Booking a slot

A creator names the coin, points at its metadata and picks a start between one hour and one week away. The booking holds a 0.05 SOL deposit; at the open it pays what pump.fun charges to create the coin, and the rest comes back. A coin nobody opens within a day of its slot is called off and the deposit comes back whole.

The dark hour

Until the slot the coin does not exist on pump.fun: there is no mint, no curve, so there is nothing to snipe. It takes sealed orders. An order escrows one of four round sizes, 0.25, 0.5, 1 or 2 SOL, and commits to keccak256(coin, order, amount, salt). The chain sees who ordered and which size; it does not see how much. The browser writes the salt into a ticket file, because nothing else holds it.

An order counts up to 2 SOL. The batch buys at most 20 SOL. Above that every order is cut by the same fraction and the rest comes back as SOL at delivery. Up to 256 orders fit in one slot.

The reveal

The slot opens a ten minute window. Each sealed order names its amount with its ticket; the program checks the hash, counts the amount into the batch and returns the difference in the same transaction. An order that stays sealed is out of the batch, and its escrow comes back on request once the window has closed.

The open

When the window closes anyone may open the coin; the keeper does it at the minute. The first transaction creates the coin on pump.fun with the mint the program derived for it and the pad's till as its creator, so the creator fee accrues to the till. In the next block the second spends the whole revealed batch as the coin's first trade. Every order gets the same price. Tokens are then delivered order by order, or all at once by whoever pays the fees; a recipient that is a fresh address needs no SOL of its own.

The ZEC lane

A lane order gets a one-time address on Solana, a program address computed from the coin and the order number, which no key controls. NEAR Intents takes native ZEC from any Zcash wallet, shielded or transparent, and pays native SOL to that address. Anyone may collect it: the SOL moves into the batch, up to the size of one order. A delivery that arrives after the window, or past the size, goes to the recipient as SOL with no fee.

The site asks NEAR Intents for the deposit address and hands it to your browser. Nothing about a lane is stored on our side; the pass address is on chain, and the chain is where every step can be checked.

Fees

Each coin's pump.fun creator fee accrues to a till of its own and anyone may harvest it: half to the creator, forty percent to the Kiln, ten percent to the pad. Sealed orders pay 0.3% of what they spend and lane orders 0.5%, both to the Kiln. After the open the coin trades on pump.fun like any pump coin, with no Zslot fee.

The Kiln holds SOL until ops names $ZSLOT, once. From then on anyone may fire it: it buys the coin on its curve and burns every token it gets.

Who can do what

Anyone: book, order, reveal, collect, open, fill, deliver, refund, call off, harvest a till, fire the Kiln. The keeper is a name for whoever does it on time; it has no power the public lacks. Ops can pause new bookings, name the keeper and name the Kiln's coin once. Nobody can move an order's SOL anywhere but where the program says: the escrow and the batch sit on program addresses that only the program's own rules can spend.

What stays hidden

The size of a sealed order and its wallet are public; its amount is hidden until the reveal. A lane order shows its pass and recipient; the Zcash side stays on Zcash. A recipient can be an address that has never been used: the tokens and any change land there without it ever sending a transaction.

Tests

The program's checks run on a local validator with pump.fun cloned from mainnet: a coin created on the real pump program, the batch bought on the real curve, the creator fee collected from the real vault, the cap, the call-offs and the refunds. Not audited.