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

``bash
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:

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`bash
cd hardhat
touch .env
`

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`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
`

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

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`bash


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:

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`
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
`

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`bash

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
``

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- ✅ 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