Credit Lines: Drawdowns, Repayments, and Interest Accrual

// Example: draw from credit line using ethers.js
// RPC_URL, PRIVATE_KEY, BORROW_ROUTER_ADDRESS, and BORROW_ROUTER_ABI must be
// set from your environment. Contract addresses are published at:
// https://docs.synclear.fi/get-started/contract-addresses
const { ethers } = require("ethers");

const provider = new ethers.JsonRpcProvider(RPC_URL);
const signer = new ethers.Wallet(PRIVATE_KEY, provider);
const borrowRouter = new ethers.Contract(BORROW_ROUTER_ADDRESS, BORROW_ROUTER_ABI, signer);

// Draw 10,000 USDC from an existing credit line
const creditLineId = "0xabc123..."; // bytes32 identifier returned at credit line activation
const amount = ethers.parseUnits("10000", 6); // USDC uses 6 decimals
const recipientAddress = "0x0000000000000000000000000000000000000001"; // replace with your operating wallet address

const tx = await borrowRouter.draw(creditLineId, amount, recipientAddress);
const receipt = await tx.wait();

console.log("Draw confirmed in block:", receipt.blockNumber);

accruedInterest = principal × ratePerBlock × blocksDelta

// Example: repay credit line (full repayment)
// Assumes provider, signer, borrowRouter, and creditLineId are initialized
// as shown in the drawdown example above.
// USDC_ADDRESS and ERC20_ABI must be set from your environment.
const outstandingBalance = await borrowRouter.outstandingBalance(creditLineId);

// Approve the borrow router to pull repayment funds
const usdc = new ethers.Contract(USDC_ADDRESS, ERC20_ABI, signer);
await usdc.approve(BORROW_ROUTER_ADDRESS, outstandingBalance);

// Execute repayment — pass ethers.MaxUint256 to repay in full
const repayTx = await borrowRouter.repay(
  creditLineId,
  ethers.MaxUint256 // repay full outstanding balance (principal + accrued interest)
);
await repayTx.wait();

utilization = outstandingBalance / creditLimit