Non-Fungible Tokens (NFT)
A non-fungible token (NFT) is a token on the Blockchain to represent unique items such as art and collectibles. Each NFT is unique and has different properties that distinguishes it from other NFTs. Unlike cryptocurrencies such as Bitcoin, NFTs are not interchangeable and are indivisible. And NFT is traded as a whole and fractional exchanges such as in other cryptocurrencies are not allowed.
XRP Ledger (XRP)
The XRP Ledger (XRPL) is a decentralized, public blockchain led by a global community of developers.
It’s fast, energy efficient, and reliable. With ease of development, low transaction costs, and a knowledgeable community, it provides developers with a strong open-source foundation for executing on the most demanding projects—without hurting the environment.
XRPL uses a consensus protocol, in which designated servers called validators come to an agreement on the order and outcome of XRP transactions every 3-5 seconds.
All servers in the network process each transaction according to the same rules, and any transaction that follows the protocol is confirmed right away. All transactions are public, with strong cryptography to guarantee the integrity of the system.
Anyone can operate a validator; currently, over 150 validators are active on the ledger, operated by universities, exchanges, businesses, and individuals. Additionally, the consensus protocol ensures the blockchain becomes more decentralized over time as the validator pool grows.
XRP Ledger Issued Tokens
The XRP Ledger Blockchain provides a way for any currencies to be issued on the network using IOUs. This feature allows users to issue tokens that can be exchanged on the network through transfers or the built-in Decentralized Exchange on the XRPL.
While the token issuance on the XRP Ledger works really well for issued crypto currencies such as SOLO out of the box, it needs to be tweaked to be used for indivisible assets such as NFTs.
The XRP Ledger has an issued token precision of 15 significant figures. The smallest amount of an issued token the XRPL can handle is 1000000000000000e-96. That means for a token to be indivisible, the issuer must only create 1000000000000000e-96 of the token to represent an NFT.
XLS-14d
Full details: https://github.com/XRPLF/XRPL-Standards/discussions/30
The XLS-14d proposal originally by Wietse Wind from the XRP Ledger developer community introduced a set of standards to be followed for NFTs issuances.
This proposal has been welcomed by the community as a way to issue NFTs on the XRP Ledger, but since the underlying technology is not built for NFT use-cases, it lacks some features and makes the overall minting a complicated process.
XLS-14d/SOLO variation
The SOLO variation of the XLS-14d follows many aspects of the original XLS-14d but tearts an XRP address as a “collection” that can hold many NFTs within it.
This allows users to mint a collection of NFTs using only 1 account, thus reducing multiple account activation fees.
Sologenic NFT Marketplace is made up of 2 components. A Backend component that is responsible for minting NFTs on user’s behalf, indexing data directly from the ledger and the Frontend, which is connected to the ledger and the API data provided by the backend. Together these components make up the minting, searching and trading of NFTs.
Minting Process:
Each NFT must be minted inside a collection, a collection is an issuer that mints only 1 of each asset type, but can hold multiple NFTs.
Minting is done through the NFT workshop section on the Sologenic.org platform.
Each collection has a unique ID, which is the XRPL address of the issuer. E.g. rwTw6Bm5AXce4PgDnY7HcdAqkSj6DgUXjq
This address has the following metadata:
{
"address":"Address of the issuer",
"minted_by":"Address of the user who minted the nft",
"colllection_uid":"A unique ID representing this collection within Sologeinc",
"colllection_name":"Name of the collection",
"description":"Description of the collection",
"collection_item_count": Total count of items (NFTs) in this collection - Integer,
"nfts":[
{
"currency":"NFT currency code",
"metadata":"ipfs://cid/metadata.json",
"content_type":"NFT content type"
}
],
"minter":"The system that minted the NFT",
"created":"ISO 8601 timestamp"
}
Sample collection metadata:
{
"address":"r9HMSHstaQwzEEEuVi8jK4npsXXr7mzuRK",
"minted_by":"ryxnAR3uaBTuVjuz899JLCFHgoYJSk1Yr",
"colllection_uid":"ff0c22c2-434a-45a1-b1b3-b61303d34a38",
"colllection_name":"Animal",
"collection_item_count":3,
"nfts":[
{
"currency":"023031516D5073334E4654000000000000000000",
"metadata":"ipfs://bafybeiawutbfxa6sdaax66alcwcbz2oqvc3axngzyyjk277tjsyayrrfa4/metadata.json",
"content_type":"image/jpeg"
},
{
"currency":"023031516D5363634E4654000000000000000000",
"metadata":"ipfs://bafybeib7qwxoepqad7xwraxk2y2xf6r3gb4xx6ntwees2flav4ty5r5pia/metadata.json",
"content_type":"image/jpeg"
},
{
"currency":"023031516D6637374E4654000000000000000000",
"metadata":"ipfs://bafybeihzd5dwjgsal22lauvebegyxng7umgcasw4mokbdcruepgy6pjxdm/metadata.json",
"content_type":"video/mp4"
}
],
"description":"This is my second collection",
"minter":"https://sologenic.org",
"created":"2021-12-06 16:41:43.000"
}
Each minted NFT has a unique currency code with the following format:
"023031" + HEX(ipfs.cid.substring(0, 5) + "NFT") + "000000000000000000"
Each NFT has the following metadata that is uploaded to IPFS:
{
"address": "Address of the issuer",
"minted_by": "Minted by this address",
"name": "The name of NFT",
"category": "category name",
"md5hash": "Unique content MD5 hash",
"content_type": "Content type MIME",
"file_extension": "File extension of NFT",
"description": "Description of the NFT",
"external_link": "External link provided for this NFT",
"properties": {
"property": "value"
},
"stats": {
"property": [
min,
max
]
},
"is_explicit": "true/false",
"standard": "XLS-14d/SOLO",
"blockchain": "XRPL",
"minter": "https://sologenic.org",
"created": "ISO 8601 timestamp"
}
Once a collection is minted, the transfers NFT IOUs to the minter and blackholes the issuer address.
The following transactions are conducted on the issuer accounts:
1st TX:
{
TransactionType: "AccountSet",
Account: ISSUER_ADDRESS,
Fee: FEE,
SetFlag: 8,
Domain: toHex(
"ipfs://" + CID.parse(cid).toV1().toString() + "/metadata.json"
),
}
2nd TX:
(This TX happens for all NFTs in the collection)
{
TransactionType: "Payment",
Account: ISSUER_ADDRESS,
Destination: MINTER,
Fee: FEE,
DestinationTag: 0,
Memos: [
{
Memo: {
JWT(ES256).sign(
{
metadata: CID.parse(nft.cid).toV1().toString() + "/metadata.json",
issuer: NFT_ISSUER,
minter: NFT_MINTER,
}
},
],
Amount: {
currency: NFT_CURRENCY,
issuer: ISSUER_ADDRESS,
value: 1000000000000000e-96,
},
SendMax: {
currency: NFT_CURRENCY,,
issuer: ISSUER_ADDRESS,
value: 1000000000000000e-96,
},
}
}
3rd TX:
{
TransactionType: "SetRegularKey",
Account: ISSUER_ADDRESS,
Fee: FEE,
RegularKey: "rrrrrrrrrrrrrrrrrrrrBZbvji",
}
4th TX:
{
TransactionType: "AccountSet",
Fee: FEE,
Account: ISSUER_ADDRESS,
SetFlag: 4,
}
XLS-20d
Full details: https://github.com/XRPLF/XRPL-Standards/discussions/46
Migration From XLS-14d/SOLO to XLS-20d
Upon release of the XLS-20d, Sologenic will allow minters to transfer their collections to the new standard. A document detailing migration of the XLS-14d/SOLO to XLS-20d will be released as a separate document.