cellfi

SMS-USDC: Borderless Payments Without Internet

Our project enables peer-to-peer transactions using USDC stablecoin via simple SMS messages, removing the need for internet connectivity. This solution bridges the digital divide by bringing cryptocurrency payments to the 3.8 billion people worldwide who have mobile phones but limited or no internet access. Users can send, receive, and check balances of USDC through text messages from any mobile device. Our system translates SMS commands into blockchain transactions, allowing for truly offline crypto payments. This creates a seamless experience where users can participate in the digital economy using familiar SMS technology, without requiring smartphones, data plans, or technical knowledge of cryptocurrency.

Our solution is built with a robust technical stack designed for reliability and accessibility:

Backend: High-performance server using Bun runtime with Hono framework and TypeScript for exceptional speed and reliability. Frontend: Administrative interfaces and onboarding portal developed with React and Next.js. SMS Gateway: Android phone running HTTPSMS serves as our bridge between the cellular network and backend services. Blockchain Integration: Circle's SDK manages smart contract wallets, enabling secure USDC transactions with minimal gas fees. User Identity: ENS (Ethereum Name Service) integration allows users to have human-readable identities instead of complex wallet addresses.

The system architecture enables SMS commands to be processed, validated, and executed as blockchain transactions, creating an accessible bridge between traditional mobile technology and cryptocurrency infrastructure.