Exploring the Programmability Expansion Solutions of the BTC Ecosystem

Since the beginning of this year, the speculative enthusiasm in the Bitcoin ecosystem has somewhat declined, but the progress on the technical front has been very rapid, especially in enhancing programmability. This article will introduce several highly anticipated BTC scaling solutions, including Fractal, AVM, OP_NET, BRC100, and programmable runes.

Fractal: Recursive Bitcoin Expansion Framework

Fractal is a scalable framework based on the Bitcoin core client virtualization, which enhances overall network performance by recursively creating tree structures. It is fully compatible with Bitcoin but activates the OP_CAT operator for more logic.

Fractal is developed by the Unisat team and is expected to launch its mainnet in September this year. In its tokenomics design, 50% is generated from mining, 15% is allocated to the ecosystem, 5% is for early investor pre-sales, 20% is for advisors and core contributors, and 10% is designated as community subsidies.

In terms of architecture, Fractal encapsulates the Bitcoin Core client into a deployable blockchain software package (BCSP), running multiple BCSP instances on the Bitcoin mainnet through recursive anchoring. It makes some modifications to the Bitcoin Core, such as shortening the block confirmation time to 30 seconds and increasing the block size to 20MB.

Fractal has activated the OP_CAT operator, providing more possibilities for scalability solutions on BTC. Different instance chains can communicate, allowing for seamless asset transfers. Bitcoin and assets like BRC-20 and Ordinals can enter the Fractal network through decentralized bridging.

The security of Fractal mainly relies on its hash power scale. It introduces a joint mining mechanism, where one out of every three blocks is generated through merged mining with BTC miners to prevent a 51% attack.

AVM: Simulating Smart Contracts on Bitcoin

AVM( Atomicals Virtual Machine ) is the Bitcoin smart contract implementation of the Atomicals protocol. It creates a virtual machine that simulates BTC scripts and opens multiple raw BTC opcodes, allowing developers to implement smart contracts through combinations of Bitcoin scripts.

AVM maximizes the capabilities of BTC's original opcodes and achieves Turing completeness through a dual-stack PDA. It operates in a sandbox that includes an indexer, instruction parser, and global state to handle smart contracts and synchronously verify state.

The instruction set of AVM includes the complete BTC opcodes, allowing developers to program using the unused features of BTC. It is an architecture that can be applied to various metadata protocols such as BRC20, ARC20, Runes, CBRC, and more.

OP_NET: Introducing Ethereum-style Smart Contracts on Bitcoin

OP_NET aims to introduce Ethereum-like smart contract functionality to the Bitcoin network, but more in line with the characteristics of Bitcoin. It provides a complete development library written in AssemblyScript, simplifying the creation and operation of Bitcoin-related technologies.

OP_NET retains the block consensus and data availability of Bitcoin, executing complex calculations on Bitcoin blocks through the virtual machine (OP_VM). It supports multiple programming languages and utilizes Tapscript to enable advanced smart contract functionalities.

When interacting on the OP_NET network, users need to pay an additional fee of at least 330 Satoshis. OP_NET provides a Proof of Authority system that allows BTC to be wrapped as WBTC to expand DeFi applications.

The ecological projects of OP_NET cover multiple areas such as decentralized trading, lending, market making, liquidity provision, and cross-chain bridges, including Motoswap, Stash, Ordinal Novus, Ichigai, and more.

BRC100: Decentralized Computing Protocol Based on Ordinals

BRC-100 is a decentralized computing protocol built on the Ordinals theory, which adds new operations such as "burn" and "mint" to brc20, enabling complex DeFi functionalities. It provides operations like mint2/mint3 and burn2/burn3, allowing tokens to be converted between the UTXO model and the state machine model.

The BRC-100 protocol and its extension protocols are collectively referred to as the BRC-100 protocol stack, with all extension protocols being mutually compatible. Currently, there are the BRC-101( decentralized on-chain governance protocol), the BRC-102( automated liquidity protocol), and the BRC-104( liquidity staking/re-staking pool protocol).

The main projects in the BRC-100 ecosystem include inBRC(, the first BRC-100 marketplace and indexer ), 100Swap(, an AMM DEX) based on the BRC-102 protocol, and 100Layer(, a liquidity protocol on Bitcoin L1 ).

Programmability Runes ( Protorunes ): The Expansive Layer of Runes

Programmable runes are an extension layer of runes that allow the creation of programmable assets with runes. The main project is the Proto-Runes Protocol, which provides a framework for programmable runes and supports the management and transfer of rune assets between sub-protocols.

The key mechanism of Proto-Runes is Protoburn, which allows runes to be destroyed and converted into a form used by sub-protocols. Protomessage is the operational instruction executed within the sub-protocol, encoded through the Protostone structure and parsed by the indexer.

Currently, the first Protorune(QUORUM•GENESIS•PROTORUNE) has successfully completed the Protoburn. The development team is working on a WASM indexer for this genesis protorune, aimed at achieving on-chain governance functionality on Bitcoin L1.