Coreum Non-Fungible Token
This document specifies assetnft module, which allows public users of the blockchain to create
non-fungible tokens on the Coreum blockchain.
Concepts
This module provides transactions and queries which allows public users of the blockchain to issue
non-fungible tokens. The information for the NFTs themselves are stored in the nft module
developed by Cosmos team, but that module does not allow public users to issue NFT classes or mint
NFTs, and that's where this module comes in. The interaction between the two modules is described
here. This module also introduces features
that defines specific behavior for the nft (described here).
Interaction with nft module, introducing wnft module
The Cosmos team has developed the nft module (which we hereby refer to as the
original nft module), which can be used to store the information about NFTs, their classes, their
ownership, etc. But as mentioned earlier this module does not provide any functionalities to public
users to create their own NFTs, or define custom behavior for transferring tokens. Because of this
reason we have wrapped the original nft module into the wnft module, which allows injecting
custom logic into the transfer method of the original nft module. We have also created the
assetnft module (this module), to allow public users to create their own NFTs with their own
custom behavior.
In other words the assetnft module defines the custom behavior for NFTs, enforces that behavior by
injecting custom logic into wnft module, and keeps most NFT related information on the
original nft module.
This design means that some portion of data relating to NFTs will live in this module, and some will
live in the original nft module, so to get the final NFT functionality one should be aware and
understand that they should make some of the queries to the original nft module.
Token Features
NFT tokens come with a set of features that the issuer can specify at the time of issuing a class, and then in some cases configured on each NFT level later.
Here is the list of features:
- minting
- burning
- freezing
- whitelisting
- disable sending
- soulbound
- update data
We will discuss each feature separately.
Minting
The minting is enabled for all issued NFT classes. The minting allows to mint a token for an NFT class by the issuer of the class.
There are two data types that can be used for NFT minting DataBytes and DataDynamic. The DataBytes contains immutable data bytes
array. The DataDynamic contains the list of the DataDynamicItem which can be updated depending on item's editors.
Currently supported DataEditors are admin and owner. If only one editor is set for the item, only that editor can update the
item's data using theMsgUpdateData. If both, both can update the data. If the editors list is empty no one can update the data.
Burning
If this feature is enabled, it allows the holders of the token to burn the tokens they hold. It should be noted here that the issuer can burn their token regardless of this feature.
Freezing
If this feature is enabled, it allows the issuer of the class to freeze any NFT token in that class. A frozen token cannot be transferred until it is unfrozen by the issuer.
Whitelisting
If this feature is enabled, then for any user to receive any NFT of that class, they must be whitelisted to receive that specific NFT. It follows that this feature allows the issuer of the class to whitelist an account to hold a specific NFT of that class, or remove an account from whitelisted accounts for that NFT.
Disable Sending
If this feature is enabled, then the NFT cannot be directly transferred between users, meaning that user A cannot send the tokens they hold directly to user B. This feature opens up the door for different use cases in the future, one of which is that it might be used to force transfer of ownership to go via DEX, so that the royalty fee is applied and the creator of the NFT always gets a royalty fee.
Soulbound
If this feature is enabled, then the NFT can not be sent by anyone, except the issuer. This feature is useful for NFTs that are created for a specific user, and the issuer wants to make sure that the NFT is not transferred to anyone else.
Update Data
update the data of the specified NFT with the information provided in the data file