What is Full Mempool Protection?
Over the past few months at Magic Eden, we’ve reimagined our marketplace’s transaction and listing processes to eliminate transaction sniping. This new backend infrastructure - first of its kind, provides a trustless experience for sellers and a trust-minimized experience for buyers.
More technicals on how all of this works from our co-founder's big-brained thread here.
How Does Full Mempool Protection Work?
Firstly, wallets must be whitelisted by Magic Eden in order to enjoy Full Mempool Protection.
Wallet Whitelisting
If you have traded Ordinals or Runes in prior months, your wallet should already be whitelisted. If you’re just starting out, fret not - Magic Eden regularly whitelists new Taproot Wallet addresses (starting with bc1p) upon completing a single Ordinals or Runes sale.
Note: Full Mempool Protection is not compatible with a Native Segwit Address (addresses starting with bc1q)
Once a wallet is whitelisted, Full Mempool Protection will be enabled for that wallet.
The Listing Flow
All wallets will create listings via our new backend infrastructure. This means that the seller signs a PSBT transaction (Partially Signed Bitcoin Transaction) that atomically commits to transferring their assets using tapscript to a specific address while simultaneously receiving payment. During this time, the seller’s assets sit securely in their wallet.
Users will be required to sign more than 1 transaction when listing to created 'Protected Listings'. More information can be found here.
2 transactions are signed above for 1 ordinal.
Do ensure to sign ALL transaction pop-ups from your wallet provider to ensure your listings are protected!
Understanding Protected Listings
Protected listings will show an orange shield next to the price of a listed Ordinal. This means that the item is fully protected and cannot be sniped.
You will also be able to filter and sweep fully protected listings using the toggle on Collection Pages.
The Buying Flow
By purchasing an asset that has an orange shield displayed on it, and you can sit back knowing that no third party can snipe them.
The purchasing flow consists of 3 transactions:
First transaction: It consolidates the buyer's UTXOs to match the required payment amount.
Second transaction: This transaction submits the payment to the seller while simultaneously transferring the asset out.
Third transaction: This transaction transfers the asset to the buyer (using CPFP).
Each transaction is non-custodial, as the API response returns a PSBT that only the buyer can use to unilaterally spend the asset UTXO.
All three transactions utilize Child-Pay-For-Parent (CPFP) in order to make sure that they get confirmed together on the same block. This allows users to receive their assets as fast as possible, at the specific fee rate chosen when checking out.
To dive deeper on how each of these transactions work, more information can be found here.
Purchasing Protected & Non-Protected Listings Together
Protected & Non-protected assets can be purchased together in the same cart.
Users can still add 'Partial Protection' on Non-protected assets, or use our live sniping tool on their profile's 'Pending Orders' tab.
Full Mempool Protection Unavailable?
Sometimes, you may notice a grey shield with the text “Full Protection Unavailable” in your cart.
A grey shield in your cart labeled “Full Protection Unavailable” indicates insufficient confirmed funds (UTXOs) for protected purchasing. This occurs if other unconfirmed transactions use those funds. In these instances, your cart will fall back to the old signature path.
Confirmed funds are funds that are not being used in any other unconfirmed transaction on Mempool.
You can choose to proceed with Partial Protection or wait for your transactions to confirm in order to re-enable purchases with Full Mempool Protection.