Eopay Protocol

Most lending forces a choice: sell your assets for liquidity, or keep your exposure and stay illiquid. Eopay removes that trade-off. Deposit Solana assets as collateral, borrow SOL against them instantly, and keep every bit of your upside. Repay whenever you want to unlock your collateral.

Beyond borrowing, Eopay turns wallet history into financial reputation. Every repayment, loan and unit of borrowing volume contributes to an on-chain credit score that unlocks better LTVs and lower rates over time — a portable, verifiable identity that no centralized lender can take away.

The protocol is composed of four cooperating systems:

A borrow flows top to bottom: you lock collateral in the Vault, the Loan Engine issues SOL against it, the Risk Layer continuously monitors solvency, and if a position becomes unhealthy the Liquidation Flow unwinds it automatically.

Install the SDK:

pnpm add @eopay/sdk @solana/web3.js

Connect a wallet and borrow SOL against collateral in one transaction:

import { Eopay } from '@eopay/sdk'

const eopay = new Eopay({
  cluster: 'mainnet-beta',
  wallet: phantom.publicKey,
})

const loan = await eopay.borrow({
  collateral: 'BONK',
  deposit: 2_500_000,   // amount of collateral to lock
  borrow: 'SOL',
  amount: 18.4,         // ~62% LTV
})

console.log(loan.signature, loan.healthFactor)

The Vault is a non-custodial Solana program that escrows your deposited assets. Funds are never held by a company — only by on-chain program-derived accounts that you can always withdraw from once any outstanding loan is repaid.

• Supports memecoins, SPL tokens, LSTs, LP positions and tokenized stocks.
• Each asset has isolated risk parameters set by the Risk Layer.
• Deposits keep your market exposure intact — you still hold the upside.

The Loan Engine prices your locked collateral using live oracle feeds, applies the asset's maximum loan-to-value (LTV) ratio, and issues SOL to your wallet. Interest accrues per second and is set algorithmically by pool utilization.

// Health factor = (collateralValue × liquidationThreshold) / debtValue
// A position is liquidatable when healthFactor < 1.0

const hf = (collateralUsd * liquidationThreshold) / borrowedUsd

Repay any portion of the loan at any time to raise your health factor and reduce interest.

The Risk Layer keeps the protocol solvent. It ingests real-time prices from Pyth and Switchboard, assigns per-asset LTV and liquidation thresholds, and enforces supply caps so that a single volatile asset can never threaten the lending pool.

When a position's health factor drops below 1.0, it becomes eligible for liquidation. Permissionless keepers repay a portion of the debt in exchange for discounted collateral, restoring the position to a healthy state. The process is fully automated and predictable — there are no surprise margin calls.

• Partial liquidations minimize borrower losses where possible.
• A liquidation penalty is split between keepers and the protocol reserve.
• Liquidation events are recorded and factored into your credit score.

Eopay reads your verifiable on-chain activity and distills it into a single score from 0 to 850. It is portable, owned by your wallet, and improves as you demonstrate responsible borrowing. A higher score unlocks higher LTVs, lower borrow APRs and larger credit lines.

const score = await eopay.creditScore(wallet)
// { value: 742, tier: 'EXCELLENT', maxLtvBonus: 0.08, aprDiscount: 0.014 }

Borrow and supply rates are dynamic and driven by pool utilization (the ratio of borrowed to supplied liquidity). As utilization rises, borrow APR increases to incentivize repayment and new supply; lender APY rises in tandem.

borrowApr = baseRate + utilization * slope
lenderApy = borrowApr * utilization * (1 - reserveFactor)

Core methods exposed by @eopay/sdk:

eopay.deposit({ asset, amount })        // lock collateral
eopay.borrow({ collateral, borrow, amount })  // open a loan
eopay.repay({ loan, amount })           // repay (use 'max' to close)
eopay.withdraw({ vault, amount })       // unlock collateral
eopay.supply({ amount })                // provide SOL liquidity
eopay.creditScore(wallet)               // read on-chain score