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OP-20

BRC-20's JSON shape on OP_RETURN plus a required credit address; no indexer has ever existed, so BTI's replay is the record.

OP-20 0.00 % of the chain's bytes in Book A, as of block 972,299, 2026-10-20 09:30:48 UTC

OP-20 is a fungible tick ledger. In BTI's token table its tokens are OP-20 ticks, each identified by the case-folded tick, written op20/…. BTI is its indexer: it is a native protocol, read by BTI's own op20 decoder. The roster records that no indexer for it has ever existed, so BTI's replay is the record (ruling B32).

How OP-20 writes to Bitcoin #

OP-20 uses BRC-20's JSON shape, but in an OP_RETURN rather than an inscription, and with one extra field. Its mint carries add, a credit address, and that field is required. The ruleset gives the reason: OP-20 mints were paid over Lightning through a bot, so the transaction's signer is not the minter. The launch coverage it quotes said there was "no official index or transaction transfer tool available".

How BTI attributes its bytes #

The ruleset describes the decoder as the same machine as BTI's BRC-20-on-OP_RETURN decoder, with that one protocol fact added: add is the mint's credit instruction. The shared machine is deploy-gated (a mint naming an undeployed tick is residue). A transfer debits the first input's previous output script and credits the minimum-value output that is not an OP_RETURN, and the last mint is clamped to what remains.

OP-20 entered the roster on 2026-08-11 through ruling U3's transferability gate, with this chain of evidence:

  1. a deploy at block 895,638;
  2. a mint at 895,843 that credits its add address;
  3. a transfer of 500 to the same holder at 896,654;
  4. a transfer of 300 to a different script at 896,662, within the balance.

Findings of the August review #

The BTI protocol review of 2026-08-29 found OP-20 quiet since block 959,972, with its decoder still running. Its top three ticks (op_return, op_pepe and oink) were at their deploy caps, which the review called "a sufficient explanation for a mint-only micro-protocol going silent".

It also found a blind spot of known size. The OP-20 and BRC-20-on-OP_RETURN decoders choose blocks by the census marker {"p. A block whose only JSON OP_RETURN starts with a space after the brace, { "p, is never fetched. That leaves 441 carriers in 16 blocks out of reach. Whether any of them is a real record the census cannot say, so the review recorded it as a blind spot, not a proven loss.

Live figures #

OP-20 holds 1,722,430 bytes in Book A and 0 in Book C. The books count 99 ticks across 7,104 operations, from block 895541 to 959972 (as of block 972,299, 2026-10-20 09:30:48 UTC).

Sources #

  1. block.space protocols API · block.space/api/protocols
  2. Blockspace Holdings records

Live figures: protocols as of block 972,299, 2026-10-20 09:30:48 UTC. Refreshed hourly.

Updated 2026-10-20 · This page as Markdown