import { Quickstart } from "/snippets/quickstart.mdx";

Helius provides REST and JSON-RPC APIs for building any Solana application — from analytic platforms and DeFi dashboards to trading bots and compliance tools. Query token balances, fetch NFT metadata, stream real-time blockchain events, send optimized transactions, and monitor wallets with a single API key. This guide walks you through your first API call and a working application in minutes.

Agents looking to programmatically create a Helius account should use the [Helius CLI](/agents/cli) and reference the [Agent signup instructions](https://dashboard.helius.dev/agents.md).

<Tip>
  **Performance Tip**: Use our Gatekeeper (Beta) endpoint: `https://beta.helius-rpc.com` instead of `https://mainnet.helius-rpc.com` for lower latency. Your API key works on both. [Learn more →](/gatekeeper/overview)
</Tip>

<Quickstart />

**What's happening here?** The DAS API allows you to query compressed and standard NFTs with a single call. Notice how the response includes metadata, image URLs, and ownership information - all the data you need to build rich user experiences.

Now let's implement this in a real application. We'll create a simple NFT portfolio viewer that you can expand upon.

class NFTPortfolioViewer { constructor(apiKey) { this.apiKey = apiKey; this.baseUrl = 'https://mainnet.helius-rpc.com'; }

async fetchNFTsByOwner(ownerAddress, limit = 10) { try { const response = await fetch(${this.baseUrl}/?api-key=${this.apiKey}, { method: 'POST', headers: { 'Content-Type': 'application/json', }, body: JSON.stringify({ jsonrpc: '2.0', id: '1', method: 'getAssetsByOwner', params: { ownerAddress, page: 1, limit, displayOptions: { showFungible: false, showNativeBalance: false, }, }, }), });

  const data = await response.json();

  if (data.error) {
    throw new Error(data.error.message);
  }

  return data.result;
} catch (error) {
  console.error('Error fetching NFTs:', error.message);
  throw error;
}

}

displayNFTPortfolio(nfts) { console.log('\n🖼️ NFT Portfolio Summary'); console.log('========================'); console.log(Total NFTs: ${nfts.total}); console.log(Showing: ${nfts.items.length} items\n);

nfts.items.forEach((nft, index) => {
  console.log(`${index + 1}. ${nft.content?.metadata?.name || 'Unnamed NFT'}`);
  console.log(`   Collection: ${nft.grouping?.[0]?.group_value || 'Individual'}`);
  console.log(`   Compressed: ${nft.compression?.compressed ? 'Yes' : 'No'}`);
  console.log(`   Image: ${nft.content?.files?.[0]?.uri || 'No image'}`);
  console.log(`   ID: ${nft.id}\n`);
});

}

async getRandomNFT(ownerAddress) { const portfolio = await this.fetchNFTsByOwner(ownerAddress, 50);

if (portfolio.items.length === 0) {
  console.log('No NFTs found for this address.');
  return null;
}

const randomIndex = Math.floor(Math.random() * portfolio.items.length);
return portfolio.items[randomIndex];

} }

// Usage example async function main() { const viewer = new NFTPortfolioViewer('YOUR_API_KEY');

// Anatoly's wallet address const walletAddress = '86xCnPeV69n6t3DnyGvkKobf9FdN2H9oiVDdaMpo2MMY';

console.log('🚀 Fetching NFT portfolio...');

try { // Get full portfolio overview const portfolio = await viewer.fetchNFTsByOwner(walletAddress); viewer.displayNFTPortfolio(portfolio);

// Get a random NFT for featured display
console.log('🎲 Featured Random NFT:');
console.log('=====================');
const randomNFT = await viewer.getRandomNFT(walletAddress);

if (randomNFT) {
  console.log(`Name: ${randomNFT.content?.metadata?.name}`);
  console.log(`Description: ${randomNFT.content?.metadata?.description || 'No description'}`);
  console.log(`Image: ${randomNFT.content?.files?.[0]?.uri}`);
}

} catch (error) { console.error('Failed to fetch NFT data:', error.message); } }

main();

</Step>
<Step title="Add your API key">
  Replace `YOUR_API_KEY` with your actual API key from the Helius dashboard.
</Step>
<Step title="Run your NFT portfolio viewer">
```bash
node nft-portfolio.js

What you've learned:

• How to structure API calls to Helius
• Working with the DAS API response format
• Handling compressed vs standard NFTs
• Building reusable code for NFT operations

Now that you understand the basics, explore these advanced features:

You've successfully built your first Solana application with Helius! Here are some ideas to expand your project:

• Add wallet connection: Integrate with wallets
• Build a UI: Create a React/Vue frontend to display the portfolio
• Add filtering: Search by collection, traits, or mint date
• Real-time updates: Use WebSockets to show live portfolio changes
• Analytics: Track portfolio value and NFT price history