Fetching on-chain Metaplex token metadata (through lightweight getAccountInfo).

rpc_fetch_metaplex_token_metadata.ts

import * as web3 from "@solana/web3.js";
import {
  MPL_TOKEN_METADATA_PROGRAM_ID,
  MetadataAccountData as MplMetadataAccountData,
  getMetadataAccountDataSerializer,
} from "@metaplex-foundation/mpl-token-metadata";

//////////////////////////////////////////////////

const METAPLEX_PROGRAM_ID = new web3.PublicKey(MPL_TOKEN_METADATA_PROGRAM_ID);

function findTokenMetadataAccountAddress(tokenMint: web3.PublicKey): web3.PublicKey | null {
  try {
    const [mplAccount] = web3.PublicKey.findProgramAddressSync(
      [Buffer.from("metadata"), METAPLEX_PROGRAM_ID.toBuffer(), tokenMint.toBuffer()],
      METAPLEX_PROGRAM_ID,
    );

    return mplAccount;
  } catch (e) {}

  return null;
}

async function getTokenMetadata(conn: web3.Connection, tokenMint: web3.PublicKey): Promise<MplMetadataAccountData | null> {
  const serializer = getMetadataAccountDataSerializer();
  if (!serializer) {
    throw new Error("getMetadataAccountDataSerializer failed");
  }

  const mplTokenAccount = findTokenMetadataAccountAddress(tokenMint);
  if (!mplTokenAccount) return null;

  const info = await conn.getAccountInfo(mplTokenAccount);
  if (!info || !info.data) {
    throw new Error("unexpected getAccountInfo response");
  }

  let metadata: MplMetadataAccountData | null = null;
  try {
    [metadata] = serializer.deserialize(info.data);
    if (typeof metadata !== "object") metadata = null;
  } catch (e) {}

  return metadata;
}

//////////////////////////////////////////////////

(async (rpcUrl: string) => {

  const conn = new web3.Connection(rpcUrl, "confirmed");

  const tokenMint = new web3.PublicKey("EKpQGSJtjMFqKZ9KQanSqYXRcF8fBopzLHYxdM65zcjm");
  const tokenMetadata = await getTokenMetadata(conn, tokenMint);
  if (!tokenMetadata) return;

  //////////////////////////////////////////////////

  console.log(`Token metadata (${tokenMint.toBase58()}):`);
  console.dir(tokenMetadata)

  //
  //   --- OUTPUT ---
  //
  //     Token metadata (EKpQGSJtjMFqKZ9KQanSqYXRcF8fBopzLHYxdM65zcjm):
  //     {
  //       key: 4,
  //       updateAuthority: 'wifq4CRwpXCK8NYtKNsQAYoDethT1aR7R1DaKCLFgAd',
  //       mint: 'EKpQGSJtjMFqKZ9KQanSqYXRcF8fBopzLHYxdM65zcjm',
  //       name: 'dogwifhat',
  //       symbol: '$WIF',
  //       uri: 'https://bafkreihwqhounu3cdwgvk2gc2dqcinpntlccbo3xcy4xuerd24yndldl5q.ipfs.nftstorage.link',
  //       sellerFeeBasisPoints: 0,
  //       creators: { __option: 'None' },
  //       primarySaleHappened: false,
  //       isMutable: false,
  //       editionNonce: { __option: 'Some', value: 254 },
  //       tokenStandard: { __option: 'Some', value: 2 },
  //       collection: { __option: 'None' },
  //       uses: { __option: 'None' },
  //       collectionDetails: { __option: 'None' },
  //       programmableConfig: { __option: 'None' }
  //     }
  //
  //   --------------
  //

})(process.env.SOL_RPC_URL || "https://mainnet.helius-rpc.com/?api-key=00000000-0000-0000-0000-000000000000");