Skip to main content

How to mint a Soulbound NFT on-chain

A soulbound token (SBT) is a unique and indivisible Basic NFT that is bound to a specific account and cannot be traded or transferred to another account once it has been received from the creator.

Prerequisites​

Before getting started, make sure you have the following ready:

  1. Create a Ternoa account with Alphanet CAPS
  2. Install and set up your editor of choice (we will use Visual Studio Code [VSC] in this tutorial)
  3. Install NodeJS v.14+ & NPM
  4. Install & initialize Ternoa-JS

Minting a Soulbound NFT on-chain using Ternoa-JS​

In order to create an NFT on the Ternoa chain, Ternoa-JS provides you with a createNft helper to do so. It returns an object promise containing the NFTCreatedEvent returned by the Ternoa blockchain. The only difference with a Basic NFT creation is to set 4th parameter isSoulbound to true.

Replace IPFS_CID in the following code snippet with your CID hash previouly generated in "How to prepare Basic NFT assets":

// Imports
import { initializeApi } from "ternoa-js";
import { createNft } from "ternoa-js/nft";

const mintSBT = async () => {
  try {
    const keyring = await getKeyringFromSeed("//TernoaTestAccount");
    const newSBT = await createNft(
      "My first SBT",
      0,
      undefined,
      true, // Is soulbound
      keyring,
      WaitUntil.BlockInclusion
    );
    console.log("The on-chain NFT id is: ", nftData.nftId);
  } catch (e) {
    console.error(e);
  }
};
info

Use your own account by updating the //TernoaTestAccount with your account seed when retrieving the keyring from the example below.

Here are detailed the createNft helper parameters:

`offchainData`: a string that can be IPFS CID hash that points to a JSON file, a plain text, a small JSON string, or a link to either a static or a dynamic file.
`royalty`: a number (in percentage between 0 an 100) to set the royalties taken by the owner for each NFT sale.
`collectionId`: an optional parameter. If you want your NFT to belong to a collection, add the collection id here otherwise keep it undefined.
`isSoulbound`: (boolean): when set to true, the NFT will be a soulbound NFT. Default is false.
`keyring`: the provided keyring (containing the address) will be used to sign the transactio and pay the execution fee.
`waitUntil`: WaitUntil define at which point we want to get the results of the transaction execution: BlockInclusion or BlockFinalization.

The response returned includes an NFTCreatedEvent if the transaction succeed. The particularity here is that the isSoulbound field is true. Note that MintFee refers to the fee paid to mint the NFT in Big Number format (MintFeeRounded is the humanized format, more easy and friendly to use).

`nftId`: ID of the NFT.
`owner`: The owner of the NFT.
`offchainData`: The off-chain data provided for the NFT.
`royalty`: The royalty fee set for the NFT.
`collectionId`: The ID of the collection the NFT belongs.
`isSoulbound`: True if the NFT is soulbound. False if the NFT is not soulbound.
`mintFee`: Minting fee for the NFT. Big Number format
`mintFeeRounded`: Minting fee for the NFT. Basic number format.

Next​

Next step ill be getting the NFT data from the Ternoa Indexer using the NFT id just generated. Keep it and continue on the "How to retrieve a Basic NFT" guide.

Support​

If you face any trouble, feel free to reach out to our community engineers in our Discord.