Technical

What you need to run Guild Buyback, what it sends and keeps, and how it is built.

Requirements

• The game: World of Warcraft: Forever. Guild Buyback is made for Forever and built for its patch 1.60.1. On any other version of World of Warcraft, such as Retail or Classic Era, it stays off and leaves its saved data untouched. It has not yet run in the live game, which opens on 4 November 2026.
• The banker needs the addon. The banker is the character that runs the buyback, usually an officer or a bank alt: it publishes the price list, accepts the sale mail and keeps the books.
• The guild master needs it once, to name the banker, unless the guild master is the banker. Members' addons take prices only from a banker the guild master named.
• Members can sell with or without it. Without it, a member mails items by hand at the prices the banker posts, for example in Discord (see the FAQ). With the addon, a member also gets the guild's prices in item tooltips, the Sell panel at the mailbox, the choice to be paid gold later, the guild store and their own balance.

Optional for the banker

• Auctionator, an auction house addon that records prices when you scan the auction house. Guild Buyback takes each item's reference price from it: the lowest buyout, as the middle value of a week of daily scans. It can also add every material Auctionator has seen to the price list. Without Auctionator, the banker types each price.
• Guild Armory, a guild addon that records which characters belong to the same player: a main and their alts. Guild Buyback reads those links and counts one player's characters as one player: for the optional daily limit per player, the limit of open store orders, the account summary and the top-suppliers list. Credit stays with the character that earned it. Without Guild Armory, each character counts on its own.

What it sends and stores

Everything stays inside the game. Guild Buyback has no website or server behind it; it uses only what the game offers every addon.

What it sends

• Addon messages: messages between copies of the addon, which nobody sees in chat. To the whole guild: the price list, the list of bankers, the store's stock, and a short note for each sale sent and each sale settled, so every copy knows how many items the guild still takes. To one player only: their balance, their account summary, and their store orders and the answers.
• In-game mail: sales, payouts and store orders are ordinary mail.
• Chat: a whisper telling a seller why the banker returned their mail (the banker can turn it off), and the top-suppliers list in guild chat when the banker chooses to post it.

Exports, such as the price list for Discord or the ledger as CSV for a spreadsheet, are text the banker copies out by hand.

What it keeps

Like every addon, it keeps its data in the game's saved-data files on each player's own computer.

• The banker's books (the ledger and the gold owed) belong to the banker's character and are kept only on the banker's computer. Members' addons keep a copy of the price list and their own sales. Export the ledger now and then with /gbb ledger csv for a record you can read outside the game.
• A spare copy: each character also saves the data it uses in a second file of its own. If the main file fails to load, the addon loads that copy instead. For the banker, the copy includes the books.
• A copy before upgrades: when a new version changes the way data is saved, the old data is kept for 14 days, and /gbb backup can put it back.

How it is built

Guild Buyback is written in Lua, the language of World of Warcraft addons. The parts that decide about money (prices, the checks on each mail, the ledger, the guild's balance sheet) make no calls to the game, so they are tested outside it, on two different Lua 5.1 engines; Lua 5.1 is the version the game runs. The windows, the mail and the messages are tested in a simulated game client that plays mail, chat and several characters on one clock, with a server that answers late. The demo on the home page is that simulated client running the addon.

The tools and sources behind it: How was it made?

Rules it follows with the guild's gold

• Pay only for what is in the mail when it is opened: each mail is checked again just before.
• Record a sale or a payment only after the game confirms it, and never twice.
• Treat what other players write as possibly hostile, guild members included: names, numbers and messages are checked before use and shown as plain text.
• Take prices only from the banker. While the banker is offline, members' addons pass the price list on to each other, but your addon uses such a copy only if it is exactly the version it heard the banker announce; until then it keeps the list it had. The list of bankers comes only from the guild master.
• Move no gold without a person's click.

What each rule means in practice: What keeps the gold and the books accurate?

Licence

Free and open source under the MIT licence. The source code is published with the first release.