Class Definition

To define a class, you’ll need to start with a JSON file:

{
  "data": {
    "settings": {
      "freeBuild": {
	"boolean": true,
        "inherited": { "notInherited": true }
      },
      "childrenMustBeEditions": null,
      "builderMustBeHolder": null,
      "updatePermissiveness": null,
      "buildPermissiveness": [
        {
          "permissivenessType": { "parentTokenHolder": true },
          "inherited": { "notInherited": true }
        }
      ],
      "stakingWarmUpDuration": null,
      "stakingCooldownDuration": null,
      "stakingPermissiveness": null,
      "unstakingPermissiveness": null,
      "childUpdatePropagationPermissiveness": [
        {
          "childUpdatePropagationPermissivenessType": { "usages": true },
          "inherited": { "notInherited": true }
        },
        {
          "childUpdatePropagationPermissivenessType": { "components": true },
          "inherited": { "notInherited": true }
        },
        {
          "childUpdatePropagationPermissivenessType": {
            "updatePermissiveness": true
          },
          "inherited": { "notInherited": true }
        },
        {
          "childUpdatePropagationPermissivenessType": {
            "buildPermissiveness": true
          },
          "inherited": { "notInherited": true }
        },
        {
          "childUpdatePropagationPermissivenessType": {
            "stakingPermissiveness": true
          },
          "inherited": { "notInherited": true }
        },
        {
          "childUpdatePropagationPermissivenessType": {
            "freeBuildPermissiveness": true
          },
          "inherited": { "notInherited": true }
        }
      ]
    },
    "config": {
      "usageRoot": null,
      "usageStateRoot": null,
      "componentRoot": null,
      "usages": [
        {
          "index": 0,
          "basicItemEffects": null,
          "usagePermissiveness": [{ "updateAuthority": true }],
          "inherited": { "notInherited": true },
          "itemClassType": {
            "consumable": {
              "maxUses": null,
              "maxPlayersPerUse": null,
              "itemUsageType": { "infinite": true },
              "cooldownDuration": 500,
              "warmupDuration": null
            }
          }
        }
      ],
      "components": [
        {
          "mint": "FvGU3HCV4BjtFs2YbvbMugySMbXDE7i2iKsaQqvNyWZx",
          "amount": 1,
          "classIndex": 0,
          "timeToBuild": null,
          "componentScope": "set1",
          "useUsageIndex": 0,
          "condition": { "presence": true },
          "inherited": { "notInherited": true }
        }
      ]
    }
  },
  "metadataUpdateAuthority": null,
  "storeMint": false,
  "storeMetadataFields": false,
  "mint": "Hz5x6myaWWSKKzAhh2LHA5YmXExLiyTfj89S9zXyT17M",
  "index": 9,
  "updatePermissivenessToUse": { "updateAuthority": true },
  "namespaceRequirement": 1,
  "totalSpaceBytes": 300
}

Now there’s a lot to unpack here, so let’s go step by step.

Your settings contains mostly permissions arrays that use the PermissivenessType described in Concepts to tell the ItemClass who is allowed to do which things. Examples include who can stake, who can unstake, who can build, and who can update.

You’ll also notice two special options which are optional Booleans (a boolean + an inheritance marker), free_build and children_must_be_editions. For a traditional ItemClass, a lack of Components means that it cannot be built. Setting free_build to true indicates that rather than indicating the ItemClass cannot be used to build an NFT into an Item, it can be done for free (no components required). children_must_be_editions is fairly straightforward - all Items created from this ItemClass must be a limited edition of the ItemClass’s underlying NFT. This requirement is not enforced for child ItemClasses.

Whenever you are using the JSON files to define Permissivenesses, you’ll notice notInherited is exclusively used. This is by design. Overridden and Inherited values are provided by the program when class propagation occurs.

The config part of the JSON file covers how an item may be used, and what components are required to build it. You’ll notice that usages are required to have indexes that match up with their position in the array - this is for later use in item activation. You’ll also see that you can configure the way your item is used to have different permissions depending on the type of use.

The top-level of the JSON file lets the CLI know what permissions to use to define or update the class, how much space should be used for the ItemClass struct, and whether or not you wish to store the metadata and mint fields on the ItemClass for reverse-lookups.

Once you have this file, you can create an ItemClass on top of an existing NFT (no SFTs allowed, sorry) like so:

item-cli create_item_class \
         -k <keypair> \
         --env devnet \
         -cp example-configs/itemClass.json

Updating it is just as easy:

item-cli update_item_class \
         -k <keypair> \
         --env devnet \
         -cp example-configs/itemClass.json

Remember, if you want to propagate updates from a parent ItemClass to your ItemClass, you must start at the highest parent that has changed, and issue updates in sequence from parent to child via the update_item_class command until all updates are propagated. If you wish to do this permissionlessly, use the -iu flag with update_item_class.

Want to see what you made? Run show_item_class!

item-cli show_item_class \
         -k <keypair> \
         --env devnet \
         -cp example-configs/itemClass.json