Mempool Introduces Bitcoin Transaction Acceleration Service

The Mempool team has launched an off-chain service to accelerate Bitcoin transactions outside the blockchain through partner mining pools. This service is particularly useful amid sudden changes in fees.

Mempool Accelerator™ fixes this

Launch of open beta starts today!

Click Accelerate from the transaction page and pay with lightning or fiat.
No sign up necessary.

Initial mining pool partners make up 40% of Bitcoin’s global hashrate: @FoundryServices, @MarathonDH, @SBICrypto,… pic.twitter.com/NIQXq53ZRb

— mempool (@mempool) July 27, 2024

The platform collaborates with Foundry USA Pool, MARA Pool, SBICrypto, SpiderPool, and Ocean Pool, which collectively account for approximately 40% of the hashrate, according to the organisation’s data.

To confirm “stuck” transfers, users of Mempool Accelerator will need to pay an additional mining and service fee.

The process is as follows:

• find the transaction on mempool.space;
• select the acceleration option;
• pay with Bitcoin via the Lightning Network (LN) or fiat through Cash App, Apple Pay, or Google Pay without registration.

Mempool sends a request to partners, who can decide on acceleration based on the new fee rate.

The transaction is not replaced; pools consider it with higher priority. This increases the chances of its validation in the next block, though it is not guaranteed.

“Your transaction will be prioritised for 43.4% of miners. This will reduce the expected waiting time for the first confirmation to ~9 minutes,” states the project’s website.

Bitcoin applications can integrate Mempool Accelerator through its API.

To enhance transparency, acceleration requests are displayed on the Mempool block audit panel, highlighted in purple.

As part of our mission to improve transparency, the block audit feature has been updated to incorporate acceleration bid boosts (the numbers in purple). pic.twitter.com/YGdPiBmRCz

— mempool (@mempool) July 27, 2024

Once requests are sent, they cannot be altered, and some may be marked as non-refundable to ensure the service is not used for “transaction pinning or other forms of abuse.” This is intended to prevent unfair advantages over other users.

Mempool Accelerator offers an alternative to existing on-chain methods to increase miners’ chances of including a transfer: replace-by-fee (RBF) and child-pays-for-parent (CPFP).

In RBF, the sender of an unconfirmed transaction creates a new one with a higher fee, using some of the inputs in the UTXO, often accepted over the original operation.

However, the new transaction must be signed, the sender’s wallet must support RBF, and the identifier will change.

In CPFP, the recipient spends their unconfirmed output, increasing the effective fee of the original operation, as the miner cannot include the new transaction without processing the original.

In this case, a new transfer must also be signed, the sender’s wallet must support CPFP, and limitations mean it is not possible for some transactions.

Alternatively, Mempool Accelerator relies on off-chain payment. In this case, there is no need to sign a new transaction.

The main drawback is that users rely on a centralised third party rather than the network of the first cryptocurrency.

Additionally, the service fee significantly exceeds the average fee—approximately 100 times compared to its current level of $0.39, according to The Block. In other words, the service is suitable only for higher-priority transactions.

According to the Mempool team, users should always apply RBF or CPFP if possible.

Mempool Accelerator is useful in the following scenarios:

• limited wallet capabilities for transactions;
• multisig difficulties;
• opening and closing LN channels;
• maintaining the same transaction identifier.

Back in October 2023, Casa co-founder and CTO Jameson Lopp urged developers to experiment more actively with the first cryptocurrency to expand and improve its ecosystem.

In particular, the specialist noted relatively recent solutions—drivechains, Spiderchain, and BitVM. In his view, they allow for “unloading” the mempool and expanding smart contract capabilities on Bitcoin.