Players can auction items by clicking a sign (easier to determine who clicked on a sign. - plag)at spawn to start a listing of the item in their hand.
Listings send a message to the server saying they are trying to sell an item and for the next 60 seconds players can bid.
When you start a listing you can choose the base price 1 gold, 10 gold 25 gold 50 gold 100 gold.
Players can choose to bid on the item in increments of 1 5 10 25 50 when you bid immediately the gold is taken from your inventory to prevent false sales.
When another player outbids on the item the gold is returned to the previous bidder so that they can rebid.
When an item is sold the item is transfered to the person who won and the gold is transfered to the seller.
If you are outbid you will be direct messaged ‘you have been outbid’ but during the sale it will only broadcast the current price every 10 seconds to prevent spam.
The UI for auctions. The listing only broadcasts 1 message to prevent spam, players who click the ‘BID’ button on the auction line will be given information about the item and how to bid on it. They will be spammed during the auctions lifespan to bid onto it.

Datapack Features

Debug Commands
/loot give @s loot nutiler:auction/item/auction_house