Library · Crypto, word by word · Inside Bitcoin
What is BRC-20?
BRC-20 is an experimental way to create fungible tokens on Bitcoin by inscribing small pieces of JSON text with Ordinals. Deploying a token, minting it and transferring it are each an inscription, and outside programs called indexers add up the balances.
What it means for you
Bitcoin itself does not know BRC-20 balances exist: they are whatever the indexers agree on, read from inscriptions. A wallet that is not aware of inscriptions can spend the ones that hold your tokens by accident. Its creator wrote that these tokens would be worthless and discouraged basing any financial decision on its design.
How it works
Every operation is a JSON inscription with "p": "brc-20" and an "op" field. Deploy sets a ticker, a maximum supply and an optional limit per mint; mint claims an amount until the supply runs out; transfer is inscribed first and then sent to the recipient as an ordinary inscription. The first deployment of a ticker is the only one that counts. Because the rules live in indexers rather than in Bitcoin, two indexers that disagree show different balances, and Runes was later designed to do the same job inside Bitcoin transactions.
Source: BRC-20 experiment: the original documentation · checked 5 October 2026
Related words
Educational content, not financial advice. Written by hand and checked against the source named above. Something wrong? Tell us and we reply within two business days.