Metadata

The Metadata extension allows for assets to have on-chain description, symbol and uri pointing to off-chain metadata, for compatibility with existing NFT standards.

The extension consists of:

Field	Description
symbol	(optional) Symbol of the asset.
description	(optional) Description of the asset.
uri	(optional) URI for external metadata information.

Each of these fields is limited to 255 length, but their size is not fixed — data is stored on-chain only when a value is set.

Creating Metadata

The Metadata extension can be created using either the allocate, create or update instructions.

JavaScript

import { allocate, metadata } from '@nifty-oss/asset';

await allocate(umi, {
  asset,
  payer,
  extension: metadata({
    symbol: 'SMB',
    description: 'A metadata extension',
    uri: 'https://arweave.net/62Z5yOFbIeFqvoOl-aq75EAGSDzS-GxpIKC2ws5LVDc',
  }),
}).sendAndConfirm(umi);

Rust

use nifty_asset::{
  extensions::{ExtensionBuilder, MetadataBuilder},
  instructions::AllocateBuilder,
  types::{ExtensionInput, ExtensionType},
};

let mut metadata = MetadataBuilder::default();
metadata.set(
    Some("SMB"),
    None,
    Some("https://arweave.net/62Z5yOFbIeFqvoOl-aq75EAGSDzS-GxpIKC2ws5LVDc"),
);

let ix = AllocateBuilder::new()
  .asset(asset.pubkey())
  .payer(Some(payer.pubkey()))
  .system_program(Some(system_program::id()))
  .extension(ExtensionInput {
    extension_type: ExtensionType::Metadata,
    length: metadata.len() as u32,
    data: Some(metadata),
})
.instruction();

Rust (on-chain)

use nifty_asset::{
  extensions::{ExtensionBuilder, MetadataBuilder},
  instructions::AllocateCpiBuilder,
  types::{ExtensionInput, ExtensionType},
};

let mut metadata = MetadataBuilder::default();
metadata.set(
    Some("SMB"),
    None,
    Some("https://arweave.net/62Z5yOFbIeFqvoOl-aq75EAGSDzS-GxpIKC2ws5LVDc"),
);

AllocateCpiBuilder::new(ctx.accounts.nifty_asset_program)
  .asset(ctx.accounts.group)
  .payer(Some(ctx.accounts.payer))
  .system_program(Some(ctx.accounts.system_program))
  .extension(ExtensionInput {
    extension_type: ExtensionType::Metadata,
    length: metadata.len() as u32,
    data: Some(metadata),
})
.invoke();

Fetching Metadata

Given an asset account, it is possible to retrieve the metadata information of an asset. Note that not all assets might have the extension, therefore it is necessary to assert if the extension was found.

JavaScript

import {
  ExtensionType,
  fetchAsset,
  getExtension
} from '@nifty-oss/asset';

const asset = await fetchAsset(umi, address);
const metadata = getExtension(asset, ExtensionType.Metadata);

if (metadata) {
    console.log("Symbol: " + metadata.symbol);
    console.log("Description: " + metadata.description);
    console.log("URI: " + metadata.uri);
}

Rust

use nifty_asset::{
  extensions::Metadata,
  state::Asset,
};

let account = get_account(address)
  .await
  .unwrap();
let account_data = account.data.as_ref();

if let Some(metadata) = Asset::get::<Metadata>(account_data) {
  println!("metadata: {:?}", metadata);
}

Rust (on-chain)

use nifty_asset::{
  extensions::Metadata,
  state::Asset,
};

let data = (*ctx.accounts.asset.data).borrow();

if let Some(metadata) = Asset::get::<Metadata>(&data) {
  msg!("metadata: {:?}", metadata);
}