RMRK legos

What are RMRK legos?
RMRK is a set of NFT standards that compose several "NFT 2.0 lego" primitives. Putting these legos together allows a user to create NFT systems of arbitrary complexity.
There are various possibilities on how to combine these legos, all of which are ERC721 compatible:
  1. 1.
    • Only uses the MultiAsset RMRK lego
  2. 2.
    • Only uses the Nestable RMRK lego
  3. 3.
    Nestable with MultiAsset
    • Uses both Nestable and MultiAsset RMRK legos
  4. 4.
    Equippable MultiAsset with Nestable and Catalog (ERC-6220: Composable NFTs utilizing Equippable Parts)
    • Merged equippable is a more compact RMRK lego composite that uses fewer smart contracts, but has less space for custom logic implementation
    • Split equippable is a more customizable RMRK lego composite that uses more smart contracts but has more space for custom logic implementation
The first 3 use cases have stand-alone versions with both minimal and ready-to-use implementations. The latter two, due to Solidity contract size constraints, MultiAsset and Equippable logic are included in a single smart contract, while Nestable and ownership are handled by either the same smart contract or a separate one. Catalog is also a separate smart contract for practical reasons since one Catalog can be used by multiple tokens.
Infographic of RMRK lego combinations