237-combo/examples/ts/aave-supply-borrow.ts

/**
 * Aave v3: Supply collateral, enable as collateral, and borrow
 * 
 * This example demonstrates:
 * 1. Supplying assets to Aave v3
 * 2. Enabling supplied asset as collateral
 * 3. Borrowing against collateral
 * 
 * Note: In Aave v3.3+, stable-rate borrowing has been deprecated. Use variable rate (mode = 2).
 */

import { createWalletRpcClient } from '../../src/utils/chain-config.js';
import { getAavePoolAddress } from '../../src/utils/addresses.js';
import { getTokenMetadata, parseTokenAmount } from '../../src/utils/tokens.js';
import { waitForTransaction } from '../../src/utils/rpc.js';
import { parseUnits } from 'viem';

const CHAIN_ID = 1; // Mainnet (change to 8453 for Base, 42161 for Arbitrum, etc.)
const PRIVATE_KEY = process.env.PRIVATE_KEY as `0x${string}`;

// ABI for Aave Pool
const POOL_ABI = [
  {
    name: 'supply',
    type: 'function',
    stateMutability: 'nonpayable',
    inputs: [
      { name: 'asset', type: 'address' },
      { name: 'amount', type: 'uint256' },
      { name: 'onBehalfOf', type: 'address' },
      { name: 'referralCode', type: 'uint16' },
    ],
    outputs: [],
  },
  {
    name: 'setUserUseReserveAsCollateral',
    type: 'function',
    stateMutability: 'nonpayable',
    inputs: [
      { name: 'asset', type: 'address' },
      { name: 'useAsCollateral', type: 'bool' },
    ],
    outputs: [],
  },
  {
    name: 'borrow',
    type: 'function',
    stateMutability: 'nonpayable',
    inputs: [
      { name: 'asset', type: 'address' },
      { name: 'amount', type: 'uint256' },
      { name: 'interestRateMode', type: 'uint256' },
      { name: 'referralCode', type: 'uint16' },
      { name: 'onBehalfOf', type: 'address' },
    ],
    outputs: [],
  },
] as const;

// ERC20 ABI for approvals
const ERC20_ABI = [
  {
    name: 'approve',
    type: 'function',
    stateMutability: 'nonpayable',
    inputs: [
      { name: 'spender', type: 'address' },
      { name: 'amount', type: 'uint256' },
    ],
    outputs: [{ name: '', type: 'bool' }],
  },
  {
    name: 'allowance',
    type: 'function',
    stateMutability: 'view',
    inputs: [
      { name: 'owner', type: 'address' },
      { name: 'spender', type: 'address' },
    ],
    outputs: [{ name: '', type: 'uint256' }],
  },
] as const;

async function supplyAndBorrow() {
  const walletClient = createWalletRpcClient(CHAIN_ID, PRIVATE_KEY);
  const publicClient = walletClient as any;
  const account = walletClient.account?.address;
  
  if (!account) {
    throw new Error('No account available');
  }

  const poolAddress = getAavePoolAddress(CHAIN_ID);
  
  // Token configuration
  const collateralToken = getTokenMetadata(CHAIN_ID, 'USDC');
  const debtToken = getTokenMetadata(CHAIN_ID, 'USDT');
  
  // Amounts
  const supplyAmount = parseTokenAmount('1000', collateralToken.decimals);
  const borrowAmount = parseTokenAmount('500', debtToken.decimals);
  
  console.log(`Supplying ${supplyAmount} ${collateralToken.symbol}`);
  console.log(`Borrowing ${borrowAmount} ${debtToken.symbol}`);
  console.log(`Pool: ${poolAddress}`);
  console.log(`Account: ${account}`);

  // Step 1: Approve token spending
  console.log('\n1. Approving token spending...');
  const approveTx = await walletClient.writeContract({
    address: collateralToken.address,
    abi: ERC20_ABI,
    functionName: 'approve',
    args: [poolAddress, supplyAmount],
  });
  await waitForTransaction(publicClient, approveTx);
  console.log(`Approved: ${approveTx}`);

  // Step 2: Supply collateral
  console.log('\n2. Supplying collateral...');
  const supplyTx = await walletClient.writeContract({
    address: poolAddress,
    abi: POOL_ABI,
    functionName: 'supply',
    args: [collateralToken.address, supplyAmount, account, 0],
  });
  await waitForTransaction(publicClient, supplyTx);
  console.log(`Supplied: ${supplyTx}`);

  // Step 3: Enable as collateral
  console.log('\n3. Enabling as collateral...');
  const enableCollateralTx = await walletClient.writeContract({
    address: poolAddress,
    abi: POOL_ABI,
    functionName: 'setUserUseReserveAsCollateral',
    args: [collateralToken.address, true],
  });
  await waitForTransaction(publicClient, enableCollateralTx);
  console.log(`Enabled collateral: ${enableCollateralTx}`);

  // Step 4: Borrow (variable rate = 2, stable rate is deprecated)
  console.log('\n4. Borrowing...');
  const borrowTx = await walletClient.writeContract({
    address: poolAddress,
    abi: POOL_ABI,
    functionName: 'borrow',
    args: [debtToken.address, borrowAmount, 2, 0, account], // mode 2 = variable
  });
  await waitForTransaction(publicClient, borrowTx);
  console.log(`Borrowed: ${borrowTx}`);

  console.log('\n✅ Supply and borrow completed successfully!');
}

// Run if executed directly
if (import.meta.url === `file://${process.argv[1]}`) {
  supplyAndBorrow().catch(console.error);
}

export { supplyAndBorrow };