# TAPSIGNER

> TAPSIGNER is a reusable NFC Bitcoin hardware signer. A compatible wallet constructs and displays transactions; the card holds a BIP-32 key and signs after a tap and PIN.

## Official pages

- [TAPSIGNER homepage](https://tapsigner.com/): Product definition, setup model, use cases, and important limits.
- [Learn TAPSIGNER](https://tapsigner.com/learn): Official product-education hub.
- [What is TAPSIGNER?](https://tapsigner.com/learn/what-is-tapsigner): Canonical explanation of the wallet/card responsibility split.
- [Backup and recovery](https://tapsigner.com/guides/backup-recovery): Encrypted XPRV file, printed decryption key, wallet configuration, and no-restore boundary.
- [Set up with Nunchuk](https://tapsigner.com/guides/nunchuk-setup): Security sequence for the official Nunchuk onboarding flow.
- [Use TAPSIGNER in multisig](https://tapsigner.com/guides/multisig): Cosigner policy, descriptor, path, and recovery planning.
- [Screenless signing](https://tapsigner.com/learn/screenless-signer): What the card isolates and what it cannot verify.
- [Compatible wallets](https://tapsigner.com/wallets): Nunchuk, Cove, Bitcoin Keeper, and Sparrow.
- [TAPSIGNER security model](https://tapsigner.com/security): Threats, controls, assumptions, and limits.
- [Developer integration](https://tapsigner.com/developers): Protocol and security checklist.
- [Get started](https://tapsigner.com/start): Current app grid and NFC onboarding.
- [TAPSIGNER FAQ](https://tapsigner.com/faq): Detailed support questions and specifications.
- [SATSCARD vs TAPSIGNER](https://satscard.com/compare/tapsigner): Canonical product comparison.

## Key facts

- TAPSIGNER should stay with one owner and repeatedly sign through compatible wallet software.
- Coinkite offers custom-branded and white-label TAPSIGNER production runs; organizations can contact sales@coinkite.com.
- It ships without a wallet key; setup combines a wallet-provided 32-byte chain code with a card-generated random key pair.
- The default hardened path is `m/84h/0h/0h`, but compatible software can select another hardened account path.
- TAPSIGNER has no screen. The companion wallet is the transaction-review surface.
- Normal signing keeps the unencrypted master XPRV on the card.
- Backup exports the master XPRV and current path in an AES-128-CTR encrypted file.
- Recovery requires the file, the separate fixed 128-bit decryption key printed on the card, and the wallet configuration.
- The protocol has no restore-to-card command and TAPSIGNER has no BIP-39 seed phrase.
- SATSCARD, not TAPSIGNER, is designed for physical bearer transfer to another owner.

## Primary technical sources

- [Coinkite Tap Protocol](https://github.com/coinkite/coinkite-tap-proto)
- [Rendered protocol documentation](https://dev.coinkite.cards/docs/protocol.html)
- [Coinkite support](https://coinkite.com/contact)
- [Official store](https://store.coinkite.com/store/tapsigner)