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name: bitcoin-metaprotocols-brc-20 description: | BRC-20: fungible token standard via JSON inscriptions. Deploy / mint / transfer operations. Permissionless and unaudited; large ecosystem post-2023. USE WHEN: building BRC-20 tooling, evaluating token issuance on Bitcoin, comparing with Runes / Taproot Assets. allowed-tools: Read, Grep, Glob

BRC-20

Token standard defined via JSON inscriptions. Created May 2023 by @domodata. Originally a "fun experiment", became massive ecosystem.

Mechanics

Each operation is a JSON inscription:

Deploy

{
  "p": "brc-20",
  "op": "deploy",
  "tick": "ordi",
  "max": "21000000",
  "lim": "1000"
}

tick = 4-character ticker (case-insensitive). Once deployed, max supply fixed.

Mint

{
  "p": "brc-20",
  "op": "mint",
  "tick": "ordi",
  "amt": "1000"
}

Each mint must respect lim and total max. First-come-first-served until cap.

Transfer (two steps)

Step 1: inscribe transfer:

{
  "p": "brc-20",
  "op": "transfer",
  "tick": "ordi",
  "amt": "100"
}

Step 2: send the inscription to recipient. Receipt = balance moves.

State tracking

BRC-20 has no on-chain validation — it's an indexer convention. Each indexer must:

• Watch inscriptions for BRC-20 ops.
• Compute balances per address.
• Validate against max / lim constraints.

Indexers must agree on rules (otherwise different indexers see different balances).

Major indexers

• OrdiScan — primary public indexer.
• UniSat — wallet + indexer.
• OKX — exchange-side.
• Magic Eden — former BRC-20 marketplace; closed its entire Bitcoin marketplace on 9 March 2026 (announced 27 February 2026, Bitcoin API retired 27 March 2026) to refocus on Solana.

Compared to other token standards

Aspect	BRC-20	Runes	Taproot Assets
Activation	May 2023	April 2024 (halving)	2023
Mechanism	JSON inscriptions	Native protocol op_returns	Client-side validation
State tracking	Off-chain indexer convention	Native (each rune is a UTXO commitment)	Client-side merkle
Efficiency	High overhead	Native, smaller	Smaller
Validation rules	Indexer-defined	Protocol-defined	Schema-defined

Most agree: Runes > BRC-20 in efficiency. BRC-20 is "first-mover" but architecturally suboptimal.

Critique

• Off-chain validation = consensus uncertainty about what is "valid".
• First-mint-wins rewards bots over real users.
• High fees during deployment / minting frenzies.

Status

As of September 2026:

• Active ecosystem; many tokens exist.
• Trading volume on UniSat and OKX; Magic Eden closed its Bitcoin marketplace on 9 March 2026 and no longer carries BRC-20.
• Some migration to Runes underway (similar use cases).

Use cases

• Memecoins on Bitcoin.
• Loyalty / community tokens for projects.
• Trading vehicles within Bitcoin.

Common bugs

• Indexer disagreement on edge cases (e.g., simultaneous mints in same block, ordering rules).
• Stale balance display when wallet doesn't sync indexer state.
• Two-step transfer: forgetting step 2 (just inscribing transfer doesn't move funds).

See also

• inscriptions/SKILL.md
• runes/SKILL.md
• atomicals/SKILL.md