PayDrip 💧

Programmable micro-payment pipeline on Base L2. Create recurring payments, subscriptions, vesting, and more with fiat on-ramp support.

🚀 Features

Core Functionality

• 📅 Discrete Step Payments - Execute payments at specific intervals or events
• 💰 Fiat On-Ramp - Pay with credit card via Base Pay integration
• 🔗 Payment Links - Share payment links for easy subscriptions
• 💱 Real-time Quotes - Fiat-to-crypto conversion with multiple currencies
• 🔄 UUPS Upgradeable - Future-proof smart contracts
• ⚡ Gas Optimized - Efficient on Base L2

Use Cases

• 📺 Creator Subscriptions - Monthly payments to content creators
• 👥 Team Vesting - Token distribution for team members
• 🏢 Service Payments - Weekly/monthly service invoices
• 💳 Usage-Based Billing - Event-driven payment execution
• 🎁 Recurring Donations - Automated charitable giving

📦 Quick Start

For Users

1. Create a Drip with Crypto

import { PayDrip } from '@paydrip/sdk';

const drip = await payDrip.createDrip({
  receiver: '0xReceiverAddress',
  amountPerStep: '100', // 100 USDC
  totalSteps: 12,
  interval: 30 * 24 * 60 * 60, // 30 days
  token: USDC_ADDRESS
});
// 💸 12 monthly payments of 100 USDC

2. Create a Drip with Fiat (Credit Card)

const { paymentId, checkoutUrl } = await basePayDrip.initiateDripWithFiat({
  receiver: '0xReceiverAddress',
  amountPerStep: '50',
  totalSteps: 6,
  interval: 7 * 24 * 60 * 60, // 7 days
  returnUrl: 'https://yourapp.com/success'
});

// Redirect user to checkoutUrl for credit card payment
window.location.href = checkoutUrl;

3. Create a Payment Link

const linkId = await linkFactory.createPaymentLink({
  receiver: '0xReceiverAddress',
  amountPerStep: '25',
  totalSteps: 4,
  interval: 14 * 24 * 60 * 60, // 14 days
  expiry: Date.now() + 30 * 24 * 60 * 60 * 1000, // 30 days
  memo: 'Premium Subscription',
  multiUse: true
});

// Share link: https://paydrip.app/pay/{linkId}

For Developers

# Clone repository
git clone https://github.com/shpak-vlad/PayDrip.git
cd PayDrip/contracts

# Install dependencies
forge install

# Run tests
forge test -vv

# Deploy
forge script script/Deploy.s.sol --rpc-url base --broadcast

🏗️ Architecture

Core Contracts

PayDrip.sol

Main contract for drip creation and execution.

struct Drip {
  address sender;
  address receiver;
  address token;
  uint96 amountPerStep;
  uint32 totalSteps;
  uint32 currentStep;
  uint32 interval;
  uint64 lastExecuted;
  bool active;
}

BasePayDrip.sol

Fiat on-ramp integration via Base Pay API.

Features:

• Credit card to crypto conversion
• Oracle-based payment confirmation
• Automatic drip creation after payment

PaymentLinkFactory.sol

Generate shareable payment links.

Features:

• Single-use or multi-use links
• Crypto and fiat payment options
• Link expiration and validation

FiatQuoter.sol

Real-time fiat-to-crypto quotes.

Features:

• Support for USD, EUR, GBP
• Oracle-based rate updates
• Fee calculation

Execution Flow

┌──────────────┐
│ User creates │
│    drip      │
└──────┬───────┘
       │
       ▼
┌──────────────┐     ┌─────────────┐
│ Lock funds   │────▶│ Step 1      │
│ (1000 USDC)  │     │ Transfer    │
└──────────────┘     │ 100 USDC    │
                     └──────┬──────┘
                            │ Wait 30 days
                            ▼
                     ┌─────────────┐
                     │ Step 2      │
                     │ Transfer    │
                     │ 100 USDC    │
                     └──────┬──────┘
                            │ ...
                            ▼
                     ┌─────────────┐
                     │ Step 10     │
                     │ Completed   │
                     └─────────────┘

🌐 Deployments

Base Mainnet

• PayDrip Proxy: 0x6f2bd18433b0aea1a10be7af88d3a6bbdd0f8b1e
• USDC: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• BasePayDrip: TBD
• PaymentLinkFactory: TBD
• FiatQuoter: TBD

Base Sepolia (Testnet)

• PayDrip Proxy: See contracts/deployments/base-sepolia.json

📖 Documentation

• Base Pay Integration Guide
• Deployment Guide
• Security
• Testing
• Gas Report

🔐 Security

• ✅ UUPS Upgradeable pattern
• ✅ ReentrancyGuard on all external functions
• ✅ Oracle verification for fiat payments
• ✅ Payment timeout protection (24 hours)
• ✅ Comprehensive test coverage

Audit Status: Pending

🛠️ Tech Stack

• Blockchain: Base L2 (Optimistic Rollup)
• Language: Solidity 0.8.23
• Framework: Foundry
• Libraries: OpenZeppelin Upgradeable
• Integration: Base Pay API

💡 Examples

Monthly Subscription

// User subscribes to premium content
payDrip.createDrip(
    10e6,        // 10 USDC/month
    12,          // 12 months
    30 days,     // Monthly
    creator,
    USDC
);

Team Vesting

// 100k tokens vesting quarterly over 1 year
payDrip.createDrip(
    25000e18,    // 25k tokens
    4,           // 4 quarters
    90 days,     // Quarterly
    teamMember,
    TOKEN
);

Service Payment

// Weekly service payment for 6 months
payDrip.createDrip(
    100e6,       // 100 USDC/week
    24,          // 24 weeks
    7 days,      // Weekly
    provider,
    USDC
);

🤝 Contributing

Contributions are welcome! Please read our contributing guidelines.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'feat: add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

MIT License - see LICENSE file for details

🔗 Links

• Website: https://paydrip.app (coming soon)
• Documentation: https://docs.paydrip.app (coming soon)
• Base: https://base.org
• GitHub: https://github.com/shpak-vlad/PayDrip

🙏 Acknowledgments

Built on Base - the secure, low-cost, builder-friendly Ethereum L2 by Coinbase.

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Made with ❤️ for the Base ecosystem