Gigipay

A multichain crypto payment protocol on Celo and Base. Send to multiple wallets in one transaction, create claim-code vouchers, and pay Nigerian utility bills (airtime, data, TV, electricity) with crypto.

What you can do

• Batch Transfer — send tokens to hundreds of addresses in a single transaction
• Payment Vouchers — send crypto without knowing the recipient's wallet address; they claim with a secret code
• Bill Payments — buy airtime, data bundles, pay DSTV/GOtv, pay electricity bills using any supported token
• Gmail Login — recipients can sign in with Google; Privy creates an embedded wallet automatically

Monorepo Structure

Gigipay/
├── apps/
│   └── web/          # Next.js frontend
Gigipay-backend/       # NestJS API server
contracts/             # Solidity smart contracts (Foundry)

Each folder has its own README with full setup instructions:

• contracts/README.md — smart contract docs, deployment, tests
• Gigipay-backend/README.md — backend API, auth, bill fulfilment
• apps/web/README.md — frontend setup, hooks, architecture

Deployed Contracts

Network	Address
Celo Mainnet	0x70b92a67F391F674aFFfCE3Dd7EB3d99e1f1E9a8
Base Mainnet	0xEdc6abb2f1A25A191dAf8B648c1A3686EfFE6Dd6

Quick Start

Frontend (monorepo)

pnpm install
pnpm dev

Runs at http://localhost:3000

Backend

cd Gigipay-backend
pnpm install
cp .env.example .env   # fill in your values
pnpm start:dev

Runs at http://localhost:3001
Swagger docs at http://localhost:3001/api/docs

Contracts

cd contracts
forge build
forge test

How it works

User (browser wallet)
  │
  ├── write txs (create voucher, claim, batch transfer, pay bill)
  │     └── wagmi writeContract → user signs → broadcasts to chain
  │
  └── read data (voucher state, balances, order status)
        └── fetch → Backend API → viem readContract → chain

For bill payments specifically:

1. User calls payBill() on contract (wallet signs)
2. Contract holds crypto, emits BillPaymentInitiated event
3. Backend listener picks up event
4. Backend calls ClubKonnect API → airtime/data/TV/electricity delivered
5. Order status stored in DB, polled by frontend

Supported Wallets

• MetaMask
• WalletConnect (any compatible wallet)
• MiniPay (Celo mobile wallet — auto-detected)
• Privy embedded wallet (email/phone/Google login)

Tech Stack

Layer	Tech
Smart Contracts	Solidity 0.8.27, Foundry, OpenZeppelin Upgradeable
Backend	NestJS, TypeORM, PostgreSQL, viem, Privy
Frontend	Next.js 15, wagmi, viem, RainbowKit, Privy, TailwindCSS
Auth	SIWE wallet signatures + Privy (email/phone) → JWT
Bill API	ClubKonnect (airtime, data, TV, electricity)

Requirements

• Node.js >= 18
• pnpm >= 9
• PostgreSQL (for backend)
• Foundry (for contracts)