kyrers / sealed-bid-auction-house

Patrick McCorry Cryptocurrency Class 2022 Challenge 2

Sealed bid auction house

This project expands the challenge presented by Patrick McCorry in his second Cryptocurrency Class 2022 challenge. The main goal was to implement a contract capable of handling deposits and withdrawals. However, it mentioned sealed bids and timed withdrawals as possible use cases. So I decided to build this simple auction house.

This is in no way a fully secure project. This was just practice. Keep that in mind.

With that said, here's the most important project capabilities:

• Only the Auction House owner can start an auction. There are two important deadlines set when starting an auction:
  • Auction End: the frontend only allows auctions to be between 5 and 1440 minutes¹;
  • Open Bid Deadline: 5 minutes after the auction end;
• If there's a live auction for which the auction end has not been reached yet, users can place sealed bids. Multiple bids by the same user will be summed up².
• After the auction end is reached, users have 5 minutes to open their bids:
  • If the user bid is not the highest to have been open to date, the user receives his funds;
  • If the user bid is the highest to have been open to date, the user will either win the auction or receive is funds if another user opens an higher bid.
  • Funds from sealed bids after the auction is no longer live stay in the Auction House contract.

Functionalities not implemented:

• Prizes - both setting prizes and distributing them afterwards;
• Auction history.

To see the project working, you can check out this contract and this UI of which I am the owner, meaning only I can start an auction. But the best way to get the hang of this is to clone and modify/deploy the project yourself.

kyrers

Footnotes

1. The contract does not validate this, meaning that the owner could start an auction with different duration values by sending a transaction directly to the contract. ↩

2. Even though bids are sealed, checking a block explorer would allow everyone to see what the value passed to the contract was. ↩