The Problem
Roughly 60% of Africa remains functionally offline or without smartphones. Financial services, government subsidies, and civic tools are built for the smartphone-and-data assumption, excluding the majority. You can't tell someone to "download the app" when they own a Nokia 3310.
What I Built
A financial-inclusion infrastructure that lets users on basic feature phones spin up non-custodial wallets and execute on-chain transactions using GSM protocols (USSD). No smartphone, no internet, no data plan required — just the phone people already own.
The Decisions
USSD over SMS
USSD sessions are real-time and menu-driven — more secure and interactive than SMS-based flows. Tradeoff: sessions time out (~180s on most telcos), so every flow must be fast and decisive.
Base L2 + Celo
Chose L2s with minimal gas costs. Celo has existing African adoption and mobile-first DNA. Base provides Coinbase ecosystem access. Both keep transaction costs under fractions of a cent.
Non-custodial wallets
Users own their keys. This is harder to implement over USSD than a custodial model, but custodial crypto wallets for unbanked populations repeat the same power dynamics we're trying to break.
Africa's Talking gateway
The most reliable USSD integration for African telcos. Sandbox-validated, ready for production carrier integration.
"The same GSM-to-chain pattern generalizes to civic services: voter registration, infrastructure fault reporting, government transfer receipts. Meeting people where they already are."
Recognition
Selected from a continent-wide pool as a finalist at the W3Node Hackathon 2026 in Cape Town, South Africa. Pitched live on stage to venture capitalists, investors, and protocol founders.
See It in Action
Full product walkthrough — from USSD dial to on-chain confirmation.
What It Can't Do Yet
- Feature phone key management still experimental (secure key storage on basic devices is an unsolved UX problem industry-wide)
- USSD session timeouts limit complex multi-step transactions
- No production telco integration yet (sandbox only)
- KYC/AML compliance layer not implemented