SeedSigner

Meet SeedSigner

SeedSigner is an open-source Bitcoin signing device that you can assemble from a Raspberry Pi, a small screen, and a camera. It works offline and exchanges transaction information with compatible wallet software through QR codes, so signing does not require a USB data connection or network access. You scan a proposed transaction, review its details on the device, then scan the signed response back into your wallet.

The software supports single-signature and multisignature setups, seed generation using dice rolls or a photograph, BIP39 passphrases, and address verification. Its stateless design keeps private keys in memory only during use, requiring you to load your seed again after restarting. SeedSigner is intended for people who want a build-it-yourself approach to Bitcoin self-custody and control over both the hardware and software they use.