Build DeFi Apps
Without CORS Blocking You

// Fetch token icons from CoinGecko (like Uniswap does)
const CORS_PROXY = 'https://corsproxy.io/?url=';

async function getTokenIcon(coingeckoId) {
  const apiUrl = `https://api.coingecko.com/api/v3/coins/${coingeckoId}`;
  const response = await fetch(CORS_PROXY + encodeURIComponent(apiUrl));
  const data = await response.json();
  return data.image.large;
}

// Display token icons in your DeFi app
const ethIcon = await getTokenIcon('ethereum');
document.getElementById('eth-icon').src = ethIcon;

// Fetch real-time crypto prices
const CORS_PROXY = 'https://corsproxy.io/?url=';

async function getCryptoPrices(ids) {
  const url = 'https://api.coingecko.com/api/v3/simple/price' +
    '?ids=' + ids.join(',') +
    '&vs_currencies=usd&include_24hr_change=true';

  const response = await fetch(CORS_PROXY + encodeURIComponent(url));
  return response.json();
}

// Get prices for multiple tokens
const prices = await getCryptoPrices(['bitcoin', 'ethereum', 'uniswap']);
console.log('BTC:', prices.bitcoin.usd);
console.log('ETH:', prices.ethereum.usd);

// Web3 DApp - Load token metadata
const CORS_PROXY = 'https://corsproxy.io/?url=';

async function loadTokenList() {
  // Fetch Uniswap's default token list
  const tokenListUrl = 'https://tokens.uniswap.org';
  const response = await fetch(CORS_PROXY + encodeURIComponent(tokenListUrl));
  const { tokens } = await response.json();

  return tokens.map(token => ({
    symbol: token.symbol,
    name: token.name,
    address: token.address,
    logoURI: token.logoURI
  }));
}