Samourai Wallet is becoming increasingly popular as a wallet that focuses on privacy and security for its users above all else, but a recent tool released by this wallet’s team of developers has a focus on user experience. The new app, called Bitcoin Afterburner, allows users of many different bitcoin wallets to boost transactions that have become stuck due to low fees.



The app works for transactions that have been sent or received, and it is compatible with all BIP 39 and BIP 44 wallets. Examples of compatible wallets include Mycelium, Blockchain.info, Airbitz and Electrum.

To get more details about Bitcoin Afterburner and the concept of fee bumping in general, Bitcoin Magazine reached out to the anonymous CEO of Samourai Wallet.

“Afterburner is one more example of how we are experimenting and developing ways of monetizing our business without resorting to accepting fiat or exposing our users to harmful KYC/AML collection,” said the CEO.

Samourai Wallet monetizes the Bitcoin Afterburner app by adding a $5.99 fee for helping users with their stuck transactions. This fee is added to the child-pays-for-parent (CPFP) transaction that is used to bump the user’s bitcoin transaction fee. CPFP is a process by which the recipient of a transaction can spend the inputs of an unconfirmed transaction by using them in a new transaction that has a higher fee (and incentivizes miners to mine both transactions at once).

The full question and answer session with the CEO of Samourai Wallet can be read below.

Bitcoin Magazine: Will fee bumping eventually become the norm on Bitcoin?

Samourai Wallet: We believe that over time as legitimate transactions start to fill block space, and a fee market begins to mature, wallets that have implemented sophisticated fee management mechanisms such as fee bumping will provide their users with the most competitive transaction fees and confirmation times. The tech is there today, the challenge — and it isn’t a small challenge — is entirely UX. We’re working on this today while others are playing catch-up.

BM: Could you compare and contrast this app with the transaction accelerators offered by ViaBTC and BTC.com?

SW: The difference between the miner operated TX Accelerators is that Afterburner is not an off-chain 1-to-1 with a specific miner. Instead, Afterburner broadcasts a bitcoin transaction to all miners using the standard bitcoin p2p network. All the miners on the network compete for the new transaction with the higher fee, meaning it often works much quicker than the miner operated TX Accelerators. Afterburner was very much a defensive response to the miners who have been blocking SegWit activation and broadcasting empty blocks, some of those same miners are the ones who run the TX Accelerators.

BM: Is Bitcoin Afterburner getting much use so far?

SW: Afterburner has a good number of installs, but not many paid ‘Boosts.’ A few days after we released Afterburner the transaction backlog that was driving up fees and confirmation times completely dried up. The fees required for next block confirmation dropped from 300 sat/b to 25 sat/b. Once the mempool gets saturated again, we will have a much better idea of the potential utility of the app.

BM: Why do you think more wallet providers don’t offer this sort of service?

SW: Many wallet providers — inexplicably the most well-funded ones are the most guilty — haven’t invested any time into proper fee estimation and management until very recently. A misguided industry-driven quest to make the bitcoin wallet for “grandma” resulted in an unusable bitcoin wallet for actual users. Samourai has focused from inception on actual bitcoin users first.

BM: Do you think this sort of fee bumping will eventually be free? Does Samourai Wallet offer fee bumping like this natively or do they need to use this separate app?

SW: Samourai Wallet provides the exact same functionality as Afterburner natively. Afterburner was designed to allow users of any other BIP 44 HD wallet to boost their stuck transaction using CPFP (Child-Pays-for-Parent) under the hood. Hopefully they move over to Samourai Wallet if they are satisfied with the service. In addition to CPFP-based boosting more advanced users may opt-in to RBF-based boosting which is also available in the wallet. Both options are available to Samourai Wallet users free of charge.