A privacy-enhancing augmentation layer that sits alongside your existing payment rails. Generate cryptographic payment proofs that attest to transaction validity—without exposing sensitive financial data.
Core data flow for cryptographic payment proofs
We verify the authenticity of payment events (Stripe, PayPal, etc.) following the official procedures of the providers, and on-chain stablecoins.
The SDK captures attestations and transforms them into zero-knowledge proofs using Circom circuits. Proofs validate payment authenticity without exposing amounts, identities, or transaction IDs.
Optional on-chain registration on EVM-compatible networks provides immutable, publicly verifiable records.
TypeScript SDK for browser and Node.js environments
The ZKIW Client SDK integrates seamlessly into merchant flows. Capture attestations, communicate with backend services, and generate cryptographic receipts—without modifying your payment core.
// Initialize ZKIW SDK
const payProof = ZKIWPayProof.init({
apiBase: "https://api.zkiw.com",
merchantId: "MERCHANT-123",
railAuthPublicRoot: "0xabc123..."
});
// Generate proof on payment completion
gateway.on("payment:completed", async (evt) => {
const attestation = {
rail: "BANK",
amount: evt.amount,
payerHash: evt.payerHash,
timestamp: evt.timestamp,
settlement: true
};
const proof = await payProof.generate(attestation);
// Render ZK receipt widget
payProof.renderWidget("#receipt", proof);
});The PaymentProofRegistry smart contract stores proof commitments on Ethereum and L2 networks. Provides immutable, publicly verifiable records with Merkle-based processor authorization—no sensitive data exposed.
Built for privacy, compatibility, and production deployment
Payment proofs never expose sensitive financial data (amounts, identities, raw transaction IDs) unless explicitly disclosed through controlled mechanisms.
Integrates with conventional bank transfers, card processors (Stripe/PayPal), and on-chain stablecoins—without requiring changes to underlying payment infrastructure.
Proofs backed by Circom circuits using Poseidon hashing and Merkle verification—providing formal guarantees on correctness and soundness.
Supports selective disclosure, structured audit trails, and regulator-oriented views. Enable compliance workflows without mass data exposure.
Containerized services, on-chain registries, documented infrastructure, and observability tooling. Self-hosted or managed SaaS configurations available.
Critical invariants modeled and machine-checked in Lean. CI-integrated theorem checking guards core protocol properties and cryptographic assumptions.
Self-hosted or managed SaaS—integrate cryptographic payment verification into your workflows