Thirty-two bitcoin developers and contributors signed an “Open Letter to the Bitcoin Community” urging bitcoiners to solve the scalability question together finding a compromise.

The letter, published on, is signed by such bitcoin core developers as Wladimir van der Laan, Cory Fields, Luke Dashjr, Jonas Schnelli, Greg Maxwell and by people who created various bitcoin applications and platforms (Blockstream, Darkwallet, Libbitcoin, Tidbit etc.). The signatories state they’ve played an important role in bringing bitcoin where it is now:

“We’re committed to Bitcoin and responsive to the needs of the community. For the past five years, we’ve written code and managed over 50 Bitcoin releases and reviewed more than 45 formal proposals to improve Bitcoin’s performance, security, and scalability. Technical discussions, while heated at times, are always focused on improving Bitcoin.”

While many good things have been already done, “a number of key challenges still remain”, according to the authors. However, it is most important to be careful, as bitcoin “is many things to many people” and billions of dollars of users’ assets are at the stake. Moreover, it is important to scale the bitcoin without damaging its “core features of decentralization, security, and permissionless innovation”. Insisting that they “have worked on bitcoin scaling for years”, the authors imply that no one is in better position than themselves to judge what should be done.

However, they state their wish to look for the solutions together with the other members of bitcoin community. To achieve a “technical consensus” in the block size debate, the authors propose to hold two scaling bitcoin workshops, the first in Montreal on 12-13 September, and the second in Hong Kong, on 6-7 December. They express their confidence that “by working together we can agree on the best course of action”.

The letter, endorsed by many bitcoin core developers, is signed neither by Gavin Andresen nor by Mike Hearn. The two best-known developers believe they had already found the solution to the problem, known as BIP101. They proposed  to increase the maximum block size in the blockchain  from the current 1MB to 8MB in the beginning of 2016, with further doubling every two years, reaching 16 MB in 2018 and 32MB in 2020 and so on.

As many bitcoiners expressed their doubts, Mike Hearn decided to implement BIP101-based Bitcoin XT, forking the bitcoin and forcing the miners to choose between Bitcoin Core and Bitcoin XT. However, this move did not gain popularity with the bitcoin community. Despite the support given to BIP101 and Gavin Andresen in an open letter signed by the representatives of BitPay,, Circle, KnCMiner, Xapo, Bitnet, ItBit and BitGo, a majority of bitcoin mining pools expressed their support for the alternative proposal – Jeff Garzik’s BIP100, implying that the block size limit would change every three months based on the decision of bitcoin miners. Even KnCMiner, despite its previous promise to support BIP101, decided to back BIP100. 


 Alexey Tereshchenko