KMarket

KMarket is a server-authoritative economy and marketplace mod for Minecraft Java Edition 26.1.2 using Fabric.

It provides a configurable server shop, secure player marketplace, instant item selling, persistent balances, and a transparent community treasury.

Features

Configurable buy, sell, and player-market prices
Support for vanilla and modded items
Typo-tolerant shop search
Instant selling with /sell
Enchanted-item pricing bonuses up to 70%
Enchanted book support
Player listings with complete ItemStack component preservation
Persistent player balances, listings, claims, and transaction history
Player payments and donations
Market taxes collected into a server fund
Owner-controlled treasury payments and adjustments
Compact balance display for large amounts
Automatic detection of unconfigured items
Atomic JSON saving with automatic backups
Secure, server-side transaction validation
Protection against duplicate purchases, overflow, and negative balances

Requirements

Minecraft Java Edition 26.1.2
Fabric Loader 0.19.3 or newer
Fabric API for Minecraft 26.1.2
Java 25

KMarket uses vanilla inventory interfaces and is designed primarily as a server-side mod. Players still require any content mods used by the server’s modpack.

Prices, categories, owners, transaction limits, taxes, and other settings can be configured under config/kmarket. Modded items are supported through their registry IDs; unavailable items are safely ignored.

Setup

Install Fabric Loader for Minecraft 26.1.2.
Install the matching Fabric API.
Place kmarket-1.0.0.jar in the server’s mods folder.
Start the server once to generate config/kmarket.
Stop the server before editing the generated configuration.
Add owner UUIDs to config/kmarket/owners.json.
Configure prices inside config/kmarket/prices/.
Restart the server, or use /kmarket reload after changing prices.

Example owners.json:

{
  "owners": [
    "00000000-0000-0000-0000-000000000000"
  ]
}

Owners must also have Minecraft permission level 4. The dedicated server console is authorized automatically.

KMarket automatically places unknown registered items in:

config/kmarket/unconfigured.json

Items must be enabled and given prices before appearing in the shop. Modded items use their complete registry IDs, such as examplemod:item_name.

Player Commands

/market — open the player marketplace
/market sell <quantity> — list copies of the held item
/market mine — view and manage your listings
/market cancel <listing-uuid> — cancel a listing
/market claim — collect returned or expired items
/market notifications — view market notifications
/shop — open the server shop
/shop search <text> — search with typo tolerance
/shop buy <registry-id> <quantity> — buy an item
/shop sell <registry-id> <quantity> — sell an item
/sell — instantly sell one held item
/sell <quantity> — instantly sell the selected quantity
/sell all — instantly sell all matching held items
/balance — display your balance
/balance <player> — display an online player’s balance
/pay <player> <amount> — send money to another player
/donate <player> <amount> — donate money to another player
/serverfund — display the public community treasury balance

Owner Commands

These commands require permission level 4 and a UUID listed in owners.json.

/kmarket reload — validate and reload the configuration
/serverfund pay <player> <amount> — pay a player using existing treasury funds
/serverfund add <amount> — add an audited treasury correction
/serverfund remove <amount> — remove an audited treasury correction
/serverfund history — view recent tax and treasury transactions
/vaultgrant status — verify owner authorization
/vaultgrant money add <player> <amount> — add money
/vaultgrant money set <player> <amount> — set a balance
/vaultgrant money remove <player> <amount> — remove money

Every treasury transaction is audited. Treasury payments subtract from collected funds instead of automatically generating additional money.