Phantasma NFT Creation

A developers guide to creating Phantasma NFTs compatible with GhostMarket

Introduction

This page provides step-by-step instructions for deploying GhostMarket compatible NFTs on the Phantasma blockchain.

The NFT creation process requires interaction with the blockchain. For retrieving existing NFT metadata, see Accessing NFT data, which uses the GhostMarket APIs.

The code snippets also assume a node.js environment.

See our Metadata Reference for full details and requirements of GhostMarket NFT metadata.

NFT Creation

The NFT creation process on all blockchains broadly consists of the following steps.

1. Prepare Off-Chain Metadata and persist it.

2. Assemble On-Chain Metadata and build a transaction.

3. Sign the transaction.

4. Broadcast to the blockchain.

1. Prepare Off-Chain Metadata

The preferred decentralised platform for persisting image/media data for your NFT is IPFS.

This guide will use Pinãta to upload and pin your images to IPFS.

Set up a Pinata account and get started here.

You can either manually upload you metadata, noting the IPFS hash, or dive into the Pinata js-sdk to interract with Pinata programatically.

Note the IPFS hash of the uploaded metadata, you will need it in the next step.

2. Assemble On-Chain Metadata

Ghostmarket Phantasma NFT contract stores all metadata on-chain, so you must assemble it into a Phantasma transaction script.

We will use the phantasma-ts npm module to work with the Phantasma blockchain.

Install the module

% npm install phantasma-ts

Import the library

const { phantasmaJS } = require("phantasma-ts");

The Minting Data is sent to the contract as an array. The following table specifies the contents of the array.

All elements must be provided.

Phantasma "ghost" mint contract parameters

index	name	type	descr
0	editionId	number	0 for new series // != 0 for existing series
1	editionMax	number	Maximum number possible
2	editionMode	number	1 = duplicated, 2 = unique // only allow duplicate for now
3	creator	address	Address of the creator
4	royalties	number	Royalties in BPS (0.01%) - must be integer
5	mintTicker	string
6	numOfNfts	number	number to mint
7	name	string	Short name of the NFT
8	description	string	long descriptive name of the NFT
9	type	number/integer	Genre of the NFT - see Genre reference
10	imageURL	string	URL of the image - ipfs://<hash>
11	infoURL	string	Currently unused
12	attrT1	string	First attribute Type/Key, e.g. "Color"
13	attrV1	string	First attribute Value, e.g. "Red"
14	attrT2	string	Second attribute Type/Key
15	attrV2	string	Second attribute Value
16	attrT3	string	Third attribute Type/Key
17	attrV3	string	Third attribute Value
18	lockedContent	string	String containing the encrypted content
19	listPrice	number	If listing with Mint, the listing price
20	listPriceCurrency	string	If listing with Mint, the listing currency, e.g. "KCAL"
21	listLastEndDate	timestamp	If listing with Mint, the Unix Epoch end time of listing
22	infusedAsset	string	If infusing, the asset being infused e.g. "KCAL", otherwise ""
23	infusedAmount	number	If infusing , the amount of infusedAsset to infuse, otherwise 0
24	hasLocked	bool	True if lockedContent is specified, otherwise false

---

Assemble the Minting Parameter Array

let creatorAdd = "<my Phantasma address>";

mintParamArrayGhost = [
  0, // editionID
  100, // editionMax
  1, // editionMode
  creatorAdd, // creator - address
  2000, // royalties - 20% expressed as BPS (0.01%)
  "GHOST", // mintTicker - string
  1, // numOfNfts - Mint one NFT
  "My Shiny NFT", // name
  "This NFT will be a classic", // description
  1, // type - See Metadata Reference "Genre"
  "ipfs://QmTy8w65yBXgyfG2ZBg5TrfB2hPjrDQH3RCQFJGkARStJb", // imageURL - from step 1
  "", // infoURL - not used
  "color", // attrT1
  "red", // attrV1
  "size", // attrT2
  "small", // attrV2
  "", // attrT3 - empty string if unused
  "", // attrV3 - empty string if unused
  "This is your mystery content", // lockedContent
  0, // listPrice - we can list later, not now
  "", // listPriceCurrency - not listing with mint
  0, // listLastEndDate - not listing
  "", // infusedAsset - string
  0, // infusedAmount - number
  true, // hasLocked - true
];

3. Build the transaction script

//Create a new Script Builder Object
let sb = new phantasmaJS.ScriptBuilder();

// Assemble the Script
sb.callContract("gas", "AllowGas", [
  "fromAddress",
  sb.nullAddress,
  "100000",
  "900",
])
  .callContract("ghost", "mintToken", mintParamArrayGhost)
  .callContract("gas", "SpendGas", ["fromAddress"])
  .endScript();

3. Construct & Sign the transaction

// stringify the script
let script = sb.str;
let privateKey = "Your Private Key";

//build an expiration date for the transaction of 5 minutes
let expiration = 5; //Expiration time, in minutes
let getTime = new Date();
let expDate = new Date(getTime() + expiration * 60000);

//Creating New Transaction Object
let transaction = new phantasmaJS.Transaction(
  "mainnet", //Nexus Name
  "main", //Chain
  script, //In string format
  date, //Expiration Date
  ""
); //Extra Info to attach to Transaction in Serialized Hex - not needed

//Sign's Transaction with Private Key
await transaction.sign(privateKey);

4. Broadcast to the blockchain

Finally, broadcast the transaction

//Send Transaction
let txHash = await RPC.sendRawTransaction(transaction.toString(true));

Congratulations! you have successfully deployed a GhostMarket compatible NFT to the "ghost" contract on the Phantasma blockchain.

For clarity, all of the above snippets exclude error and promise handling for clarity. Production code should include thorough exception management and handle promises appropriately.