hashlock-lending-sdk 🔒

Yield on Bitcoin. Locked by code. Verified by hash.

The first developer-ready JavaScript SDK for interacting with HashLock Lending — the Bitcoin L2 lending protocol powered by Clarity 4.

No admin keys • No upgrades • No trust assumptions • Verified vaults

Installation

npm install hashlock-lending-sdk

or

yarn add hashlock-lending-sdk

Quick Start (ES Modules)

import { HashlockClient } from 'hashlock-lending-sdk';

// Initialize SDK
const client = new HashlockClient({ network: "mainnet" });

// Connect wallet (Xverse / Leather)
await client.connectWallet({ appName: "HashLock SDK Demo" });

// Create a new loan
const loanId = await client.createLoan({
  loanId: "loan_888",
  borrower: "SP123...",
  lender: "SP456...",
  amount: 1000000, // 1 STX in micro-STX
  preimage: "my-secure-preimage"
});

// Repay loan using the secret preimage
await client.repayLoan("loan_888", "my-secure-preimage");

const status = client.getLoanStatus("loan_888");
console.log("Is Repaid:", status.repaid);

Core Features

| Feature | hashlock-lending-sdk | Other Lending Protocols | |---------|--------------------|-----------------------| | On-chain code hash verification | ✅ contract-hash? enforced on every deposit | ❌ None | | Auto-revert rogue transfers | ✅ restrict-assets? post-conditions | ❌ Admin keys only | | Immutable vaults | ✅ Pure templates | ❌ Proxy upgrades required | | Admin keys | ✅ None | ❌ Always present | | Clarity version | ✅ 4 | ❌ 2/3 | | Wallet Integration | ✅ Xverse / Leather | ❌ None |

Live Contracts (Stacks Mainnet)

| Contract | Purpose | Address | |----------|---------|---------| | hashlock-core | Lending pool + template registry | SP2C2YFP12AJZB4MABJBAJ55XECVS7E4PMMZ89YZR.hashlock-core | | hashlock-isolated-sbtc-v1 | First whitelisted vault (sBTC flash loans) | SP2C2YFP12AJZB4MABJBAJ55XECVS7E4PMMZ89YZR.hashlock-isolated-sbtc-v1 | | safe-vault-base | Shared immutable safety traits | SP2C2YFP12AJZB4MABJBAJ55XECVS7E4PMMZ89YZR.safe-vault-base |

Developer Guide

1. Clone the Repo

git clone [https://github.com/investorphem/hashlock-lending-sdk.git](https://github.com/investorphem/hashlock-lending-sdk.git)
cd hashlock-lending-sdk

2. Install Dependencies

npm install

3. Connect Wallet (Xverse or Leather)

await client.connectWallet({ appName: "Your App Name" });

4. Create & Repay Loans

Use createLoan, repayLoan, and getLoanStatus methods as shown in the Quick Start.

5. Call Clarity Contracts

• callContract → For securely triggering on-chain contract calls via wallet popup.

Tech Stack

• Smart Contracts: Clarity 4 on Stacks (Bitcoin-secured via PoX + sBTC)
• Frontend: React + Vite + @stacks/connect (Leather/Xverse)
• Hosting: Vercel (zero-config)
• Supported Assets: sBTC (mainnet), xBTC, USDA, stSTX coming

Resources

• App: hashlocklending.vercel.app
• Explorer: Hiro Explorer
• Twitter: @investorphem