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XChain Platform SDK — NFT & Registry Builders

This document covers two pure-builder namespaces exposed on the SDK instance:

  • sdk.nft.* — param builders for the NFT pattern (ISSUE with DECIMALS=0 and LOCK_MAX_SUPPLY=1), collection child ticks, content attachment (LINK params), TIS documents, and the canonical NFT classifier.
  • sdk.project.* — param builders for official-token project rosters (TICK-type LIST + owner-validated LINK).

Neither namespace makes network calls. Submit-flow recipes that wire these builders into live actions live on sdk.workflows (see Workflows).

Protocol specs:

sdk.nft.*

sdk.nft.unique(params) → ISSUE params

Build ISSUE params for a unique 1-of-1 NFT fully minted to the issuer.

const params = sdk.nft.unique({
    tick:        'MYART',         // required
    description: 'action:12345', // optional — TIS data_ref or URL
    transfer:    null,            // optional — transfer issuer ownership after issue
    memo:        null             // optional
});
// Returns: { tick, maxSupply: '1', mintSupply: '1', decimals: '0', lockMaxSupply: '1', ... }

The SDK’s key invariant: DECIMALS=0 and LOCK_MAX_SUPPLY=1. Every unique token’s maximum supply is exactly 1.

sdk.nft.edition(params) → ISSUE params

Build ISSUE params for an edition of N identical, indivisible prints.

// Pre-minted edition — full supply goes to the issuer immediately
const params = sdk.nft.edition({
    tick:   'PRINTS',            // required
    supply: '100',               // required — MAX_SUPPLY (edition size)
    description: null,
    transfer:    null,
    memo:        null
});

// Fair-mint edition — MINT window; zero prints self-minted at issuance
const params = sdk.nft.edition({
    tick:   'PRINTS',
    supply: '100',
    mint: {
        maxMint:    '1',       // MAX_MINT per mint call
        perAddress: '2',       // optional — MINT_ADDRESS_MAX
        startBlock: 850000,    // optional — MINT_START_BLOCK
        stopBlock:  860000     // optional — MINT_STOP_BLOCK
    }
});

When mint is present, LOCK_MAX_SUPPLY validates the declared cap (not minted supply), so the full supply stays publicly mintable.

sdk.nft.collectionItem(params) → ISSUE params

Build ISSUE params for a distinct 1-of-1 collection item. The resulting tick is parent.name. The issuer must own the parent tick (enforced by the indexer; this builder only constructs params).

const params = sdk.nft.collectionItem({
    parent: 'MYCOLLECTION',   // required
    name:   'item001',        // required — child segment only, must not contain '.'
    description: null,
    transfer:    null,
    memo:        null
});
// Equivalent to sdk.nft.unique({ tick: 'MYCOLLECTION.item001', ... })

Build LINK params that officially attach a FILE to a token (the NFT content-attachment pattern). The LINK source must own the token; the indexer validates ownership.

const params = sdk.nft.attachContentParams({
    coin:             'BTC',   // or pass fileCoin/issueCoin separately for cross-chain
    fileActionIndex:  12345,   // ACTION_INDEX of the FILE upload
    issueActionIndex: 99,      // ACTION_INDEX of the token's ISSUE
    memo:             null
});
// Returns: { coin1, coin1ActionIndex, coin2, coin2ActionIndex, memo }

For cross-chain attachments pass fileCoin and issueCoin instead of coin.

sdk.nft.tisDocument(params) → { doc, json }

Build a minimal TIS v1.0.0 document for an NFT-pattern token. The intended workflow is: upload the returned JSON as a FILE action (TYPE application/json), then set the token’s DESCRIPTION to action:<index> of that upload.

const { doc, json } = sdk.nft.tisDocument({
    tick:             'MYART',              // required
    name:             'My Art Token',       // optional — display name
    description:      'A 1-of-1 collectible', // optional — prose description
    imageActionIndex: 12345,                // optional — on-chain artwork FILE
    imageCoin:        null,                 // optional — base coin ticker when artwork
                                            //   is on a sibling chain (e.g. 'DOGE')
    imageUrl:         null,                 // optional — off-chain URL (data_ref preferred)
    imageType:        'image/png',          // optional — artwork MIME type
    imageName:        'artwork.png'         // optional — artwork filename
});

doc shape:

{
  "tick": "MYART",
  "categories": [{ "type": "main", "data": "NFT" }],
  "name": "My Art Token",
  "description": "A 1-of-1 collectible",
  "images": [
    {
      "data_ref": "action:12345",
      "type": "image/png",
      "name": "artwork.png"
    }
  ]
}

Cross-chain data_ref form: when imageCoin is provided, the reference becomes action:<COIN>:<index> (e.g. action:DOGE:12345). The base coin ticker is used; the network tier (mainnet/testnet/regtest) is implied by context. This is the same form used in TIS data_ref fields and on-chain DESCRIPTION pointers.

sdk.nft.isNft(token) → boolean

Canonical NFT classification predicate. Returns true when a token record satisfies the NFT pattern: DECIMALS=0 and LOCK_MAX_SUPPLY=1. Accepts UPPER_SNAKE (indexer shape), snake_case (explorer JSON), or camelCase SDK shapes.

const token = await sdk.getToken('MYART');
if (sdk.nft.isNft(token)) {
    console.log('MYART is an NFT');
}

sdk.project.*

sdk.project.rosterParams(params) → LIST params

Build LIST v0 params for a new official-token roster (TYPE=TICK).

const params = sdk.project.rosterParams({
    ticks: ['TOKENA', 'TOKENB', 'TOKENC']   // required — non-empty array of TICK names
});
// Returns: { type: '1', item: ['TOKENA', 'TOKENB', 'TOKENC'] }

sdk.project.rosterEditParams(params) → LIST params

Build LIST v1 params that derive a new roster from an existing one. Pass add OR remove — not both (two edits require two LIST actions).

// Add a tick
const params = sdk.project.rosterEditParams({
    listActionIndex: 200,          // required — ACTION_INDEX of the existing roster LIST
    add:             ['TOKEND']    // or remove: ['TOKENA'] — never both
});
// Returns: { edit: '1', listActionIndex: '200', item: ['TOKEND'] }

Build LINK params that attest a roster to a project (the owner-validated green-banner binding). Both sides must be on the project’s own chain — cross-chain LINK rows carry no authority (the indexer skips owner validation when COIN2 is remote).

const params = sdk.project.attestRosterParams({
    coin:             'BTC',   // required — the project's chain
    listActionIndex:  200,     // required — ACTION_INDEX of the roster LIST
    issueActionIndex: 99,      // required — ACTION_INDEX of the project tick's ISSUE
    memo:             null     // optional
});
// Returns: { coin1: 'BTC', coin1ActionIndex: '200', coin2: 'BTC', coin2ActionIndex: '99', memo }

The LINK source must be the project tick’s current owner. The indexer rejects the LINK during ownership escrow.

Copyright © 2025–2026 Dankest, LLC

Based on XChain Platform by Dankest, LLC – https://dankest.llc

Licensed under the GNU Affero General Public License v3.0 (AGPL-3.0-or-later) with a commercial license available for proprietary use.

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