Hello, I am one of the developers and maintainers of the award winning Soneso Stellar iOS SDK. And today, I would like to present our new Soneso Stellar Flutter SDK . It is a SDK for Flutter developers, a Dart Package, that facilitates integration with the Stellar Horizon API server and submission of Stellar transactions. It is now ready for beta testing. If you are a Flutter developer and interested in using it for your app or wallet, please check it out. Here are some examples of typical usage: Keypair generation // create a completely new and unique pair of keys. KeyPair keyPair = KeyPair.random(); print(keyPair.accountId); // GCFXHS4GXL6BVUCXBWXGTITROWLVYXQKQLF4YH5O5JT3YZXCYPAFBJZB print(keyPair.secretSeed); // SAV76USXIJOBMEQXPANUOQM6F5LIOTLPDIDVRJBFFE2MDJXG24TAPUU7 Check 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]}"); } Send Payment // Load sender account data from the stellar network. AccountResponse sender = await sdk.accounts.account(senderKeyPair.accountId); // Build the payment operation. PaymentOperation paymentOperation = PaymentOperationBuilder(destinationId,Asset.NATIVE, "100").build(); // Build the transaction containing the payment operation. Transaction transaction = new TransactionBuilder(sender, Network.TESTNET) .addOperation(paymentOperation) .build(); // Sign the transaction with the sender's key pair. transaction.sign(senderKeyPair); // Submit the transaction to the stellar network. SubmitTransactionResponse response = await sdk.submitTransaction(transaction); if (response.success) { // ... } else { // ... } Stream Payments 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."); } } }); GitHub Repo: https://github.com/Soneso/stellar_flutter_sdk Installation: https://github.com/Soneso/stellar_flutter_sdk#installation Quick Start: https://github.com/Soneso/stellar_flutter_sdk#quick-start Examples: https://github.com/Soneso/stellar_flutter_sdk#documentation-and-examples Testing feedback and all suggestions are welcome. You can create issues here: add issue

Stellar Flutter SDK

CR-Soneso

Hello, I am one of the developers and maintainers of the award winning Soneso Stellar iOS SDK.

And today, I would like to present our new Soneso Stellar Flutter SDK.

It is a SDK for Flutter developers, a Dart Package, that facilitates integration with the Stellar Horizon API server and submission of Stellar transactions. It is now ready for beta testing.

If you are a Flutter developer and interested in using it for your app or wallet, please check it out.

Here are some examples of typical usage:

Keypair generation

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

print(keyPair.accountId);
// GCFXHS4GXL6BVUCXBWXGTITROWLVYXQKQLF4YH5O5JT3YZXCYPAFBJZB

print(keyPair.secretSeed);
// SAV76USXIJOBMEQXPANUOQM6F5LIOTLPDIDVRJBFFE2MDJXG24TAPUU7

Check 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]}");
}

Send Payment

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

// Build the payment operation.
PaymentOperation paymentOperation = PaymentOperationBuilder(destinationId,Asset.NATIVE, "100").build();

// Build the transaction containing the payment operation.
Transaction transaction = new TransactionBuilder(sender, Network.TESTNET)
	.addOperation(paymentOperation)
	.build();

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

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

if (response.success) {
  // ...
} else {
  // ...
}

Stream Payments

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.");
    }
  }
});

GitHub Repo: https://github.com/Soneso/stellar_flutter_sdk
Installation: https://github.com/Soneso/stellar_flutter_sdk#installation
Quick Start: https://github.com/Soneso/stellar_flutter_sdk#quick-start
Examples: https://github.com/Soneso/stellar_flutter_sdk#documentation-and-examples

Testing feedback and all suggestions are welcome. You can create issues here: add issue

ZachStetson

I have recently started buying a flutter and Dart. I have a fascinating idea for an app and this platform is just perfect Something I have been wanting to do for years but never had the skill or know how to do it but now I know I must pursue this idea what do I do? To help?

CR-Soneso

Hi guys, thank you for your feedback!

In the meantime the beta phase of the Flutter SDK is finished and I added implementation for SEP-0001 stellar.toml, SEP-0002 Federation and SEP-0005 Key derivation

stellar.toml (SEP-0001)

The data can be parsed from a string or loaded and parsed from a given domain.

From string

To parse the data from a string you can use the default constructor of the StellarToml class.

String toml = '''
# Sample stellar.toml
VERSION="2.0.0"
# ...
''';

StellarToml stellarToml = StellarToml(toml);
GeneralInformation generalInformation = stellarToml.generalInformation;
print(generalInformation.version);

After parsing, the StellarToml class provides: generalInformation, documentation, pointsOfContact, currencies and validators

From domain

To load and parse the data from a domain you can use the fromDomain constructor of the StellarToml class. It automatically composes the needed url. In the following example the data is loaded from: https://soneso.com/.well-known/stellar.toml - only the domain "soneso.com" has to be provided:

StellarToml stellarToml = await StellarToml.fromDomain("soneso.com");
GeneralInformation generalInformation = stellarToml.generalInformation;
//...

Linked currency

Alternately to specifying a specific currency in it's content, stellar.toml can link out to a separate TOML file for a given currency by specifying toml="https://DOMAIN/.well-known/CURRENCY.toml" as the currency's only field.

VERSION="2.0.0"
#...
[[CURRENCIES]]
toml="https://soneso.com/.well-known/TESTC.toml"
#...

To load the data of this currency, you can use the static method: StellarToml.currencyFromUrl(String toml) - as shown in the example below:

StellarToml stellarToml = await StellarToml.fromDomain("soneso.com");
List<Currency> currencies = stellarToml.currencies;
for (Currency currency in currencies) {
  if (currency.toml != null) {
    Currency linkedCurrency = await StellarToml.currencyFromUrl(currency.toml);
    print(linkedCurrency.code);
  }
}

Federation (SEP-0002)

Resolving a stellar address

To resolve a stellar address like for example bob*soneso.com we can use the static method Federation.resolveStellarAddress as shown below:

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

Resolving a stellar account id

To resolve a stellar account id like for example GBVPKXWMAB3FIUJB6T7LF66DABKKA2ZHRHDOQZ25GBAEFZVHTBPJNOJI we can use the static method Federation.resolveStellarAccountId. We need to provide the account id and the federation server url as parameters:

FederationResponse response = await Federation.resolveStellarAccountId("GBVPKXWMAB3FIUJB6T7LF66DABKKA2ZHRHDOQZ25GBAEFZVHTBPJNOJI", "https://stellarid.io/federation/");

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

print(response.accountId);
// GBVPKXWMAB3FIUJB6T7LF66DABKKA2ZHRHDOQZ25GBAEFZVHTBPJNOJI

print(response.memoType);
// text

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

Resolving a stellar transaction id

To resolve a stellar transaction id like for example c1b368c00e9852351361e07cc58c54277e7a6366580044ab152b8db9cd8ec52a we can use the static method Federation.resolveStellarTransactionId. We need to provide the transaction id and the federation server url as parameters:

// Returns the federation record of the sender of the transaction if known by the server
FederationResponse response = await Federation.resolveStellarTransactionId("c1b368c00e9852351361e07cc58c54277e7a6366580044ab152b8db9cd8ec52a", "https://stellarid.io/federation/");

Resolving a forward

Used for forwarding the payment on to a different network or different financial institution. Here we can use the static method Federation.resolveForward . We need to provide the needed query parameters as Map<String, String> and the federation server url:

FederationResponse response = await Federation.resolveForward({
  "forward_type": "bank_account",
  "swift": "BOPBPHMM",
  "acct": "2382376"
}, "https://stellarid.io/federation/");

// resulting request url: 
// https://stellarid.io/federation/?type=forward&forward_type=bank_account&swift=BOPBPHMM&acct=2382376

Key Derivation Methods for Stellar Key (SEP-0005)

Methods for key derivation for Stellar are described in SEP-005. This improves key storage and moving keys between wallets and apps.

In the following examples you can see how to generate 12 or 24 words mnemonics for different languages using the Flutter SDK, how to generate key pairs from a mnemonic (with and without BIP 39 passphrase) and how to generate key pairs from a BIP 39 seed.

Generate mnemonic

String mnemonic =  Wallet.generate12WordsMnemonic(); 
print(mnemonic);
// twice news void fiction lamp chaos few code rate donkey supreme primary

mnemonic =  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

Default language is english.

Generate other language mnemonic

String frenchMnemonic = Wallet.generate12WordsMnemonic(language: LANGUAGE_FRENCH);
print(frenchMnemonic);
// pouvoir aménager lagune alliage bermuda taxer dogme avancer espadon sucre bermuda aboyer

String koreanMnemonic = Wallet.generate24WordsMnemonic(language: LANGUAGE_KOREAN);
print(koreanMnemonic);
// 합리적 채널 침대 달걀 기념 정성 세종대왕 한식 불안 독창적 착각 체계 순서 학급 평화 마약 냉면 멀리 남매 초반 치약 여권 지방 물음

Supported languages are:

english
french
spanish
italian
korean
japanese
simplified chinese
traditional chinese

Generate key pairs from mnemonic

Wallet wallet = Wallet.from("shell green recycle learn purchase able oxygen right echo claim hill again hidden evidence nice decade panic enemy cake version say furnace garment glue");

KeyPair keyPair0 = wallet.getKeyPair(index: 0);
print("${keyPair0.accountId} : ${keyPair0.secretSeed}");
// GCVSEBHB6CTMEHUHIUY4DDFMWQ7PJTHFZGOK2JUD5EG2ARNVS6S22E3K : SATLGMF3SP2V47SJLBFVKZZJQARDOBDQ7DNSSPUV7NLQNPN3QB7M74XH

KeyPair keyPair1 = wallet.getKeyPair(index: 1);
print("${keyPair1.accountId} : ${keyPair1.secretSeed}");
// GBPHPX7SZKYEDV5CVOA5JOJE2RHJJDCJMRWMV4KBOIE5VSDJ6VAESR2W : SCAYXPIDEUVDGDTKF4NGVMN7HCZOTZJ43E62EEYKVUYXEE7HMU4DFQA6

Generate key pairs from mnemonic of other language

Wallet wallet = Wallet.from("절차 튀김 건강 평가 테스트 민족 몹시 어른 주민 형제 발레 만점 산길 물고기 방면 여학생 결국 수명 애정 정치 관심 상자 축하 고무신",
        language: LANGUAGE_KOREAN);
KeyPair keyPair0 = wallet.getKeyPair(index: 0);
print("${keyPair0.accountId} : ${keyPair0.secretSeed}");
// GCITEFHNYX3ZCD6XQXPWPZGGS2KTYE4C6RPDUIYOW33PC3PU3PGU667E : SB6KJ2HFH32PXSRATDPSV65DNYCN2XA6RVHKSFI3NSGU5YRSDLB56M76

KeyPair keyPair1 = wallet.getKeyPair(index: 1);
print("${keyPair1.accountId} : ${keyPair1.secretSeed}");
// GB6LTLB32AFIZL5DPOLHYRVZNHGFBBWGJ5DZCVHMBEW3U4DOXHTX3UQV : SBJJXYH3HPBZ2BDJ5NBE3EJLYDPMVBGG7ZZIYGEED2EKWMNKLCVFPAY7

Generate key pairs from mnemonic with BIP 39 passphrase

Wallet wallet = Wallet.from("cable spray genius state float twenty onion head street palace net private method loan turn phrase state blanket interest dry amazing dress blast tube",
        passphrase: "p4ssphr4se");
    
KeyPair keyPair0 = wallet.getKeyPair(index: 0);
print("${keyPair0.accountId} : ${keyPair0.secretSeed}");
// GDAHPZ2NSYIIHZXM56Y36SBVTV5QKFIZGYMMBHOU53ETUSWTP62B63EQ : SAFWTGXVS7ELMNCXELFWCFZOPMHUZ5LXNBGUVRCY3FHLFPXK4QPXYP2X

KeyPair keyPair1 = wallet.getKeyPair(index: 1);
print("${keyPair1.accountId} : ${keyPair1.secretSeed}");
// GDY47CJARRHHL66JH3RJURDYXAMIQ5DMXZLP3TDAUJ6IN2GUOFX4OJOC : SBQPDFUGLMWJYEYXFRM5TQX3AX2BR47WKI4FDS7EJQUSEUUVY72MZPJF

Generate key pairs from BIP 39 seed

Wallet wallet = Wallet.fromBip39HexSeed("e4a5a632e70943ae7f07659df1332160937fad82587216a4c64315a0fb39497ee4a01f76ddab4cba68147977f3a147b6ad584c41808e8238a07f6cc4b582f186");

KeyPair keyPair0 = wallet.getKeyPair(index: 0);
print("${keyPair0.accountId} : ${keyPair0.secretSeed}");
// GDRXE2BQUC3AZNPVFSCEZ76NJ3WWL25FYFK6RGZGIEKWE4SOOHSUJUJ6 : SBGWSG6BTNCKCOB3DIFBGCVMUPQFYPA2G4O34RMTB343OYPXU5DJDVMN

KeyPair keyPair1 = wallet.getKeyPair(index: 1);
print("${keyPair1.accountId} : ${keyPair1.secretSeed}");
// GBAW5XGWORWVFE2XTJYDTLDHXTY2Q2MO73HYCGB3XMFMQ562Q2W2GJQX : SCEPFFWGAG5P2VX5DHIYK3XEMZYLTYWIPWYEKXFHSK25RVMIUNJ7CTIS

If you want to learn more about the open source Flutter SDK please take a look at our Github repository.

I look forward to your feedback and suggestions for improvement.

CR-Soneso

Added support for SEP-10 in Stellar Flutter SDK.