Attach metadata to token with metaplex

Question

I am trying to attach metadata uploaded to arweave to a token. I am using createCreateMetadataAccountV3Instruction from @metaplex-foundation/mpl-token-metadata, but I am getting an error.

This is the fc

createCreateMetadataAccountV3Instruction(
      {
        metadata: pda,
        mint: mintKeypair.publicKey,
        mintAuthority: mintAuthority,
        payer: payer.publicKey,
        updateAuthority: mintAuthority,
      },
      {
        createMetadataAccountArgsV3: {
          data: ON_CHAIN_METADATA,
          isMutable: true,
          collectionDetails: null,
        },
      }
    )

what I am unsure of

1. where to get pda? All I'm doing rn is const pda = await metaplex.nfts().pdas().metadata({ mint: wallet.publicKey }); but I am not sure this is the correct way

2. what is collectionDetails: null? I put null because I do not know

ERROR I am getting:

'Program log: IX: Create Metadata Accounts v3',
    "Program log: panicked at 'range end index 36 out of range for slice of length 0', library/core/src/slice/index.rs:73:5",
    'Program metaqbxxUerdq28cj1RbAWkYQm3ybzjb6a8bt518x1s consumed 7998 of 972240 compute units',

Answer 1

Instead of wallet.publicKey, you should be using the mint address of the token you're trying to create a metadata account for. The address of the metadata account is derived using the token mint address.

const pda = await metaplex.nfts().pdas().metadata({ mint: TOKEN_MINT_ADDRESS })

https://docs.metaplex.com/programs/token-metadata/overview#nfts

collectionDetails is only used for NFTs to specify a "collection nft". Its correct to leave as null if you are creating the metadata account for a fungible token. You can read more about metaplex collections from their docs.

https://docs.metaplex.com/programs/token-metadata/certified-collections#collection-nfts

Also, the data for createMetadataAccountArgsV3 should be in the format of the DataV2 type from @metaplex-foundation/mpl-token-metadata

For example:

const ON_CHAIN_METADATA= {
  name: "Token Name",
  symbol: "SYMBOL",
  uri: uri, // this is the uri to the offchain metadata
  sellerFeeBasisPoints: 0,
  creators: null,
  collection: null,
  uses: null,
} as DataV2

createMetadataAccountArgsV3: {
  data: ON_CHAIN_METADATA,
  isMutable: true,
  collectionDetails: null,
}

https://docs.metaplex.com/programs/token-metadata/overview#a-json-standard