
ThinAir: ReLived
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.
Screenshots

About this Mod
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.
Feel free to reach out for compatibility patches.
⚠️ 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.tomlunder each world'sserverconfig/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-*.jarfrom Releases. - Drop the mod
.jarinto yourmods/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).
Credits
| Role | Author |
|---|---|
| Original mod | fuzs |
| 1.21.1 NeoForge port | Marie (kgbcupcake) |
References
License
MIT — same as the original Thin Air project. Asset rights follow the upstream LICENSE-ASSETS terms where applicable.
Available Versions
How to Install ThinAir: ReLived on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set neoforge Loader
In the panel under "Egg", select the neoforge loader and matching Minecraft version (1.21.1).
Install Mod
Open the mod browser in the dashboard and search for "ThinAir: ReLived". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.1
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
ThinAir: ReLived server crashes on startup – what to do?
Most common cause: wrong neoforge version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.1). You can switch loaders with one click in the panel.
Is ThinAir: ReLived compatible with neoforge?
ThinAir: ReLived officially supports neoforge for Minecraft 1.21.1. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with ThinAir: ReLived – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if ThinAir: ReLived consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
Rent Modded Server
Install ThinAir: ReLived with just one click on your server.