@lelantos-org/sdk / wallet / sizeBNote

Function: sizeBNote()

function sizeBNote(
   minOut, 
   scaleOut, 
   feeBps, 
   relayerFee?
): bigint;

Defined in: @lelantos-org/sdk/dist/wallet/swap.d.ts:32

Smallest B-note value whose on-chain Permit2 pull covers minOut.

The wrapper enforces a window, not a ceiling: minOut ≤ pulled ≤ actualOut, as MaspPullBelowMinOut and MaspPullExceedsActualOut. Solving only the upper bound — the closed form minOut * BPS / (scale * (BPS + feeBps)) — lands below minOut whenever the division is inexact, and reverts.

pulled is principal, the pool's fee, and the note paying whoever flushes the deposit — and the pool floors its fee, so the pull advances in steps no closed form always hits. Start from the floor-div estimate and walk to the smallest v that still covers minOut. Minimality is what keeps the answer under actualOut; any overshoot is wrapper-side dust forwarded to the treasury.

relayerFee is in circuit units of the out asset and rides in the same pull, so a non-zero one makes the B-note smaller: the flush is paid for out of the swap's own output rather than by a second charge to the user.

Public because it is the only correct answer to "how much will this swap credit me?", and that is a question every caller showing a quote has to answer before the user commits. executeSwap encodes this exact value as the deposit leg's publicIn, so it is what the wallet receives — not a floor, since the wrapper pulls only what the B-note needs and forwards any better-than-quoted fill to the treasury. Callers that derive it themselves reach for the closed form above and get a figure that is both wrong on screen and, if used to size a transaction, reverting on chain.

Parameters

Parameter	Type
minOut	bigint
scaleOut	bigint
feeBps	bigint
relayerFee?	bigint

Returns

bigint