Buy NFT

How to purchase an NFT from the Wayup Marketplace

Introduction

This guide demonstrates how to find and purchase an NFT on the Wayup Marketplace using the API. The process involves two main steps:

1. Finding an NFT listing using the get-collection-assets endpoint. See Get Collection Assets

2. Building a purchase transaction with the build-tx endpoint

Requirements

• A Cardano wallet with sufficient ADA

• UTXOs from your wallet to fund the transaction. See Select UTXOs

• Policy ID of the NFT collection you're interested in

API Request Structure

Configuration

// API endpoint for Wayup Marketplace
const BASE_URL = "https://prod.api.ada-anvil.app/marketplace/api";

// NFT Collection to purchase from
const POLICY_ID = "6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01";

// Wallet address to receive change and NFT
const BUYER_CHANGE_ADDRESS = "addr1qx33ycd2ymg02dxh6vnnf8dsk54l8ranr9cfjk9qrlj3309c69jc4n8h3uvnczncaqu2sm03pl99h99n75uvtl3mhv0q3z8s8m";

// UTXOs from your wallet to fund the transaction
const BUYER_UTXOS: string[] = [
    "828258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac90182583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e821a001344eea1581c6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01a24f4646506f776572436f72657336323901504646506f776572436f7265733132343801",
    "828258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac90282583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e1a005b1fe1",
    "82825820daac1d3b80dcab8817c2f02f2d43ab2b33a4e74419679939eb8aa5f70b03f35c0182583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e821a007a089da1581c6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01a1504646506f776572436f7265733137323001"
];

Type Definitions

interface AssetResult {
  policyId: string;
  assetName: string;
  listing?: {
    txHashIndex: string;
    price: number;
  } | null;
}

Implementation

Step 1: Find Available Listings

First, query the API to find NFTs for sale, sorted by price:

// Step 1: Define the API request to find the cheapest listing
const url = `${BASE_URL}/get-collection-assets?policyId=${POLICY_ID}&saleType=list&orderBy=priceAsc&limit=1`;

// Step 2: Fetch the listing
const response = await fetch(url);
const json = await response.json();
const results: AssetResult[] = json?.results ?? [];
const listing = results[0];

console.log(`Found asset: ${listing.assetName} | Price: ${listing.listing?.price} lovelace`);

Step 2: Build the Purchase Transaction

Next, construct a purchase transaction using the listing:

// Step 3: Create the purchase payload
const buyPayload = {
  changeAddress: BUYER_CHANGE_ADDRESS,
  utxos: BUYER_UTXOS,
  buy: [
    {
      policyId: listing.policyId,
      txHashIndex: listing?.listing?.txHashIndex,

      // 1 ADA = 1_000_000 lovelace
      priceAda: listing?.listing?.price / 1_000_000,
    },
  ],
};

// Step 4: Build the transaction
const txResponse = await fetch(`${BASE_URL}/build-tx`, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(buyPayload),
});

const txResult = await txResponse.json();
console.log("Transaction:", txResult.transactions);

Running the Example

deno run --allow-net purchase-nft-test.ts

Example Output

Found asset: 4646506f776572436f7265733437 | Price: 5000000 lovelace
{
  changeAddress: "addr1qx33ycd2ymg02dxh6vnnf8dsk54l8ranr9cfjk9qrlj3309c69jc4n8h3uvnczncaqu2sm03pl99h99n75uvtl3mhv0q3z8s8m",
  utxos: [
    "828258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac90182583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e821a001344eea1581c6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01a24f4646506f776572436f72657336323901504646506f776572436f7265733132343801",
    "828258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac90282583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e1a005b1fe1",
    "82825820daac1d3b80dcab8817c2f02f2d43ab2b33a4e74419679939eb8aa5f70b03f35c0182583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e821a007a089da1581c6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01a1504646506f776572436f7265733137323001"
  ],
  buy: [
    {
      policyId: "6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01",
      txHashIndex: "4baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac9#0",
      priceAda: 5
    }
  ]
}
Transaction: [
  "84aa00d90102838258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac9008258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac902825820daac1d3b80dcab8817c2f02f2d43ab2b33a4e74419679939eb8aa5f70b03f35c010184a30058393184cc25ea4c29951d40b443b95bbc5676bc425470f96376d1984af9ab2c967f4bd28944b06462e13c5e3f5d5fa6e03f8567569438cd833e6d011a0011a008028201d81858225820c7dc7a987b9367993b617821ad64c3506b9015de1744270000a97a8d84e56df0825839015288ee085dc108f6fdc262b9e0cdfa92663b302836830efc0c5b4fdf41ff84ecc10aae4f3ba8526ba742c739de9d513ace95e17170b1f04c1a000f424082583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e1a002dc6c082583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e821a00955df2a1581c6fb0ce0d80bce539333b0b16f4a29a0d40c786249f86850d3a36fa01a24e4646506f776572436f726573343701504646506f776572436f7265733137323001021a000562fc031a09744dc407582010d70a7bf1ff1ed57b4ac55c6ed323880724390905b3f69b92615166c3ac96990b5820ff02484b059bcb0f3c47368c465fa38ebedabae6561eadf02f1eba621f963c470dd90102818258204baa167631a62343cc4f37f9313ee05d6149b1fda39fd563e12832c8dd49fac9021082583901a31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1e1a0043fdbf111a0017222212d90102818258201693c508b6132e89b932754d657d28b24068ff5ff1715fec36c010d4d6470b3d00a204d901029fd8799f9fd8799fd8799fd8799f581c5288ee085dc108f6fdc262b9e0cdfa92663b302836830efc0c5b4fdfffd8799fd8799fd8799f581c41ff84ecc10aae4f3ba8526ba742c739de9d513ace95e17170b1f04cffffffff1a000f4240ffd8799fd8799fd8799f581ca31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcffd8799fd8799fd8799f581cb8d1658accf78f193c0a78e838a86df10fca5b94b3f538c5fe3bbb1effffffff1a002dc6c0ffff581ca31261aa26d0f534d7d327349db0b52bf38fb319709958a01fe518bcffff05a182000082d8799f00ff821a000377541a04c44bfcf5a11902a2a1636d7367715761797570205472616e73616374696f6e"
]

The Complete File

See our examples repository for the complete file: buy-nft-test.ts

purchase-nft-test.ts

// API endpoint for Wayup Marketplace
const BASE_URL = "https://prod.api.ada-anvil.app/marketplace/api";

// NFT Collection to purchase from
const POLICY_ID = "POLICY_ID";

// Wallet address to receive change and NFT
const BUYER_CHANGE_ADDRESS = "BUYER_CHANGE_ADDRESS";

// UTXOs from your wallet to fund the transaction
const BUYER_UTXOS: string[] = [
  "BUYER_UTXOS"
];

interface AssetResult {
  policyId: string;
  assetName: string;
  listing?: {
    txHashIndex: string;
    price: number;
  } | null;
}

// Step 1: Define the API request to find the cheapest listing
const url = `${BASE_URL}/get-collection-assets?policyId=${POLICY_ID}&saleType=list&orderBy=priceAsc&limit=1`;

// Step 2: Fetch the listing
const response = await fetch(url);
const json = await response.json();
const results: AssetResult[] = json?.results ?? [];
const listing = results[0];

console.log(`Found asset: ${listing.assetName} | Price: ${listing.listing?.price} lovelace`);

// Step 3: Create the purchase payload
const buyPayload = {
  changeAddress: BUYER_CHANGE_ADDRESS,
  utxos: BUYER_UTXOS,
  buy: [
    {
      policyId: listing.policyId,
      txHashIndex: listing?.listing?.txHashIndex,

      // 1 ADA = 1_000_000 lovelace
      priceAda: listing?.listing?.price / 1_000_000,
    },
  ],
};

console.log(buyPayload);

// Step 4: Build the transaction
const txResponse = await fetch(`${BASE_URL}/build-tx`, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(buyPayload),
});

const txResult = await txResponse.json();
console.log("Transaction:", txResult.transactions);

// Next steps: Sign the hex with your wallet and submit via /submit endpoint

// Run this with: deno run --allow-net purchase-nft-test.ts

Next Steps

After building the transaction:

1. Sign the transaction hex with your wallet. See Sign Transactions

2. Submit the signed transaction using the /submit endpoint. See Submit Transactions

3. Wait for confirmation on the blockchain