Pricing

A paykit.Gate carries the price and the fee splits. The amount is a typed Price built with MustParseUSD (or the error-returning ParseUSD).

Amounts

import "github.com/solana-foundation/pay-kit/go/paykit"

paykit.MustParseUSD("0.10")                              // $0.10, default settlement (USDC)
paykit.MustParseUSD("0.10", paykit.USDC, paykit.USDT)    // narrow/order the settlement assets

The customer is quoted in USD; the settlement stablecoin (USDC, USDT, …) is what actually transfers. ParseUSD returns an error instead of panicking on a malformed amount.

The Gate struct

gate := paykit.Gate{
    Amount: paykit.MustParseUSD("0.10"),
    Desc:   "Premium report",
    Name:   "report",        // optional; identifies the gate in receipts
    PayTo:  "Ay…",           // optional; defaults to the operator recipient
}

Kind selects the settlement shape (GateFixed by default, or GateUsage — see Schemes).

Fees and splits

FeeWithin carves a fee out of the amount (the recipient nets less); FeeOnTop adds a surcharge on top (the customer pays more, the recipient nets full). Both route to a fee recipient address:

gate := paykit.Gate{
    Amount:    paykit.MustParseUSD("10.00"),
    PayTo:     paykit.Address("Ay…"), // seller
    FeeWithin: paykit.Fees{paykit.Address("CX…"): paykit.MustParseUSD("0.30")}, // seller nets $9.70
}

Fees is a map[paykit.Address]paykit.Price.

Fee-bearing gates require MPP (x402 exact is single-recipient), so an x402-only gate with fees returns ErrSchemeIncompatible at New time.