Consider adding a Dutch Auction implementation

🧐 Motivation

TL;DR: Price starts at X reduces by Y every Z minutes until it reaches W.

📝 Details

Found this PR https://github.com/OpenZeppelin/openzeppelin-contracts/pull/989, but it’s way too complex and closed due to staleness.

Example: https://github.com/divergencetech/ethier/blob/main/contracts/sales/LinearDutchAuction.sol (I’m not sure if it’s production-ready)

It would be pretty straightforward to implement, as follows:

uint256 public constant startPrice = 1 ether;
uint256 public constant endPrice = 0.5 ether;
uint256 public constant priceCurveLength = 120 minutes;
uint256 public constant dropInterval = 40 minutes;
uint256 public constant dropPerStep = (startPrice - endPrice) / (priceCurveLength / dropInterval);

function getAuctionPrice() public view returns (uint256) {
    if (block.timestamp < startTime) {
        return startPrice;
    }
    if (block.timestamp - startTime >= priceCurveLength) {
        return endPrice;
    }
    uint256 steps = (block.timestamp - startTime) / dropInterval;
    return startPrice - (steps * dropPerStep);
}

[frangio]

So far I don’t think we should implement a dutch auction. I think the problem of NFT drops is more about mechanism design rather than secure implementation. As far as I can tell, dutch auctions are not necessarily the best way to sell NFTs, and it is an active research area. This is an example of a post from just a few days ago proposing a variation on the mechanism.

[mw2000]

@frangio @Amxx do you think we should proceed with building a potential dutch auction mechanism? To answer @frangio’s question, many NFT drops today are happening via Dutch Auction, and by having a standard mechanism to do so, a lot of devs would benefit since they wouldn’t have to write code for it that is more susceptible to having issues.