Skip to main content

Issue an NFT

The Go SDK path to issuing MLS-03 NFTs. The same workflow in JavaScript lives in the JavaScript guides; the wallet-cli version is Issuing and managing an NFT. On-chain, an NFT is an MLS-03 issuance carrying the creator, name, description, ticker, icon, media URI, and media hash; the JSON standard for the off-chain metadata is defined in the Token Metadata Standards.

Immutable by design

NFT metadata is set at issuance and cannot be changed: there is no equivalent of changeMetadataUri for NFTs. Compute and record the media hash before issuing. Mintlayer does not prescribe an algorithm; use a standard one (e.g. SHA-256) and record which one you used.

Issuing​

import "github.com/mintlayer/go-sdk/wallet"

wc := wallet.New("http://127.0.0.1:3034")

ownerAddr, err := wc.NewAddress(ctx, 0)

result, err := wc.IssueNFT(ctx, wallet.IssueNFTParams{
    Account:            0,
    DestinationAddress: ownerAddr,
    Metadata: wallet.NFTMetadata{
        Name:        "Sunset #1",
        Description: "A photograph of a sunset",
        Ticker:      "SUNST",
        MediaHash:   "a3f1e2...d9c4",
        MediaURI:    stringPtr("https://example.com/sunset.png"),
        IconURI:     stringPtr("https://example.com/icon.png"),
    },
})
fmt.Printf("nft id: %s\n", result.TokenID)

Each issuance transaction creates exactly one NFT: there is no mint step afterwards.

Transferring​

An NFT transfer is a token transfer of the NFT id; use the wallet transaction APIs (see Go SDK: Wallet) or the wasm output encoders.

Reading NFT state​

import "github.com/mintlayer/go-sdk/indexer"

idx := indexer.New("http://127.0.0.1:3000")

nft, err := idx.GetNFT(ctx, result.TokenID)
fmt.Printf("owner: %s  name: %s\n", nft.Owner, nft.Metadata.Name)

Metadata standard​

For the JSON document at the metadata URI (media details, editions, licensing, collections), follow the MLS-03 schema in Token Metadata Standards: it includes ready-made templates for art, gaming, tickets, credentials, and more.