CurseForge · Minecraft mod
Underlay
Place any block (such as carpets) inside anything!
This page is having a moment, so a few details may be a little behind.
Quick answer
Which Underlay release matches 1.21.7?
Underlay [1.21.6] Underlay v1.0.1 targets 1.21.8, 1.21.6, 1.21.7 with Fabric. The project page does not say whether this file belongs on the client, dedicated server, or both. All 1 required mods have matching files.
Where it goes
Is Underlay 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 Underlay [1.21.6] Underlay v1.0.1 need?
[1.21.6] Underlay v1.0.1 on 1.21.7. Every mod below is checked against that same setup.
Install Fabric API first. We found matching files for this game-version and loader setup.
We only count dependency files that match this setup. A file for another loader does not fill the gap.
Before you install it
Add Underlay without breaking your instance.
Built for Underlay [1.21.6] Underlay v1.0.1 on 1.21.7. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use [1.21.6] Underlay v1.0.1. It targets 1.21.8, 1.21.6, 1.21.7 with Fabric; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
Install Fabric API first. We found matching files for this game-version and loader setup.
- 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 [1.21.6] Underlay v1.0.1. It opens that exact file at the source.
About this project
What does Underlay add?
Underlay is a Minecraft mod that lets you place carpets (and anything else) under any block with space beneath it (e.g. chests, beds, signs, torches, etc.)!
Just right click a block face with a block to place it, (for example, under an upside-down stair), and you're done! Right click again with another item to replace it quickly, or left click it to remove it. Works in Survival too!

By default, you can place the following blocks as overlays: carpets, trapdoors, buttons, rails, slabs and pressure plates. To expand this to other blocks, such as grass, see "How to add support for more blocks (or exclude some)".
Join the Discord server for sneak peeks on upcoming updates!
How does this work?
They are not block entities! Underlay adds these things called "overlays" but they're really more like underlays xd, essentially they are fake versions of the item you place - which lets you place two things in the same block space!
How to add support for more blocks (or exclude some)
In your Minecraft folder you can find config/Underlay/underlay.json. Use overlay_blocks to add blocks, exclude_blocks to exclude them, and to not allow overlays to be placed on certain blocks use target_exclude_blocks, like this:
{
"overlay_blocks": [
"minecraft:short_grass",
"mymod:shiny_block"
],
"exclude_blocks": [
"minecraft:oak_button",
"minecraft:rail"
],
"target_exclude_blocks": [
"minecraft:oak_door",
"minecraft:spruce_door"
]
}
Mod Integration
Some versions of Underlay include integration with Create, Jade and Flashback.
Project description from CurseForge.
Pick your setup
Underlay by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
26.2
1 loader build26.1.2
1 loader build26.1.1
1 loader build26.1
1 loader build1.21.11
1 loader build1.21.10
1 loader build1.21.9
1 loader build1.21.8
1 loader build1.21.7
1 loader build1.21.6
1 loader build1.21.5
1 loader build1.21.4
1 loader buildShowing the newest 12 of 18 game versions. Older files are in the list below.
Check the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
Underlay versions and loaders
[1.21.6] Underlay v1.0.1
underlay-1.0.1-fabric-mc1.21.6.jar
1 Apr 2026
[1.21.6] Underlay v1.0.0-hotfix.1
underlay-1.0.0-hotfix.1-fabric-mc1.21.6.jar
21 Feb 2026
[1.21.6] Underlay v1.0.0
underlay-1.0.0-fabric-mc1.21.6.jar
18 Feb 2026
Looking for an older file? The official CurseForge project page is in Resources.