mods.
Before you install it
Add Fluidlogged API without breaking your instance.
Built for Fluidlogged API Fluidlogged-API-v3.3.3-mc1.12.2.jar. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use Fluidlogged-API-v3.3.3-mc1.12.2.jar. It targets 1.12.2 with Forge; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
This file does not list any required mods. Do not add a library just because a different file uses it.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 04
Pick the file you checked
Use the “Get this file” button beside Fluidlogged-API-v3.3.3-mc1.12.2.jar. It opens that exact file at the source.
About this project
What does Fluidlogged API add?
A library mod that adds highly customizable fluidlogging to 1.12.2!
Fluidlogging is a mechanic that's inspired by Vanilla's Waterlogging mechanic, and that functions very similarly. The main difference is that Fluidlogged API has support for non-source fluids and all modded fluids!

If you're a modpack developer wanting to add Fluidlogged API to a modpack distributed outside of CurseForge or Modrinth, use File Director to avoid reuploading Fluidlogged API's files.
Any blocks can be made fluidloggable or non-fluidloggable through Fluidlogged API's configs, however it does make certain types of blocks fluidloggable by default. Any properly coded modded variants of these blocks are supported by default. Mods may also add fluidloggable blocks from their end. To see the full list of fluidloggable blocks, run the /fluidlogged_api print command in-game to create text files containing all active fluidlogging information.
Along with this, Fluidlogged API will download and apply community configs! This is to minimize the amount of work that players must do to have complete fluidlogging across mods, but this behavior can be fully disabled in fluidlogged_api/general.cfg if desired.
Fluidlogged API also heavily improves fluid collision accuracy, and fixes various Vanilla and modded fluid-related issues. Some Vanilla bug fixes include:
- MC-2591 Walking over the corner of lava deals damage
- MC-4533 Water graphical glitch when connecting diagonally
- MC-68129 Smooth lighting doesn't work properly underwater
- MC-100886 Falling sand with ID of water or lava does not render
- MC-125771 Block selection not showing up underwater
- MC-127030 Flowing water attempts to connect to waterlogged blocks when it shouldn't
- MC-127108 Waterlogged blocks turn lava into obsidian or cobblestone on physically unconnected sides
- MC-127270 Visual water level inside waterlogged blocks does not adjust correctly
- MC-227302 Smooth lighting doesn't work properly on the water surface
| Known Incompatibilities | Known Solutions |
|---|---|
| Better Water Mesh | None. |
| Corail Tombstone | Use Corail Tombstone v4.6.0 or later! |
| Oceanic Expanse | Use Oceanic Expanse v1.2.0 or later! |
| Phosphor | Use Alfheim or 燐/Hesperus instead! |
| The Aether II | Phosphor comes bundled with The Aether II. Luckily there exists The Aether II: Phosphor Not Included, which does as the name suggests! |
| Vintagium | Use Celeritas instead! |
Q / A:
How does this mod work?
Reading through the source code would be the best way of truly understanding the inner workings of this mod, but I'll describe a simplified version here:
For each block in the world, Vanilla has two features that get stored in each chunk: a required IBlockState and an optional TileEntity. Fluidlogged API adds a third feature that gets stored in each chunk: an optional FluidState, which stores the fluidlogged fluid if present.
This mod applies ASM (a bytecode manipulation library that's bundled with Forge) to allow Vanilla and Forge to properly read and make use of FluidStates.
Is this mod safe to add to existing worlds?
It's generally a good idea to always back up your worlds before adding any new mods. That being said, this mod doesn't change the behavior of IBlockStates, so adding it to existing worlds should be fine! Removing this mod from existing worlds should also be fine, just note that existing FluidStates will be removed and won't be recoverable upon doing so.
How do I use this mod's configs? How do I use this mod as a dependency?
This mod's wiki will eventually cover both of those topics, for now it only covers how to use this mod's config. If you want to use Fluidlogged API as a library (optional or required dependency), the best I can do until I finish the wiki is reference you to the source code of these other projects of mine: Campfire, Seared Ladder Backport, Subaquatic.
What should I do if I run into any bugs, crashes, or mod incompatibilities?
Reporting anything you find to this mod's issue tracker would greatly help me improve this mod! Without people generously taking the time to do so, this mod would not be where it is today!
If you want fluidlogging for versions beyond 1.12.2, check out Fluidlogged (not affiliated with Fluidlogged API) and Towelette!
Direct contact: jbred.dev@gmail.com
This mod will not be ported.
Project description from CurseForge.
Pick your setup
Fluidlogged API by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
Check the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
Fluidlogged API versions and loaders
Fluidlogged-API-v3.3.3-mc1.12.2.jar
16 Jul 2026
Fluidlogged-API-v3.3.2-mc1.12.2.jar
7 Jun 2026
Fluidlogged-API-v3.3.1-mc1.12.2.jar
23 May 2026
Fluidlogged-API-v3.3.0-mc1.12.2.jar
22 May 2026
Fluidlogged-API-v3.2.0-mc1.12.2.jar
5 Feb 2026
Fluidlogged-API-v3.1.3-mc1.12.2.jar
4 Jan 2026
Fluidlogged-API-v3.1.2-mc1.12.2.jar
12 Nov 2025
3.1.2
Fluidlogged-API-v3.1.2-mc1.12.2.jar
12 Nov 2025
Fluidlogged-API-v3.1.1-mc1.12.2.jar
1 Oct 2025
Fluidlogged-API-v3.1.0-mc1.12.2.jar
22 Sept 2025
3.0.6
Fluidlogged-API-v3.0.6-mc1.12.2.jar
7 Apr 2025
3.0.5
Fluidlogged-API-v3.0.5-mc1.12.2.jar
27 Mar 2025
Looking for an older file? The official CurseForge project page is in Resources.

