At a high level, each item in the series would contain a reference to the immediate previous item. Only one item at any given "height" will exist, and once the next item is minted it is impossible to insert any items in between or at the same height without detection.
Each item would be sold loaded (amount TBD) - Face values could vary across items
The rough mechanics would look something like:
1. A new collectible is offered for sale each day, with that date stamped/prominent on the item (for example, 2024-07-04)
2. Bidding starts at ~10 USD equivalent of BTC, or 0.0001 BTC, whichever is lower
3. There are 24 hours to place a bid, standard auction rules of 5-minute anti snipe apply
4. The highest bidder has 24 hours to make payment - if not, it is offered to the next highest bidder for two bidders, before the auction fails
5. If no bids are received, or the top 3 bidders fail to pay, that specific date is not minted.
This way, an unbreakable chain of collectibles is created - each item links directly to the previous mint, and any gaps are cemented in when the next item is sold.
Each item in the series is a 1/1 - designs may be shared, but serials and dates will make it 1/1.
Designs and form factor could be varied over time (for example, a new design every 210 days).
This way over time I could mint the series using coins, canvases, slabs, stamps, etc.
Hypothetically, the first few days could look something like this
2024-07-05 - 001 - sold -> Coin(001 | Date 2024-07-05 | Prev 2024-07-04)
2024-07-06 - 002 - fail
2024-07-07 - 002 - fail
2024-07-08 - 002 - sold -> Coin(002 | Date 2024-07-08 | Prev 2024-07-05)
2024-07-09 - 003 - sold -> Coin(003 | Date 2024-07-09 | Prev 2024-07-08)
Here, across 6 days, a total of 4 items are produced - numeric serials run consecutively (000, 001, 002, 003), while the dates that create the chain allow gaps.
This creates a Proof of Mint chain - as more items are minted on top of previous ones, rewriting the history and setting a new canonical chain becomes harder and harder.
Additionally, as each item is loaded, the private keys will lead to a UTXO mined within a day or two of the date on the item - this also makes attacking the chain harder and harder, as it requires an attacker to have a UTXO on hand that meets the date criteria.
This could potentially run indefinitely, but there could also be a hard limit such as a max serial or a "kill" period where if no new items are minted for X consecutive days the chain dies (and restarts afresh?).
If collectors here are keen, I'll start looking at the actual manufacturing and auctioning process.
I foresee the chain becoming a mix of various physical forms like coins, slabs, stamps, canvases etc, with consecutive serials sharing the same form factor (depending on how expensive it is/minimum orders for blanks).
Any unused items from a series could be sold as DIY or destroyed - For example, if the minimum order for a coin is 50 pcs, and only 20 days sell, the remaining 30 could be destroyed or sold separately under a separate line of serials/markings.
Would like to hear the community's feedback and interest!