Thin_Air_1.21.1_Port

Mod

A NeoForge 1.21.1 port of Thin Air by fuzs and a foundation for more. The air isn't always breathable. Go too deep, too high, or into the wrong dimension and you'll need to come prepared. Respirators, air bladders, and soulfire can keep you alive.

Type

Mod

Modrinth Downloads

Modrinth ID

OPyUN2Vn

Last Updated

Jun 13, 2026

Description

Thin Air

NeoForge 1.21.1 Port

A faithful NeoForge port of fuzs's Thin Air. The air is not always breathable deep underground and in other dimensions.

The original mod is archived on Modrinth (last release: Minecraft 1.20.4). This fork brings it forward to Minecraft 1.21.1 on NeoForge while staying close to the upstream design (not a ground-up rewrite) with some features added.

⚠️ Please report bugs for this port only in this repository's issue tracker. Do not contact fuzs about issues specific to this port.

What's Different

NeoForge-only: Direct port of the 1.20.4 codebase and data, updated for NeoForge 1.21.1 APIs and datapack path changes (recipe/, advancement/, loot_table/, and so on).
Server-authoritative config: Settings live in thinair-server.toml under each world's serverconfig/ folder, with an optional in-game config screen (Mods menu) via Cloth Config.
Optional Curios: Respirator uses the Curios head slot when Curios is installed; the mod works without it.
No bundled compatibility layers: Create and other mods are not baked in; compatibility stays optional and separate.
Work in progress: Full parity testing is ongoing.

Features

Air quality levels: Green, yellow, red, and blue air affect breathing and what equipment helps, by dimension and height.
Safety Lantern: Shows nearby air quality by color; can be dyed and scraped with an axe.
Signal Torch: Right-click to emit particles (configurable).
Respirator: Protects against choking air (Curios head slot when available).
Air Bladder / Reinforced Air Bladder: Portable air refill; reinforced variant crafted with netherite and copies durability from the ingredient bladder.
Bottle of Soulfire: Emergency air restore in the Nether.
Advancements, recipes, loot injections, drowned air-drain behavior, chunk air-quality sync, and English / Russian / Chinese lang files.

Blocks

Safety Lantern: shows nearby air quality by color; can be dyed and scraped with an axe
Signal Torch: right-click to emit particles (configurable)

Items

Respirator: protects against choking air (Curios head slot when available)
Air Bladder / Reinforced Air Bladder: portable air refill (reinforced recipe copies bladder durability)
Bottle of Soulfire: emergency air restore in the Nether

Advancements

Air Bladder: use an Air Bladder to refill your air supply on the go
Blue Air: breathe the life force given off by Soul Fire to maintain your air (but not increase it!)
Disco Lantern: use a piece of Dye to manually change the color of a Safety Lamp (you can scrape the color off with an axe)
Respirator: protect yourself from choking air with something like a Respirator
Safety Lantern — use a Safety Lantern to check the air quality around you
Signal Torch: right-click a torch to make it spew particles, perhaps to signal the exit of a cave
Soulfire Bottle: restore your lungs with the souls trapped in a Bottle of Soulfire
Water Breathing: breathe freely where there is no air at all

Known limitations

Work still in progress compared to the original 1.20.4 release:

Full parity testing (multiplayer, worldgen-placed air providers) is ongoing
Loot table injections not yet verified, Air Bladder and Soulfire Bottle may not appear in dungeon/structure chests

Technical Info

Dependency Version Notes NeoForge 1.21.1 Required Java 21 Required Curios 9.5.1+1.21.1 Optional: respirator head slot, belt lantern, Curios rendering Cloth Config 15.0.140 Recommended: in-game config screen from the Mods menu; otherwise edit serverconfig/thinair-server.toml

Installation

Install NeoForge for Minecraft 1.21.1.
Download or build thinair-*.jar from Releases.
Drop the mod .jar into your mods/ folder.
Optionally install Curios for respirator slot support.
Launch the game.

After the first launch, change settings from the Mods menu config screen or by editing <world>/serverconfig/thinair-server.toml (air quality, signal torches, drowned choking, and air-provider bubble ranges).