lending-apy-fetcher-ts/examples/basic-usage.ts

TypeScript library for fetching APYs from DeFi lending protocols

#!/usr/bin/env ts-node

import { 
  getApys, 
  getBestApyForToken, 
  ApyFetcher,
  Protocol
} from '../src';

import { AaveEthProtocol } from '../src/protocols/aave-eth';
import { AavePolygonProtocol } from '../src/protocols/aave-polygon';
import { AaveArbitrumProtocol } from '../src/protocols/aave-arbitrum';

const protocols: Protocol[] = [
  new AaveEthProtocol(),
  new AavePolygonProtocol(),
  new AaveArbitrumProtocol()
];

async function testFullFetcher() {
  console.log('\nTesting full APY fetcher...');
  try {
    const fetcher = new ApyFetcher(protocols);
    const apys = await fetcher.fetchApys();
    
    console.log(`Found ${apys.length} APY opportunities`);
    
    // Show Aave results
    const aaveApysArbitrum = apys.filter(apy => apy.protocol_name === 'Aave' && apy.network === 'Arbitrum');
    const aaveApysEth = apys.filter(apy => apy.protocol_name === 'Aave' && apy.network === 'Ethereum');
    const aaveApysOptimism = apys.filter(apy => apy.protocol_name === 'Aave' && apy.network === 'Optimism');

    console.log(`\nAave APYs (${aaveApysArbitrum.length} tokens):`);
    aaveApysArbitrum.slice(0, 5).forEach(apy => {
      console.log(`  ${apy.token_symbol}: ${(apy.apy * 100).toFixed(2)}% (${apy.network})`);
    });

    console.log(`\nAave APYs (${aaveApysEth.length} tokens):`);
    aaveApysEth.slice(0, 5).forEach(apy => {
      console.log(`  ${apy.token_symbol}: ${(apy.apy * 100).toFixed(2)}% (${apy.network})`);
    });

    console.log(`\nAave APYs (${aaveApysOptimism.length} tokens):`);
    aaveApysOptimism.slice(0, 5).forEach(apy => {
      console.log(`  ${apy.token_symbol}: ${(apy.apy * 100).toFixed(2)}% (${apy.network})`);
    });

    aaveApysEth.forEach(apy => {
      console.log(`  ${apy.token_symbol}: ${(apy.apy * 100).toFixed(2)}% (${apy.network})`);
    });

    // best apy for token and network
    for (const token of ['DAI', 'USDT', 'ETH', 'WETH', 'WBTC', 'USDC', 'rsETH', 'USDS', 'USDe', 'weETH', 'wstETH', 'LINK']) {
      const bestApyForToken = await getBestApyForToken(protocols, token);
      console.log(`\nBest APY for ${token}: ${(bestApyForToken?.apy ?? 0 * 100).toFixed(2)}% (${bestApyForToken?.network})`);
    }
  } catch (error) {
    console.error('Full fetcher failed:', error);
  }
}

async function main() {
  await testFullFetcher();
}

// Run the example
if (require.main === module) {
  main()
    .then(() => {
      console.log('\n✅ Example completed successfully!');
      process.exit(0);
    })
    .catch((error) => {
      console.error('\n💥 Example failed:', error);
      process.exit(1);
    });
}

export { main };