When Samurai Wallet developers were arrested, its users faced a problem beyond confiscated funds: they risked losing their entire payment history. The wallet relied on a centralized server, PayNIM, to store BIP47 reusable payment codes and their connection metadata. That server went offline, severing the link between a user's payment code and the addresses they had paid.
Max Tannahill's solution is BIP47DB.org, a permanent, on-chain database built using Bitcoin inscriptions. By storing compressed payment codes in the witness space, it creates an append-only directory any wallet can rebuild locally. This isn't speculative; the Ashigaru team, which took over Samurai's codebase, has inscribed approximately 20,000 existing codes onto mainnet. At current fee rates, the total cost to secure the directory was only $150.
"Moving this data onto the blockchain is the only way to ensure resilience against state interference."
- Max Tannahill, Ungovernable Misfits
Tannahill argues the database solves a fundamental recovery flaw in BIP47. If you restore a wallet from a seed phrase, you can see incoming payments but often lose the history of connections you initiated. Centralized servers like PayNIM acted as a lookup table for these notification transactions, a 'metadata crutch' wallets depended on.
The new on-chain index allows wallets to scan a specific 'numbers address' to find every registered payment code locally. This means wallets like BlueWallet could support BIP47 without ever querying a central server. In the long term, Tannahill envisions this infrastructure could eliminate the notification transaction itself. If every payment code is indexed on-chain, wallets could scan new blocks for potential payments, shifting the burden from the sender announcing a payment to the receiver scanning a decentralized list.
