SyncCurseCraft Bootstrap

Companion file for SyncCurseCraft. Not useful on its own.

If you are looking for the mod itself, go to SyncCurseCraft — this file comes with it automatically as a dependency.

What this is

An early boot service for the SyncCurseCraft client. It runs during NeoForge's mod discovery, before the game exists, and applies the mod changes that were downloaded in the previous session.

Why it is a separate download

NeoForge will not let a single jar be both an early boot service and a mod. With the service inside the main jar, FML loads that jar into the service layer and then skips it during mod discovery — the mod does not load at all. Splitting it in two is the only arrangement that works.

They also have to stay separate at the module level. Two jars exporting the same Java package make the module system refuse to resolve them, which is why this one has its own exclusive package and no mod metadata of its own.

Why the work happens at boot

Windows will not let you replace a .jar that the running game has open. So SyncCurseCraft never modifies a loaded mod: it downloads into a staging folder, writes a plan, and this service carries the plan out at the next launch, before anything is loaded.

That also makes it safe to interrupt. If the game is closed halfway through, the plan is still on disk and the next launch starts it again from the beginning.

What it does with your files

It only moves and deletes .jar files inside /mods/, and only the ones named in a plan that SyncCurseCraft itself wrote. File names are re-validated against path traversal at this stage too — this code writes to your mods folder with nothing else running, so it does not even trust what the previous session wrote.

It never touches config/, options.txt, shaders, resource packs or saves.

Installation

Put it in .minecraft/mods next to the main jar. Client only — it does nothing on a server.

Without it, SyncCurseCraft still works, but it can only add new mods and can never update or remove ones that are already loaded. The sync screen tells you when it is missing.

Requirements

Minecraft 1.21.1 · NeoForge 21.1.x · Java 21

Licence: CC BY-NC-SA 4.0 · by el_this_boy