What this page is
Public fees and address-only balances — never your seed.
If a lookup fails, status is unknown/error — never a silent fake 0 balance.
Privacy: looking up an address tells the API host you care about it (like typing an account number into a public search box). Lab stays offline for secrets.
Is / is not
Is: fee snapshot, mempool traffic, optional address balances.
Is not: a wallet, price charts, or spending tools.
Fees & traffic
Optional public snapshot via mempool proxy. Does not send any of your addresses — only general fee/mempool stats (still reveals your IP to the host). Public APIs may rate-limit or fail under load; retry later if a fetch errors.
Fees are paid from UTXOs you spend — not from a separate “fee account”. Higher sat/vB competes for block space when the mempool is full.
Educational context only — not financial advice.
Address balances (address-only)
Addresses only — never a seed phrase.
Public tx lookup (from V2 inspect dock)
Tick leak-ack, then this page fetches that txid via the mempool proxy. Missing txs say not found — never a fake confirm.
Waiting for leak-ack.
Checking balance reveals interest in those addresses to the API host.
Load / Fetch stay grayed out until you tick the leak-ack above.
0 sats with status ok means the address is empty (valid). Failures show status unknown/error — never a silent fake zero.
| # | Address | Status | Balance (sats) | Detail |
|---|---|---|---|---|
| No balances yet — acknowledge, add addresses, then Fetch. | ||||
Private balance via CLI (not this page)
Lab never loads balances (browser CSP blocks network from the Lab page). For privacy, query an address only with the CLI — never a seed. Public explorers learn which address you care about; a local node does not send that lookup to a third party. Full privacy still needs network hygiene (e.g. Tor / careful peer exposure) — a self-hosted node alone is not “invisible.”
If the CLI below looks unfamiliar, use the public balance form above (after leak-ack) as the simpler path.
Your node (preferred) — Knots or Core, pruned is enough for current UTXOs:
python -m bip39lab balance bc1q… \ --backend knots --rpc-cookie ~/.bitcoin/.cookie
Public review (address leak to mempool.space):
python -m bip39lab balance bc1q… \ --backend mempool --i-understand-address-leak
Remote node: SSH tunnel 8332 to loopback, then same CLI with
--rpc-url http://127.0.0.1:8332.
Guide: docs/BITCOIN_KNOTS.md.
Never expose RPC to the public internet.