How to upload to arweave at backend using solana metaplex js sdk?

[JohnVersus]

I have tried uploading metadata to arweave from the frontend using the metaplex.nfts().uploadMetadata and it is working great. I would like to know if it is possible to upload from the backend using metaplex.nfts().uploadMetadata and privateKey. If possible please share an example code or docs for the same.

Thanks🙏

[JohnVersus]

I figured this out. Here is the solution in case if some have the same question

const connection = new Connection(clusterApiUrl('devnet'));
  const metaplex = new Metaplex(connection);
  const key = Uint8Array.from(
    base58.decode('PrivateKey'),
  );

  const keypair = Keypair.fromSecretKey(key);
  console.log(`keypair created: ${keypair.publicKey.toString()}`);

  metaplex.use(walletAdapterIdentity(keypair));
  metaplex.use(
    bundlrStorage({
      address: 'https://devnet.bundlr.network',
      providerUrl: 'https://api.devnet.solana.com',
      timeout: 60000,
      identity: keypair,
    }),
  );

[devusvulgaris]

Is there a way to send private key from Phantom wallet from frontend to backend. In case I want to upload file or create NFT on backend? I would need private key to recreate keypair on backend.

[JohnVersus]

That does not seem like a good idea to send privatekey from frontend. You need to have the private stored on the backend env file, for safety reasons.

// use this to generate the solana key pair in backend
const key = Uint8Array.from(base58.decode(process.env.PRIVATE_KEY));
const keypair = Keypair.fromSecretKey(key);