A scheme for assigning serial numbers to satoshis upon creation and tracking them across subsequent transactions.

Satoshi serial numbers can be used as an addressing scheme for NFTs.

Satoshis are numbered in ascending order, starting at 0 in the genesis block, and ending with 2099999997689999, mined in block 6929999, the last block with a subsidy.

Satoshi numbers only depend on how many satoshis could have been created in previous blocks, not how many were actually created.

In particular, this means that block 124724, which underpaid the block subsidy by one satoshi, does not reduce the serial numbers of satoshis in subsequent blocks.

The range command gives the half-open range of satoshis mined in the block at a given height:

$ sat-tracker range 0
[0,5000000000)

See src/range.rs for the numbering algorithm.

Satoshis input to a transaction are transferred to the transaction outputs according to the order and value of the inputs and outputs. Satoshis paid as fees are assigned in the same fashion to the outputs of the coinbase transaction.

fn transfer(transaction: Transaction) {
  let mut numbers = Vec::new();

  for input in transaction.inputs {
    for number in input.numbers {
      numbers.push(number);
    }
  }

  for output in transaction.outputs {
    let rest = numbers.split_off(output.value);
    output.numbers = numbers;
    numbers = rest;
  }

  coinbase.input.numbers.extend_from_slice(&numbers);
}

The find command, as of yet unfinished, gives the current outpoint containing a given satoshi as of a given height:

$ sat-tracker find --blocksdir ~/.bicoin/blocks 0 0
4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b:0

Satoshis have traits, based on their number.

NB: Traits should be considered UNSTABLE. In particular, the satoshis with short names will not be available for quite some time, which might be desirable to fix, and would require an overhaul of the name trait.

The traits command prints out the traits of a given satoshi:

$ sat-tracker traits 0
even
square
cube
luck: 0/1
population: 0
name: nvtdijuwxlo
character: '\u{0}'
shiny
block: 0

Each satoshi is assigned a name, consisting of lowercase ASCII characters. Satoshi 0 has name nvtdijuwxlo, and names get shorter as the satoshi number gets larger. This is to ensure that short names aren't locked in the genesis block output which is unspendable, and other outputs, which are unlikely to ever be spent.

The name command finds the satoshi with the given name:

$ sat-tracker name nvtdijuwxlo
0
$ sat-tracker name hello
2099999993937872
$ sat-tracker name ''
2099999997689999