Flutter and Phantom Together

[uemirhanselim]

How can I connect a phantom wallet to an app, my purpose is to show my phantom wallet balance in flutter app. Is there a doc for flutter that I can use, I couldn't find any.

[adamdelphantom]

Hello @uemirhanselim,

We do not have any native libraries for flutter. Currently all Phantom interactions with other mobile dapps are acheived using deeplinks. But that is only for signing messages and sending transactions.

In order to display a users balance you will need some other service like an RPC provider in order to read data from the blockchain.

So you would use a deep link to connect phantom to your dapp and with the pub key you could query your blockchain data service for balances and transaction history.

[uemirhanselim]

Thank you! I will dig into it.

[emfarih]

Hi @adamdelphantom and @uemirhanselim ,

I am learning how to integrate phantom with flutter (web platform). My progress currently is

1. Connect to wallet -> OK (using phantom object JS)
2. Get balance -> OK (using solana_web3 library)
3. Sign & Send transaction (Send SOL) -> NOK

previously I try to use solana-wallet-adapter library, but somehow recently it just give an error on both wallet supported on that adapter. So, i try to use js interop and directly integrate with Phantom. But when trying to do no 3 above, it give me an error.

Below is my function to sendSol.

Future<String?> sendSol(String recipient, double amount) async {
    try {
      if (!isConnected) {
        throw Exception("Wallet is not connected.");
      }

      final Connection connection = Connection(cluster);

      // Convert amount to lamports
      final lamports = BigInt.from(amount * lamportsPerSol);

      // Create transaction
      final blockhash = await connection.getLatestBlockhash();
      final transferInstruction = SystemProgram.transfer(
        fromPubkey: accountPubkey,
        toPubkey: Pubkey.fromBase58(recipient),
        lamports: lamports,
      );
      final transaction = Transaction.v0(
        payer: accountPubkey,
        instructions: [transferInstruction],
        recentBlockhash: blockhash.blockhash,
      );
      print('Transaction created: ${transaction.toJson()}');

      // Serialize the transaction to a Buffer
      final serializedBuffer = transaction.serialize();
      final Uint8List serializedTransaction =
          Uint8List.fromList(serializedBuffer.toList());

      // Encode the serialized transaction to base64
      final String base64Transaction = base64Encode(serializedTransaction);

      final signedTransaction = await promiseToFuture(
        provider.callMethod('signAndSendTransaction', [base64Transaction]),
      );
      print('Transaction signed: $signedTransaction');

      // Update balance after transaction
      await updateBalance();
      return null;
    } catch (e, stackTrace) {
      print('Error sending SOL: $e');
      print('Stack trace: $stackTrace');
      return null;
    }
  }

Below is the error i got:

Transaction created: {signatures: [[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]], message: {version: 0, accountKeys: [EXLRFGKBjZFVrVDMqHCKyNG3HeQHZdWqfaG3X7m5fkN2, 11111111111111111111111111111111], header: {numRequiredSignatures: 1, numReadonlySignedAccounts: 0, numReadonlyUnsignedAccounts: 1}, recentBlockhash: 5aHk5orSJ9rkQrebjJ67SPHh3zwg1PgDLPvzgghi1uR7, instructions: [{programIdIndex: 1, accounts: [0, 0], data: 3Bxs4NN8M2Yn4TLb}], addressTableLookups: []}}

Error sending SOL: TypeError: Cannot use 'in' operator to search for 'version' in AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAQABAsjtT3NuRH8gz5qm7BqCwDsUggURGhOJJzhjJswILcP/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABD9dh2itR6/aq5ftIvK/xMkHRzFtRueWYvConPR5BhlgEBAgAADAIAAACAlpgAAAAAAAA=

Stack trace: 
solana.js:3 Uncaught (in promise) TypeError: Cannot use 'in' operator to search for 'version' in AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAQABAsjtT3NuRH8gz5qm7BqCwDsUggURGhOJJzhjJswILcP/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABD9dh2itR6/aq5ftIvK/xMkHRzFtRueWYvConPR5BhlgEBAgAADAIAAACAlpgAAAAAAAA=

Any clue what is wrong with my code, I believe the issue is the format of transaction payload that i send to the signAndSendTransaction, but i have no idea what is the format and how to convert to it.

Thanks.