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XBT
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BTC
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Unsplit coins
Taproot address — derived from their npub
Lightning —
Recent transactions
Chain
XBT · BLAKE2b
BTC · SHA-256
XBT esplora endpoint (optional — default is mempool.guide through this app's proxy)
From — your wallet
Coin control
Leave all unchecked for automatic selection, or check specific coins to spend exactly those. unsplit coins exist on both chains; XBT only and BTC only coins are already split.
Split status — this address on both chains
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XBT
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BTC
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Unsplit
How splitting works
Until block 961,631 BTC and XBT share one history, so every coin you held before the split exists on both chains, and an ordinary signature is valid on both — spend on one chain and someone can copy the transaction to the other.

XBT added an opt-in signature type, SIGHASH_UNIFIED, that only verifies on XBT. Split builds one transaction that sends every unsplit coin back to your own address on XBT with that signature. It cannot be replayed onto BTC. The Pocket Signer signs it like any other PSBT.

Once it confirms on XBT, the original coins still sit untouched on BTC and are yours to spend there with a normal signature — that spend can no longer touch XBT because the XBT side has already moved. Sell, send or ignore the BTC as you like.
To — search a name, or paste npub / address
Amount (sats)
OP_RETURN message (optional)
Fee rate
Slow…
Normal…
Fast…
Customsat/vB
Replay warning:
Unsigned PSBT — sign on the device
Sign on device sends this transaction to your hardware signer through the relays (keep its bridge tab open on the computer it's plugged into) — approve on the device screen and the signed result lands in the Broadcast tab. Or move it by SD card as unsigned.psbt.
History
Pending signatures
Your multisig wallets
No wallets yet — create one below. Any set of npubs can jointly control coins; the co-signers don't need to do anything until it's time to spend.
Create — Nostr-Derived Taproot Multisig
Co-signers — search names or paste npubs
Threshold
of 0 keys
Same scheme as the signer extension: a taproot address whose script tree holds one OP_CHECKSIGADD leaf over the sorted co-signer keys, with an unspendable internal key — spending must go through the multisig script.
Wallets
Deposit address
Spend — build unsigned PSBT
Amount (sats)
Each co-signer signs this same PSBT — on the hardware signer (SD card as unsigned.psbt) or in the extension — then paste every signed copy below.
Collect signatures
No transaction being signed.
Broadcast to
XBT
BTC
Both
Broadcast through
Public API
My node
Esplora / mempool REST
Bitcoin Core RPC
How to point this at your own node
Why bother: broadcasting through your own node means no third party ever learns which transactions are yours — the explorer only sees them once your node has relayed them like any other traffic.

Which chain is your node on? Bitcoin Knots 29.4.1+ follows XBT (BLAKE2b); Bitcoin Core follows BTC. The app trusts your node to be on the chain you selected above.

Option 1 — Esplora / mempool REST (easiest in a browser).
1. Run a self-hosted esplora or mempool instance (umbrel, Start9, raspiblitz all ship one).
2. Enter its REST base URL above, e.g. http://umbrel.local:3006/api.
3. Broadcast here does POST {base}/tx with the raw hex.

Option 2 — Bitcoin Core RPC.
1. In bitcoin.conf add:
server=1
rpcuser=youruser
rpcpassword=yourpassword
rpcallowip=192.168.1.0/24  # your LAN
rpcbind=0.0.0.0
2. Restart bitcoind, enter http://node-ip:8332 and youruser:yourpassword above.
3. Broadcast here calls sendrawtransaction over JSON-RPC.

The CORS caveat: browsers block cross-origin requests unless the server sends CORS headers, and Bitcoin Core never does. If Test connection fails with a network/CORS error, put a small reverse proxy (nginx, Caddy) in front of the RPC port that adds Access-Control-Allow-Origin — or simply use a self-hosted Esplora endpoint, which usually allows it out of the box.
Public API routes through this app's proxy — convenient, but the proxy sees the tx first. Switch to your own node for full sovereignty.
Signed transaction (hex) or signed PSBT (base64)
The flow
1. Build the transaction here — this page is watch-only, it never sees a key.
2. Move the PSBT to the signer (SD card) and sign on its screen, airgapped.
3. Paste or scan the signed result here and broadcast to the chain you intend.

Since the split: a transaction built for XBT is signed with SIGHASH_UNIFIED and is only valid on XBT — this page detects that and broadcasts it to XBT only. A transaction signed the ordinary way is valid on both chains while its coins are unsplit, so it is only safe to send to one chain after those coins have been split (Wallet → Split).
Discover
Wallet
Multisig
Broadcast