GemEngine – Plugin Description

GemEngine is a Minecraft plugin for Paper servers that provides a flexible multi-economy system. It allows you to manage multiple independent currencies per player, accessible via commands and PlaceholderAPI.

⚙️ Requirements

| Plugin | Required? | Purpose |
|---|---|---|
| PlaceholderAPI | ✅ Required | Provides the %gemengine_...% placeholders |
| Vault | ❌ Optional | Automatic detection of installed economies (e.g. Essentials) |

📂 Files

config.yml – Configure Economies

This is where all currencies managed by the plugin are defined.

economies:
  gems:
    name: "Gems"        # Display name of the currency
    allow-pay: true     # Can players transfer to each other?
  coins:
    name: "Coins"
    allow-pay: false

Tip: If Vault + Essentials are installed, an entry for the Essentials economy will be generated automatically on server start — no manual setup required.

data.yml – Player Data

All player balances are stored here. This file is managed automatically and should not be edited manually.

#Example
550e8400-e29b-41d4-a716-446655440000:
  gems: 150.0
  coins: 320.50

💬 Commands

/gpay <economy> <player> <amount>

Transfers an amount of a specific currency to another player.

| Argument | Description |
|---|---|
| <economy> | The economy key from config.yml (e.g. gems) |
| <player> | Name of the target player (must be online) |
| <amount> | The amount to transfer (must be positive) |

Example:

/gpay gems Steve 50

⚠️ Transfers must be enabled per economy in config.yml via allow-pay: true. The sender also needs a sufficient balance.

/gemengine eco <set|add|remove> <economy> <player> <amount>

Admin command for manually managing player balances.

| Action | Description |
|---|---|
| set | Sets the balance to a specific value |
| add | Adds an amount to the balance |
| remove | Deducts an amount from the balance (minimum 0, no negative balance) |

Examples:

/gemengine eco set gems Steve 500
/gemengine eco add coins Steve 100
/gemengine eco remove gems Steve 25

🔑 Permissions

| Permission | Description |
|---|---|
| gemengine.admin | Access to /gemengine eco |

📊 Placeholders (PlaceholderAPI)

The placeholder format is:

%gemengine_<economy>%

The <economy> part corresponds to the key defined in config.yml.

Examples:

| Placeholder | Returns |
|---|---|
| %gemengine_gems% | The player's balance in the "gems" economy |
| %gemengine_coins% | The player's balance in the "coins" economy |

Values are always returned with 2 decimal places, e.g. 150.00

🔗 Vault Integration

If Vault is installed alongside an economy plugin such as EssentialsX, GemEngine will automatically detect it on startup and add a matching entry to config.yml.

Example: EssentialsX is installed and uses Dollars as its currency.

On the first server start, the following will appear in the console:

[GemEngine] Vault Economy 'Essentials Economy' detected!
[GemEngine] Entry 'essentials_economy' has been automatically added to config.yml.
[GemEngine] Placeholder: %gemengine_essentials_economy%

The config.yml will then be automatically updated with this entry:

economies:
  essentials_economy:
    name: "Dollars"
    allow-pay: false

Note: allow-pay is intentionally set to false to prevent accidental transfers from being enabled. This can be changed manually in config.yml. For more help and explanations look in the config.yml and message.yml.

🚀 Installation

1. Drop GemEngine.jar into your server's plugins/ folder
2. Make sure PlaceholderAPI is installed as well
3. Start the server — config files will be created automatically
4. Add your own economies in plugins/GemEngine/config.yml
5. Restart the server