Mantissa

Features

• 🔐 Seedless Authentication - Use device biometrics instead of seed phrases

• 📱 WebAuthn/FIDO2 - Industry-standard passkey protocol

• ⛽ ERC-4337 Compatible - Account abstraction ready

• 🔑 Multi-Owner Support - Add backup passkeys for recovery

• ⚡ Mantle Optimized - Built for low gas costs on Mantle L2

🏗️ Architecture

┌─────────────────────────────────────────────────────────┐
│                    User Device                          │
│  ┌─────────────┐    ┌──────────────┐    ┌───────────┐  │
│  │  Biometric  │───▶│   Passkey    │───▶│  Wallet   │  │
│  │   Prompt    │    │  (WebAuthn)  │    │   SDK     │  │
│  └─────────────┘    └──────────────┘    └───────────┘  │
└────────────────────────────┬────────────────────────────┘
                             │ Sign Transaction
                             ▼
┌─────────────────────────────────────────────────────────┐
│                    Mantle L2                            │
│  ┌─────────────────┐    ┌───────────────────────────┐  │
│  │ MantissaFactory│───▶│  MantissaWallet (Clone)  │  │
│  │ (Deploys Wallets)│    │  • P-256 Signature Verify │  │
│  └─────────────────┘    │  • Execute Transactions   │  │
│                          │  • Multi-Owner Support    │  │
│                          └───────────────────────────┘  │
└─────────────────────────────────────────────────────────┘

📦 Packages

🚀 Quick Start

Prerequisites

• Node.js 18+

• Foundry

Installation

# Clone the repo
git clone https://github.com/subh/keymantle.git
cd keymantle

# Install dependencies
npm install

# Build all packages
npm run build

Run Demo

# Terminal 1: Start local Mantle forkcd packages/contracts
anvil --fork-url https://rpc.sepolia.mantle.xyz

# Terminal 2: Deploy contracts
PRIVATE_KEY=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 \
forge script script/Deploy.s.sol --rpc-url http://127.0.0.1:8545 --broadcast

# Terminal 3: Run demo appcd packages/demo
npm run dev

Open http://localhost:3000 and click "Create Passkey Wallet"!

📚 Documentation

Smart Contracts

The core contracts implement a passkey-authenticated smart wallet:

• MantissaWallet.sol - Smart wallet with P-256 signature verification

• MantissaFactory.sol - Factory for deploying wallets (CREATE2)

• WebAuthnVerifier.sol - On-chain WebAuthn signature verification

See packages/contracts/DEPLOYMENT.md for deployment instructions.

SDK Usage

import { MantissaClient } from '@mantlepass/sdk';

// Initialize clientconst client = new MantissaClient({
  rpcUrl: 'https://rpc.sepolia.mantle.xyz',
  factoryAddress: '0x...',
});

// Create wallet with passkeyconst wallet = await client.createWallet({
  name: 'My Wallet',
});

// Sign and send transactionconst txHash = await client.sendTransaction({
  to: '0x...',
  value: 1000000000000000000n, // 1 MNTdata: '0x',
});

Networks

🧪 Testing

# Run contract testscd packages/contracts
forge test -vvv

# Run SDK testscd packages/sdk
npm test

🛠️ Development

Project Structure

keymantle/
├── packages/
│   ├── contracts/          # Solidity contracts
│   │   ├── src/           # Contract source files
│   │   ├── test/          # Foundry tests
│   │   └── script/        # Deployment scripts
│   ├── sdk/               # TypeScript SDK
│   │   └── src/
│   │       ├── client/    # MantissaClient
│   │       ├── webauthn/  # Passkey utilities
│   │       └── utils/     # Helpers
│   └── demo/              # Next.js demo app
├── package.json           # Monorepo root
└── README.md

Build Commands

# Build everything
npm run build

# Build specific package
npm run build --workspace=packages/sdk

# Run tests
npm test

🔐 Security

• P-256 (secp256r1) - Hardware-backed elliptic curve cryptography

• WebAuthn - W3C standard for passwordless authentication

• On-chain verification - All signatures verified by smart contracts

• No private key exposure - Keys never leave secure hardware

Audit Status

⚠️ Not audited - This is experimental software. Use at your own risk.

🗺️ Roadmap

• Core smart contracts

• TypeScript SDK

• Demo application

• ERC-4337 Bundler integration

• Social recovery module

• Session keys for dApps

• Mobile SDK (React Native)

• Hardware wallet backup

Team Bio:
Eric:

Audio Visual Professional with over a decade of history working in the corporate event and film production services. Played a vital role in producing over 420+ corporate events. Strong arts and design professional, skilled in Photography, Adobe Creative Cloud, Autodesk, Microsoft computers, and software. Working capabilities with HTML5, CSS, Java, JavaScript, React. Focused on VR/AR, Blockchain, and game development in Unity and Unreal Engines in my free time.

Shub:
I like building things in Rust,

mostly tools and experiments

that solve problems I face myself. I believe the best way to

learn is by doing, breaking things, and rebuilding them

better.

My PRs are in Surfpool and Scilla.

Ivc:
Over the past few years, I've had the privilege of working with incredible people on projects that pushed boundaries. We've won hackathons, earned grants, and built things people actually use.

But here's what I've learned: the real win isn't the prize money or the recognition. It's finding the right people who stick around after the confetti falls.

I create digital experiences that blend art with technology—from immersive audio-visual pieces to interactive NFTs and Web3 applications. Every project is an opportunity to push creative boundaries and build something meaningful.