ETH Mood Meter - Farcaster Mini-App A production-ready Farcaster mini-app built with Next.js 14, TypeScript, and Ethers v6 that allows users to vote on their Ethereum sentiment (Bullish or Bearish) on Base network. Features

✅ Vote once per day (Bullish or Bearish) ✅ Real-time sentiment tracking ✅ Works as Farcaster miniapp and standalone web page ✅ Base network integration via Ethers v6 ✅ Mobile-first responsive design ✅ Auto-refresh counts every 10 seconds ✅ LocalStorage vote tracking ✅ MetaMask/Web3 wallet integration

Prerequisites

Node.js 18+ and npm EthMoodMeter contract deployed on Base Vercel account (for deployment) Farcaster account (for miniapp registration)

Installation

Clone and install dependencies:

bashnpm install

Create .env.local file:

bashcp .env.example .env.local

Configure environment variables:

bash# .env.local NEXT_PUBLIC_URL=http://localhost:3000 NEXT_PUBLIC_RPC=https://mainnet.base.org NEXT_PUBLIC_CHAIN_ID=8453 NEXT_PUBLIC_CONTRACT=0xYourContractAddressHere

Run development server:

bashnpm run dev Visit http://localhost:3000 Environment Variables VariableDescriptionDefaultRequiredNEXT_PUBLIC_URLYour app's public URL-✅ YesNEXT_PUBLIC_RPCBase RPC endpointhttps://mainnet.base.orgNoNEXT_PUBLIC_CHAIN_IDNetwork chain ID8453NoNEXT_PUBLIC_CONTRACTEthMoodMeter contract address-✅ Yes Deploying to Vercel

Push code to GitHub Import project in Vercel:

Go to vercel.com Click "New Project" Import your GitHub repository

Configure environment variables:

Add all variables from .env.local Set NEXT_PUBLIC_URL to your Vercel domain

Deploy:

bash vercel --prod Generating Farcaster Account Association To register your mini-app with Farcaster, you need to generate account association credentials:

Install Farcaster Auth Kit:

bash npm install @farcaster/auth-kit

Generate credentials using Farcaster's tools:

Visit Farcaster Developer Portal Follow the account association protocol Generate header, payload, and signature

Update manifest route: Replace placeholders in app/.well-known/farcaster.json/route.ts:

typescript header: "YOUR_GENERATED_HEADER", payload: "YOUR_GENERATED_PAYLOAD", signature: "YOUR_GENERATED_SIGNATURE",

Verify manifest:

bash curl https://your-domain.com/.well-known/farcaster.json Switching to Base Sepolia (Testnet) For testing, use Base Sepolia testnet:

Update .env.local:

bash NEXT_PUBLIC_RPC=https://sepolia.base.org NEXT_PUBLIC_CHAIN_ID=84532 NEXT_PUBLIC_CONTRACT=0xYourSepoliaContractAddress

Get testnet ETH:

Visit Base Sepolia Faucet Request testnet tokens

Deploy contract to Sepolia (if needed)

Project Structure ├── app/ │ ├── page.tsx # Main page │ ├── layout.tsx # Root layout │ ├── globals.css # Global styles │ └── .well-known/farcaster.json/ │ └── route.ts # Farcaster manifest ├── components/ │ └── MoodWidget.tsx # Main UI component ├── lib/ │ ├── abi.ts # Contract ABI │ ├── utils.ts # Utility functions │ └── contract.ts # Contract interactions ├── hooks/ │ └── useFarcasterContext.ts # Farcaster context hook └── .env.local # Environment variables Contract Interface The EthMoodMeter contract implements: solidityfunction vote(uint256 fid, uint8 mood) external function today() external view returns (uint256 day, uint256 bullish, uint256 bearish) function totals() external view returns (uint256 bullish, uint256 bearish) Where mood: 0 = Bearish, 1 = Bullish Adding Static Assets Place these images in the public/ folder:

icon.png - App icon (512x512px recommended) preview.png - Preview image (1200x630px) splash.png - Splash screen (1200x1200px)

Troubleshooting Contract calls failing:

Verify NEXT_PUBLIC_CONTRACT address is correct Ensure RPC endpoint is working Check network (Base mainnet vs Sepolia)

Wallet not connecting:

Install MetaMask or compatible wallet Switch to Base network in wallet Ensure wallet has ETH for gas

Manifest not loading:

Verify NEXT_PUBLIC_URL is set correctly Check .well-known/farcaster.json route is accessible Ensure CORS is configured properly

Security Notes

Never commit private keys or sensitive data Use environment variables for all configuration Validate all user inputs Rate limit voting on contract level Implement proper error handling

License MIT Support For issues or questions:

Check GitHub Issues Review Farcaster documentation Review Base network documentation

Built with ❤️ for the Farcaster and Base communities