Features
Creating Assets
As discussed in the Core overview, digital assets on Core are composed of exactly one on-chain account and off-chain data describing the token. On this page, we'll go over the process of minting these assets.
The Creation Process
- Upload off-chain data. First, we must ensure our off-chain data is ready. This means we must have a JSON file stored somewhere that describes our asset. It doesn't matter how or where that JSON file is stored, as long as it's accessible via a URI. The off chain metadata can look similar to the old token metadata standard.
- Create on-chain Asset account. Then, we must create the on-chain Asset account that will hold our asset's data.
Let's dig into these steps in more detail, whilst providing concrete code examples.
Uploading off-chain data
You may use any storage service (Arweave, IPFS, AWS etc...) to upload your off-chain data or simply store it on your own server. To make some of these easier for the user Umi
has some dedicated plugins including the likes of Irys (uploads to Arweave)
and nftStorage (uploads to IPFS)
. Once a plugin is selected this grants the user a unified interface for you to upload your data.
Upload assets and JSON data
const [imageUri] = await umi.uploader.upload([imageFile])
const uri = await umi.uploader.uploadJson({
name: 'My NFT',
description: 'This is my NFT',
image: imageUri,
// ...
})
Now that we have our URI, we can move on to the next step.
Create an Asset
To create an Asset use the createV1
instruction. The createV1
instruction, in addition to setting the basic metadata of the Asset, encompasses the likes of adding your Asset to a collection and assigning plugins which is described a bit later.
Below is a simple example:
Create Asset
import { generateSigner } from '@metaplex-foundation/umi'
import { create } from '@metaplex-foundation/mpl-core'
const assetSigner = generateSigner(umi)
const result = await create(umi, {
asset: assetSigner,
name: 'My Asset',
uri: 'https://example.com/my-asset.json',
}).sendAndConfirm(umi)
Create an Asset into a Collection
MPL Core Assets can be created straight into a collection if your MPL Core Collection already exists. To create a Collection Asset visit here.
Create Asset into Collection
import { generateSigner } from '@metaplex-foundation/umi'
import { createCollection, create } from '@metaplex-foundation/mpl-core'
const collectionSigner = generateSigner(umi)
await createCollection(umi, {
collection: collectionSigner,
name: 'My Collection',
uri: 'https://example.com/my-collection.json',
}).sendAndConfirm(umi)
const asset = generateSigner(umi)
await create(umi, {
asset: assetSigner,
collection: collection,
name: 'My Asset',
uri: 'https://example.com/my-asset.json',
}).sendAndConfirm(umi)
Create an Asset with Plugins
MPL Core Assets support the use of plugins at both the Collection and Asset levels. To create a Core Asset with a plugin you pass in the plugin type and its parameters into the plugins
array arg during creation. The below example creates a mint with the Freeze
plugin.
Create Asset with Plugin
import { generateSigner } from '@metaplex-foundation/umi'
import { create, ruleSet } from '@metaplex-foundation/mpl-core'
const creator1 = publicKey('11111111111111111111111111111111')
const creator2 = publicKey('22222222222222222222222222222222')
const assetSigner = generateSigner(umi)
await create(umi, {
asset: assetSigner,
name: "My Asset",
uri: "https://example.com/my-asset.json",
plugins: [
{
type: "Royalties",
basisPoints: 500,
creators: [
{
address: creator1,
percentage: 20,
},
{
address: creator2,
percentage: 80,
},
],
ruleSet: ruleSet("None"), // Compatibility rule set
},
],
}).sendAndConfirm(umi)
The list of plugins includes but is not limited to: