# What are Counters?

Numbered file events: files in Bitcoin witness data, owned through Counterparty assets, numbered from #0.

URL: https://blockspace.wiki/answers/what-are-counters/

A Bitcoin [counter](https://blockspace.wiki/glossary/counter/) is "a numbered file event": a file committed to Bitcoin as the description of a [Counterparty](https://blockspace.wiki/glossary/counterparty/) asset, carried in [witness data](https://blockspace.wiki/glossary/witness/), and numbered gap-free in order of creation from #0. Counter #0, XDUALS, came at block 902,005, five blocks after Counterparty's taproot encoding activated. counters.gallery is their explorer; counters.fun is their market.

Sources:

- Bitcoin Counters build reference v3 · https://github.com/BitcoinCounters/counters/blob/HEAD/docs/build-reference-v3.md
- Bitcoin Counters v3, indexer and wallet: README (BitcoinCounters/counters) · https://github.com/BitcoinCounters/counters
- Counters notes · https://github.com/BitcoinCounters/counters/blob/HEAD/docs/notes.md
- The project list at block.space/projects · https://block.space/projects

Updated: 2026-10-20