Recap: Bitcoin SV DevCon 2021 – Day 2

Alex Speirs 512 x 320
By Jamie McKane Published: May 20, 2021
Bitcoin SV Devcon Day 2 poster

The second day of Bitcoin SV DevCon 2021 kicked off on Sunday, May 16, bringing more in-depth discussions about Bitcoin development and the exciting new applications being built on Bitcoin SV.

If you missed the first day of sessions, you can still watch the full event here or read through our Day 1 recap.

Bitcoin SV DevCon 2021 was hosted by Bitcoin Association in partnership with WeAreDevelopers and nChain. The event focused on development on the Bitcoin SV blockchain, which is the blockchain most closely aligned with the original vision of Bitcoin as outlined in Satoshi Nakamoto’s 2008 white paper. Bitcoin SV offers unbounded scaling, ultra-fast and cheap transactions, support for a fully-featured scripting language and smart contracts, as well as a stable and secure protocol – making it the best choice for blockchain developers around the world.

The event took place on May 15-16, and both days were packed with comprehensive and interactive sessions.


Welcome – Steve Shadders

The second day of Bitcoin SV DevCon 2021 opened with a welcome by nChain CTO Steve Shadders.

Shadders gave attendees an idea of what to expect from the second day, which sported an exciting and diverse line-up of speakers and industry experts.

He noted that each presentation would be followed by a Q&A session, during which those viewing from home could send written questions for the presenter to answer.

Sunday’s line-up offered in-depth discussions around nano-payments, interoperability between mainstream software and blockchain applications, as well as building and deploying Bitcoin smart contracts.

It was also revealed that a major announcement would be made at the end of the day and developers were encouraged to stick around for some exciting news.


Nano-services and dust return transactions – Matej Trampuš and Steve Shadders

The first session of the day saw CREA co-founder and CTO Matej Trampuš share the stage with Shadders to discuss nano-services on Bitcoin SV, dust return transactions and long chains of dependent transactions.

These functionalities have been enabled thanks to developments by the Bitcoin SV Infrastructure Team, and Shadders and Trampuš unpacked the potential of these changes and what they mean for Bitcoin developers.

Shadders explained the concept of a ‘dusting attack’, which aims to compromise the privacy of Bitcoin users that reuse addresses, and how this is mitigated by dust return transactions.

‘A dusting attack is a mechanism of basically breaking the privacy of Bitcoin users. The current mitigation for this is not one that has been adopted by all wallets and it is to identify dust and never spend it.’

‘We’ve come up with a new way to address this problem, and it is a special type of transaction called a dust return transaction. It basically allows you to send the dust out of your wallet and to a miner,’ he said.

Another new type of transaction the team has created is the consolidation transaction, which enables nano-services – small online services that allow developers to reuse already available code with minimal fees.

Trampuš spoke about the removal of Bitcoin SV’s 25 ancestor limit and the development of double-spend notifications through mAPI, demonstrating how these can deliver performance and usability improvements for merchants and consumers.

Shadders and Trampuš analysed a range of different use cases for these specialised transaction types, including covering the mechanics of how each of these transaction types are assessed, accepted and propagated.


HandCash Connect SDK – Rafa Jimenez

Next up, HandCash co-founder and CTO Rafa Jimenez spoke about his company’s latest product built for Bitcoin SV – the HandCash Connect SDK.

HandCash and the HandCash Connect SDK are built on Bitcoin SV and allow application and web developers to easily integrate digital asset payments into their applications and platforms without in-depth knowledge of blockchain transactions and interfaces.

‘HandCash is an ecosystem of different apps and games where users have a single identity with a single account balance that can connect to all of these applications,’ Jimenez said.

‘That is possible because, among other things, we have a universal money called Duro, which is equal to 500 satoshis.’

Thanks to the ability of Bitcoin SV to support ultra-small payments due to its low transactions fees, the HandCash Connect SDK is also able to provide businesses with an accessible and efficient system to facilitate nano-payments.

Jimenez explained that this support for nano-payments unlocks exciting opportunities for HandCash and the development industry, as previously unsustainable nano-payment business models that were limited by traditional payment mechanisms are now able to cost-effectively deploy their solutions.

He demonstrated to viewers how they could quickly and effectively integrate nano-payments into their apps and games, as well as a host of other blockchain functions – including encrypted data and messages.

Jimenez also explained a use case of the HandCash Connect with Twetch through the use of a Duro faucet chatbot.

‘The idea is that on Twetch chat, every time somebody sends a message to the HandCash handle, they will be given 5 Duros.’

He then went on to demonstrate how to implement this Duro faucet on Twetch chat, showing how easy the HandCash Connect SDK makes it easy to link applications and services to the blockchain.


Bitcoin smart contracts – Xiaohui Liu

sCrypt CEO Xiaohui Liu took the stage next to speak about the finer details of Bitcoin smart contracts and the use of the OP_PUSH_TX opcode in Bitcoin Script.

Liu explained that this opcode is a critical feature for building complex smart contracts on the Bitcoin SV blockchain. This is because it allows smart contracts to inspect the context of each transaction that contains it, creating the foundation for the building of a wide range of previously impossible smart contracts.

He demonstrated the potential of the OP_PUSH_TX opcode in a live demonstration which looked at blockchain-based video games that run fully on-chain.

‘State can be propagated and maintained through the OP_PUSH_TX technique,’ Liu said.

He added that this functionality was demonstrable proof that Bitcoin was Turing-complete and could enable a variety of high-level applications, including on-chain peer-to-peer multiplayer video games.

This means that game logic and rules can be enforced by miners and act as an entirely decentralised part of the gaming experience.

Liu showed off live implementations of blockchain-based video games as an example of the power of this opcode, adding that leveraging blockchain in this manner could remove the ability to cheat or otherwise contravene game rules.


ElectrumSV SDK – Hayden Donnelly

The next session focussed on an SDK from Bitcoin SV wallet provider ElectrumSV, which allows users to interact with a regtest blockchain and try out their applications before deploying them to the mainnet.

ElectrumSV software engineer Hayden Donnelly explained how developers can test applications in a regtest environment and how this allows for the development of safer and more efficient SPV applications.

He said that while public testnet networks are easy to use and remove the need to manage your own third-party service, regtest environments provide a lot more control and completely remove network latency effects.

‘Regtest removes network latency from the equation entirely – which can be either good or bad depending on what you’re doing,’ he explained.

If you want to test core application logic without falling prey to connectivity problems and other potential pitfalls of deploying on a live network, the regtest environment is the ideal choice, he added.

Donnelly provided a comprehensive outline of both the Electrum SDK and Bitcoin application testing, including how to create a regtest blockchain session and test applications within it.

He also gave an overview of the Electrum SDK’s main features and functionalities and showed how these work using case study examples.


FYX Gaming SDK – David Case

FYX Gaming CTO and Chief Architect David Case took the stage next to speak about his company’s new SDK for merging traditional games with blockchain technology and building NFTs on Bitcoin SV.

FYX Gaming is the company behind CryptoFights – an online multiplayer game where every move made by players is stored on the Bitcoin SV blockchain. CryptoFights characters and items are stored as non-fungible tokens (NFTs) on the Bitcoin SV blockchain and are owned and controlled directly by the players.

Case began with a demo of CryptoFights in its current implementation and then moved on to detailing the technology behind the platform and how this ties in with the FYX Gaming SDK.

He explained that the FYX Gaming SDK enables this type of functionality and much more, providing everything from the ability to integrate game items with the Bitcoin SV blockchain to a tool for building NFTs that are compatible with other platforms using the FYX SDK.

‘We built much of our platform on RUN on Bitcoin, which is one of the most accessible environments for Bitcoin developers,’ Case said.

‘RUN allows you to create jigs, which are interactive ownable objects. The interactivity is stored within JavaScript on-chain, but at the core layer, ownership is defined on Bitcoin Script enforced by miners.’

This allows non-fungible tokens to be customised, shared and implemented in various application while remaining interoperable, opening up unique opportunities for inter-game interaction and item marketplaces.

‘In order to build up CryptoFights we have had to build up significant infrastructure to support what we are doing, and much of that we are going to be opening up to developers in the coming months,’ Case said.

‘This starts with our portal, which includes a jig wallet, the ability to mint and melt NFTs, as well as our marketplace; a crypto-to-BSV on-ramp with fiat coming soon; the ability for games to make leaderboards and custom data explorers for different games.’

This wide range of diverse features make the accessible FYX Gaming SDK a great choice for developers interested in creating blockchain-based video games.


Closing remarks and Hackathon announcement – Steve Shadders

After Case’s presentation, Steve Shadders took the stage again to close off Bitcoin SV DevCon 2021, as well as to make an exciting announcement.

‘Thank you for being with us for these last couple of days, and I really hope you’ve taken something valuable away from it,’ Shadders said.

‘I just want to remind you of a few things that are going on. Firstly, the Bitcoin SV Academy has launched the Bitcoin Essentials stream – that is now live. The CoinGeek conference is also coming up in June and will be held in Zurich – I’ll be there presenting and one of my colleagues from the Technical Standards Committee (TSC) will also be there, and we’ll be talking about how you can get involved with that.’

He also announced that the fourth Bitcoin SV Hackathon would take place from June 14 to July 26, 2021, giving developers the opportunity to experiment with Bitcoin development and win their share of a $100,000 prize pool paid out in BSV.

‘Finalists for that hackathon will be announced on August 24 and the winners will be announced at the next CoinGeek conference,’ he said.

‘It is a unique opportunity to build something on Bitcoin SV. You will have access to support from BSV specialists, including a team from nChain, and you can get more details at’

If you want to dive deeper into the sessions described above, check out the full livestream of Bitcoin SV DevCon 2021 Day 2: