SafePay ZK — Testnet Progress Update

Camilo Tenorio

19d • 📣 Promote Your Work

SafePay ZK is a Nimiq Pay Mini App concept focused on one simple idea:

Verify before you pay.

The current version is now working as a testnet prototype using a blockchain-only flow.

SafePay ZK runs inside Nimiq Pay as a Mini App. You can open Nimiq Pay, add/search a Mini App by URL, and use:

https://safepayzk.com

What works today:

Request Payment flow:

A business connects with Nimiq Pay, creates a SafePay payment request, adds order details, generates a QR code, and waits for payment.

Verify Payment flow:

A user scans the QR code, reviews the payment request, verifies it, and pays through Nimiq Pay on testnet.

Payment confirmation:

The payment is sent through Nimiq Pay with SafePay data attached to the transaction. Business can detect the payment on-chain and show the order as Paid. If the order expires without payment, it can be marked as Expired.

Current architecture:

SafePay ZK currently uses a testnet + blockchain-only approach. There is no backend yet. The app checks the Nimiq testnet while Business is open and updates order status based on what it finds on-chain.

Current status:

Runs inside Nimiq Pay as a Mini App
Can be opened by URL: https://safepayzk.com

Create payment requests
Generate QR codes
Scan SafePay requests
Review order details before payment
Verify before enabling payment
Pay through Nimiq Pay on testnet
Attach SafePay intent data to the payment transaction
Detect Paid / Expired status from the blockchain
Show receipts in Business and Personal flows

Why this matters:

SafePay ZK is not trying to replace Nimiq Pay. Nimiq Pay still handles the wallet, user confirmation, and transaction. SafePay adds a verification layer before payment, helping users confirm that the request they are about to pay matches the intended recipient, amount, network, and order data.

Roadmap:

Phase 1 — Competition prototype polish

Keep the app stable on testnet, polish the Request Payment and Verify Payment flows, improve receipts, add anti-self-payment checks, and clearly present the app as a working testnet prototype.

Phase 2 — Real ZK verification

Connect the ZK proof to each real payment request, remove the fixed demo proof, generate a unique intentHash per order, and verify the proof before enabling PAY.

Phase 3 — Mainnet preparation

Add strict mainnet validation, separate testnet/mainnet storage, prevent network mixing, block self-payments, and test with very small real payments.

Phase 4 — Backend or indexer

Add a backend or indexer so Business order status can update even when the Business device is closed. This would allow stronger Paid / Expired tracking without depending only on the open app.

Phase 5 — Production hardening

Review the ZK circuit, audit the payment flow, improve error handling, add privacy documentation, improve receipts, and prepare the app for real-world usage.

SafePay ZK is still a prototype, but the core flow is now working:

Business creates a request.

Users verifies before paying.

Nimiq Pay sends the transaction.

SafePay reads the blockchain and updates the order status.

Verify before you pay.

1 comment

SafePay ZK — Testnet Progress Update