Stellar SDK for Flutter provides APIs to build and sign transactions

Stellar SDK for Flutter

The Soneso open source Stellar SDK for Flutter is build with Dart and provides APIs to build and sign transactions, connect and query Horizon.

Installation

From pub.dev

1. Add the dependency to your pubspec.yaml file:

dependencies:
  stellar_flutter_sdk: ^1.2.3

2. Install it (command line or IDE):

flutter pub get

3. In your source file import the SDK, initialize and use it:

import 'package:stellar_flutter_sdk/stellar_flutter_sdk.dart';

final StellarSDK sdk = StellarSDK.TESTNET;

String accountId = "GASYKQXV47TPTB6HKXWZNB6IRVPMTQ6M6B27IM5L2LYMNYBX2O53YJAL";
AccountResponse account = await sdk.accounts.account(accountId);
print("sequence number: ${account.sequenceNumber}");

Manual

Add the SDK is a Flutter Dart plugin. Here is a step by step that we recommend:

1. Clone this repo.
2. Open the project in your IDE (e.g. Android Studio).
3. Open the file pubspec.yaml and press Pub get in your IDE.
4. Go to the project's test directory, run a test from there and you are good to go!

Add it to your app:

5. In your Flutter app add the local dependency in pubspec.yaml and then run pub get:

dependencies:
   flutter:
     sdk: flutter
   stellar_flutter_sdk:
     path: ../stellar_flutter_sdk

6. In your source file import the SDK, initialize and use it:

import 'package:stellar_flutter_sdk/stellar_flutter_sdk.dart';

final StellarSDK sdk = StellarSDK.TESTNET;

String accountId = "GASYKQXV47TPTB6HKXWZNB6IRVPMTQ6M6B27IM5L2LYMNYBX2O53YJAL";
AccountResponse account = await sdk.accounts.account(accountId);
print("sequence number: ${account.sequenceNumber}");

Quick Start

1. Create a Stellar key pair

Random generation

// create a completely new and unique pair of keys.
KeyPair keyPair = KeyPair.random();

print("${keyPair.accountId}");
// GCFXHS4GXL6BVUCXBWXGTITROWLVYXQKQLF4YH5O5JT3YZXCYPAFBJZB

print("${keyPair.secretSeed}");
// SAV76USXIJOBMEQXPANUOQM6F5LIOTLPDIDVRJBFFE2MDJXG24TAPUU7

Deterministic generation

The Stellar Ecosystem Proposal SEP-005 describes methods for key derivation for Stellar Accounts. This improves key storage and moving keys between wallets and apps.

Generate mnemonic

String mnemonic =  await Wallet.generate24WordsMnemonic();
print(mnemonic);
// mango debris lumber vivid bar risk prosper verify photo put ridge sell range pet indoor lava sister around panther brush twice cattle sauce romance

Generate key pairs

Wallet wallet = await Wallet.from("mango debris lumber vivid bar risk prosper verify photo put ridge sell range pet indoor lava sister around panther brush twice cattle sauce romance");

KeyPair keyPair0 = await wallet.getKeyPair(index: 0);
print("${keyPair0.accountId} : ${keyPair0.secretSeed}");
// GBYTVBTOVXBIT23X4YUEE32QBAAA537OAF553FWABUAZHT3FNPN3FUGG : SBEQZ4XGS434POXNQYUXQYFV6JYUHV56U2MNMUZBBBLBGR5X6PUUCYO5

KeyPair keyPair1 = await wallet.getKeyPair(index: 1);
print("${keyPair1.accountId} : ${keyPair1.secretSeed}");
// GD5JFZ6U4TBKLWOVGAJQZ4CWRHNVXIFF65BBXZG6UEQE74RUXWAKQVQN : SD3IXULYMZKB6ML7AJW4OLAXKN6U3BYDUMOZLKUZTCCGZXUFXAS7NKIO

Supported languages are: english, french, spanish, italian, korean, japanese, simplified chinese and traditional chinese. Find more details in our SEP-005 examples.

2. Create an account

After the key pair generation, you have already got the address, but it is not activated until someone transfers at least 1 lumen into it.

2.1 Testnet

If you want to play in the Stellar test network, the SDK can ask Friendbot to create an account for you as shown below:

bool funded = await FriendBot.fundTestAccount(keyPair.accountId);
print ("funded: ${funded}");

2.2 Public net

On the other hand, if you would like to create an account in the public net, you should buy some Stellar Lumens (XLM) from an exchange. When you withdraw the Lumens into your new account, the exchange will automatically create the account for you. However, if you want to create an account from another account of your own, you may run the following code:

/// Create a key pair for your existing account.
KeyPair keyA = KeyPair.fromSecretSeed("SAPS66IJDXUSFDSDKIHR4LN6YPXIGCM5FBZ7GE66FDKFJRYJGFW7ZHYF");

/// Load the data of your account from the stellar network.
AccountResponse accA = await sdk.accounts.account(keyA.accountId);

/// Create a keypair for a new account.
KeyPair keyB = KeyPair.random();

/// Create the operation builder.
CreateAccountOperationBuilder createAccBuilder = CreateAccountOperationBuilder(keyB.accountId, "3"); // send 3 XLM (lumen)

// Create the transaction.
Transaction transaction = new TransactionBuilder(accA)
        .addOperation(createAccBuilder.build())
        .build();

/// Sign the transaction with the key pair of your existing account.
transaction.sign(keyA, Network.PUBLIC);

/// Submit the transaction to the stellar network.
SubmitTransactionResponse response = await sdk.submitTransaction(transaction);

if (response.success) {
  print ("account ${keyB.accountId} created");
}

3. Check account

3.1 Basic info

After creating the account, we may check the basic information of the account.

String accountId = "GASYKQXV47TPTB6HKXWZNB6IRVPMTQ6M6B27IM5L2LYMNYBX2O53YJAL";

// Request the account data.
AccountResponse account = await sdk.accounts.account(accountId);

// You can check the `balance`, `sequence`, `flags`, `signers`, `data` etc.

for (Balance balance in account.balances) {
  switch (balance.assetType) {
    case Asset.TYPE_NATIVE:
      print("Balance: ${balance.balance} XLM");
      break;
    default:
      print("Balance: ${balance.balance} ${balance
          .assetCode} Issuer: ${balance.assetIssuer}");
  }
}

print("Sequence number: ${account.sequenceNumber}");

for (Signer signer in account.signers) {
  print("Signer public key: ${signer.accountId}");
}

for (String key in account.data.keys) {
  print("Data key: ${key} value: ${account.data[key]}");
}

3.2 Check payments

You can check the payments connected to an account:

Page<OperationResponse> payments = await sdk.payments.forAccount(accountAId).order(RequestBuilderOrder.DESC).execute();

for (OperationResponse response in payments.records) {
  if (response is PaymentOperationResponse) {
    PaymentOperationResponse por = response as PaymentOperationResponse;
    if (por.transactionSuccessful) {
      print("Transaction hash: ${por.transactionHash}");
    }
  }
}

You can use:limit, order, and cursor to customize the query. Get the most recent payments for accounts, ledgers and transactions.

Horizon has SSE support for push data. You can use it like this:

String accountId = "GDXPJR65A6EXW7ZIWWIQPO6RKTPG3T2VWFBS3EAHJZNFW6ZXG3VWTTSK";

sdk.payments.forAccount(accountId).cursor("now").stream().listen((response) {
  if (response is PaymentOperationResponse) {
    switch (response.assetType) {
      case Asset.TYPE_NATIVE:
        print("Payment of ${response.amount} XLM from ${response.sourceAccount} received.");
        break;
      default:
        print("Payment of ${response.amount} ${response.assetCode} from ${response.sourceAccount} received.");
    }
  }
});

3.3 Check others

Just like payments, you you check assets, transactions, effects, offers, operations, ledgers etc.

sdk.assets.
sdk.transactions.
sdk.effects.
sdk.offers.
sdk.operations.
sdk.orderBook.
sdk.trades.
// add so on ...

4. Building and submitting transactions

Example "send native payment":

KeyPair senderKeyPair = KeyPair.fromSecretSeed("SAPS66IJDXUSFDSDKIHR4LN6YPXIGCM5FBZ7GE66FDKFJRYJGFW7ZHYF");
String destination = "GDXPJR65A6EXW7ZIWWIQPO6RKTPG3T2VWFBS3EAHJZNFW6ZXG3VWTTSK";

// Load sender account data from the stellar network.
AccountResponse sender = await sdk.accounts.account(senderKeyPair.accountId);

// Build the transaction to send 100 XLM native payment from sender to destination
Transaction transaction = new TransactionBuilder(sender)
    .addOperation(PaymentOperationBuilder(destination,Asset.NATIVE, "100").build())
    .build();

// Sign the transaction with the sender's key pair.
transaction.sign(senderKeyPair, Network.TESTNET);

// Submit the transaction to the stellar network.
SubmitTransactionResponse response = await sdk.submitTransaction(transaction);
if (response.success) {
  print("Payment sent");
}

5. Resolving a stellar address by using Federation

FederationResponse response = await Federation.resolveStellarAddress("bob*soneso.com");

print(response.stellarAddress);
// bob*soneso.com

print(response.accountId);
// GBVPKXWMAB3FIUJB6T7LF66DABKKA2ZHRHDOQZ25GBAEFZVHTBPJNOJI

print(response.memoType);
// text

print(response.memo);
// hello memo text

Documentation and Examples

Examples

Additional examples can be found in the tests.

SEPs implemented

• SEP-0001 (stellar.toml)
• SEP-0002 (Federation)
• SEP-0005 (Key derivation)
• SEP-0010 (Stellar Web Authentication)
• SEP-0011 (Txrep)

License

The Stellar Sdk for Flutter is licensed under an MIT license. See the LICENSE file for details.

GitHub

https://github.com/Soneso/stellar_flutter_sdk