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How to directly buy an auctioned NFT on a marketplace

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

Buy directly an auctioned NFT using Ternoa-JS​

This function buys an auctioned NFT before the auction has started on the Ternoa chain. It returns an object promise containing the AuctionCompletedEvent provided by the Ternoa blockchain.

info

Use your own account by updating the //TernoaTestAccount with your account seed when retrieving the keyring from the example below. Replace the NFT_ID with the existing one to buy. Note: BuyItNow is optional when creating the auction. If no amount is provided at auction creation, it's not possible to run this transaction.

import {
    buyItNow,
    initializeApi,
    getKeyringFromSeed,
    WaitUntil,
} from "ternoa-js";

const auctionBid = async () => {
    try {
        await initializeApi();
        const keyring = await getKeyringFromSeed("//TernoaTestAccount");
        const NFT_ID = // update with the nft id you want to buy.
        const res = await buyItNow(
            NFT_ID,
            keyring,
            WaitUntil.BlockInclusion
        );
        console.log(`BuyItNow_Auction: NFT id ${res.nftId} bought for ${res.amountRounded}CAPS`);
    } catch (e) {
        console.error(e);
    }
};

The expected params​

`nftId`: The ID of the auctioned NFT.
`keyring`: The provided keyring (containing the address) will be used to sign the transaction and pay the execution fee.
`waitUntil`: WaitUntil defines at which point we want to get the results of the transaction execution: BlockInclusion or BlockFinalization.

Response​

The response provided from the blockchain event includes all the information below according to the parameters provided when buying the auctioned NFT.

`nftId`: NFT id auctioned.
`newOwner`: The new NFT owner.
`amount`: The NFT price as a string corresponding to the value in a big number.
`amountRounded`: The NFT price as a number.
`marketplaceCut`: The marketplace commission fee on the auctioned NFT as a string corresponding to the value in a big number.
`marketplaceCutRounded`: The marketplace commission fee on the auctioned NFT as a number.
`royaltyCut`: The NFT creator royalty fee on the auctioned NFT as a string corresponding to the value in a big number.
`royaltyCutRounded`: The NFT creator royalty fee on the auctioned NFT as a number.

Support​

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