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Subprotocols

Canto Identity Subprotocols are smart contracts which use NFTs (subprotocolNFTs) to represent identity traits. Users choose which traits to include in their on chain identities by adding pointers to them to their CIDs.

Subprotocols should implement ERC721 and should additionally start minting at tokenID == 1. However, as there is no strict interface for Subprotocols, developers can introduce arbitrary minting and ownership logic.

Subprotocol Registration

Subprotocols must be registered with SubprotocolRegistry.sol for a one-time fee in order to be used within Canto Identity Protocol. The register function takes the following inputs:

  • _ordered, a boolean specifiying whether the Subprotocol uses the ordered Association Type
  • _primary, a boolean specifiying whether the Subprotocol uses the primary Association Type
  • _active, a boolean specifiying whether the Subprotocol uses the active Association Type
  • _nftAddress, the smart contract address of the Subprotocol
  • _name, a unique name for the Subprotocol
  • _fee, the fee in $NOTE to mint a subprotocolNFT

Association Types

For each Subprotcol, subprotocolNFTs associate with CIDs according to three mutually inclusive Association Types:

  • primary: no more than one subprotocolNFT can be added to a CID
  • active: the subprotocolNFTs added to a CID have no order
  • ordered: the subprotocolNFTs added to a CID are strictly ordered

The Assocation Types used by a Subprotocol are specified by the Subprotocol creator at registration based on how the Subprotocol is intended to be used.

Registration Fee

A one-time 100 $NOTE registration fee is charged when registering a Subprotocol. Before calling the register method, the Subprotocol creator should ensure they have approved $NOTE to SubprotocolRegistry.sol and have the required number of tokens in their wallet.

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