How to add metadata on spl-token?

Question

I already succeed create token using spl-token, now how to add metadata?

    const mint = Keypair.generate();
    const ata = getAssociatedTokenAddressSync(
      mint.publicKey,
      wallet.publicKey!
    );

    const tx = new Transaction().add(
      SystemProgram.createAccount({
        fromPubkey: wallet.publicKey!,
        newAccountPubkey: mint.publicKey,
        space: MINT_SIZE,
        lamports: await connection.getMinimumBalanceForRentExemption(MINT_SIZE),
        programId: TOKEN_PROGRAM_ID,
      }),
      createInitializeMintInstruction(
        mint.publicKey,
        Number(formData.decimals),
        wallet.publicKey!,
        null
      ),
      createAssociatedTokenAccountInstruction(
        wallet.publicKey!,
        ata,
        wallet.publicKey!,
        mint.publicKey
      ),
      createMintToCheckedInstruction(
        mint.publicKey,
        ata,
        wallet.publicKey!,
        Number(formData.supply) * 10 ** Number(formData.decimals),
        Number(formData.decimals)
      ),
    );

    const blockhash = (await connection.getLatestBlockhash()).blockhash;
    tx.recentBlockhash = blockhash;
    tx.feePayer = wallet.publicKey!;
    tx.sign(mint);

    const signedTx = awalt wallet.signTransaction(tx,connection);
    await wallet.sendTransaction(signedTx);

Answer 1

You can use npm i mpl-token-metadata version 2 with createCreateMetadataAccountV3Instruction, if you still want to continue your code

npm i @metaplex-foundation/mpl-token-metadata@2

base on your code:

    // define metadata program id
    const TOKEN_METADATA_PROGRAM_ID = new PublicKey(
    "metaqbxxUerdq28cj1RbAWkYQm3ybzjb6a8bt518x1s"
    );

    const mint = Keypair.generate();
    const ata = getAssociatedTokenAddressSync(
      mint.publicKey,
      wallet.publicKey!
    );
    
    // Get metadataPDA
    const getMetadataPDA = PublicKey.findProgramAddressSync(
      [
        Buffer.from("metadata"),
        TOKEN_METADATA_PROGRAM_ID.toBuffer(),
        mint.publicKey.toBuffer(),
      ],
      TOKEN_METADATA_PROGRAM_ID
    );

    const metadataPDA = getMetadataPDA[0];

    const tx = new Transaction().add(
      SystemProgram.createAccount({
        fromPubkey: wallet.publicKey!,
        newAccountPubkey: mint.publicKey,
        space: MINT_SIZE,
        lamports: await connection.getMinimumBalanceForRentExemption(MINT_SIZE),
        programId: TOKEN_PROGRAM_ID,
      }),
      createInitializeMintInstruction(
        mint.publicKey,
        Number(formData.decimals),
        wallet.publicKey!,
        null
      ),
      createAssociatedTokenAccountInstruction(
        wallet.publicKey!,
        ata,
        wallet.publicKey!,
        mint.publicKey
      ),
      createMintToCheckedInstruction(
        mint.publicKey,
        ata,
        wallet.publicKey!,
        Number(formData.supply) * 10 ** Number(formData.decimals),
        Number(formData.decimals)
      ),
      // Instruction metadata here
      createCreateMetadataAccountV3Instruction(
        {
          metadata: metadataPDA,
          mint: mint.publicKey,
          mintAuthority: wallet.publicKey!,
          payer: wallet.publicKey!,
          updateAuthority: wallet.publicKey!,
        },
        {
          createMetadataAccountArgsV3: {
            collectionDetails: null,
            data: metadata,
            isMutable: !immutable,
          },
        }
      )
    );

    const blockhash = (await connection.getLatestBlockhash()).blockhash;
    tx.recentBlockhash = blockhash;
    tx.feePayer = wallet.publicKey!;
    tx.sign(mint);

    const signedTx = await wallet.signAndSendTransaction(tx);

If you want malicious warning to be immediately resolved, just use signAndSendTransaction, I think it's works properly. Good luck!