That flow works on-chain today. The buyer's wallet only needs its own coins from the last sync: it builds and signs the transaction offline, shows it as a QR, and the seller's phone scans and broadcasts it. Same idea as air-gapped signing with PSBTs (Sparrow, Keystone and others do it with QR codes).
The catch is on the seller's side: they get an unconfirmed transaction, which the buyer could still try to double-spend, so it fits small amounts or people who know each other.
For Africa specifically, look at Machankura: bitcoin over USSD on any basic phone, no internet. Custodial though.
zhashtoshi_ / Zhash
npub1v7…hvl8a
2026-10-23 17:12:58 UTC
in reply to nevent1q…73yd
Author Public Key
npub1v7nf76fh474q4dnqfjpnkyqsmg439n5uw9x9jdpvzmmgczvrwhcsuhvl8aSeen on
wss://relay.primal.netPublished at
2026-10-23 17:12:58 UTCEvent JSON
{
"id": "7d74515b3dd532723de9129e4b00778906c945677d85a487a6b5b0a698ca940e",
"pubkey": "67a69f6937afaa0ab6604c833b1010da2b12ce9c714c59342c16f68c098375f1",
"created_at": 1792775578,
"kind": 1,
"tags": [
[
"e",
"325d5213c9d7eabd7c2860d9519c8775937072442ece70f74bf48d1154b59cb1",
"",
"root"
],
[
"e",
"dccde69d2791d7de95fd10f7e120490de1f9cdc97d76a566361f7c899dccb366",
"",
"reply"
],
[
"p",
"99a391add0b9d35221d91cc3cc3a0cf463176aaefbedfa6eb5f3f272feb8155c"
],
[
"p",
"27505421c268f363078bf5400d68273b9871e8e35263fdc4532600025eaf3f13"
],
[
"p",
"67a69f6937afaa0ab6604c833b1010da2b12ce9c714c59342c16f68c098375f1"
]
],
"content": "That flow works on-chain today. The buyer's wallet only needs its own coins from the last sync: it builds and signs the transaction offline, shows it as a QR, and the seller's phone scans and broadcasts it. Same idea as air-gapped signing with PSBTs (Sparrow, Keystone and others do it with QR codes).\n\nThe catch is on the seller's side: they get an unconfirmed transaction, which the buyer could still try to double-spend, so it fits small amounts or people who know each other.\n\nFor Africa specifically, look at Machankura: bitcoin over USSD on any basic phone, no internet. Custodial though.",
"sig": "5530269236953218b7b792f73356e694f7ca891bb73a1e98a3a5787fe5757d3ebe616d4e3f16b6d3ebb940d28ef3ecb6c73ea6d54c7c6e9dab163e5677a3a935"
}