create-fhevm-nextjs

A CLI to create a Next.js app with FHEVM SDK integration.

✨ Updated for FHEVM 0.9.1: This package now uses FHEVM 0.9.1 with the new self-relaying decryption pattern, decryptMultipleHandles support, ZamaEthereumConfig, FHE.checkSignatures, and updated contract addresses on Sepolia testnet.

Usage

npx create-fhevm-nextjs my-app
cd my-app
npm install
npm run dev

Environment Setup

Before deploying contracts, you need to set up your environment variables:

1. Create a .env file in the hardhat directory:

cd hardhat
touch .env

2. Add your environment variables to .env:

# Your wallet mnemonic (12 or 24 words)
MNEMONIC=your wallet mnemonic phrase here

# Your Infura API key (get one at https://infura.io)
INFURA_API_KEY=your_infura_api_key_here

# Optional: Etherscan API key for contract verification
ETHERSCAN_API_KEY=your_etherscan_api_key_here

3. Get your Infura API key:

• Visit https://infura.io
• Sign up for a free account
• Create a new project
• Copy your project API key

4. Deploy your contracts:

# Deploy to Sepolia testnet
npm run deploy:sepolia

What you get

• Complete React application with FHEVM SDK integration
• Bundled FHEVM SDK (no external dependencies)
• Beautiful Zama-branded UI
• TypeScript support
• Tailwind CSS styling
• Working FHEVM operations (encryption, decryption, contract interactions)
• Three Complete FHE Contracts for testing on Sepolia testnet:
  • FHECounter: Encrypted counter with increment/decrement
  • ReviewCardsFHE: Encrypted rating system with public decryption
  • SimpleVoting: Encrypted voting system with tally reveal
• Public decryption demo with hardcoded ciphertexts
• Ready-to-use React hooks
• Complete Hardhat development environment with:
  • All three FHE smart contracts
  • Deployment scripts for Sepolia testnet
  • Contract testing utilities
  • TypeScript support for contracts
• Universal FHEVM SDK (FHEVM 0.9.1) with utilities for:
  • FHEVM initialization
  • Encrypted inputs creation
  • User decryption with EIP-712 signing
  • Public decryption flows
  • decryptMultipleHandles for batch decryption with proofs
  • Self-relaying decryption pattern for contract callbacks

Deployed FHE Contracts (FHEVM 0.9.1)

The generated app includes pre-deployed FHE Contracts on Sepolia testnet for testing:

• FHECounter Contract: 0x7A14b454D19A4CB4c55E0386d04Eb0B66e6717EC (FHEVM 0.9.1)
• ReviewCardsFHE Contract: 0xf80A030984a0AB6111B6e60973A6c16C668ede7a (FHEVM 0.9.1)
• SimpleVoting Contract: 0x4189777Eb42f68Ce959E498a171e328BfDA90C46 (FHEVM 0.9.1)
• Network: Sepolia testnet (Chain ID: 11155111)
• Features:
  • Get encrypted count from contract
  • Increment/decrement with encrypted inputs
  • User decryption with EIP-712 signing
  • Public decryption with decryptMultipleHandles
  • Self-relaying decryption pattern for voting tallies

Features

• ✅ Self-contained: No need to install FHEVM SDK separately
• ✅ Cross-platform: Works on Windows, Mac, Linux
• ✅ Zero configuration: Works out of the box
• ✅ Production ready: Includes all necessary files and configurations
• ✅ Beautiful UI: Zama design system with Tailwind CSS
• ✅ Real FHEVM operations: Actual encryption/decryption functionality
• ✅ Live contract: Pre-deployed FHE counter for immediate testing
• ✅ Complete development environment: Includes Hardhat for smart contract development

Smart Contract Development

The generated app includes a complete Hardhat development environment with all necessary files for FHEVM smart contract development:

📁 Hardhat Directory Structure:

hardhat/
├── contracts/
│   ├── FHECounter.sol          # FHE Counter smart contract
│   ├── ReviewCardsFHE_uint32.sol # FHE Rating system contract
│   └── SimpleVoting_uint32.sol  # FHE Voting system contract
├── deploy/
│   └── deploy.ts              # Deployment script for all contracts
├── hardhat.config.js          # Hardhat configuration (JavaScript)
├── package.json               # Hardhat dependencies
└── tsconfig.json             # TypeScript configuration

🔧 Available Commands:

# Navigate to the hardhat directory
cd hardhat

# Install dependencies
npm install

# Compile contracts
npm run compile

# Start local hardhat node
npm run chain

# Deploy to hardhat network
npm run deploy:hardhat

# Deploy to Sepolia testnet (requires INFURA_API_KEY)
npm run deploy:sepolia

📋 What's Included:

• ✅ FHE Counter Contract - Complete Solidity smart contract
• ✅ Deployment Scripts - Ready-to-use deployment scripts
• ✅ TypeScript Support - Full type safety for contracts
• ✅ Network Configuration - Pre-configured for hardhat and sepolia
• ✅ FHEVM Integration - Built-in FHEVM contract support
• ✅ Simplified Scripts - Clean, focused deployment commands
• ✅ JavaScript Config - No TypeScript compilation issues

Requirements

• Node.js 16 or higher
• npm or yarn

License

MIT