# Supported Asset Types

The Sun Protocol supports almost all mainstream asset types in the current web3 ecosystem.

Bitcoin Ecosystem Asset Types:

**Lightning Network Assets**

The Lightning Network is a second-layer scaling solution for the Bitcoin network, designed to address scalability and transaction speed issues. It is a smart contract-based payment protocol that allows participants to conduct fast, low-cost micropayments without the need to record every transaction on the Bitcoin blockchain.

In the Lightning Network, participants can open a multisignature payment channel, allowing them to make almost instant payments within the channel and avoiding the need to transact each payment on the Bitcoin main chain. Settlement with the Bitcoin main chain only occurs when channels are opened and closed. This greatly enhances the processing capacity of the Bitcoin network, reduces transaction fees, and speeds up transaction confirmation times.

The Lightning Network operates similarly to a network of relay stations, where payments are passed from one node to another through multiple payment channels, forming a payment network that covers the entire network. This design allows participants to make payments across nodes and channels, achieving a high level of interoperability. Its core features include:

* Issuance of stablecoins: Providing users with stablecoins in the borderless financial world using Bitcoin's own value, such as creating a new stablecoin like taUSD and being able to use a single Bitcoin transaction to transfer BTC and taUSD into the Lightning Network channel for DeFi operations.
* Multi-Universes Mode: Universes are repositories that store all the information required for Taproot Asset wallet initialization and synchronization of specific Taproot Asset states.
* Asset issuance and redemption API: Making it as easy for users to trade various assets on Bitcoin as investing in stocks and bonds in the real world, mapping to the issuance of real-world assets.
* Asynchronous receipt feature: Providing developers with tools to add Uniform Resource Identifiers (URIs) to on-chain addresses.
* Scalability: Introducing the new build-loadtest command to allow developers to stress-test the software.

**RGB**

RGB is a standard developed by the LNP/BP Association (Lightning Network Protocol / Bitcoin Protocol), a non-profit organization overseeing development across various layers of Bitcoin. It covers the Bitcoin protocol, Lightning Network protocol, and RGB smart contracts. The RGB protocol is designed for scalable and privacy-preserving Bitcoin and Lightning Network smart contract systems. Its purpose is to run complex smart contracts on UTXO to introduce them into the Bitcoin ecosystem. The official description states: "A scalable and confidential smart contract protocol suite for Bitcoin and Lightning Network, used for asset issuance, transfer, and broader rights."

**Ordinals Protocol (BRC-20)**

In January 2023, Bitcoin developer Casey Rodarmor released the Ordinals Protocol, which is an asset issuance protocol based on Bitcoin. It consists of two core components: Ordinals ordinal theory and Inscription engraving. Casey, the author of the Ordinals protocol, associates content with unspent transaction outputs (UTXOs) through engraving, assigning unique identifiers to Satoshis, the smallest unit of Bitcoin—21 million trillion Satoshis. The asset issuance process of the Ordinals protocol is akin to writing information into witness data and recording token information in JSON format using the BRC-20 form.

**BRC-20 Tokens**

BRC-20 is an experimental token standard created by Domo in March 2023, leveraging JSON data from Ordinal Inscriptions. Through the BRC-20 standard, users can easily implement key functions such as Token contract deployment, Token minting, and Token transfer. As of December 18, 2023, statistics show that the total market value of the BRC-20 track has reached $640 million, highlighting the importance of this token standard in the Bitcoin ecosystem and opening up new possibilities for the development of digital assets.

**BRC-100**

BRC-100 is a Bitcoin DeFi protocol built on Ordinals. Apart from its token attributes, BRC-100 also serves as an application protocol, allowing developers to design DeFi and other application-based products based on the BRC-100 protocol. According to developer MikaelBTC, BRC-100 introduces protocol inheritance, application nesting, state machine models, and decentralized governance, bringing computational capabilities to the Bitcoin blockchain and making it possible to build Bitcoin-native decentralized applications such as AMM DEX and lending.

**Ordinals NFT**

Software engineer Casey Rodarmor has launched the Ordinals NFT protocol on the Bitcoin blockchain, which has been officially launched. Now, users can create and own their NFTs on the smallest unit of Bitcoin, Satoshi (Sat), using a random but logically consistent sorting system, making each sat unique. Ordinals NFT differs from Ethereum NFT mainly in three aspects:

* All related data is stored on the Bitcoin network, without relying on external storage such as IPFS, AWS S3, etc.
* Permissionless: Transactions can be completed in a decentralized manner via PSBT without requiring "authorization."
* The cost of minting is proportional to the transaction volume.

**BRC-420**

According to the introduction in the RCSV official Gitbook, BRC-420 focuses on modularizing on-chain inscriptions, including two key parts: the Metaverse Standard and the Royalties Standard, defining open and flexible formats for assets in the metaverse and setting specific on-chain protocols for creator economies. Unlike other Ordinals protocols that are single-inscription, BRC-420 protocol adopts multi-inscription recursive composition.

**Atomicals Protocol (ARC-20)**

The Atomicals Protocol, also known as the Atomic Protocol, encompasses various asset types, including the fungible token ARC20 standard, NFTs, Realms, and Collection Containers. As a blockchain asset issuance protocol based on the UTXO type, Atomicals offers two minting methods: decentralized minting and direct minting. Decentralized minting introduces Bitwork Mining, a minting method based on the Proof of Work (PoW) mechanism. The protocol considers Satoshi, the smallest unit of Bitcoin, as the minimum unit for issuing assets, with the current minimum divisible unit of ATOM being 546, which can be sold or transferred.

Unlike Ordinals in asset transaction ordering, the Atomicals Protocol does not rely on third-party sorters and can be used to create (mint), transfer, and upgrade various digital items, including native NFTs, games, digital identities, domains, and social networks. Additionally, the protocol supports the creation of interchangeable tokens, named ATOM (distinct from Cosmos' ATOM, solely sharing the name).

Recently, founder Arthur shared his views on Meta-Protocols in an interview on December 13th. He sees Meta-Protocols as a new approach that allows developers to create their own data structures and rules without being confined to existing rigid structures. Protocols representing Meta-Protocols, such as the Atomicals Protocol, are emerging, providing developers with opportunities to create entirely new structures using smart contracts. This trend enables creators to focus more on the Atomicals Virtual Machine (AVM). The introduction of this virtual machine allows developers to build smart contract programs on the Bitcoin network, providing them with unprecedented ways to create experiences. This means creators can focus more on realizing smart contracts in the Bitcoin ecosystem, driving the process of digital innovation.

**Atomicals Asset Types:**

* ARC20: Similar to the BRC20 token format standard on Ordinals.
* Realm: A new concept proposed by Atomicals, aiming to disrupt traditional domains and be used as a prefix.
* Collection Containers:A data type for defining NFT Collections, primarily used for storing readable NFTs and related metadata. As of December 20th, data shows that TOOTHY, currently leading in market value, has a total market value of 46.12 BTC, with a 7-day trading volume of 25.74 BTC.

**ARC-20 AVM**

On December 13th, Atomicals founder Arthur stated in an interview that Meta-Protocols are a new method for developers to create their own data structures and rules, unrestricted by existing strict structures. Meta-Protocols such as the Atomicals Protocol continue to emerge, enabling developers to create entirely new structures using smart contracts. This allows creators to focus on the Atomicals Virtual Machine (AVM), which allows developers to build smart contract programs on the Bitcoin network.

**Runes Protocol**

The Runes protocol, proposed by Casey Rodarmor, the creator of the Ordinals protocol, aims to address the efficiency issues present in BRC-20. Unlike the complexity of certain protocols, Runes is designed to be simple and elegant. By using OP\_RETURN in transactions, Runes ensures that tokens are allocated to specific UTXOs, with output indices, token quantities, and token IDs.

The Runes protocol is a fungible token protocol based on the Bitcoin UTXO model, managing and transferring tokens through simple tuples (ID, OUTPUT, AMOUNT) and OP\_RETURN operations. Its main feature is its simplicity, supporting partial operations without the need for additional off-chain data or native tokens, optimizing on-chain data usage.

The inception of the Runes protocol stemmed from Casey's dissatisfaction with the use of the Ordinals protocol to create a large number of UTXOs for BRC20. Hence, he proposed a fungible token protocol based on the Bitcoin UTXO model. Currently, the Runes Protocol remains a concept by Casey and does not yet have complete client and development tools, although it is subject to controversy in certain areas.

**PIPE Protocol**

The PIPE protocol is an asset issuance protocol developed by developer Benny, inspired by Casey's design of the Runes protocol and Domo's proposal of the Ordinals-based BRC-20 standard. The PIPE protocol ingeniously integrates the characteristics of the Runes protocol and these two protocol standards, introducing three protocols in the BTC ecosystem: Trac Core, Tap, and Pipe (referred to as TTP, collectively known as Trac Systems).

The main functionalities of the PIPE protocol include Deployment (Deploy), Minting (Mint), and Transfer (Transfer), abbreviated as DMT. These functionalities enable PIPE protocol assets to be easily created, distributed, and transferred within the Bitcoin network. In addition to supporting fungible tokens, the PIPE protocol also provides a complete structure and standard for non-fungible tokens.

* Trac Core: A prophetic machine and decentralized indexer for Bitcoin inscriptions.
* Tap: An extension of the Ordinals protocol rather than a fork, hence seamlessly compatible with BRC20.
* Pipe: A new protocol forked from Ordinals, but actual processes require liquidity recasting.
* Trac Token: Deployed on the Ordinals-BRC20 protocol, later serving as the governance token for the Tap protocol.
* TAP Token: Deployed on the Ordinals-Tap protocol.

**Stamps (SRC-20)**

On December 6th, Bitcoin core developer Luke Dashjr revealed on social media that Inscriptions were exploiting a vulnerability in the Bitcoin Core client to send spam messages to the blockchain. This vulnerability allowed users to set additional data size limits when forwarding or mining transactions, and Inscriptions bypassed this limit by disguising their data as program code. Dashjr stated that this vulnerability would be fixed in the upcoming v27 release. However, he later clarified in response to questions about Ordinals that Inscriptions itself did not exist and was a hoax.

This statement cast a shadow over the Ordinals ecosystem, leading to drastic fluctuations in BRC-20 token prices, with ORDI prices plummeting by over 25% in a single day. Critics of Dashjr argued that the Bitcoin network belongs to the community, and developers have no right to determine the fate of the Ordinals protocol based on personal preferences. Even if Dashjr completes the update to the Bitcoin program, if miners do not adopt the updated program, the entire Bitcoin network will be unable to upgrade.

While the controversy surrounding Inscriptions has yet to be resolved, it has prompted reflection on Ordinals and the essence of blockchain, while also drawing attention to another token standard, SRC-20, and the Bitcoin Stamps protocol. The Ordinals protocol is a derivative protocol that uses Bitcoin UTXOs as a data storage medium, storing arbitrary data through Bitcoin's OP\_RETURN function. This protocol results in larger Bitcoin blocks, centralization risks, and increased network operating costs. On the other hand, the Bitcoin Stamps protocol, created by Mike In Space, is based on the Counterparty (XCP) protocol and is the first NFT token protocol standard on the Bitcoin blockchain. Stamps encode image data as Base64 strings, stored in Bitcoin UTXOs. Compared to Ordinals, Stamps prioritize data reliability and the inability to be permanently removed from the Bitcoin public ledger.

This controversy has spurred reflection on Ordinals and the essence of blockchain, while also prompting attention to the SRC-20 standard and the Bitcoin Stamps protocol. SRC-20, similar to BRC-20, avoids the controversies associated with Ordinals. Bitcoin Stamps directly write image data into Bitcoin UTXOs, emphasizing data reliability and immutability.

In addition to the mentioned Bitcoin and Bitcoin ecosystem asset types, Sun Protocol also supports other public chain asset types:

EVM class: Ethereum/BNB Chain/opBNB/Arbitrum/Optimism/Avalanche/Polygon/Blast/Linea/StarkNet

Substrate class: Polkadot/Moonbeam/MantaNetwork

Cosmos modules: Cosmos/SeiNetwork

Solana ecosystem

Move blockchain: Aptos/Sui
