Relay Pay

(About)

This is a decentralized crypto to fiat payment rail and market maker that does NOT require any KYC from the end users. It enables users first to make any payment they want in crypto and make sure the counterpart receives in fiat. Secondly it also functions as a market maker where users can buy and sell crypto in a p2p basis. Currently it only integrates Brazilian PIX, but PayPal and Venmo are in the timeline.

(Role)

Protocol Architecture, Full Stack Dev, Smart Contracts

(Stack)

EVM, ZK-TLS, Notary-TLS, Solidity, Rust

(Links & resources)

* This is an open source project. Feel free to contact me directly if you are interested in contributing in any way.


    Depositor                    Escrow Contract                    Relayer
        │                              │                               │
        │── deposit(token, amount, ───►│                               │
        │    fiatDetails, deadline)    │  crypto locked                │
        │                              │                               │
        │                              │◄── claimOrder(orderId) ───────│
        │                              │    order assigned to relayer  │
        │                              │                               │
        │                              │              ┌────────────────│
        │                              │              │ relayer pays   │
        │                              │              │ fiat to        │
        │                              │              │ recipient      │
        │                              │              │ off-chain      │
        │                              │              └────────────────│
        │                              │                               │
        │                              │◄── submitProof(orderId, ──────│
        │                              │     attestation, signature)   │
        │                              │                               │
        │                              │  verify Notary signature      │
        │                              │  match attested fields        │
        │                              │  to order details             │
        │                              │                               │
        │                              │── release crypto ────────────►│
        │                              │                               │


    Relayer Agent              Notary Server            Payment API
        │                         │                        │
        │── MPC-TLS setup  ──────►│                        │
        │◄─────────────────────── │                        │
        │                         │                        │
        │── API request (via MPC-TLS tunnel)  ────────────►│
        │◄── API response (encrypted, co-held keys)  ──────│
        │                         │                        │
        │── selective disclosure─►│                        │
        │◄── signed attestation ──│                        │
        │                         │                        │
        │── submit on-chain                                │