How auctions work
Three auction modes, from simplest to most advanced. Live auctions are running today; Reserve and Sealed ship next. All of them settle on Pentagon Chain with the same fee: 2.5% per side, of which 80% is rebated — 40% to the winner, 40% to the seller — in the settlement transaction itself.
Live auction (English ascending)
The classic format: bids only go up, the highest bid when the clock runs out wins. A soft close stops sniping — any bid in the final 10 minutes extends the auction by 10 more, until 10 quiet minutes pass.
For the seller
- 1Open your NFT (My Vault → the item) and find Start an auction.
- 2Set a start price (the minimum first bid) and a duration — 24h, 3 or 7 days.
- 3Approve the auction house once per collection (one-time transaction), then create. Your NFT escrows into the contract — it can’t be sold or transferred elsewhere while live.
- 4Watch bids come in on the auction board or the NFT page. You can cancel only while there are zero bids.
- 5After the clock ends anyone can settle. You receive highest bid − 2.5% fee − royalty + 40% of the fee back, straight to your wallet. If nobody bid, the NFT returns to you.
For the bidder
- 1Open the auction from the board or the NFT page. The button always shows the exact minimum next bid (current bid + 0.01 PC).
- 2Bid in native PC — the amount escrows in the contract.
- 3If someone outbids you, your PC is refunded instantly and automatically — nothing to claim.
- 4Bids in the last 10 minutes extend the clock 10 minutes (anti-snipe) — no last-second steals.
- 5Win: after the end time, settlement sends you the NFT and 40% of the fee back. Settlement is permissionless — anyone can trigger it, so nobody can hold up your win.
Reserve auction (hidden floor)
Identical bidding mechanics to a Live auction, plus a secret minimum price. The reserve is stored on-chain only as a hash — nobody can read it, not even by inspecting the contract. The moment a bid meets it, it’s revealed to everyone and the auction is guaranteed to sell.
For the seller
- 1Set a start price and a hidden reserve price (committed as a hash + salt — provably fixed upfront, impossible to raise later).
- 2Your NFT escrows exactly like a Live auction.
- 3Bids below the reserve still stack up publicly — useful price discovery with zero risk of selling too cheap.
- 4If a bid meets the reserve, the contract emits “Reserve revealed” and it becomes a normal soft-close auction that will sell.
- 5If the reserve is never met, you cancel after the end time: NFT back to you, the highest bidder auto-refunded.
For the bidder
- 1Bid normally — the UI shows “reserve not met” until someone crosses the hidden floor.
- 2Your escrow + instant-refund guarantees are identical to Live auctions.
- 3When your bid triggers the reveal, you’re the leader of a now-guaranteed sale.
- 4If the auction ends under reserve, your bid is refunded in full — you can never be stuck.
Sealed bids (blind auction)
For high-value pieces. Nobody sees anyone’s bid until the reveal phase — no bidding wars, no anchoring, everyone commits to their true maximum. Two phases: commit, then reveal.
For the seller
- 1Set a minimum bid, a commit deadline, and a reveal deadline. The NFT escrows.
- 2During the commit phase you see how many sealed bids exist, never the amounts.
- 3After reveal closes, the highest revealed bid wins automatically.
- 4If no valid bids were revealed above the minimum, the NFT returns to you.
For the bidder
- 1Commit: submit a hash of your bid + a secret salt, with your funds escrowed. The amount is invisible to everyone.
- 2Reveal: after the commit deadline, publish your bid + salt. The contract checks it matches your hash.
- 3Highest valid reveal wins; everyone else is refunded automatically.
- 4Forget to reveal and your escrow is refunded after the reveal window — but your bid can’t win, so set a reminder.