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Compat APIMinecraft mod for 1.21.1

Universal compat api that auto-loads integrations, data packs and loot modifiers for mods that depend on it.

client and servernewest supported 1.21.1UtilityLibraryManagement
Latest version
1.0.3
Minecraft
1.20.1 to 1.21.1
Java
Java 21+
Loaders
Fabric, Forge, NeoForge
Licence
MIT
Downloads
15.8k
Updated
6 mo ago
Available on
Modrinth
Space NodeOur hosting

Host Compat API servers

One click and Compat API is installed with the right loader, on hardware built for it.

  • 1.21.1
  • Fabric
  • Forge
  • NeoForge
  • One click mod install
  • Loader matched for you
  • Ryzen CPUs
  • NVMe SSD
Deploy a serverFrom €0.90 per GB

Minecraft versions

Every version Compat API declares support for, newest first, with the Java runtime that version needs.

Other mods
MinecraftThroughJavaEvidenceReleased
1.21.1Fabric, Forge, NeoForge21+declared8 Aug 2024
1.20.1Fabric, Forge, NeoForge17+declared12 Jun 2023

Download

From Compat API’s own host. Nothing is re-hosted here.

1.0.3release20 Mar 2026

compatapi-1.0.3.jar · 0.2 MB · for 1.21.1

Download latest
8494f4885eb2…
Older versions3
  • 1.0.228 Dec 20251.20.1102 KB957 downloadsbadc9d2f994f…Get
  • 1.0.114 Dec 20251.21.157 KB178 downloadseb977f47b354…Get
  • 1.0.027 Nov 20251.20.130 KB51 downloads9552a941043e…Get

Frequently asked

Does Compat API work on Minecraft 1.21.1?

Yes. 1.21.1 is the newest Minecraft version Compat API declares support for, and the claim comes from the author's own release metadata rather than from a compatibility list somebody maintains by hand.

Which Minecraft versions does Compat API support?

Everything the author has declared, from 1.20.1 up to 1.21.1. The full list is in the table above, with the Java runtime each version needs next to it.

Do I need to install Compat API on the client or the server?

Both. Every player needs it installed and so does the server, so anyone joining without it will be refused.

Which platform or loader does Compat API support?

Fabric, Forge, NeoForge. A build for one platform or loader will not necessarily load on another, so this is the first thing to check before the Minecraft version.

Which Java version do I need for Compat API?

On the newest Minecraft version it supports, Java 21 or newer. The requirement comes from the Minecraft version you run rather than from the mod itself, so on an older supported Minecraft the answer is that version's Java, not this one.

What licence is Compat API under?

MIT, as stated by the author on the platform we synced it from. Check the project's own page before redistributing or bundling it.

How do I install Compat API?

Install the matching loader first, then put the downloaded file in your mods folder and start the game. The loader, the mod and Minecraft all have to be on the same version, which is the usual reason a mod does not appear in game.

Where do I download Compat API safely?

Start with the author's page on Modrinth, which is where the data here is synced from. MCReference does not host or repackage files. The download link goes to the source recorded for that release; verify the publisher, filename and checksum before running it.

Works on the same versions

Ordered by how much of the recent Minecraft version coverage overlaps, not by popularity.

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Details from Modrinth, where the author last updated it on 20 Mar 2026. We do not host files and we do not republish descriptions; every download link points at the author’s own release.

Is this information wrong or missing something? .