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Non System Service Payment

The "Non System Service Payment" module is a system smart contract responsible for processing payments related to services in which DAO Ace Stream does not receive a fee (for example, system payments related to prediction market).

All the payments in this category are done in XAB only.

Payment with XAT is possible, but in such case the network performs an automatic exchange XAT -> XAB on built-in DEX (decentralized exchange) before making a transaction. Such an exchange is outside the scope of this smart contract, therefore, in this section only payment in XAB is described.

Payment Algorithm

  • if the payer has enough XAB then:
    • the required amount of XAB is being charged from the payer and burned
    • if the lockedPool is not empty then the same amount of XAB is put into circulation (moved from lockedPool to unlockedPool)
  • if the payer doesn't has enough XAB then the transaction is declined


def makeNonSystemServicePayment(sourceAccount, amount):
    sourceAccount - the payer account
    amount - amount of payment in XAB
    if sourceAccount.balance.xab >= amount:
        # Burn `amount` XAB from the source account
        sourceAccount.balance.xab -= amount
        System.BLACKHOLE.balance.xab += amount

        # Unlock at most `amount` XAB
        toUnlock = min(amount, System.lockedPool.amount)
        if toUnlock > 0:
            System.lockedPool.amount -= toUnlock
            System.unlockedPool.amount += toUnlock
        raise Exception('not enough tokens')