Trade NFT

An ERC-721 contract that represents trade ownership as a transferable NFT. Token IDs map 1:1 to trade IDs in the Symmio protocol. Transferring the NFT automatically updates trade ownership in the protocol, and vice versa.

How It Works

Token ID = Trade ID. When an NFT is minted for trade 42, the token ID is 42. No auto-increment.

NFTs are opt-in. Not every trade gets an NFT. PartyA must explicitly mint one via the core protocol.

Two transfer paths exist, kept in sync:

1. User moves the NFT → _beforeTokenTransfer hook calls symmio.transferTradeFromNFT() to update the protocol.

2. Protocol moves the NFT → transferTradeNFT() sets a flag (transferInitiatedInSymmio) so the hook doesn't call back into the protocol, avoiding an infinite loop.

---

Constructor

constructor(address symmio_) ERC721("Trade Ownership NFT", "TRNFT")

Reverts with InvalidSymmioAddress if symmio_ is address(0).

---

Functions

mintNFTForTrade()

function mintNFTForTrade(address partyA, uint256 tradeId) external onlySymmio;

Mints token tradeId to partyA. Only the Symmio contract can call this.

The _beforeTokenTransfer hook fires but skips the sync logic because from == address(0) (mint).

Event: TradeNFTMinted(partyA, tradeId)

transferTradeNFT()

function transferTradeNFT(address from, address to, uint256 tradeId) external onlySymmio;

Transfer trade ownership associated with NFT.

---

Events

Event	When
TradeNFTMinted(address indexed owner, uint256 indexed tokenId)	NFT minted
TradeNFTTransferred(uint256 indexed tokenId, address indexed from, address indexed to)	User-initiated NFT transfer only