lending-apy-fetcher-ts/src/protocols/aave-polygon.ts

TypeScript library for fetching APYs from DeFi lending protocols

import { Protocol, ApyData, NetworkError } from '../types';
import { getAaveSupplyRates } from '../utils/aave-helpers';
import { ChainId, UiPoolDataProvider } from '@aave/contract-helpers';
import * as markets from '@bgd-labs/aave-address-book';
import { ethers } from 'ethers';
import { POLYGON } from './index';
    
export class AavePolygonProtocol implements Protocol {
  public readonly name = 'Aave';
  public readonly network = POLYGON;
  public readonly provider: ethers.providers.JsonRpcProvider;

  constructor(
    rpc_url: string = 'https://polygon-rpc.com',
  ) {
    this.provider = new ethers.providers.JsonRpcProvider(rpc_url);
  }

  async fetchApys(): Promise<ApyData[]> {
    try {
        let contract =new UiPoolDataProvider({
            uiPoolDataProviderAddress: markets.AaveV3Polygon.UI_POOL_DATA_PROVIDER,
            provider: this.provider,
            chainId: ChainId.polygon,
        });
      return await getAaveSupplyRates(this.network, contract, markets.AaveV3Polygon.POOL_ADDRESSES_PROVIDER);
    } catch (error) {
      throw new NetworkError(`Failed to fetch Aave Polygon APYs: ${error}`, this.name, error as Error);
    }
  }
}