Whirlpool.Observer

A CoinJoin implementation by Samourai Wallet that creates transactions with exactly 5 equal outputs at fixed denominations, now run by the Ashigaru Open Source Project. Whirlpool.Observer tracks the 0.25 BTC and 0.025 BTC pools.

The preparation transaction in Whirlpool. It takes a user's deposit UTXO(s) and splits them into equal-sized premix outputs matching the pool denomination. Any leftover bitcoin becomes doxxic change. The Tx0 also pays the coordinator a one-time pool entry fee.

Whirlpool.Observer estimates fee efficiency as coordinator fee divided by detected entered capacity, expressed as a percentage. Entered capacity is counted as detected premix output count multiplied by the pool denomination, ignoring the tiny extra sats attached for miner fees. Larger Tx0s are more efficient because the fixed coordinator fee is spread across more premix outputs.

The cumulative BTC that entered a pool through detected Tx0 premix outputs. For example, 20 detected 0.025 BTC premix outputs count as 0.5 BTC entered capacity.

The value of tracked Whirlpool outputs that remain unspent and still in their fixed pool denominations.

One Whirlpool CoinJoin transaction, following the 5 inputs and 5 outputs structure with the fixed pool denominations.

The Tx0 transactions that directly funded a Whirlpool cycle input. All mature Whirlpool cycles have 3 remix inputs and 2 Tx0 inputs; early cycles (genesis adjecent) can have more Tx0 inputs because no prior whirlpool outputs existed.

Leftover change from a Tx0 that does not enter the equal-output Whirlpool pool.