SxMobCoins | Mob Coins & NPC Shops

Mobs drop coins as a real item. Players carry them, trade them, lose them on death, and spend them at shop keepers you place anywhere in the world — each keeper selling whatever you put inside it, at whatever price you set.

No Vault. No economy plugin. No NPC library. No database. One jar.

Why coins as items?
A balance is a number only the plugin can see. An item is in the player's hands: they can sort it, hide it in an ender chest, hand it to a friend, and lose it when something kills them far from spawn. That is what makes a second currency feel like part of the game instead of a scoreboard.

The cost of that choice is forgery — which is why every coin is signed.

Features

• Signed against forgery. Being a coin is decided by an HMAC signature made with a key that exists only in your server's database — not by the material, name or lore. A sunflower renamed in an anvil buys nothing. Coins from another server buy nothing.
• They still stack. Every genuine coin carries the same signature, so a purse looks like any other stack.
• Per-mob drop table. Chance and amount for every mob type, a default for the rest, and an ignore list so a cow farm is not a business.
• Shop keepers with their own stock. Place as many as you like — a starter shop at spawn and a very different one on the end island.
• Filled like a chest. Drag an item onto a shelf or shift click it across from your inventory. Left click raises the price, right click lowers it, shift click takes it back.
• Named shops. The name sits over the keeper's head and in the title of the window it opens.
• Farm limits that keep the currency worth something. Spawner mobs pay a fraction or nothing at all, kills nobody landed pay nothing, and there is an hourly cap per player.
• Survives restarts. Shops, stock, prices and the signing key live in SQLite; keepers are rebuilt from the database when their chunks load, so no stray villagers are ever left standing.
• Folia ready. Regionised threading is detected at startup and used where it exists.

How it plays
For a player: kill mobs, pick up coins, right click a keeper, click what you want. The action bar tells them the moment a kill pays.

For an admin: stand where the shop should be, run /mobcoins shop create, name it with /mobcoins shop rename Blacksmith, then /mobcoins edit and drag in what it sells. The keeper you are editing glows for a few seconds, and its name and number are in the window title, so there is no guessing which shop you have open.



Requirements
Minecraft 1.21+, Java 21. Paper, Spigot, CraftBukkit, Purpur and Folia from the same jar.

Tested, not assumed
Every claim here was checked on a live server with automated players: the buying flow, double click spam against duplication, a full inventory being refused instead of charged, spawner mobs paying nothing, forged coins turned away, and shops, prices and coins surviving a full restart.

Statistics
Anonymous usage statistics through bStats: server software and version, Java version, player count, plugin version, language, coin delivery and roughly how many shops exist. No player names, no addresses, nothing about what anyone bought. Switch it off in plugins/bStats/config.yml.