"""BRC-20 token protocol implementation.
BRC-20 is a token standard using JSON inscriptions:
- Deploy: Create new token
- Mint: Mint tokens
- Transfer: Transfer tokens
Reference: https://domo-2.gitbook.io/brc-20-experiment/
"""
import json
from dataclasses import dataclass
from typing import Optional, Union
from mcp_bitcoin_cli.envelope import encode_envelope, EnvelopeType
from mcp_bitcoin_cli.protocols.base import Protocol
@dataclass
class BRC20Deploy(Protocol):
"""BRC-20 deploy operation."""
tick: str
max_supply: int
mint_limit: Optional[int] = None
decimals: int = 18
def __post_init__(self):
if len(self.tick) != 4:
raise ValueError(f"Tick must be exactly 4 characters, got {len(self.tick)}")
def to_json(self) -> str:
"""Convert to BRC-20 JSON format."""
data = {
"p": "brc-20",
"op": "deploy",
"tick": self.tick,
"max": str(self.max_supply),
}
if self.mint_limit is not None:
data["lim"] = str(self.mint_limit)
if self.decimals != 18:
data["dec"] = str(self.decimals)
return json.dumps(data, separators=(',', ':'))
def to_bytes(self) -> bytes:
"""Convert to raw bytes."""
return self.to_json().encode('utf-8')
def to_envelope(self) -> bytes:
"""Convert to BTCD envelope format."""
return encode_envelope(self.to_bytes(), EnvelopeType.TOKEN)
@dataclass
class BRC20Mint(Protocol):
"""BRC-20 mint operation."""
tick: str
amount: int
def __post_init__(self):
if len(self.tick) != 4:
raise ValueError(f"Tick must be exactly 4 characters, got {len(self.tick)}")
def to_json(self) -> str:
"""Convert to BRC-20 JSON format."""
return json.dumps({
"p": "brc-20",
"op": "mint",
"tick": self.tick,
"amt": str(self.amount),
}, separators=(',', ':'))
def to_bytes(self) -> bytes:
return self.to_json().encode('utf-8')
def to_envelope(self) -> bytes:
return encode_envelope(self.to_bytes(), EnvelopeType.TOKEN)
@dataclass
class BRC20Transfer(Protocol):
"""BRC-20 transfer operation."""
tick: str
amount: int
def __post_init__(self):
if len(self.tick) != 4:
raise ValueError(f"Tick must be exactly 4 characters, got {len(self.tick)}")
def to_json(self) -> str:
"""Convert to BRC-20 JSON format."""
return json.dumps({
"p": "brc-20",
"op": "transfer",
"tick": self.tick,
"amt": str(self.amount),
}, separators=(',', ':'))
def to_bytes(self) -> bytes:
return self.to_json().encode('utf-8')
def to_envelope(self) -> bytes:
return encode_envelope(self.to_bytes(), EnvelopeType.TOKEN)
BRC20Operation = Union[BRC20Deploy, BRC20Mint, BRC20Transfer]
class BRC20Protocol:
"""BRC-20 protocol parser and helpers."""
@staticmethod
def parse(json_str: str) -> BRC20Operation:
"""Parse BRC-20 JSON into operation object.
Args:
json_str: BRC-20 JSON string
Returns:
Appropriate BRC20 operation object
Raises:
ValueError: If not valid BRC-20 JSON
"""
data = json.loads(json_str)
if data.get("p") != "brc-20":
raise ValueError(f"Not a BRC-20 inscription: p={data.get('p')}")
op = data.get("op")
tick = data.get("tick", "")
if op == "deploy":
return BRC20Deploy(
tick=tick,
max_supply=int(data.get("max", 0)),
mint_limit=int(data["lim"]) if "lim" in data else None,
decimals=int(data.get("dec", 18)),
)
elif op == "mint":
return BRC20Mint(
tick=tick,
amount=int(data.get("amt", 0)),
)
elif op == "transfer":
return BRC20Transfer(
tick=tick,
amount=int(data.get("amt", 0)),
)
else:
raise ValueError(f"Unknown BRC-20 operation: {op}")
