Wrapper and metadata

The wrapper is a display layer with one hard check: the netlist must hash to a registered drawing.

wrap(uint16 epoch, uint8 drawingId, address cpu, uint256 circuitId)

Before minting anything, the wrapper checks, in order:

1. processor[cpu] is true — the processor is accepted.
2. wrapperOf[cpu][circuitId] == 0 — this circuit is not already wrapped.
3. ownerOf(circuitId) == msg.sender — you own the raw circuit.
4. circuitInfo(circuitId).gates != 0 — the circuit exists.
5. keccak256(netlist(circuitId)) == drawings(epoch, drawingId).hash — the netlist is the registered drawing.

Then it pulls the original into the contract, increments nextId, writes the mapping in both directions, and mints the TFD.

Stored per token

struct Original {
    address cpu;        // processor that minted the circuit
    uint32  circuitId;  // id on that processor
    uint32  gates;      // burned gate count
    uint16  edition;    // number in the drawing
    uint16  epoch;      // series epoch
    uint8   drawing;    // drawing id
}

All of it is public: original(tfdId) and wrapperOf(cpu, circuitId).

tokenURI

Metadata is generated on chain and returned as a base64 data URI. No server, no IPFS.

{
  "name": "TapeFoundry 4-bit Adder #7",
  "description": "A circuit taped out on TapeOut, wrapped so its drawing,
                  gate count and edition travel with the token…",
  "image": "data:image/svg+xml;base64,…",
  "attributes": [
    {"trait_type":"Drawing","value":"4-bit Adder"},
    {"trait_type":"Gates","value":46},
    {"trait_type":"Edition","value":"6 / 100"},
    {"trait_type":"Series","value":1},
    {"trait_type":"Processor","value":"0x5a4e…ba83"},
    {"trait_type":"Source token","value":"7"}
  ]
}

The SVG is generated from the same fields: drawing label, gate count, edition, and the processor address in small type.

Edition display

If the circuit had no number at wrap time, the edition reads UNSTAMPED. refresh(id) re-reads the registry and updates the stored edition — useful when a card is wrapped before claiming.

Royalty

ERC-2981, 500 basis points (5%), receiver set at deployment and changeable by the owner. Marketplaces that support ERC-2981 pay it on secondary sales.

unwrap

Burns the TFD, deletes both mappings, and transfers the original back. Token ids are never reused, so the wrapper's numbering accumulates gaps — the count of TFDs ever minted is not the count that exists.