FluxPay

Problem Statement

FluxPay is a solver-enabled payment system that lets AI agents accept and settle payments across multiple blockchain networks. It powers chain-agnostic Agent-to-Agent (A2A) payments, allowing users to pay on one chain (e.g., Polygon Amoy) while merchants receive funds on another (e.g., 0G Testnet). Using EIP-3009 gasless authorizations and a solver architecture, FluxPay executes real on-chain transactions with verifiable settlement. This makes it ideal for onchain agentic workflows, cross-chain dApps, and AI-driven services that need seamless, trustless payments.

Solution

FluxPay is built with a multi-layer architecture combining frontend, backend, facilitator, and smart contracts:Frontend: Next.js 14 + React with wagmi for wallet integration and Tailwind CSS for a sleek, responsive UI.Backend: FastAPI (Python 3.13) powers the REST API, handles payment gating, and manages EIP-3009 authorization requests. aiohttp enables async communication with the facilitator.Facilitator (Solver): Node.js + TypeScript, using the viem Ethereum library to handle cross-chain settlement. The facilitator provides liquidity and executes payments between networks.Smart Contracts: Solidity contracts are EIP-3009-compliant ERC-20 tokens, deployed with Hardhat to enable secure, gasless payment authorizations.Networks: Currently supports Polygon Amoy (payer chain) and 0G Testnet (receiver chain), with an extensible design for future networks.A particularly hacky but powerful element is the solver-based facilitator, which acts as a real-time liquidity bridge—allowing users to pay on one chain while merchants receive instantly on another, without complicated swaps or custodial risk