unsup

Unsup is a compact implementation of a working directory synchronization system in Java. The mod can operate as a Java agent, utilizing the launch of another program for its own activation.

An ideal solution for small private packs or one-off projects in small groups where full public distribution (for example, through Modrinth) is excessive or undesirable. The tool can download mods from their original sources—anywhere that supports the HTTP(S) protocol.

For operation, a configuration file unsup.ini placed in the working directory is required, or the path to it can be specified via the JVM argument -Dunsup.bootstrapUrl=.

Reliability and Security

The update system is built to ensure the working directory is never left in an inconsistent state. Except for sudden power loss during the application of changes (an extremely unlikely scenario), the unsup update process guarantees proper completion.

The tool performs integrity checks based on hash sums (with support for various algorithms, SHA-256 recommended) for all downloaded files as well as before overwriting them. The user will be warned if a locally modified file is subject to update. Additionally, manifest signing using OpenBSD Signify is supported to enhance security levels.

Compatibility

Thanks to its unique simplified design, unsup is compatible with all popular launchers—from the standard option to MultiMC. Simply add -javaagent:unsup.jar to the JVM arguments and place the unsup.jar and unsup.ini files in the .minecraft directory.

In Prism Launcher, unsup can be used as a component by importing com.unascribed.unsup.json from the latest release on Forgejo. This allows the launcher to download and manage unsup automatically. (MultiMC, despite requests, does not support Java agent components.)

Functionality

The system supports the concepts of environments and flavors, enabling management not only of client installations but also server ones. Users can choose between multiple mutually exclusive mod sets through a convenient interface unparalleled among other update tools.

Unsup is also capable of updating MultiMC components, including itself if added as such. This opens the possibility of updating mod loaders or even the Minecraft version itself.

Creating Packs

You can point unsup to a pack.toml file from Packwiz (recommended) or write a native unsup manifest manually. The graphical interface for creating manifests is temporarily not under development as Packwiz has become the de facto standard for Minecraft mod packs.

Stability

The tool has been successfully used for packs on versions from b1.7.3 to 1.21.5, both on client and server. Compatibility is confirmed with Forge (both legacy and modern versions), Fabric, Quilt, and NeoForge. Unsap has been utilized in numerous packs—from modest to large-scale. Native manifest support and Packwiz manifest support are stable and tested in real conditions.

The signing feature is still experimental and has not been deployed in large projects. Perhaps you will be the first—share feedback if everything works well!

Interface

Unsap features a minimalist and elegant graphical interface that works on all platforms (including macOS). All interface colors are customizable to harmonize with your branding. By default, a dark theme with mint accents is used.