Offline stablecoin payments, over SMS
Offline stablecoin payments over SMS. Send and receive USDC and USDT from any phone — no internet, no app, no wallet seed.
USDC Shielded Pool
🔒 Confidential[ How Offline SMS Payments
Actually Work ]
Sign on the Phone
A keypair lives on the SIM-secure element. Your transaction is signed offline — the private key never leaves the device.
SMS Carrier Rails
The signed payload is compressed into a single 160-character SMS and sent to a Lumen short code over normal carrier networks.
Relayer Decodes
A Lumen relayer parses the SMS, reconstructs the transaction, pays the gas in ETH, and broadcasts it to Base on your behalf.
Settled on Base
USDC or USDT lands in the recipient's shielded pool. Both sides get a confirmation SMS — no data plan ever required.
hold stablecoins on a feature phone ]
[ One SMS. One stablecoin
payment, end to end ]
Sign on a feature phone, relay over the carrier network, settle on Base.
Compose
Open Lumen on any phone — smart or feature. Pick a recipient, type an amount in USDC or USDT, hit send. Works in airplane mode.
Sign Offline
The transaction is signed locally by the on-device keypair and packed into a single 160-character SMS. No data, no Wi-Fi, no app store needed.
Relay
The SMS hits the Lumen short code via any carrier. A relayer pays the gas in ETH and broadcasts your transaction to Base in seconds.
Confirm
Funds settle in the recipient's shielded pool. Both sender and receiver get an SMS receipt — even if neither has ever been online.
[ Works with every carrier, every phone ]
From a $20 feature phone in rural Kenya to a flagship handset in São Paulo — if it can send a text, it can send USDC. Lumen plugs into existing carrier SMS gateways and routes payments to Base.
[ Powered by Carrier SMS
& Base Settlement ]
Sign on-device. Send over the carrier. Settle on Base.
Lumen SMS v1
The first stablecoin rail that doesn't need the internet. Built for the 2 billion people on feature phones — and the merchants who want to serve them.
Read the spec