Bids arrive from anywhere
An authenticated bidder can bid from your auction website, from your native app, or from an external platform integrated over our API. The engine treats all three the same way, and pushes the new state back to every connected client at once — every website, every app, every open catalogue page.
That last part is what makes an auction feel live. A bidder watching on a phone and a bidder watching on a desktop see the same number at the same moment.
The closing minute
Auction load is not steady. Six days of quiet, then every bidder arrives in the final sixty seconds. The engine is built around that shape, and the platform scales automatically as the curve rises rather than being provisioned for the average.
Lot extension handles the other half of the problem. Set how close to closing a bid must land to trigger an extension, and how much time it adds — for example, a bid inside the final 120 seconds extends the lot by 600 seconds. Late bidders do not win by arriving last.
Bid types
| Type | Behaviour |
|---|---|
| Direct bid | The bidder names an amount. Standard increments apply. |
| Automatic bid | The bidder sets a maximum. The engine raises their bid incrementally to stay ahead until the maximum is reached. |
| Sealed bid | No feedback on standing. Winners are notified only after the auction closes. |
| Absentee bid | Staff place a bid for a bidder who gave a maximum by phone or email. |
| Phone bid | A live-auction process for bidders participating by telephone. |
| Offer below limit | Where the reserve is not met, a bidder can make an offer for the consignor to consider. |
| Buy now | Fixed-price purchase, typically after the auction closes. |
The full contract — how increments and proxies resolve, what happens at the close, and every outcome a bid can produce — is documented in how the bidding engine works.
Live auctions
In a live auction the engine keeps in-room and remote bidders on equal footing, which is harder than it sounds. It resolves simultaneous and identical bids, gives the auctioneer controls to correct a bid, pause, or move between lots, and notifies both the auctioneer and the bidders when the sale runs behind schedule. A near real-time video stream carries the room to the remote audience.
We built this in 2013 for a family auction house that had been running room auctions for three decades and would not accept a solution that damaged the experience. It is still the design we use.
Lots per auction grew from a few hundred to several thousand. Today they are one of the Netherlands' leading auction houses with international reach.
Luxury segment · live auction case studyWhat this covers in full
The full feature list →Bidding engine on the full list →
- Real-time bidding from web, app or an external siteA bid placed on the phone shows up instantly on the website and in the room. One engine behind all of them.
- Proxy bidding up to a maximumA bidder sets their limit and walks away. The system bids for them, one step at a time, only as far as it needs to.
- Static biddingA bidder places exactly the amount they typed, with no automatic follow-up.
- Bid steps that change by price bracket€5 steps up to €100, €25 steps to €1,000, €100 above that — so bidding stays sensible at every price.
- Skip the first incrementLet the first bid land on the opening price itself rather than one step above it.
- Soft close — extends when a late bid landsA bid in the final seconds pushes the closing time out, so nobody wins by sniping and lots reach their real price.
- Reserve price hidden from biddersSet the minimum you will accept without telling the room what it is.
- Override a reserve that was not metThe consignor agrees on the phone to accept €900 on a €1,000 reserve, and you push it through.
- Award a lot manually below reserveGrant the lot to the highest bidder anyway, with a record of who decided it and when.
- Staff placing absentee bids for a bidderA client phones in their maximum before the sale and your staff enter it on their behalf.
- Phone bids with caller assignmentAssign a staff member to each phone bidder for the lots they care about, so nobody is left ringing out.
- Retract a bidCancel a bid entered in error and put the lot back to where it was, with an audit record.
- Bid limits per memberCap a new or unverified bidder at €5,000 until they are established.
- Guard against implausibly large bidsStop the €500,000 bid on a €500 lot where someone clearly missed the decimal point.
- Bidders blocked from their own lotsA consignor cannot bid up their own goods.
- Tied highest bids handled explicitlyWhen two sealed bids come in identical, the system says so rather than picking one silently.
- Every bid attempt logged with IP addressEvery bid, accepted or refused, is on record — which settles disputes and shows regulators what happened.
- More than thirty distinct bid outcomesWhen a bid is refused the bidder is told why — under the reserve, past their limit, registration needed — not just 'failed'.
- Bid origin tracked — hall, internet, proxy, phone, Lot-tissimo, InvaluableKnow whether the winning bid came from the room, your website, the app or a marketplace, and prove which channel earns its keep.