Transactions broadcasted to mempool are not immediately confirmed, most transactions stay "pending" or "unconfirmed" for a little while. A transaction would only be confirmed upon the mining of a new block, which could take from a couple of minutes to more than an hour.
Since block times vary, “unconfirmed” transactions are susceptible to being replaced by other users who use a higher fee rate (RBF = Replace-By-Fee), dropping the original buyer's transaction. This is commonly known as “sniping”.
Sniping causes the original buyer to lose out on his purchase, and all ordinals/runes would be transferred to the sniper - as the replaced transaction (by the sniper) will be the transaction that is eventually confirmed.
⚠️ If your transaction gets replaced, no funds are deducted at all. Fees are only paid upon confirmation of a transaction.
An example of transaction sniping (using RBF) on Mempool.
These days, sniping has become more commonplace while trading Ordinals/Runes, disrupting users' trading experience. However, we're implementing some changes to help improve the UX on Magic Eden.
Below are 2 methods you can use to secure your purchases, one used before you submit a transaction, and another after you've submitted one.
Pre-Transaction RBF Prevention
Adding Mempool Protection
What is it?
Mempool Protection automatically broadcasts additional transactions at a higher fee rate on your behalf, in the event your transactions get replaced/sniped.
How do I use it?
1. Head to any Ordinal item details or Runes collection page, you will see a new 'Add mempool protection' toggle.
2. You will be able to set a 'Max network fee' multiplier based on the current fee rate. (20 x base of 9 sats/vB = 180 sats/vB)
3. Upon clicking 'Buy Now', you will be prompted to sign 3 transactions.
Looking at the example above:
Signing the first transaction will broadcast your purchase at the 'First Fee' (current network fee rate of 9 sats/vB).
The next transaction is to authorize Magic Eden to broadcast another transaction at the 'Second Fee' rate of 95 sats/vB, in the event your first transaction gets sniped.
The third transaction authorizes Magic Eden to broadcast a final transaction at the 'Max Fee' rate of 180 sats/vB, if your second transaction gets sniped again.
Post-Transaction RBF Prevention
Checking 'Pending Orders'
On top of using Mempool Protection, users have the option to manually submit an RBF transaction for an order that’s currently pending and unconfirmed on Mempool.
After submitting an order, you can click 'Track your pending purchase here' to locate your order. Alternatively, you can head to your Profile > Pending Orders.
On your Pending Orders, you will be able to see all your orders that are still pending on Mempool.
If your transaction is still live and valid, you will see 'Top Fee' under the 'Status' field.
However, if your transaction has been sniped, you will see 'Getting Replaced'. At this point, you will be able to submit a RBF transaction to try securing your purchase.
Click 'Increase Fee', and a new pop-up would appear.
Here you can submit another transaction with an increased network fee. This fee is decided by you, and must be above the minimum required fee rate displayed on the right. Click 'Increase Network Fee' and you're good to go!
With this new transaction submitted, you can sit back and monitor your 'Pending Orders' to see if the transaction goes through on Mempool.
Facing Errors? You May Have Unconfirmed Funds.
Due to the nature of how Bitcoin transactions work, in order for an RBF transaction to be submitted, only confirmed funds can be used.
Confirmed funds are funds that are not being used in any other unconfirmed transaction on Mempool.
Check your wallet balance on Mempool for any pending transactions you have, and wait for the transaction to confirm before performing your RBF transaction.
We understand that these additions do not eliminate sniping entirely. A longterm solution for sniping would probably require a more significant change, but we hope that these products would help improve the overall trading experience for users.