Send USDC or EURC peer-to-peer on Arc Network Testnet with near-zero fees (~$0.01). No ETH needed — USDC is the gas token.
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ARC payment is a peer-to-peer stablecoin transfer DApp built on Arc Network Testnet. It lets users send USDC or EURC directly to any wallet address with:
- Near-zero fees — gas costs ~$0.01 paid in USDC (no ETH required)
- Gasless relay — optional relayer sponsors gas entirely; only a 0.1% protocol fee is charged
- Instant finality — transactions confirm in under 1 second
- Persistent history — all transfers stored in PostgreSQL across sessions
| Page | Description |
|---|---|
| Dashboard | Wallet balances, transfer stats (total volume, avg gas fee), recent activity feed |
| Send | Full P2P transfer form — token picker (USDC/EURC), gasless toggle, fee preview, on-chain execution |
| History | Paginated transfer log with status badges and ArcScan explorer links |
| Relay | Gasless relay explanation + live relayer status (balance, address) |
| Network | Arc Testnet config, contract addresses, faucet link, one-click MetaMask setup |
| Parameter | Value |
|---|---|
| Chain ID | 5042002 (0x4cef52) |
| RPC URL | https://rpc.testnet.arc.network |
| Explorer | https://testnet.arcscan.app |
| USDC | 0x3600000000000000000000000000000000000000 |
| EURC | 0x89B50855Aa3bE2F677cD6303Cec089B5F319D72a |
| Faucet | https://faucet.circle.com |
User signs EIP-2612 permit (off-chain, free)
│
▼
POST /api/relay
│
▼
Relayer calls permit() on-chain ← relayer pays gas
│
▼
Relayer calls transferFrom() ← pulls gross amount from user
│
▼
Relayer calls transfer() ← sends 99.9% to recipient
│ keeps 0.1% as protocol fee
▼
Transaction confirmed < 1s
The user never spends any gas. They only sign a typed message (EIP-712) which authorises the relayer to move tokens on their behalf.
| Transfer type | Gas cost | Protocol fee |
|---|---|---|
| Standard (direct) | ~$0.01 USDC | None |
| Gasless relay | $0.00 (sponsored) | 0.1% of amount |
| Layer | Technology |
|---|---|
| Frontend | React 18 + Vite + TypeScript |
| Styling | Tailwind CSS + shadcn/ui |
| API | Express 5 |
| Database | PostgreSQL + Drizzle ORM |
| Blockchain | viem (Arc Testnet RPC) |
| Monorepo | pnpm workspaces |
| Validation | Zod + drizzle-zod |
| API contract | OpenAPI 3.1 + Orval codegen |
- Node.js 24+
- pnpm 10+
- PostgreSQL database
- MetaMask or Rabby wallet with Arc Testnet added
git clone https://github.com/osr21/arc-payment.git
cd arc-payment
pnpm install# Required
DATABASE_URL=postgresql://user:password@host:5432/dbname
# Optional — enables gasless relay endpoint
RELAYER_PRIVATE_KEY=0xyour_funded_arc_testnet_wallet_keypnpm --filter @workspace/db run push# API server (port 8080)
pnpm --filter @workspace/api-server run dev
# Frontend (port determined by PORT env var)
pnpm --filter @workspace/arc-payment run devMetaMask / Rabby — manual setup:
| Field | Value |
|---|---|
| Network name | Arc Testnet |
| RPC URL | https://rpc.testnet.arc.network |
| Chain ID | 5042002 |
| Currency symbol | USDC |
| Explorer URL | https://testnet.arcscan.app |
Get testnet USDC at faucet.circle.com — select Arc Testnet + USDC.
arc-payment/
├── artifacts/
│ ├── api-server/ # Express API (routes, relay, balance)
│ └── arc-payment/ # React Vite frontend
├── lib/
│ ├── api-spec/ # OpenAPI 3.1 contract (source of truth)
│ ├── api-zod/ # Generated Zod schemas
│ ├── api-hooks/ # Generated React Query hooks
│ └── db/ # Drizzle ORM schema + migrations
└── scripts/ # Utility scripts
See docs/API.md for the full API reference.
See docs/ARCHITECTURE.md for a deep dive into the system design.
- Rate limiting on all endpoints (100 req/15 min general, 20 req/15 min relay)
- EIP-2612 deadline validation (rejects expired permits)
- Signature length validation before on-chain submission
- Input sanitisation — error details never leaked to frontend
- All relay parameters validated via Zod before processing
MIT © 2026 ARC payment