The Sandbox SDK Integration

The Sandbox SDK Integration

The Sandbox is a metaverse based on Polygon, where land plots (LAND), game assets (ASSET), and characters (Avatar) are NFTs. SDK (VoxEdit + Game Maker) allows creating games and interactive experiences without deep blockchain knowledge. For developers — an additional level via Sandbox Game SDK and Web3 integration.

The Sandbox Ecosystem Structure

Web3 Integration via Sandbox API

import { ethers } from 'ethers';

// ABI for Sandbox main contracts
const LAND_ABI = [
  'function ownerOf(uint256 tokenId) view returns (address)',
  'function tokenOfOwnerByIndex(address owner, uint256 index) view returns (uint256)',
  'function balanceOf(address owner) view returns (uint256)',
];

const ASSET_ABI = [
  'function balanceOf(address account, uint256 id) view returns (uint256)',
  'function balanceOfBatch(address[] accounts, uint256[] ids) view returns (uint256[])',
];

// Polygon Mainnet addresses
const LAND_CONTRACT = '0x50f5474724e0Ee42D9a4e711ccFB275809Fd6d4A';
const ASSET_CONTRACT = '0xa342f5D851E866E18ff98F351f2c6637f4478dB5';

async function getUserSandboxAssets(userAddress: string) {
  const provider = new ethers.JsonRpcProvider('https://polygon-rpc.com');
  
  const landContract = new ethers.Contract(LAND_CONTRACT, LAND_ABI, provider);
  const assetContract = new ethers.Contract(ASSET_CONTRACT, ASSET_ABI, provider);
  
  // Get number of LAND tokens
  const landBalance = await landContract.balanceOf(userAddress);
  
  // Get all LAND tokenIds
  const landIds: bigint[] = [];
  for (let i = 0; i < Number(landBalance); i++) {
    const tokenId = await landContract.tokenOfOwnerByIndex(userAddress, i);
    landIds.push(tokenId);
  }
  
  return { landIds, landCount: Number(landBalance) };
}

Game Maker SDK — Programmatic Logic

The Sandbox Game Maker supports TypeScript for custom game logic:

// Example game script in Game Maker SDK
import { engine, Entity, web3 } from '@sandbox/game-sdk';

// Event on player entering zone
engine.onPlayerEnter('exclusive_zone', async (player) => {
  const walletAddress = await web3.getPlayerWallet(player.id);
  
  // Check LAND ownership in required square
  const hasLand = await checkLandOwnership(walletAddress);
  
  if (hasLand) {
    player.showMessage('Welcome, LAND owner!');
    player.grantAccess('vip_area');
  } else {
    player.showMessage('LAND NFT required for access');
    player.redirectTo('marketplace');
  }
});

// In-game asset purchase
engine.onPlayerInteract('shop_npc', async (player, npc) => {
  const items = await fetchAvailableItems();
  npc.openShop(player, items);
});

Marketplace API Integration

const SANDBOX_API = 'https://api.sandbox.game';

async function getMarketplaceListing(assetId: string) {
  const response = await fetch(`${SANDBOX_API}/v1/assets/${assetId}`);
  return response.json();
}

async function getUserCreations(walletAddress: string) {
  const response = await fetch(
    `${SANDBOX_API}/v1/assets?creator=${walletAddress}&status=published`
  );
  return response.json();
}

// Listing own ASSET on marketplace
async function listAssetForSale(assetId: string, priceInSand: string) {
  // Requires transaction signature via MetaMask
  const provider = new ethers.BrowserProvider(window.ethereum);
  const signer = await provider.getSigner();
  
  // Approve SAND token for marketplace contract
  const sandContract = new ethers.Contract(SAND_TOKEN, ERC20_ABI, signer);
  await sandContract.approve(MARKETPLACE_CONTRACT, ethers.MaxUint256);
  
  // Create listing via Exchange contract
  const marketplace = new ethers.Contract(MARKETPLACE_CONTRACT, MARKETPLACE_ABI, signer);
  await marketplace.createListing(assetId, ethers.parseEther(priceInSand));
}

LAND Coordinates and Metadata

LAND in Sandbox has coordinates (x, y) on the map. Via The Graph, you can get data:

query GetLandDetails($tokenId: String!) {
  land(id: $tokenId) {
    id
    x
    y
    owner {
      address
    }
    estate {
      id
    }
    tokenURI
  }
}

Development of The Sandbox integration (ownership verification, game logic, marketplace): 3–5 weeks depending on game experience complexity.