SeedSigner (DIY kit)

Overview

SeedSigner is a do-it-yourself, open-source air-gapped Bitcoin signer that you build yourself from cheap, off-the-shelf parts — a Raspberry Pi Zero, a camera module, and a small screen — for a fraction of the cost of commercial wallets. Its defining feature is that it is stateless: it holds no keys at rest. You enter or generate your seed for each signing session, sign the transaction, and when you power it off, nothing is stored.

This design flips the usual threat model. Because the device stores nothing, a stolen or seized SeedSigner is just a bare Pi — worthless to an attacker. It's fully air-gapped, communicating only via QR codes through its camera and screen, and pairs with wallets like Sparrow and Nunchuk, with strong multisig support. Everything is open-source and community-built, so it's maximally verifiable, and the low cost makes it easy to build several.

The honest trade-offs: it's DIY, so you assemble it yourself and there's no secure element — security rests entirely on the stateless design and your operational discipline, not tamper-resistant hardware. Entering your seed each session is more effort than a device that stores it. It's aimed squarely at tinkerers, privacy maximalists, and multisig users, not people who want a polished plug-and-play experience. For those who value verifiability, statelessness, and low cost, SeedSigner is a genuinely clever and respected option.