Reef — txbt4, BLAKE2b testnet4 · a node in this tabtestnet4 · test coins
Balances
Available:… Pending:… Immature:… Total:…
The wallet is one key held in this tab; its balance is read from the tab's own validated UTXO set, coins created since the snapshot at block 150,307.
Recent transactions
Send Coins
Transaction Fee
…Confirmation time target: the next block (about 20 minutes)
Balance: …
The transaction is built and signed in this tab, checked, and published as a kind 23503 event; a sidestr producer with a txbt4 node broadcasts it if its node's policy accepts it. It shows here once it is in a block the tab has validated.
Receive
This tab holds one key, made here and kept in this browser's storage; the address is its Taproot key-path address on txbt4. Test coins only. A faucet for txbt4: ask on the datstr miner page, or send from a node's wallet.
scan to pay this tab
Received coins
BlockOutpointConfirmationsAmount (tBTC)
nothing received since the snapshot
DateTypeLabelAmount (tBTC)
Exporting…Selected amount: 0.00000000 tBTC
Starting the node…TESTNET4 · BLAKE2b
Node windowclose
Information
Console
Network Traffic
Peers
General
Client versionReef 0.1 — a Knots-style node in a tab; engine bitcoin-desktop/schema v0.0.27, node blaketestnode@4d4b66cUser Agent/Reef:0.0.1/Datadirorigin private file system (OPFS)Blocksdir…Startup time
Snapshot
Base block150,307 · 000000000017ec2251d81c8d2ca401c713e98e85196c7f660a4088a7ca57b1ccSource…On disk…sha256not checked yethash_serialized_3not verified yetCoins…
Sync history (this tab)
nothing yet
Network
Nametxbt4 (BLAKE2b testnet4, fork at 150,308)Number of connections1 mirror, 3 relaysNostr tip (NIP-333)not seen yet
Block chain
Current number of blocks…Last block time…Last block hash…
Memory Pool
Current number of transactions0 (the tab follows no mempool yet)Memory usage…
Welcome to the Reef console.
Use up and down arrows to navigate history, and Ctrl-L to clear screen.
Use Ctrl+Shift+C to copy, Ctrl+Shift+V to paste.
Type help for an overview of available commands.
For more information on using this console, type help-console.

The node answers from this tab's own validated state; wallet commands answer for the one key kept in this tab.
>
TotalsReceived0 MBSent0 MB
PeerAgeDirectionTypeNetworkPingSentReceivedAddress
Select a peer to view detailed information.
About Reef

Reef 0.1 · a Bitcoin node in a browser tab, for txbt4, the BLAKE2b testnet4.

It looks like Knots and runs a chain Knots defined, but it is not Knots. The tab fetches the fork-point UTXO snapshot, recomputes its hashes, validates every block since the fork and follows the chain tip. The wallet is one key kept in this tab.

Source · Issues · blaketestnode · sidestr

Copyright © 2026 the Reef contributors. Licensed under the GNU Affero General Public License, version 3 or later.
Options
Main
Wallet
Network
Display
the fork-point UTXO set: a plain file served with Range and CORS
the mirror's block file, given without its .dat
…
the snapshot, its index and the block file live in the tab's private file system
sat/vBKnots shows this as tBTC/kvB; 1 sat/vB is what txbt4 blocks take today
…
the notice in the page and the console line are always shown
32 bytes as hex; anyone who has it can spend the coins. Keep a copy: the tab's storage is the only place it lives.
the current key is replaced when you press OK; coins at the old address stay at the old address, so copy that key first
a send is published as a kind 23503 event to each of these; a sidestr producer with a txbt4 node broadcasts it. The last publish: none yet
…
one mirror, read with Range requests; set on the Main tab
wss://nos.lol · wss://relay.damus.io · wss://relay.nostr.band
the node worker compares its tip with kind 33333 tip events from these; fixed in the node
pieces come from whoever seeds the snapshot over WebRTC, and from the mirror; if the swarm gives nothing in a minute the tab fetches from the mirror alone. Takes effect on the next fetch: a first visit, or after Wipe.
the tab holds the checked file read-only and answers piece requests over WebRTC; upload shows on the Peers and Network Traffic tabs
also Settings → Mask values, or Ctrl+Shift+M