NeverPay

DeFi-powered AI platform — deposit once, use forever.

Overview

NeverPay lets users deposit USDC, earn credits from yield (via Aave), and spend those credits on services - while keeping the ability to withdraw their principal at any time.

Key Features

• Deposit & Earn — Stake USDC to receive credits (50 credits per $1, 20% platform margin)
• Yield Farming — Deposits flow into Aave for continuous yield generation
• AI Image Generation — Generate images via Gemini 2.5 Flash
• AI Chat — Multi-turn conversations via Gemini 2.0 Flash
• Cross-chain Deposits — Bridge any token from any chain to Base USDC via LI.FI
• Full Withdrawal — Withdraw principal anytime (credits revoked on withdrawal)
• Real-time Dashboard — Live view of deposits, credits, yield earned, and usage

Architecture

┌──────────────────────────────────────────────────────┐
│               Frontend (Next.js App Router)           │
│  ┌────────────┐  ┌────────────┐  ┌────────────────┐  │
│  │ Wallet     │  │ Dashboard  │  │ Marketplace    │  │
│  │ (wagmi +   │  │ (Credits,  │  │ (AI platforms) │  │
│  │  Rainbow)  │  │  Yields)   │  │                │  │
│  └────────────┘  └────────────┘  └────────────────┘  │
│                                                       │
│  ┌────────────────────────────────────────────────┐   │
│  │           Next.js API Routes                   │   │
│  │  /api/generate  /api/chat  /api/credits/:addr  │   │
│  └────────────────────────────────────────────────┘   │
└──────────────────────────────────────────────────────┘
                          │
                          ▼
┌──────────────────────────────────────────────────────┐
│           Smart Contracts (Base Sepolia testnet)       │
│  ┌────────────────────────────────────────────────┐   │
│  │  YieldVault.sol                                │   │
│  │  - USDC deposits → Aave aUSDC                  │   │
│  │  - Credit minting / deduction                  │   │
│  │  - Yield accrual tracking                      │   │
│  └────────────────────────────────────────────────┘   │
└──────────────────────────────────────────────────────┘
                          │
                          ▼
      Base Sepolia · Aave V3 · LI.FI Bridge (→ Base mainnet)

Credit Formula

Credits = deposit_usdc × 50 × 0.8 (platform margin)

Example: $100 USDC deposit → 4,000 credits
Each image or chat message costs 1 credit

Contract Addresses (Base Sepolia)

Quick Start

Prerequisites

• Node.js 18+
• MetaMask or any EVM wallet
• Base Sepolia ETH (from faucet) and Base Sepolia USDC

Installation

cd frontend
npm install
cp .env.example .env.local
# Fill in GEMINI_API_KEY, NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID,
# NEXT_PUBLIC_YIELD_VAULT_ADDRESS, YIELD_VAULT_ADDRESS, BACKEND_PRIVATE_KEY

npm run dev

Environment Variables

# Client-side
NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID=
NEXT_PUBLIC_YIELD_VAULT_ADDRESS=

# Server-side (API routes)
GEMINI_API_KEY=
YIELD_VAULT_ADDRESS=
RPC_URL=https://sepolia.base.org
BACKEND_PRIVATE_KEY=

Deploy Contracts

cd contracts
npm install
PRIVATE_KEY=0x... npx hardhat run scripts/deploy.js --network baseSepolia

Project Structure

NeverPay/
├── contracts/          # Solidity — YieldVault with Aave integration
├── frontend/           # Next.js 16 (App Router)
│   ├── app/
│   │   ├── api/        # generate, chat, credits, health
│   │   ├── marketplace/
│   │   └── platform/   # yieldcredit-ai, gemini-chat
│   ├── components/     # Dashboard, DepositForm, BridgeDeposit, etc.
│   ├── contexts/       # DashboardContext
│   └── lib/            # config, contracts, lifi, contract helpers
└── README.md

License

MIT — Built for ETHGlobal HackMoney 2026