FurnaceUpgrades

FurnaceUpgrades
FurnaceUpgrades is a lightweight survival plugin that lets players upgrade regular furnaces using in-game minerals.
Each furnace can be improved in three independent paths:

Speed: smelts items faster and can trigger extra smelts
Efficiency: can refund input items on smelt
Fuel: makes fuel last longer and can retain heat between smelts
The plugin is designed for progression-based servers that want stronger furnaces without adding custom blocks or custom clients.

How It Works
Players interact with a placed furnace and open the upgrade flow (Sneak + Right Click).
Upgrades are tiered and fully configurable in config.yml.
Costs are paid with vanilla materials.
Furnace upgrade data is saved and restored, including when furnaces are broken and placed again.
Furnace status can be shown in the ActionBar for quick feedback.
Main Features
3 upgrade categories: Speed, Efficiency, Fuel
Per-level costs and effects from config
Upgrade persistence for placed and picked-up furnaces
ActionBar status display
In-game command support (help, info, upgrade management)
No client mods required
Compatibility
Minecraft: 1.21.x
Server software: Spigot / Paper / Purpur
Not intended for proxy software (BungeeCord, Velocity, Waterfall) since this is a server plugin, not a proxy plugin.
Permissions
furnaceupgrades.use (default: true)
furnaceupgrades.admin (default: op)
Notes
This plugin modifies furnace behavior only.
It does not add economy integration or custom enchant systems.
All balancing values are configurable so server owners can tune progression.