BTC Ecosystem Technology Progress: Overview of Programmability Expansion Solutions

Since the beginning of 2024, although the speculative enthusiasm in the BTC ecosystem has weakened, the development on the technical level has been very rapid, especially in the area of programmability expansion solutions. This article will introduce several notable BTC expansion solutions, including Fractal, AVM, OP_NET, BRC100, and programmable runes.

Fractal

Fractal is a scalable framework based on the virtualization of the Bitcoin Core client software. It recursively creates a tree structure, where each layer of the blockchain can enhance the performance of the entire network. Fractal is fully compatible with Bitcoin and its infrastructure, but activates the op_cat operator, allowing for more logic to be implemented.

The architecture design of Fractal encapsulates the bitcoin core client into a deployable and runnable Blockchain Software Package (BCSP), recursively anchoring it on the Bitcoin mainnet. It makes some modifications to the bitcoin core, such as shortening block confirmation times and increasing block sizes, to provide better performance and user experience.

In the field of cross-chain assets, Fractal achieves seamless asset transfer between different layers by constructing a universal asset transfer interface. Bitcoin and other assets can be transferred through decentralized bridging.

The security of Fractal mainly relies on its computational power. It introduces a joint mining mechanism, where some blocks are generated by merging mining with BTC miners to prevent potential 51% attacks.

AVM

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

AVM achieves Turing completeness through a double-stack PDA (Pushdown Automaton). It operates in a sandbox that includes an indexer, instruction parser, and global state, enabling the processing of smart contracts and state synchronization.

The AVM instruction set includes a complete set of BTC opcodes, enabling developers to program using the functionalities of BTC that are not enabled. It is suitable for various metadata protocols such as BRC20, ARC20, Runes, and CBRC, with just minor adjustments to the indexer.

OP_NET

OP_NET aims to introduce Ethereum-like smart contract functionalities to the Bitcoin network, but in a manner that is more aligned with the characteristics and architecture of Bitcoin. It provides a complete, compact, and user-friendly development library, primarily written in AssemblyScript.

OP_NET retains the block consensus and data availability of Bitcoin, executing complex calculations on Bitcoin blocks through a virtual machine (OP_VM). It supports various programming languages, such as AssemblyScript, Rust, and Python.

In the OP_NET network, users need to pay additional transaction fees, and the order of transaction packaging will be sorted based on the fees. To expand the use of BTC in DeFi applications, OP_NET provides a Proof of Authority system that allows BTC to be wrapped as WBTC.

The OP_NET ecosystem covers multiple areas including decentralized trading, lending, market making, liquidity provision, and cross-chain bridges, including several projects such as Motoswap, Stash, and Ordinal Novus.

BRC100

BRC-100 is a decentralized computing protocol built on the Ordinals theory. It implements complex DeFi operations by adding new operations such as "burn" and "mint" to brc20. BRC-100 provides operations like mint2/mint3 and burn2/burn3, allowing tokens to safely transition 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 compatible with each other. Currently, there are extensions such as BRC-101 (Decentralized On-chain Governance Protocol), BRC-102 (Automated Liquidity Protocol), and BRC-104 (Liquidity Staking/Re-staking Pool Protocol).

The BRC-100 ecosystem mainly includes three projects: inBRC, 100Swap, and 100Layer, which provide functions such as market and indexer, AMM inscription decentralized exchange, and liquidity protocols.

Programmable Protorunes

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

The key mechanisms of the Proto-Runes Protocol include Protoburn (converting runes into a form usable by sub-protocols) and Protomessage (executing operation instructions within sub-protocols). It represents protocol fields and messages using LEB128 encoding to save space and improve processing efficiency.

Recently, the first Protorune "QUORUM•GENESIS•PROTORUNE" has successfully completed Protoburn, demonstrating the functional model of on-chain governance on Bitcoin L1. This paves the way for the development of more complex smart contracts and DeFi applications on the Bitcoin network in the future.