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Gerfaut

The ultimate Bitcoin watch-only wallet.

Follow every wallet you own from its descriptor or public key, on your desktop and in your pocket.

Download Gerfaut Read the source on GitHub

Free and open source · Linux, Windows, macOS and Android

The Gerfaut desktop app on a wallet named Cold storage: a total balance of 0.676 BTC, a balance history chart over three months, the bitcoin price, the watch status and the latest received transactions

Watch any wallet you already have.

Paste it, open a file or scan a QR code, static or animated.

  • Descriptor Output descriptors, BIP‑380
  • xpub xpub, ypub, zpub and their testnet twins
  • Address One address, watched on its own
  • Multisig Any m‑of‑n, sorted or not
  • Miniscript Timelocks and recovery paths
  • BSMS Coordinator exports, BIP‑129
  • Mainnet, signet, testnet4 and regtest
  • Several wallets at once, named, iconed, reordered
  • Exports from other wallets read as they are

Also in your pocket.

The same wallets on Android, carried over from the desktop by scanning an animated QR code.

  • Every wallet on one screen, with its icon and its balance
  • Home screen widgets, amounts hidden if you say so
  • Live notifications in the background, even after a reboot, through the backend you chose
  • Light and dark mode
The Android home screen of Gerfaut in the light theme: four wallets, each with its icon and balance, from cold storage to a family vault A wallet opened in the Android app in the dark theme: the balance, then the list of transactions with their dates and signed amounts

Every transaction, in full.

Open any transaction and see where the coins come from, where they go, and what the fee cost.

The Transactions page of the desktop app with a transaction opened over it: the amount received, its confirmation and block, then a diagram with the input on the left, the two outputs on the right and the fee below

One backup, both devices.

Every wallet you watch, encrypted with a password you choose, restored on any device.

  • A file, or an animated QR code the phone scans from the desktop screen
  • Holds descriptors and addresses, never a private key
  • The history of a wallet as a CSV file, filtered by date and direction
  • Everything stays on your machines
The Backup and sync settings of the desktop app with the Export a backup dialog open: the wallets to include, a switch for the node settings, and the password typed twice

Your node. Tor built in.

Electrum or Esplora, yours or a public one. An .onion backend needs nothing else installed.

  • electrs or Fulcrum over TLS or plain TCP, Esplora over HTTPS
  • Test the connection before you save it
  • Live notifications within seconds over Electrum. Over Esplora, Gerfaut checks a few addresses a minute, in turn, so a payment can take longer to show
  • Mainnet, signet, testnet4 and regtest, each with its own backend
The Network settings of the desktop app: the Backend card with the choice between a public API, an Esplora or an Electrum server you run, then the Tor card

Locked, encrypted, disguised.

The vault is encrypted on disk. The lock is what stops someone holding your unlocked device.

  • A PIN or a password to open the app, biometrics on Android
  • Stealth mode on Android: a real calculator hides the app, type your PIN and press equals
  • Locked, Gerfaut shows no wallet, allows no screenshot and stays blank in the recent apps
  • Wrong guesses slow down: three tries, then a growing delay
An Android phone showing a plain calculator: the stealth mode of the Gerfaut app, which opens when the PIN is typed and equals is pressed The lock screen of the Android app: the Gerfaut mark, the word Locked, an empty PIN field and an Unlock button

Miniscript, read in plain words.

Every spending path of a descriptor, each timelock counted down to the block it opens.

  • Multisig m‑of‑n, sorted or not, and BSMS imports
  • Recovery paths and inheritance setups, with the wait left on each coin
  • Every signing key with its fingerprint and derivation path
  • The raw descriptor, one click away
The Policy page of the desktop app: the primary key can spend now, a recovery key can spend after a wait of three blocks, about 30 minutes

Broadcast raw transactions.

Send a transaction signed elsewhere and follow it until it confirms. Gerfaut never signs.

  • Paste a PSBT or a raw transaction, open a file, or scan an animated QR code
  • Inputs, outputs and fee drawn before anything leaves
  • A warning for anything odd: a missing signature, a high fee, dust
  • Sent through the backend you chose, over Tor when that backend is an .onion
The Broadcast page of the desktop app with a transaction ready to send: its input on the left, its two outputs on the right, the fee below, and the pill Ready to broadcast

Open source

Read the code. Build it yourself.

  • AGPL-3.0, the apps and the core alike
  • Reproducible builds: rebuild any release on Linux and get the same bytes
  • Every release signed with minisign
Fork on GitHub Verify a download 
$ git clone https://github.com/gerfaut-wallet/gerfaut-desktop
$ cd gerfaut-desktop
$ reproducible/verify.sh v0.1.0
rebuilt from the tag in a pinned container
compared byte for byte with the release page
==> VERIFIED

Your cold storage deserves a watcher.

Download Gerfaut Linux · Windows · macOS · Android