Tweazy - The best way to read tweets onchain / Powered by x402, MCP & CDP Smart Wallets

The best way to monetize AI applications & MCP, using x402, MCP & CDP Smart Wallets.
Users pay 0.01 USDC per MCP query, showcasing how to monetize AI services with seamless Web3 payments.

📺 See it in Action

🚀 What This App Does

This application demonstrates a pay-per-use AI system where:

1. Users connect their wallet (Smart Wallet with passkeys or non-custodial wallets)
2. Ask AI questions through a chat interface
3. Pay 0.01 USDC per query automatically via x402
4. Receive AI-powered responses after successful payment
5. Interact with dynamic UI components generated by AI

Perfect for developers wanting to build monetized AI applications with Web3 payments (x402)

✨ Key Features

• 🔐 Dual Wallet Support: Smart Wallets with Passkeys (CDP) or non-custodial wallets
• 💳 x402 Payment Gates: HTTP 402 Payment Required implementation for API access
• 🔑 Passkey Authentication: Biometric login with Smart Wallets (most secure, no seed phrases)
• ⛽ Gas Sponsorship: Transaction fee sponsorship via paymaster for Smart Wallets
• 🤖 Tambo AI Integration: Generative UI with React component registry
• 🔗 MCP Protocol Support: Model Context Protocol for extensible AI functionality
• 🌐 Base Network: Supports both Base testnet (default) and Base mainnet
• 🛡️ Production Ready: Clean architecture with proper error handling
• 🎨 Dynamic UI: AI can generate and render React components on demand

🚀 Quick Start

Prerequisites

• Node.js 18+ and npm
• A Tambo AI API key (free tier available)
• A wallet address to receive payments

Setup

1. Clone and install:

   git clone https://github.com/aaronjmars/tweazy
   cd tweazy
   npm install
   

2. Configure environment:

   # Copy the example environment file
   cp example.env.local .env.local
   

3. Add your API keys to .env.local:

   # Required: Get from https://tambo.co/dashboard
   NEXT_PUBLIC_TAMBO_API_KEY=your-tambo-api-key
   
   # Required: Your wallet address to receive payments
   NEXT_PUBLIC_PAYMENT_RECIPIENT=0x0000CE08fa224696A819877070BF378e8B131ACF
   
   # Optional: Network mode (defaults to Base testnet for safety)
   NEXT_PUBLIC_NETWORK_MODE=testnet  # or 'mainnet' for production
   
   # Optional: CDP Wallet credentials (for enhanced wallet features)
   CDP_API_KEY_NAME=your-cdp-key-name
   CDP_API_KEY_PRIVATE_KEY=your-cdp-private-key
   CDP_PROJECT_ID=your-cdp-project-id
   CDP_WALLET_SECRET=your-cdp-wallet-secret
   CDP_PAYMASTER_SERVICE=your-paymaster-service-url
   

4. Start the development server:

   npm run dev
   

5. Open your browser to http://localhost:3000

First Steps

1. Connect a wallet (Smart Wallet with passkeys recommended for gas-free transactions)
2. Ask a question in the chat interface
3. Confirm the 0.01 USDC payment when prompted (gas fees may be sponsored)
4. See your AI response after successful payment!

⚙️ Configuration

Environment Variables

This app uses a security-first configuration approach:

• Secrets (API keys, wallet addresses) → Environment variables
• Non-secrets (RPC URLs, contract addresses, gas settings) → src/lib/config.ts

Required Environment Variables

• NEXT_PUBLIC_TAMBO_API_KEY: Your Tambo AI API key (Get one here)
• NEXT_PUBLIC_PAYMENT_RECIPIENT: Wallet address that will receive the 0.01 USDC payments

Optional Environment Variables

• NEXT_PUBLIC_NETWORK_MODE: testnet (default) or mainnet
• CDP credentials for enhanced wallet features (see example.env.local)

Network Configuration

The app automatically switches between Base networks based on NEXT_PUBLIC_NETWORK_MODE:

Testnet Mode (Default - Safe for Development)

• Network: Base Sepolia (Chain ID: 84532)
• USDC Contract: 0x036CbD53842c5426634e7929541eC2318f3dCF7e
• RPC URL: https://sepolia.base.org
• Features: Free testnet tokens, no real money at risk

Mainnet Mode (Production)

• Network: Base Mainnet (Chain ID: 8453)
• USDC Contract: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• RPC URL: https://mainnet.base.org
• Features: Real USDC transactions, production-ready

Easy Network Switching

Change one environment variable to switch networks:

# For development (safe, uses testnet)
NEXT_PUBLIC_NETWORK_MODE=testnet

# For production (real money!)
NEXT_PUBLIC_NETWORK_MODE=mainnet

All network-specific settings (RPC URLs, contract addresses, chain IDs) update automatically.

⛽ Gas Sponsorship (Paymaster)

Smart Wallets benefit from transaction fee sponsorship via paymaster integration:

How Gas Sponsorship Works

1. Smart Wallet Selection: When users choose Smart Wallet with passkeys
2. Automatic Detection: System detects Smart Wallet capability for gas sponsorship
3. Paymaster Integration: Gas fees for USDC payments are sponsored via CDP paymaster
4. User Experience: Users only pay the 0.01 USDC for AI queries, no gas fees required
5. Fallback: If paymaster fails, transaction proceeds with user-paid gas

Benefits

• 🆓 Gas-free transactions for Smart Wallet users
• 🔄 Automatic handling - no user configuration needed
• 🛡️ Reliable fallback - always works even if sponsorship unavailable
• 💰 Cost effective - users only pay for AI queries, not network fees

Technical Implementation

• Paymaster URL: Configured via CDP_PAYMASTER_SERVICE environment variable
• Sponsorship Logic: Implemented in src/lib/payment.ts
• User Operations: ERC-4337 compatible Smart Account transactions
• Base Network: Works on both Base Sepolia (testnet) and Base Mainnet

🔄 How It Works

User Flow

1. 🔗 Connect Wallet: Choose from Smart Wallet (passkeys) or non-custodial wallet
2. 💬 Ask Questions: Type your question in the chat interface
3. 💳 Payment Prompt: App shows payment modal for 0.01 USDC
4. ✅ Confirm Payment: Approve the blockchain transaction (gas fees sponsored for Smart Wallets)
5. 🤖 AI Response: Receive AI-generated answer with dynamic UI components
6. 🔄 Repeat: Ask more questions, each requiring a new payment

Payment Flow (x402 Implementation)

graph TD
    A[User asks question] --> B[AI service returns x402]
    B --> C[Payment modal appears]
    C --> D[User approves 0.01 USDC payment]
    D --> E[Transaction confirmed on blockchain]
    E --> F[Request retried with payment proof]
    F --> G[AI response delivered]

💼 Wallet Options

🔒 Smart Wallet with Passkeys (Recommended)

Best for: New users, gas-free transactions, maximum security

• ✅ No setup required - Wallet created automatically via CDP
• ✅ Biometric authentication - Use fingerprint, Face ID, or device passkeys
• ✅ Most secure - No seed phrases or private keys to manage
• ✅ Gas sponsorship - Transaction fees sponsored via paymaster
• ✅ Instant setup - Ready in seconds
• ✅ Auto-configured - Works on Base Sepolia/Mainnet out of the box

🔗 non-custodial wallet

Best for: Existing wallet users (MetaMask, Rabby, Coinbase Wallet, etc.)

• 🔧 Any injected Web3 wallet (MetaMask, Rabby, Coinbase Wallet, etc.)
• 🌐 Auto-switches to Base Sepolia network (Chain ID: 84532)
• 💧 Get testnet ETH from Base Sepolia Faucet for gas fees
• 🪙 Get testnet USDC: Contract 0x036CbD53842c5426634e7929541eC2318f3dCF7e

🏗️ Architecture

Project Structure

src/
├── app/                    # Next.js App Router
│   ├── api/               # API routes for CDP wallet operations
│   ├── mcp-config/        # MCP server configuration page
│   └── page.tsx           # Main application page
├── components/            # React components
│   ├── ui/               # Reusable UI components
│   ├── WalletProvider.tsx # Multi-wallet context
│   ├── PaymentModal.tsx   # Payment confirmation UI
│   └── EnhancedMessageInput.tsx # Chat input with payment
├── lib/                   # Core business logic
│   ├── config.ts         # Configuration management
│   ├── payment.ts        # Universal payment handling
│   ├── smart-wallet.ts   # Smart wallet integration
│   ├── cdp-wallet.ts     # Coinbase CDP integration
│   ├── x402.ts           # HTTP 402 handling
│   └── tambo.ts          # AI component registry
└── styles/               # Global styles and Tailwind

Core Systems

💳 Payment System (src/lib/payment.ts)

• Universal payment handling for both wallet types
• x402 integration for payment-gated API calls
• Paymaster integration for gas sponsorship on Smart Wallets
• Transaction validation and error handling
• USDC transfers on Base network

🔐 Wallet Management

• Smart Wallet (src/lib/smart-wallet.ts): CDP-based passkey authentication with gas sponsorship
• non-custodial wallet (via wagmi): Support for all injected Web3 wallets
• Wallet Provider (src/components/WalletProvider.tsx): Dual-wallet context management

🤖 AI Integration

• Tambo AI: React component registry for AI-driven UI
• MCP Protocol: Model Context Protocol for extensible AI
• Dynamic Components: AI generates and renders React components
• Payment Gates: x402 responses trigger payment flows

API Routes

Smart Wallet (CDP) Operations

• POST /api/cdp/create-wallet - Create new Smart Wallet via CDP
• POST /api/cdp/balance - Check USDC balance
• POST /api/cdp/transfer - Execute USDC payments with optional gas sponsorship
• POST /api/cdp/fund-wallet - Fund wallet with testnet tokens
• POST /api/paymaster - Handle paymaster gas sponsorship for Smart Wallets

Configuration System

Environment-Based Config (src/lib/config.ts)

• Network switching: Automatic testnet/mainnet configuration
• Contract addresses: Network-specific USDC contracts
• RPC endpoints: Reliable Base network connections
• Gas settings: Optimized transaction parameters

🛠️ Development

Commands

# Development
npm run dev          # Start development server at localhost:3000
npm run build        # Build production application
npm run start        # Start production server
npm run lint         # Run ESLint for code linting

### Development Workflow

1. **Fork the repository** and clone your fork
2. **Create a feature branch**: `git checkout -b feature/your-feature`
3. **Install dependencies**: `npm install`
4. **Set up environment**: Copy `example.env.local` to `.env.local`
5. **Start development**: `npm run dev`
6. **Make your changes** and test thoroughly
7. **Run linting**: `npm run lint`
8. **Build to verify**: `npm run build`
9. **Commit and push**: Follow conventional commit format
10. **Create a pull request** with detailed description

### Code Style

- **TypeScript**: Strict mode enabled
- **ESLint**: Configured for Next.js and React
- **Prettier**: Code formatting (run with `npm run format`)
- **Conventional Commits**: Use conventional commit format

### Test Scenarios

#### Core Payment Flow

1. **Smart Wallet (Recommended)**:
   - Create passkey → Ask question → Confirm payment (gas-free) → See AI response

2. **non-custodial wallet**:
   - Connect wallet → Switch to Base Sepolia → Ask question → Pay (with gas fees) → See response

### Getting Testnet Tokens

#### For Smart Wallet Users

- **No setup required** - Smart Wallets with gas sponsorship don't need ETH for gas fees
- **USDC only** - Get testnet USDC for payments (contract: `0x036CbD53842c5426634e7929541eC2318f3dCF7e`)

#### For non-custodial wallet Users

- **Base Sepolia ETH (for gas fees)**:
  - [Alchemy Base Sepolia Faucet](https://www.alchemy.com/faucets/base-sepolia)
  - [Coinbase Faucet](https://www.coinbase.com/faucets/base-sepolia-faucet)

- **Base Sepolia USDC (for payments)**:
  - Contract: `0x036CbD53842c5426634e7929541eC2318f3dCF7e`
  - Use a testnet USDC faucet or bridge testnet ETH to USDC

## 🔧 Technical Details

### Wallet Architecture

#### Smart Wallet (CDP with Passkeys)

- **SDK**: Coinbase CDP SDK with Smart Wallet integration
- **Authentication**: WebAuthn passkeys (biometric authentication)
- **Security**: No private keys or seed phrases, device-based authentication
- **Gas Sponsorship**: ERC-4337 paymaster integration for transaction fee sponsorship
- **Network**: Base Sepolia/Mainnet with automatic configuration

#### non-custodial wallet Integration

- **Library**: wagmi + viem for Web3 wallet connections
- **Supported Wallets**: MetaMask, Rabby, Coinbase Wallet, and all injected wallets
- **Network**: Base Sepolia/Mainnet with manual gas fee payment
- **Features**: Standard Web3 wallet connection with user-controlled private keys

### x402 Payment Protocol

```mermaid
sequenceDiagram
    participant User
    participant App
    participant AI
    participant Blockchain

    User->>App: Ask question
    App->>AI: Send query
    AI-->>App: 402 Payment Required
    App->>User: Show payment modal
    User->>Blockchain: Send 0.01 USDC
    Blockchain-->>App: Transaction confirmed
    App->>AI: Retry with payment proof
    AI-->>App: Return AI response
    App->>User: Display answer

Smart Contracts

USDC Contracts

Testnet (Base Sepolia):

• Address: 0x036CbD53842c5426634e7929541eC2318f3dCF7e
• Chain ID: 84532
• Decimals: 6

Mainnet (Base):

• Address: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• Chain ID: 8453
• Decimals: 6

Network Configuration

The app automatically switches contracts and RPC endpoints based on NEXT_PUBLIC_NETWORK_MODE.

🔒 Security Considerations

Network Safety

⚠️ Defaults to testnet for safety - no real money at risk

• Testnet mode: All payments use test tokens (no real value)
• Mainnet mode: Real USDC transactions - use with caution
• Always verify NEXT_PUBLIC_NETWORK_MODE before deployment

Wallet Security

• Smart Wallets: Most secure - use passkeys, no private keys, gas sponsorship included
• non-custodial wallets: User-controlled private keys, manual gas fee management
• Payment validation: All transactions verified on-chain
• Gas sponsorship: Smart Wallets benefit from paymaster-sponsored transactions

🤝 Contributing

We welcome contributions! Here's how to get started:

Quick Contribution Guide

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Make your changes
4. Test thoroughly (run npm run build and npm run lint)
5. Commit using conventional commits: feat: add amazing feature
6. Push to your fork: git push origin feature/amazing-feature
7. Create a Pull Request with detailed description

What We're Looking For

• 🐛 Bug fixes and improvements
• ✨ New AI components for the registry
• 🔧 Wallet integrations (new wallet types)
• 📚 Documentation improvements
• 🧪 Test coverage enhancements
• 🎨 UI/UX improvements

Development Guidelines

• TypeScript: Use strict typing
• Testing: Add tests for new features
• Documentation: Update README for new features
• Code style: Follow existing patterns
• Commits: Use conventional commit format

📚 Resources & Documentation

Core Technologies

• Tambo AI: Generative UI framework with MCP support
• Tambo GitHub: Component registry and MCP integration
• Next.js: React framework for production
• Tailwind CSS: Utility-first CSS framework

Web3 & Blockchain

• Coinbase CDP: Coinbase Developer Platform
• Base Network: Ethereum L2 network
• wagmi: React hooks for Ethereum
• viem: TypeScript interface for Ethereum

Protocols & Standards

• x402 Standard: HTTP 402 Payment Required
• MCP Protocol: Model Context Protocol
• WebAuthn: Web Authentication API (for passkeys)

🆘 Support & Troubleshooting

Common Issues

"Payment recipient not configured"

• Set NEXT_PUBLIC_PAYMENT_RECIPIENT in .env.local
• Use a valid Ethereum address

"Tambo API key not found"

• Get API key from tambo.co/dashboard
• Set NEXT_PUBLIC_TAMBO_API_KEY in .env.local

"Insufficient balance"

• Get testnet tokens from Base Sepolia faucets
• Ensure you have both ETH (gas) and USDC (payments)

"Network not supported"

• Check MetaMask is connected to Base Sepolia (Chain ID: 84532)
• Verify NEXT_PUBLIC_NETWORK_MODE setting

Getting Help

• 📖 Check the docs above for detailed information
• 🐛 Open an issue for bugs or feature requests
• 💬 Start a discussion for questions or ideas
• 🔍 Check console logs for detailed error information

Debug Mode

Enable debug logging by adding to .env.local:

NEXT_PUBLIC_DEBUG=true

🚀 Ready to Build?

This project demonstrates the future of monetized AI applications with seamless Web3 payments. Fork it, customize it, and build the next generation of payment-gated AI services!

Happy coding! 🎉