Marginfi Development Guide

Build lending and borrowing applications on Solana with Marginfi - a decentralized, overcollateralized lending protocol offering deposits, borrows, flash loans, and leveraged positions.

Overview

Marginfi provides:

Lending & Borrowing: Deposit collateral to earn yield, borrow against your deposits

Multiple Accounts: Create multiple accounts per wallet with independent positions

Risk Management: Advanced health calculations using asset and liability weights

Flash Loans: Atomic, uncollateralized lending within a single transaction

Looping: Leverage positions by depositing and borrowing in a single transaction

Multi-Asset Support: SOL, USDC, LSTs (JitoSOL, mSOL), and more

Quick Start

Installation

# Marginfi client SDK
npm install @mrgnlabs/marginfi-client-v2
Common utilities

npm install @mrgnlabs/mrgn-common
Required peer dependencies

npm install @solana/web3.js @coral-xyz/anchor

Environment Setup

# .env file
SOLANA_RPC_URL=https://api.mainnet-beta.solana.com
WALLET_KEYPAIR_PATH=./keypair.json

Marginfi SDK (marginfi-client-v2)

The SDK enables interaction with Marginfi's lending protocol for deposits, borrows, repayments, withdrawals, and advanced operations.

Core Classes

| Class | Purpose |
|-------|---------|
| MarginfiClient | Main client for loading groups and banks |
| MarginfiAccountWrapper | User account management and lending operations |
| Bank | Individual lending pool configuration and state |
| Balance | Asset or liability position within an account |
| NodeWallet | Wallet adapter for server-side usage |

Initialize Client

```typescript
import { MarginfiClient, getConfig } from "@mrgnlabs/marginfi-client-v2";
import { NodeWallet } from "@mrgnlabs/mrgn-common";
import { Connection, Keypair } from "@solana/web3.js";

const connection = new Connection("https://api.mainnet-beta.solana.com");
const keypair = Keypair.fromSec