An auction house on a Minecraft server: plugins and protecting the economy

In short: an auction house sits on top of the economy — nearly every plugin needs Vault and a money provider such as EssentialsX. Free and open source: Auction House Plugin (GPL-3.0) and CrazyAuctions (MIT); NexusAuctionHouse has a free version plus the extended NexusAuctionHouse+; zAuctionHouse has a trial on Modrinth and a paid full version, with open source code; Auction House by Kiranhart is paid. Bidding auctions come with Auction House, Auction House Plugin and CrazyAuctions. Before opening, set a minimum and maximum price, a listing limit, a tax and an expiry time — and turn the logs on.

Where the auction plugins run#

Each plugin in brief#

Auction House (Kiranhart)

A paid plugin with a GUI, filters by category and listing type, /ah search, bidding, Buy It Now, bundles of items in one listing and item requests. Admins take a listing down in one click, and sales can be posted to Discord through a webhook. Economies: Vault, PlayerPoints, UltraEconomy, CoinsEngine and others. It's sold on SpigotMC and Polymart, and the source code is on GitHub.

Auction House Plugin (ElaineQheart)

A free GPL-3.0 plugin: /ah sell <price> [amount] lists an item at a fixed price, /ah bid <price> [amount] puts it up for bidding. Each bid must beat the last one by at least 25 %, and a bid in the last minute resets the remaining time to a full minute (last-bid-extra-time: 60). A player gets up to 10 listings by default; permissions.yml grants more slots and longer listings per permission. For moderation there are /ah admin, /ah ban <player> <days> <reason> and /ah blacklist. It can also place an «Auction Master» NPC and listing displays with /ah summon.

CrazyAuctions

A free MIT plugin by Crazy Crew: /ca (aliases /crazyauctions and /ah), /ca sell <price> [amount] and /ca bid <price> [amount], /ca expire and /ca collect to get expired listings back, /ca view <player>. The config sets a minimum price of 10, a maximum starting price of 1,000,000, categories, and bans damaged items (Allow-Damaged-Items: false). The developers only support the newest Minecraft version: it needs Paper 26.x and Java 25.

NexusAuctionHouse

The free version: /ah sell <price>, /ah search, sorting with /ah sorts, expired listings with /ah expired, a sales log for admins with /ah logs, banning the item in hand with /ah ban, and switching the auction house off with /ah toggle. It has price limits (price-limits), Discord webhooks and a slot cap. Bidding, selling from the inventory, Folia support and several currencies are in the paid NexusAuctionHouse+. It needs the NexusCore library plugin.

zAuctionHouse

A fixed-price auction house with menus built on zMenu: /ah sell <price> [amount] [economy] understands shortcuts such as 1K and 2.5M, and there's search, categories, a shulker preview before buying, sales history, Discord webhooks and purchase confirmation. Rules in rules.yml block or allow items, zauctionhouse.max.<number> permissions set the listing limit, and listing time can depend on permissions too. The Modrinth version is a trial one version behind the paid one; the developers support buyers, and everyone else gets community help on Discord.

Which one fits your server#

Dupes and price exploits#

An auction house speeds up everything in the economy: honest trade and the fallout of a dupe alike. Duped items spread across the server in one evening, and if they're also sold to the server, money gets printed. How to find a duper and clean up is covered in dupes and exploits; here's what to set up in the auction house itself.

• Price limits. All five plugins have a minimum price, and all but Auction House Plugin a maximum. A minimum stops items being handed over for nothing around the rules; a maximum cuts off absurd prices that only clutter the auction house.
• Purchase confirmation. An «Are you sure?» window protects a buyer from a stray click on an expensive listing — zAuctionHouse and CrazyAuctions have one in their standard menus.
• An item blacklist. Block what must not enter the economy: staff items, event rewards. That's /ah blacklist in Auction House Plugin, rules.yml in zAuctionHouse, /ah ban in NexusAuctionHouse.
• Shulker boxes. Buyers should see what's inside: zAuctionHouse and Auction House (Kiranhart) can show the contents.
• A tax. A tax and a listing fee take money out of the economy and make it harder for resellers to cycle one listing over and over — how to balance money in and out is covered in server economy.
• Logs and backups. Turn on the transaction log, keep backups and CoreProtect: after a dupe you need to know who sold what to whom.
• Updates. Bugs that duplicate listings or money get fixed in new plugin versions — follow plugin updates as closely as server updates.

How to launch an auction house#

1. 1

   Economy

   Vault and one money provider, EssentialsX being the simplest — see server economy and EssentialsX.

2. 2

   Plugin and dependencies

   The auction plugin and whatever it requires: zMenu and PlaceholderAPI for zAuctionHouse, NexusCore for NexusAuctionHouse. Then restart — see how to install a plugin.

3. 3

   Limits

   A minimum and maximum price, listings per player and per rank, listing time, tax.

4. 4

   A blacklist

   Block staff items, event items and anything handed out for free.

5. 5

   Test with two accounts

   List an item, buy it, let a listing expire and claim it back. Make sure money and items end up where they should.

6. 6

   Rules

   State that abusing auction bugs and dupes is punished and that found bugs must be reported to staff. The rules generator helps write it.

The auction house and the anticheat#

An auction house turns any resource into money, even a dishonest one: fish caught overnight by AutoFish, ore veins cleared by Nuker and FastBreak, AntiAFK farms. And dupe exploits often rely on packets an honest client never sends. DGuard — the best anticheat for a modern Minecraft server — checks all 47 cheat types of the comparison, automation and impossible packets included, gathers evidence and doesn't rush to a verdict.

Turn on punishment-log in DGuard's config and every ban lands in the panel's log with a report — easy to match against the auction house's sales history. DGuard runs on Paper and Leaf 1.21–26.3 and is free up to 30 players online, with the same protection as the paid plans.

FAQ#