David Schwartz, Ripple’s chief technology officer and one of the architects of the XRP Ledger (XRPL), has proposed a new transaction reservation system aimed at reducing front-running and sandwich attacks on the network’s decentralized exchange (DEX) and automated market maker (AMM).
The proposal follows renewed concerns from members of the XRPL community over how pending transactions can be observed before a ledger is finalized. Some users argue that this visibility allows sophisticated traders to identify profitable transactions and submit competing orders, giving them an advantage over regular users.
Concerns have been raised about the possibility of front running or transaction sandwich attacks on XRPL payments and offer crossing.
For the reasons I’ve explained, I’m not that concerned about this issue. But I have a proposal for a fairly simple scheme that would eliminate… https://t.co/lnhTv1bhBK
— David ‘JoelKatz’ Schwartz (@JoelKatz) June 29, 2026
Although Schwartz said he is not deeply concerned about the issue based on previous technical explanations, he introduced the proposal as a simple way to remove doubts and improve fairness as decentralized finance activity on XRPL continues to grow.
How would the transaction reservation system work?
The proposal introduces two new features to the XRPL protocol, which are a ReservedTxns ledger object and a TxnReserve transaction type.
Users can reserve a transaction for execution in a future ledger by paying twice the standard network fee. Reservations would only be allowed for ledgers scheduled within the next 16 ledger closes, or roughly 80 seconds.
Each target ledger would have space for up to 32 reserved transactions. Once a reservation is confirmed, the transaction ID will be stored until the selected ledger is processed.
When that ledger closes, reserved transactions will be executed before all other transactions. The reservation record would then be removed, ensuring the transaction cannot be processed twice.
Can the system prevent abuse?
Schwartz also included measures to discourage denial-of-service (DoS) attacks.
As reservation slots fill, the reservation fee would increase gradually, making it increasingly expensive for anyone trying to reserve every available slot. The design keeps costs low for normal users while making large-scale abuse financially unattractive.
The feature would remain optional, meaning users who do not need additional protection could continue using the network without paying extra fees or changing how they submit transactions.
What happens next for the proposal?
The proposal received an encouraging response from members of the XRPL community, with several developers praising its simple design while noting that it adds an extra transaction and fee for users who choose to reserve execution.
@JoelKatz Thanks for the detailed write-up and the reservation scheme proposal — it’s a clever, pragmatic idea that fits XRPL’s design philosophy well and could provide real protection for users who need it.
I agree it’s simpler and lower-risk than heavier privacy changes. The…
— XRPresso.io (@xrpresso_io) June 29, 2026
Some community members also suggested combining the proposal with privacy-focused technologies, such as encrypted pending transactions, to further reduce trading advantages. If the idea moves forward, it will undergo review by XRPL developers and the wider community before being considered through the network’s amendment process.
The proposal comes as the XRPL ecosystem continues expanding with stablecoins, tokenized real-world assets and growing decentralized trading activity. David Schwartz recently highlighted the network’s stability ahead of the rollout of the highly anticipated v3.2.0 upgrade, as node operators begin migrating to the newly renamed xrpld server.
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