The two markets
HART has two listing modes. Sellers choose one per artwork:
| Mode | How it works | Best for |
|---|---|---|
| Fixed price | Seller sets a price in hART. First buyer to sign wins. | Predictable inventory, instant collectors. |
| Auction | Time-boxed open bidding with a reserve. Highest bid at close wins. | Price discovery, scarce or contested pieces. |
Listing flow
- DRAFT Owner picks artwork, mode, and price/reserve. Adds optional duration for auctions.
- REVIEW System surfaces fee + royalty breakdown so the seller sees expected net before signing.
- SIGN Owner signs a list transaction. The artwork enters a listed state and is locked from gifts/trades.
- LIVE Listing is discoverable in the gallery, on the seller's profile, and on the artwork page.
- CLOSE Sale settles (see flows below) or seller delists. Delisting is free except network fee.
Fixed-price sale
- Buyer clicks Buy on a listed artwork.
- Buyer's wallet signs a transfer of
pricehART. - Atomic settlement: hART is split per the fee/royalty schedule, ownership transfers to buyer, listing closes.
- Both sides receive a receipt; provenance writes a sale entry.
Fixed-price listings are first-come. Race conditions are resolved on-chain — the
first transaction to settle wins; later transactions revert with a clear error.
Auction sale
- Seller starts an auction with
reserveandduration. - Each bid escrows the bid amount on-chain. Out-bid bids auto-refund.
- RULE Anti-snipe extension: a bid in the final window extends the close time by a fixed amount. This prevents last-second sniping and is published in the auction page.
- At close, if the top bid meets reserve: settle as a sale. If not: auction expires, no transfer.
- Settlement is atomic and follows the same fee/royalty split as fixed-price sales.
Fee & royalty model
Every sale (fixed or auction) splits the gross sale price three ways:
| Slice | Goes to | Notes |
|---|---|---|
| Royalty | Original creator(s) | Per-artwork rate, set at mint and immutable. Multiple creators split per their declared shares. |
| Platform fee | Platform wallet | A small, published rate. Used to fund operations, then any surplus is burned on the same cadence as canvas burns. |
| Seller proceeds | Seller wallet | Whatever remains after royalty + fee. |
Exact fee and royalty percentages are published on the platform and may be adjusted with notice.
They are not baked into this bible because they are tunable parameters, not invariants.
The burn relay
The platform wallet is a relay, not a treasury. Funds that flow through it for community-canvas auctions are burned on-chain in full. Surplus from ordinary platform fees (after operating costs) is burned on a published cadence. Every burn is a single on-chain transaction that anyone can verify against the public burn address.
- RULE Community canvas auctions: 100% burned, no carve-out.
- RULE Royalties go directly to creators on settlement, never through the relay.
- DESIGN Burns are batched and announced. The platform never silently mints, holds, or redirects burn funds.
Locking & conflicts
| Action attempted on a listed artwork | Outcome |
|---|---|
| Gift | Rejected. Delist first. |
| Trade proposal | Rejected. |
| Re-list (different mode) | Rejected. Delist first. |
| Edit metadata that affects price/royalty | Rejected. Mutable fields like description can still be edited. |
Cancellation, expiry, refunds
- Sellers may delist a fixed-price listing at any time before a buyer's transaction settles.
- Auctions cannot be cancelled once a qualifying bid is placed (this is enforced on-chain — protects bidders).
- Failed settlement (e.g., wallet rejects, network drops) reverts atomically. No partial state.
- Out-bid bids are refunded automatically by the auction contract.
Anti-abuse & integrity
- Wash-trade detection on suspicious self-circular sales — flagged listings are reviewed; provenance can be annotated with a wash flag.
- Mod removal of TOS-violating artworks voids any active listing and refunds all live bids.
- Artwork pages render canonical metadata only. Seller-supplied descriptions are sanitized; external links are inert until manually expanded.