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 descending order, starting at 2099999997689999 in the genesis block. Satoshi 0 will be 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, does not affect 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
2099999997689999 2099994997689999

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.

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

$ sat-tracker traits 0
zero
genesis
even

The name trait is of particular interest, as it can serve as the basis for a decentralized naming system.

The name command finds the satoshi with the given name:

$ sat-tracker name nvtdijuwxlp
2099999997689999