cardano_wallet_sdk 0.1.0-alpha.8

Targeting Flutter apps, the Cardano Wallet SDK is a high-level Dart library for managing cryptocurrency accounts & executing transactions on the blockchain.

---

cardano_wallet_sdk

SDK for building Cardano blockchain mobile apps in Flutter using the Dart programming language.

Status

Currently this project is a Fund 5 Project Catalyst proof-of-concept prototype with limited use-cases. It implements a light-weight client library using the BlockFrost API service for blockchain access and supports loading wallet balances and submitting simple transactions.

Under a Fund 7 proposal this library will be expanded into a fully-functional Cardano SDK, supporting smart contracts, minting, staking, key management, hardware wallets and other essential features needed to write dApps and other types of Cardano clients. If you'd like to support this project, be sure to vote for it in Catalyst Fund 7!

Kick the Tires

To see the SDK in action, you can visit the live Flutter Demonstration Wallet hosted on google cloud.

Current (Fund 5) Features

• Create Wallets - Create and restore, both read-only and transactional wallets using staking addresses, mnemonics or private keys.
• Transaction History - List transactions, rewards and fees for both ADA and Native Tokens.
• Addresses - Generate and manage Shelley key pairs and addresses.
• Transactions - Build, sign and submit simple ADA payment transactions.
• Blockchain API - Cardano blockchain access via the BlockFrost API package
• Binary Encoding - Enough CBOR support is provided to submit simple payment transactions.

Usage

Installation details can be found on pub.dev.

Wallet Management

Create a wallet builder for testnet or mainnet using a BlockFrost key.

final walletBuilder = WalletBuilder()
    ..networkId = NetworkId.testnet
    ..testnetAdapterKey = blockfrostKey;

Create a read-only wallet using a staking address.

var address = ShelleyAddress.fromBech32('stake_test1uq...vwl7a');
final walletBuilder = WalletBuilder()
    ..networkId = NetworkId.testnet
    ..testnetAdapterKey = blockfrostKey
    ..stakeAddress = address;
Result<ReadOnlyWallet, String> result = await walletBuilder.readOnlyBuildAndSync();
result.when(
    ok: (wallet) => print("${wallet.walletName}: ${wallet.balance}"),
    err: (err) => print("Error: ${err}"),
);

Restore existing wallet using 24 word mnemonic.

var mnemonic = 'rude stadium move...gallery receive just'.split(' ');
final walletBuilder = WalletBuilder()
    ..networkId = NetworkId.testnet
    ..testnetAdapterKey = blockfrostKey
    ..mnemonic = mnemonic;
Result<Wallet, String> result = await walletBuilder.buildAndSync();
if (result.isOk()) {
    var wallet = result.unwrap();
    print("${wallet.walletName}: ${wallet.balance}");
}

Update existing wallet.

final walletBuilder = WalletBuilder()
    ..networkId = NetworkId.testnet
    ..testnetAdapterKey = blockfrostKey
    ..mnemonic = mnemonic;
Result<Wallet, String> result = walletBuilder.build();
Wallet wallet = result.unwrap();
Coin oldBalance = wallet.balance;
var result2 = await wallet.update();
result2.when(
    ok: (_) => print("old:$oldBalance ADA, new: ${wallet.balance} ADA"),
    err: (err) => print("Error: ${err}"),
);

Create a new 24 word mnemonic.

List<String> mnemonic = WalletBuilder().generateNewMnemonic();
print("mnemonic: ${mnemonic.join(' ')}");

Wallet Details

List transaction history.

wallet.transactions.forEach((tx) => print(tx));

List addresses.

wallet.addresses.forEach((addr) => print(addr.toBech32()));

List currency balances.

final formatter = AdaFormattter.compactCurrency();
wallet.currencies.forEach((assetId, balance) {
    final isAda = assetId == lovelaceHex;
    print("$assetId: ${isAda ? formatter.format(balance) : balance}");
});

List staking rewards.

wallet.stakeAccounts.forEach((acct) {
    acct.rewards.forEach((reward) {
        print("epoch: ${reward.epoch}, ${reward.amount} ADA");
    });
});

Wallet Keys and Addresses

Access root private and public key pair.

Bip32KeyPair pair = wallet.rootKeyPair;
print("${pair.signingKey}, ${pair.verifyKey}");

Access staking address.

print(wallet.stakingAddress));

First unused change address.

print(wallet.firstUnusedChangeAddress));

First unused spend address.

print(wallet.firstUnusedSpendAddress));

Submit Transactions

Send 3 ADA to Bob.

var bobsAddress = ShelleyAddress.fromBech32('addr1qyy6...');
final Result<ShelleyTransaction, String> result = await wallet.sendAda(
    toAddress: bobsAddress,
    lovelace: 3 * 1000000,
);
if (result.isOk()) {
    final tx = result.unwrap();
    print("ADA sent. Fee: ${tx.body.fee} lovelace");
}

Planned Features

• Smart Contracts - Consisting of examples and supporting code.
• Persistence - Caching blockchain data to speed state restoration.
• Native Token/NFT - Provide minting and burning support.
• Staking - Provide stake pool ranking and stake delegation support.
• Blockchain Adapter - Abstraction layer to allow multiple blockchain gateways (i.e. Blockfrost, GraphQL, Ogmios and Mithril).
• Secure Storage - Encrypted storage solution for private keys and passwords.
• Multi-signature - Support multi-party signatures.
• Alternate Addresses - Support enterprise, pointer and legacy addresses.
• Hardware Wallets - Support key storage and signing delegation.
• DApp Linking - Metamask-like Chrome browser extension.

Running Integration Tests

Several of the integration tests (suffixed with '_itest.dart') require a BlockFrost key to run. Installation steps are as follows:

• git clone [e-mail]:reaster/cardano_wallet_sdk.git
• register for a free BlockFrost testnet policy-id key.
• paste the policy-id key into a text file named: blockfrost_project_id.txt in the parent directory of this project.

echo "your-project-id" > ../blockfrost_project_id.txt

Now you can include the integration tests:

dart test -P itest

---

Copyright 2021 Richard Easterling
SPDX-License-Identifier: Apache-2.0