Block

01The rule

No buy can land in the slot a coin is created in. The market records its creation slot, and every buy checks the current slot against it before it charges a fee or moves a reserve. A buy in the creation slot is refused with the program error BuyNotOpen.

02Who it covers

creator

the same rule; the creation transaction can't also buy

bundles

a transaction that creates a coin and buys it is refused, and so is any other buy in that slot

every buy

exact in, exact out, and buys that follow a call

sells

no added rule

03When trading opens

Buying opens at the creation slot plus one, about 0.4 seconds later on Solana. No delay is configured and no keeper is involved: the next slot opens the coin for every wallet at once, and the first buyer pays the curve's opening price.

04Why the creation slot

A coin's creation is the most visible chance on chain, and it goes to whoever is already waiting in that block. With the slot closed, nobody holds a coin before the rest of the market can see it exists. The rule lives in the program, so it holds for every coin and every wallet.

05What you see in the app

The coin page reads buyingOpen, createdSlot and firstTradableSlot from the API. During the creation slot it marks the slot buying opens at, holds the buy panel, and reads the coin again every half second.

A quote or build asked for in that slot comes back as a retryable BuyNotOpen with opensAtSlot, and the app asks again once that slot has come.

06For integrators

The API's create action builds creation alone, and the SDK's transaction builder refuses a transaction that creates a coin and buys it. Buy instruction builders read the market and the clock together, or take an explicit slot.