Currencies

Defined in config.yml, edited in /coins gui → Currencies.

currencies:
  coins:
    name: "Coin"
    plural: "Coins"
    icon: GOLD_INGOT
    symbol: ""
    decimals: 2
    starting-balance: 500
    primary: true
    payable: true

Key
name / plural	singular and plural, used in every message
icon	the item shown in menus
symbol	shown before the number; blank uses the name instead
decimals	0–4
starting-balance	what a new player has
primary	the one Vault sees. Exactly one currency must be primary
payable	whether players can /pay it

Making your own

Renaming a currency and changing what it looks like, in game.

Non-transferable currencies

payable: false makes a currency earnable and spendable but never handed between players. Event tokens are the obvious case — trading them defeats the point of the event.

Money and rounding

Amounts are rounded through BigDecimal at each currency's precision, not by arithmetic on doubles.

Why this matters

A currency that only exists as a double accumulates fractions of a penny on every transaction. After a few thousand trades the total money supply no longer adds up, and nobody can explain why.

Storage

Balances are held in memory and written to balances.yml on a timer (save-interval-minutes, default 5). A shutdown always forces a save, so that interval is the window you would lose to a hard crash.

The file is written to a temporary name and moved into place. A crash midway through writing a truncated balances file would otherwise wipe the entire economy, and that is not recoverable.