TIP-62

TIP-62 is an NFT smart contract standard on TON finalized on 01.02.2022.¹

In TON every NFT is a smart contract, and there's a separate smart contract for a collection.

Contract	Number of contracts
NFT	$\sum = ID_0 ~ ... ~ ID_{n-1}$
Collection	1

An $NFT ~ contract$:

An NFT contract may have any arbitrary functionality as long as it implements the following obligatory functions:

1. transfer - which moves ownership from the current owner to a new one. It has the following parameters:
   • query_id:uint64 - an arbitrary request number
   • new_owner:MsgAddress - an address of the token receiver
   • response_destination - an address for notification messages and unused tokens refund
   • custom_payload:(Maybe ^Cell) - optional arbitrary data of any type
   • forward_amount:(VarUInteger 16) - several TONs to be transferred to the NFT recipient
   • forward_payload:(Either Cell ^Cell) - optional arbitrary data, for example, a message to the receiver
2. get_static_data - it has only one parameter, query_id:uint64

An $NFT ~ collection$:

1. get_collection_data() - returns a tuple:
   • int next_item_index - the number of the last minted NFT + 1
   • cell collection_content - the collection metadata defined by the standard TIP-64
   • slice owner_address - the address of the collection owner
2. get_nft_address_by_index(int index) - gets an NFT token ID called index and returns the smart contract address of the selected NFT.
3. get_nft_content(int index, cell individual_content) - queried by an NFT ID and individual data and returns the complete NFT metadata defined by the standard TIP-64

Yet Unsolved

1. The contract cannot be queried for a list of NFT owners.
2. safeTransfer returning the NFTs to the original owner should the contract fail to execute is not implemented.

Accepted and discussed extensions

1. NFTRoyalty (TIP-66)² (Accepted)

   • royalty_params() - returns a tuple:

      - `int numerator` - the divided
      - `int denominator` - the divisor
      - `slice destination` - the address of the beneficiary

     
     Example:
     
     $$RoyaltyPercent = numerator/denominator$$

2. NFTBouncable (TIP-67) - standardizes the rollback in case of an error.

3. NFTEditable(TIP-68) - an account with an editor role can massively update NFT content.

4. NFTUpgradable (TIP-69) - currently closed without being accepted.

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1. https://github.com/ton-blockchain/TEPs/blob/master/text/0062-nft-standard.md↩
2. https://github.com/ton-blockchain/TEPs/blob/master/text/0066-nft-royalty-standard.md↩