Pick where the watch-only key (and optionally the UTXOs) come from. The Vault holds wallets at rest. The Scryer reads the same export and adds live balance and UTXO data on top. Manual paste is the catch-all for any wallet that exports an xpub, ypub, or zpub.
One click opens your operating system's file picker. The builder loads the file automatically.
Copy the file's contents into the box, then click Parse.
Add the unspent outputs you want to fund this transaction with. Get these from your watch-only tool (Scryer, mempool.space, an Electrum server you trust). The "path" column is the address index under the account, written as change/index (for example 0/3 for receive-chain index 3).
| txid | vout | path | value (sats) |
|---|
A PSBT (Partially Signed Bitcoin Transaction, BIP-174) is a standard file format for a transaction that is being put together in steps.
One tool builds the unsigned shape: which coins to spend, who gets paid, how much fee. Another tool, kept offline with the seed, signs it. A third tool broadcasts the signed transaction to the network.
Hardware wallets, Sparrow, Electrum, and this prototype all speak the same PSBT format. You can hand it around as a base64 string, a .psbt file, or a QR code.
In this tool the Build tab makes the unsigned PSBT. The Sign tab takes a PSBT and your seed, and gives you back a signed one ready to broadcast.
Paste the base64 PSBT produced by the Build tab (or any PSBT-compatible wallet that targets a BIP-84 native segwit account).
A PSBT (Partially Signed Bitcoin Transaction, BIP-174) is a standard file format for a transaction that is being put together in steps.
One tool builds the unsigned shape: which coins to spend, who gets paid, how much fee. Another tool, kept offline with the seed, signs it. A third tool broadcasts the signed transaction to the network.
Hardware wallets, Sparrow, Electrum, and this prototype all speak the same PSBT format. You can hand it around as a base64 string, a .psbt file, or a QR code.
You are now on the Sign tab: load a PSBT below, type your seed, and the tool returns it signed and ready to broadcast.
Type your seed phrase below. It stays in this tab, never leaves the page, and is wiped from memory when you press Forget seed or close the tab.
Block explorers used for the optional online balance and UTXO lookup on the Build tab. Click any name to expand and edit. Toggle the checkbox to enable or skip an endpoint. Add your own Esplora-compatible node at the bottom. Settings live in your browser only.
This is the only step in the Build tab that goes online. The tool will query the block explorers in your settings for the addresses on this page, one at a time, and read back their balance and UTXO list.
The xpub itself never leaves the page. Only individual addresses are sent. The explorers will see the IP that made the request and the addresses you queried. To hide your IP, switch to Tor in the topbar (the page must be loaded in Tor Browser).
Currently selected: Mempool.space (clearnet). Once you confirm, the consent is remembered for the rest of this tab session. Closing the tab resets it.