A decentralised P2P offramp protocol. Users lock USDC/USDT in a smart contract escrow and receive INR directly to any UPI account via a verified settler — no custodian, no KYC, non-custodial end-to-end.
User scans UPI QR → Locks USDC/USDT in escrow → Settler pays INR via UPI → Crypto released to settler
- User scans a merchant's UPI QR code (or enters a UPI ID manually)
- User approves and locks USDC/USDT into the
KrizPayP2P contract
- A verified settler picks up the open order from the dashboard
- Settler sends INR to the merchant via UPI and submits the UTR number on-chain
- Contract verifies and releases crypto to the settler (minus 0.5% platform fee)
- If the settler doesn't settle in time, the user cancels and receives a full refund
| Layer |
Tech |
| Smart Contract |
Solidity 0.8.20, Foundry, OpenZeppelin |
| Backend |
Node.js, Express, ethers.js v6 |
| Frontend |
Next.js 14, Wagmi v2, RainbowKit, Tailwind CSS |
| Settler Dashboard |
Next.js 14, Wagmi v2, RainbowKit, Tailwind CSS |
| Networks |
Base Mainnet, Sepolia Testnet |
crypto-offramp/
├── Contracts/ # Solidity contract + Foundry tests & deploy scripts
├── Backend/ # Read-only REST API (rates, orders, UPI parsing)
├── Frontend/ # User app — scan QR, lock crypto, track order
└── Settler/ # Settler dashboard — claim orders, submit UTR
| Network |
Address |
| Base Mainnet |
0x279635f011b58085FD08B80514e4fe4cA5bb024D |
| Sepolia Testnet |
0xe2556390437184eCC29D344b562C60F108c2778A |
cd Backend
npm install
cp .env.example .env # fill in CONTRACT_ADDRESS and RPC_URL
node server.js
# → http://localhost:3001
cd Frontend
npm install
cp .env.example .env # fill in NEXT_PUBLIC_WALLET_CONNECT_PROJECT_ID
npm run dev
# → http://localhost:3000
cd Settler
npm install
cp .env.example .env # fill in NEXT_PUBLIC_WALLET_CONNECT_PROJECT_ID
npm run dev
# → http://localhost:3000
# Install Foundry (once)
curl -L https://foundry.paradigm.xyz | bash && foundryup
cd Contracts
forge install # installs forge-std + openzeppelin-contracts
forge build # compile
forge test # run test suite (13/13)
# Deploy
cp .env.example .env # fill in DEPLOYER_PRIVATE_KEY and RPC URLs
source .env
forge script script/Deploy.s.sol --rpc-url $BASE_RPC_URL --broadcast --verify
# Manage settlers
forge script script/AddSettler.s.sol --rpc-url $BASE_RPC_URL --broadcast
forge script script/RemoveSettler.s.sol --rpc-url $BASE_RPC_URL --broadcast
| Method |
Endpoint |
Description |
GET |
/health |
Service health and contract info |
GET |
/api/rates |
Live USDC/USDT → INR rates |
GET |
/api/orders/open |
All open orders |
GET |
/api/orders/:id |
Order by ID |
GET |
/api/orders/user/:address |
Orders by user wallet |
GET |
/api/orders/settler/:address |
Orders by settler wallet |
GET |
/api/stats |
Platform statistics |
GET |
/api/config |
Contract configuration |
POST |
/api/parse-qr |
Parse a UPI QR string |
POST |
/api/calculate |
Calculate crypto amount for an INR value |
| Parameter |
Value |
| Platform fee |
0.5% (max 2%) |
| Order expiry |
30 minutes (unclaimed) |
| Claim window |
15 minutes (to complete after claiming) |
| Min order |
1 USDC |
| Max order |
100,000 USDC |
| Supported tokens |
USDC, USDT |
ReentrancyGuard, Ownable, Pausable from OpenZeppelin- Fee-on-transfer tokens detected and rejected at deposit
- Backend is fully read-only — no private keys stored server-side
- Settlers interact directly with the contract from their own wallet
- Full refund guaranteed if settler times out